[PATCH v4 2/7] accel/ivpu: Add Intel VPU MMU support

Jacek Lawrynowicz jacek.lawrynowicz at linux.intel.com
Mon Dec 19 13:17:02 UTC 2022


Hi,

On 18.12.2022 10:13, Oded Gabbay wrote:
> On Thu, Dec 8, 2022 at 1:08 PM Jacek Lawrynowicz
> <jacek.lawrynowicz at linux.intel.com> wrote:
>>
>> VPU Memory Management Unit is based on ARM MMU-600.
>> It allows the creation of multiple virtual address spaces for
>> the device and map noncontinuous host memory (there is no dedicated
>> memory on the VPU).
>>
>> Address space is implemented as a struct ivpu_mmu_context, it has an ID,
>> drm_mm allocator for VPU addresses and struct ivpu_mmu_pgtable that
>> holds actual 3-level, 4KB page table.
>> Context with ID 0 (global context) is created upon driver initialization
>> and it's mainly used for mapping memory required to execute
>> the firmware.
>> Contexts with non-zero IDs are user contexts allocated each time
>> the devices is open()-ed and they map command buffers and other
>> workload-related memory.
>> Workloads executing in a given contexts have access only
>> to the memory mapped in this context.
>>
>> This patch is has to main files:
> This patch has two main files:

OK

>>   - ivpu_mmu_context.c handles MMU page tables and memory mapping
>>   - ivpu_mmu.c implements a driver that programs the MMU device
>>
>> Co-developed-by: Karol Wachowski <karol.wachowski at linux.intel.com>
>> Signed-off-by: Karol Wachowski <karol.wachowski at linux.intel.com>
>> Co-developed-by: Krystian Pradzynski <krystian.pradzynski at linux.intel.com>
>> Signed-off-by: Krystian Pradzynski <krystian.pradzynski at linux.intel.com>
>> Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz at linux.intel.com>
>> ---
>>  drivers/accel/ivpu/Makefile           |   4 +-
>>  drivers/accel/ivpu/ivpu_drv.c         |  83 ++-
>>  drivers/accel/ivpu/ivpu_drv.h         |   6 +
>>  drivers/accel/ivpu/ivpu_hw_mtl.c      |  10 +
>>  drivers/accel/ivpu/ivpu_mmu.c         | 875 ++++++++++++++++++++++++++
>>  drivers/accel/ivpu/ivpu_mmu.h         |  50 ++
>>  drivers/accel/ivpu/ivpu_mmu_context.c | 385 ++++++++++++
>>  drivers/accel/ivpu/ivpu_mmu_context.h |  49 ++
>>  include/uapi/drm/ivpu_drm.h           |   4 +
>>  9 files changed, 1463 insertions(+), 3 deletions(-)
>>  create mode 100644 drivers/accel/ivpu/ivpu_mmu.c
>>  create mode 100644 drivers/accel/ivpu/ivpu_mmu.h
>>  create mode 100644 drivers/accel/ivpu/ivpu_mmu_context.c
>>  create mode 100644 drivers/accel/ivpu/ivpu_mmu_context.h
>>
>> diff --git a/drivers/accel/ivpu/Makefile b/drivers/accel/ivpu/Makefile
>> index 28330c04e52f..37b8bf1d3247 100644
>> --- a/drivers/accel/ivpu/Makefile
>> +++ b/drivers/accel/ivpu/Makefile
>> @@ -3,6 +3,8 @@
>>
>>  intel_vpu-y := \
>>         ivpu_drv.o \
>> -       ivpu_hw_mtl.o
>> +       ivpu_hw_mtl.o \
>> +       ivpu_mmu.o \
>> +       ivpu_mmu_context.o
>>
>>  obj-$(CONFIG_DRM_ACCEL_IVPU) += intel_vpu.o
>> \ No newline at end of file
>> diff --git a/drivers/accel/ivpu/ivpu_drv.c b/drivers/accel/ivpu/ivpu_drv.c
>> index 8fbccb8d888b..a22d41ca5a4b 100644
>> --- a/drivers/accel/ivpu/ivpu_drv.c
>> +++ b/drivers/accel/ivpu/ivpu_drv.c
>> @@ -15,6 +15,8 @@
>>
>>  #include "ivpu_drv.h"
>>  #include "ivpu_hw.h"
>> +#include "ivpu_mmu.h"
>> +#include "ivpu_mmu_context.h"
>>
>>  #ifndef DRIVER_VERSION_STR
>>  #define DRIVER_VERSION_STR __stringify(DRM_IVPU_DRIVER_MAJOR) "." \
>> @@ -37,23 +39,38 @@ MODULE_PARM_DESC(pll_max_ratio, "Maximum PLL ratio used to set VPU frequency");
>>
>>  struct ivpu_file_priv *ivpu_file_priv_get(struct ivpu_file_priv *file_priv)
>>  {
>> +       struct ivpu_device *vdev = file_priv->vdev;
>> +
>>         kref_get(&file_priv->ref);
>> +
>> +       ivpu_dbg(vdev, KREF, "file_priv get: ctx %u refcount %u\n",
>> +                file_priv->ctx.id, kref_read(&file_priv->ref));
>> +
>>         return file_priv;
>>  }
>>
>>  static void file_priv_release(struct kref *ref)
>>  {
>>         struct ivpu_file_priv *file_priv = container_of(ref, struct ivpu_file_priv, ref);
>> +       struct ivpu_device *vdev = file_priv->vdev;
>>
>> +       ivpu_dbg(vdev, FILE, "file_priv release: ctx %u\n", file_priv->ctx.id);
>> +
>> +       ivpu_mmu_user_context_fini(vdev, &file_priv->ctx);
>> +       WARN_ON(xa_erase_irq(&vdev->context_xa, file_priv->ctx.id) != file_priv);
>>         kfree(file_priv);
>>  }
>>
>>  void ivpu_file_priv_put(struct ivpu_file_priv **link)
>>  {
>>         struct ivpu_file_priv *file_priv = *link;
>> +       struct ivpu_device *vdev = file_priv->vdev;
>>
>>         WARN_ON(!file_priv);
>>
>> +       ivpu_dbg(vdev, KREF, "file_priv put: ctx %u refcount %u\n",
>> +                file_priv->ctx.id, kref_read(&file_priv->ref));
>> +
>>         *link = NULL;
>>         kref_put(&file_priv->ref, file_priv_release);
>>  }
>> @@ -88,6 +105,9 @@ static int ivpu_get_param_ioctl(struct drm_device *dev, void *data, struct drm_f
>>         case DRM_IVPU_PARAM_CONTEXT_PRIORITY:
>>                 args->value = file_priv->priority;
>>                 break;
>> +       case DRM_IVPU_PARAM_CONTEXT_ID:
>> +               args->value = file_priv->ctx.id;
> Why is this needed ? Why does the user need to know its context ID ?

This is not really needed by the user space, we only use this as a debug feature.

>> +               break;
>>         default:
>>                 ret = -EINVAL;
>>                 break;
>> @@ -120,22 +140,59 @@ static int ivpu_open(struct drm_device *dev, struct drm_file *file)
>>  {
>>         struct ivpu_device *vdev = to_ivpu_device(dev);
>>         struct ivpu_file_priv *file_priv;
>> +       u32 ctx_id;
>> +       void *old;
>> +       int ret;
>> +
>> +       ret = xa_alloc_irq(&vdev->context_xa, &ctx_id, NULL, vdev->context_xa_limit, GFP_KERNEL);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to allocate context id: %d\n", ret);
>> +               return ret;
>> +       }
>>
>>         file_priv = kzalloc(sizeof(*file_priv), GFP_KERNEL);
>> -       if (!file_priv)
>> -               return -ENOMEM;
>> +       if (!file_priv) {
>> +               ret = -ENOMEM;
>> +               goto err_xa_erase;
>> +       }
>>
>>         file_priv->vdev = vdev;
>>         file_priv->priority = DRM_IVPU_CONTEXT_PRIORITY_NORMAL;
>>         kref_init(&file_priv->ref);
>>
>> +       ret = ivpu_mmu_user_context_init(vdev, &file_priv->ctx, ctx_id);
>> +       if (ret)
>> +               goto err_free_file_priv;
>> +
>> +       old = xa_store_irq(&vdev->context_xa, ctx_id, file_priv, GFP_KERNEL);
>> +       if (xa_is_err(old)) {
>> +               ret = xa_err(old);
>> +               ivpu_err(vdev, "Failed to store context %u: %d\n", ctx_id, ret);
>> +               goto err_ctx_fini;
>> +       }
>> +
>> +       ivpu_dbg(vdev, FILE, "file_priv create: ctx %u process %s pid %d\n",
>> +                ctx_id, current->comm, task_pid_nr(current));
>> +
>>         file->driver_priv = file_priv;
>>         return 0;
>> +
>> +err_ctx_fini:
>> +       ivpu_mmu_user_context_fini(vdev, &file_priv->ctx);
>> +err_free_file_priv:
>> +       kfree(file_priv);
>> +err_xa_erase:
>> +       xa_erase_irq(&vdev->context_xa, ctx_id);
>> +       return ret;
>>  }
>>
>>  static void ivpu_postclose(struct drm_device *dev, struct drm_file *file)
>>  {
>>         struct ivpu_file_priv *file_priv = file->driver_priv;
>> +       struct ivpu_device *vdev = to_ivpu_device(dev);
>> +
>> +       ivpu_dbg(vdev, FILE, "file_priv close: ctx %u process %s pid %d\n",
>> +                file_priv->ctx.id, current->comm, task_pid_nr(current));
>>
>>         ivpu_file_priv_put(&file_priv);
>>  }
>> @@ -150,6 +207,7 @@ int ivpu_shutdown(struct ivpu_device *vdev)
>>         int ret;
>>
>>         ivpu_hw_irq_disable(vdev);
>> +       ivpu_mmu_disable(vdev);
>>
>>         ret = ivpu_hw_power_down(vdev);
>>         if (ret)
>> @@ -257,6 +315,10 @@ static int ivpu_dev_init(struct ivpu_device *vdev)
>>         if (!vdev->hw)
>>                 return -ENOMEM;
>>
>> +       vdev->mmu = drmm_kzalloc(&vdev->drm, sizeof(*vdev->mmu), GFP_KERNEL);
>> +       if (!vdev->mmu)
>> +               return -ENOMEM;
>> +
>>         vdev->hw->ops = &ivpu_hw_mtl_ops;
>>         vdev->platform = IVPU_PLATFORM_INVALID;
>>         vdev->context_xa_limit.min = IVPU_GLOBAL_CONTEXT_MMU_SSID + 1;
>> @@ -289,8 +351,24 @@ static int ivpu_dev_init(struct ivpu_device *vdev)
>>                 goto err_xa_destroy;
>>         }
>>
>> +       ret = ivpu_mmu_global_context_init(vdev);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to initialize global MMU context: %d\n", ret);
>> +               goto err_power_down;
>> +       }
>> +
>> +       ret = ivpu_mmu_init(vdev);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to initialize MMU device: %d\n", ret);
>> +               goto err_mmu_gctx_fini;
>> +       }
>> +
>>         return 0;
>>
>> +err_mmu_gctx_fini:
>> +       ivpu_mmu_global_context_fini(vdev);
>> +err_power_down:
>> +       ivpu_hw_power_down(vdev);
>>  err_xa_destroy:
>>         xa_destroy(&vdev->context_xa);
>>         return ret;
>> @@ -299,6 +377,7 @@ static int ivpu_dev_init(struct ivpu_device *vdev)
>>  static void ivpu_dev_fini(struct ivpu_device *vdev)
>>  {
>>         ivpu_shutdown(vdev);
>> +       ivpu_mmu_global_context_fini(vdev);
>>
>>         drm_WARN_ON(&vdev->drm, !xa_empty(&vdev->context_xa));
>>         xa_destroy(&vdev->context_xa);
>> diff --git a/drivers/accel/ivpu/ivpu_drv.h b/drivers/accel/ivpu/ivpu_drv.h
>> index 4f859e7ac09e..6e8b88068fc9 100644
>> --- a/drivers/accel/ivpu/ivpu_drv.h
>> +++ b/drivers/accel/ivpu/ivpu_drv.h
>> @@ -15,6 +15,8 @@
>>  #include <linux/xarray.h>
>>  #include <uapi/drm/ivpu_drm.h>
>>
>> +#include "ivpu_mmu_context.h"
>> +
>>  #define DRIVER_NAME "intel_vpu"
>>  #define DRIVER_DESC "Driver for Intel Versatile Processing Unit (VPU)"
>>  #define DRIVER_DATE "20221208"
>> @@ -71,6 +73,7 @@ struct ivpu_wa_table {
>>  };
>>
>>  struct ivpu_hw_info;
>> +struct ivpu_mmu_info;
>>
>>  struct ivpu_device {
>>         struct drm_device drm;
>> @@ -81,7 +84,9 @@ struct ivpu_device {
>>
>>         struct ivpu_wa_table wa;
>>         struct ivpu_hw_info *hw;
>> +       struct ivpu_mmu_info *mmu;
>>
>> +       struct ivpu_mmu_context gctx;
>>         struct xarray context_xa;
>>         struct xa_limit context_xa_limit;
>>
>> @@ -100,6 +105,7 @@ struct ivpu_device {
>>  struct ivpu_file_priv {
>>         struct kref ref;
>>         struct ivpu_device *vdev;
>> +       struct ivpu_mmu_context ctx;
>>         u32 priority;
>>  };
>>
>> diff --git a/drivers/accel/ivpu/ivpu_hw_mtl.c b/drivers/accel/ivpu/ivpu_hw_mtl.c
>> index c84bacd4d0f5..39350203452d 100644
>> --- a/drivers/accel/ivpu/ivpu_hw_mtl.c
>> +++ b/drivers/accel/ivpu/ivpu_hw_mtl.c
>> @@ -7,6 +7,7 @@
>>  #include "ivpu_hw_mtl_reg.h"
>>  #include "ivpu_hw_reg_io.h"
>>  #include "ivpu_hw.h"
>> +#include "ivpu_mmu.h"
>>
>>  #define TILE_FUSE_ENABLE_BOTH       0x0
>>  #define TILE_FUSE_ENABLE_UPPER      0x1
>> @@ -930,6 +931,15 @@ static u32 ivpu_hw_mtl_irqv_handler(struct ivpu_device *vdev, int irq)
>>
>>         REGV_WR32(MTL_VPU_HOST_SS_ICB_CLEAR_0, status);
>>
>> +       if (REG_TEST_FLD(MTL_VPU_HOST_SS_ICB_STATUS_0, MMU_IRQ_0_INT, status))
>> +               ivpu_mmu_irq_evtq_handler(vdev);
>> +
>> +       if (REG_TEST_FLD(MTL_VPU_HOST_SS_ICB_STATUS_0, MMU_IRQ_1_INT, status))
>> +               ivpu_dbg(vdev, IRQ, "MMU sync complete\n");
>> +
>> +       if (REG_TEST_FLD(MTL_VPU_HOST_SS_ICB_STATUS_0, MMU_IRQ_2_INT, status))
>> +               ivpu_mmu_irq_gerr_handler(vdev);
>> +
>>         if (REG_TEST_FLD(MTL_VPU_HOST_SS_ICB_STATUS_0, CPU_INT_REDIRECT_0_INT, status))
>>                 ivpu_hw_mtl_irq_wdt_mss_handler(vdev);
>>
>> diff --git a/drivers/accel/ivpu/ivpu_mmu.c b/drivers/accel/ivpu/ivpu_mmu.c
>> new file mode 100644
>> index 000000000000..2dd9d2287055
>> --- /dev/null
>> +++ b/drivers/accel/ivpu/ivpu_mmu.c
>> @@ -0,0 +1,875 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (C) 2020-2022 Intel Corporation
>> + */
>> +
>> +#include <linux/circ_buf.h>
>> +#include <linux/highmem.h>
>> +
>> +#include "ivpu_drv.h"
>> +#include "ivpu_hw_mtl_reg.h"
>> +#include "ivpu_hw_reg_io.h"
>> +#include "ivpu_mmu.h"
>> +#include "ivpu_mmu_context.h"
>> +
>> +#define IVPU_MMU_IDR0_REF              0x080f3e0f
>> +#define IVPU_MMU_IDR0_REF_SIMICS       0x080f3e1f
>> +#define IVPU_MMU_IDR1_REF              0x0e739d18
>> +#define IVPU_MMU_IDR3_REF              0x0000003c
>> +#define IVPU_MMU_IDR5_REF              0x00040070
>> +#define IVPU_MMU_IDR5_REF_SIMICS       0x00000075
>> +#define IVPU_MMU_IDR5_REF_FPGA         0x00800075
>> +
>> +#define IVPU_MMU_CDTAB_ENT_SIZE                64
>> +#define IVPU_MMU_CDTAB_ENT_COUNT_LOG2  8 /* 256 entries */
>> +#define IVPU_MMU_CDTAB_ENT_COUNT       ((u32)1 << IVPU_MMU_CDTAB_ENT_COUNT_LOG2)
>> +
>> +#define IVPU_MMU_STREAM_ID0            0
>> +#define IVPU_MMU_STREAM_ID3            3
>> +
>> +#define IVPU_MMU_STRTAB_ENT_SIZE       64
>> +#define IVPU_MMU_STRTAB_ENT_COUNT      4
>> +#define IVPU_MMU_STRTAB_CFG_LOG2SIZE   2
>> +#define IVPU_MMU_STRTAB_CFG            IVPU_MMU_STRTAB_CFG_LOG2SIZE
>> +
>> +#define IVPU_MMU_Q_COUNT_LOG2          4 /* 16 entries */
>> +#define IVPU_MMU_Q_COUNT               ((u32)1 << IVPU_MMU_Q_COUNT_LOG2)
>> +#define IVPU_MMU_Q_WRAP_BIT            (IVPU_MMU_Q_COUNT << 1)
>> +#define IVPU_MMU_Q_WRAP_MASK           (IVPU_MMU_Q_WRAP_BIT - 1)
>> +#define IVPU_MMU_Q_IDX_MASK            (IVPU_MMU_Q_COUNT - 1)
>> +#define IVPU_MMU_Q_IDX(val)            ((val) & IVPU_MMU_Q_IDX_MASK)
>> +
>> +#define IVPU_MMU_CMDQ_CMD_SIZE         16
>> +#define IVPU_MMU_CMDQ_SIZE             (IVPU_MMU_Q_COUNT * IVPU_MMU_CMDQ_CMD_SIZE)
>> +
>> +#define IVPU_MMU_EVTQ_CMD_SIZE         32
>> +#define IVPU_MMU_EVTQ_SIZE             (IVPU_MMU_Q_COUNT * IVPU_MMU_EVTQ_CMD_SIZE)
>> +
>> +#define IVPU_MMU_CMD_OPCODE            GENMASK(7, 0)
>> +
>> +#define IVPU_MMU_CMD_SYNC_0_CS         GENMASK(13, 12)
>> +#define IVPU_MMU_CMD_SYNC_0_MSH                GENMASK(23, 22)
>> +#define IVPU_MMU_CMD_SYNC_0_MSI_ATTR   GENMASK(27, 24)
>> +#define IVPU_MMU_CMD_SYNC_0_MSI_ATTR   GENMASK(27, 24)
>> +#define IVPU_MMU_CMD_SYNC_0_MSI_DATA   GENMASK(63, 32)
>> +
>> +#define IVPU_MMU_CMD_CFGI_0_SSEC       BIT(10)
>> +#define IVPU_MMU_CMD_CFGI_0_SSV                BIT(11)
>> +#define IVPU_MMU_CMD_CFGI_0_SSID       GENMASK(31, 12)
>> +#define IVPU_MMU_CMD_CFGI_0_SID                GENMASK(63, 32)
>> +#define IVPU_MMU_CMD_CFGI_1_RANGE      GENMASK(4, 0)
>> +
>> +#define IVPU_MMU_CMD_TLBI_0_ASID       GENMASK(63, 48)
>> +#define IVPU_MMU_CMD_TLBI_0_VMID       GENMASK(47, 32)
>> +
>> +#define CMD_PREFETCH_CFG               0x1
>> +#define CMD_CFGI_STE                   0x3
>> +#define CMD_CFGI_ALL                   0x4
>> +#define CMD_CFGI_CD                    0x5
>> +#define CMD_CFGI_CD_ALL                        0x6
>> +#define CMD_TLBI_NH_ASID               0x11
>> +#define CMD_TLBI_EL2_ALL               0x20
>> +#define CMD_TLBI_NSNH_ALL              0x30
>> +#define CMD_SYNC                       0x46
>> +
>> +#define IVPU_MMU_EVT_F_UUT             0x01
>> +#define IVPU_MMU_EVT_C_BAD_STREAMID    0x02
>> +#define IVPU_MMU_EVT_F_STE_FETCH       0x03
>> +#define IVPU_MMU_EVT_C_BAD_STE         0x04
>> +#define IVPU_MMU_EVT_F_BAD_ATS_TREQ    0x05
>> +#define IVPU_MMU_EVT_F_STREAM_DISABLED 0x06
>> +#define IVPU_MMU_EVT_F_TRANSL_FORBIDDEN        0x07
>> +#define IVPU_MMU_EVT_C_BAD_SUBSTREAMID 0x08
>> +#define IVPU_MMU_EVT_F_CD_FETCH                0x09
>> +#define IVPU_MMU_EVT_C_BAD_CD          0x0a
>> +#define IVPU_MMU_EVT_F_WALK_EABT       0x0b
>> +#define IVPU_MMU_EVT_F_TRANSLATION     0x10
>> +#define IVPU_MMU_EVT_F_ADDR_SIZE       0x11
>> +#define IVPU_MMU_EVT_F_ACCESS          0x12
>> +#define IVPU_MMU_EVT_F_PERMISSION      0x13
>> +#define IVPU_MMU_EVT_F_TLB_CONFLICT    0x20
>> +#define IVPU_MMU_EVT_F_CFG_CONFLICT    0x21
>> +#define IVPU_MMU_EVT_E_PAGE_REQUEST    0x24
>> +#define IVPU_MMU_EVT_F_VMS_FETCH       0x25
>> +
>> +#define IVPU_MMU_EVTS_MAX              8
>> +
>> +#define IVPU_MMU_EVT_OP_MASK           GENMASK_ULL(7, 0)
>> +#define IVPU_MMU_EVT_SSID_MASK         GENMASK_ULL(31, 12)
>> +
>> +#define IVPU_MMU_Q_BASE_RWA            BIT(62)
>> +#define IVPU_MMU_Q_BASE_ADDR_MASK      GENMASK_ULL(51, 5)
>> +#define IVPU_MMU_STRTAB_BASE_RA                BIT(62)
>> +#define IVPU_MMU_STRTAB_BASE_ADDR_MASK GENMASK_ULL(51, 6)
>> +
>> +#define IVPU_MMU_IRQ_EVTQ_EN           BIT(2)
>> +#define IVPU_MMU_IRQ_GERROR_EN         BIT(0)
>> +
>> +#define IVPU_MMU_CR0_ATSCHK            BIT(4)
>> +#define IVPU_MMU_CR0_CMDQEN            BIT(3)
>> +#define IVPU_MMU_CR0_EVTQEN            BIT(2)
>> +#define IVPU_MMU_CR0_PRIQEN            BIT(1)
>> +#define IVPU_MMU_CR0_SMMUEN            BIT(0)
>> +
>> +#define IVPU_MMU_CR1_TABLE_SH          GENMASK(11, 10)
>> +#define IVPU_MMU_CR1_TABLE_OC          GENMASK(9, 8)
>> +#define IVPU_MMU_CR1_TABLE_IC          GENMASK(7, 6)
>> +#define IVPU_MMU_CR1_QUEUE_SH          GENMASK(5, 4)
>> +#define IVPU_MMU_CR1_QUEUE_OC          GENMASK(3, 2)
>> +#define IVPU_MMU_CR1_QUEUE_IC          GENMASK(1, 0)
>> +#define IVPU_MMU_CACHE_NC              0
>> +#define IVPU_MMU_CACHE_WB              1
>> +#define IVPU_MMU_CACHE_WT              2
>> +#define IVPU_MMU_SH_NSH                        0
>> +#define IVPU_MMU_SH_OSH                        2
>> +#define IVPU_MMU_SH_ISH                        3
>> +
>> +#define IVPU_MMU_CMDQ_OP               GENMASK_ULL(7, 0)
>> +
>> +#define IVPU_MMU_CD_0_TCR_T0SZ         GENMASK_ULL(5, 0)
>> +#define IVPU_MMU_CD_0_TCR_TG0          GENMASK_ULL(7, 6)
>> +#define IVPU_MMU_CD_0_TCR_IRGN0                GENMASK_ULL(9, 8)
>> +#define IVPU_MMU_CD_0_TCR_ORGN0                GENMASK_ULL(11, 10)
>> +#define IVPU_MMU_CD_0_TCR_SH0          GENMASK_ULL(13, 12)
>> +#define IVPU_MMU_CD_0_TCR_EPD0         BIT_ULL(14)
>> +#define IVPU_MMU_CD_0_TCR_EPD1         BIT_ULL(30)
>> +#define IVPU_MMU_CD_0_ENDI             BIT(15)
>> +#define IVPU_MMU_CD_0_V                        BIT(31)
>> +#define IVPU_MMU_CD_0_TCR_IPS          GENMASK_ULL(34, 32)
>> +#define IVPU_MMU_CD_0_TCR_TBI0         BIT_ULL(38)
>> +#define IVPU_MMU_CD_0_AA64             BIT(41)
>> +#define IVPU_MMU_CD_0_S                        BIT(44)
>> +#define IVPU_MMU_CD_0_R                        BIT(45)
>> +#define IVPU_MMU_CD_0_A                        BIT(46)
>> +#define IVPU_MMU_CD_0_ASET             BIT(47)
>> +#define IVPU_MMU_CD_0_ASID             GENMASK_ULL(63, 48)
>> +
>> +#define IVPU_MMU_CD_1_TTB0_MASK                GENMASK_ULL(51, 4)
>> +
>> +#define IVPU_MMU_STE_0_S1CDMAX         GENMASK_ULL(63, 59)
>> +#define IVPU_MMU_STE_0_S1FMT           GENMASK_ULL(5, 4)
>> +#define IVPU_MMU_STE_0_S1FMT_LINEAR    0
>> +#define IVPU_MMU_STE_DWORDS            8
>> +#define IVPU_MMU_STE_0_CFG_S1_TRANS    5
>> +#define IVPU_MMU_STE_0_CFG             GENMASK_ULL(3, 1)
>> +#define IVPU_MMU_STE_0_S1CTXPTR_MASK   GENMASK_ULL(51, 6)
>> +#define IVPU_MMU_STE_0_V                       BIT(0)
>> +
>> +#define IVPU_MMU_STE_1_STRW_NSEL1      0ul
>> +#define IVPU_MMU_STE_1_CONT            GENMASK_ULL(16, 13)
>> +#define IVPU_MMU_STE_1_STRW            GENMASK_ULL(31, 30)
>> +#define IVPU_MMU_STE_1_PRIVCFG         GENMASK_ULL(49, 48)
>> +#define IVPU_MMU_STE_1_PRIVCFG_UNPRIV  2ul
>> +#define IVPU_MMU_STE_1_INSTCFG         GENMASK_ULL(51, 50)
>> +#define IVPU_MMU_STE_1_INSTCFG_DATA    2ul
>> +#define IVPU_MMU_STE_1_MEV             BIT(19)
>> +#define IVPU_MMU_STE_1_S1STALLD                BIT(27)
>> +#define IVPU_MMU_STE_1_S1C_CACHE_NC    0ul
>> +#define IVPU_MMU_STE_1_S1C_CACHE_WBRA  1ul
>> +#define IVPU_MMU_STE_1_S1C_CACHE_WT    2ul
>> +#define IVPU_MMU_STE_1_S1C_CACHE_WB    3ul
>> +#define IVPU_MMU_STE_1_S1CIR           GENMASK_ULL(3, 2)
>> +#define IVPU_MMU_STE_1_S1COR           GENMASK_ULL(5, 4)
>> +#define IVPU_MMU_STE_1_S1CSH           GENMASK_ULL(7, 6)
>> +#define IVPU_MMU_STE_1_S1DSS           GENMASK_ULL(1, 0)
>> +#define IVPU_MMU_STE_1_S1DSS_TERMINATE 0x0
>> +
>> +#define IVPU_MMU_REG_TIMEOUT_US                (10 * USEC_PER_MSEC)
>> +#define IVPU_MMU_QUEUE_TIMEOUT_US      (100 * USEC_PER_MSEC)
>> +
>> +#define IVPU_MMU_GERROR_ERR_MASK ((REG_FLD(MTL_VPU_HOST_MMU_GERROR, CMDQ)) | \
>> +                                 (REG_FLD(MTL_VPU_HOST_MMU_GERROR, EVTQ_ABT)) | \
>> +                                 (REG_FLD(MTL_VPU_HOST_MMU_GERROR, PRIQ_ABT)) | \
>> +                                 (REG_FLD(MTL_VPU_HOST_MMU_GERROR, MSI_CMDQ_ABT)) | \
>> +                                 (REG_FLD(MTL_VPU_HOST_MMU_GERROR, MSI_EVTQ_ABT)) | \
>> +                                 (REG_FLD(MTL_VPU_HOST_MMU_GERROR, MSI_PRIQ_ABT)) | \
>> +                                 (REG_FLD(MTL_VPU_HOST_MMU_GERROR, MSI_ABT)))
>> +
>> +static char *ivpu_mmu_event_to_str(u32 cmd)
>> +{
>> +       switch (cmd) {
>> +       case IVPU_MMU_EVT_F_UUT:
>> +               return "Unsupported Upstream Transaction";
>> +       case IVPU_MMU_EVT_C_BAD_STREAMID:
>> +               return "Transaction StreamID out of range";
>> +       case IVPU_MMU_EVT_F_STE_FETCH:
>> +               return "Fetch of STE caused external abort";
>> +       case IVPU_MMU_EVT_C_BAD_STE:
>> +               return "Used STE invalid";
>> +       case IVPU_MMU_EVT_F_BAD_ATS_TREQ:
>> +               return "Address Request disallowed for a StreamID";
>> +       case IVPU_MMU_EVT_F_STREAM_DISABLED:
>> +               return "Transaction marks non-substream disabled";
>> +       case IVPU_MMU_EVT_F_TRANSL_FORBIDDEN:
>> +               return "MMU bypass is disallowed for this StreamID";
>> +       case IVPU_MMU_EVT_C_BAD_SUBSTREAMID:
>> +               return "Invalid StreamID";
>> +       case IVPU_MMU_EVT_F_CD_FETCH:
>> +               return "Fetch of CD caused external abort";
>> +       case IVPU_MMU_EVT_C_BAD_CD:
>> +               return "Fetched CD invalid";
>> +       case IVPU_MMU_EVT_F_WALK_EABT:
>> +               return " An external abort occurred fetching a TLB";
>> +       case IVPU_MMU_EVT_F_TRANSLATION:
>> +               return "Translation fault";
>> +       case IVPU_MMU_EVT_F_ADDR_SIZE:
>> +               return " Output address caused address size fault";
>> +       case IVPU_MMU_EVT_F_ACCESS:
>> +               return "Access flag fault";
>> +       case IVPU_MMU_EVT_F_PERMISSION:
>> +               return "Permission fault occurred on page access";
>> +       case IVPU_MMU_EVT_F_TLB_CONFLICT:
>> +               return "A TLB conflict";
>> +       case IVPU_MMU_EVT_F_CFG_CONFLICT:
>> +               return "A configuration cache conflict";
>> +       case IVPU_MMU_EVT_E_PAGE_REQUEST:
>> +               return "Page request hint from a client device";
>> +       case IVPU_MMU_EVT_F_VMS_FETCH:
>> +               return "Fetch of VMS caused external abort";
>> +       default:
>> +               return "Unknown CMDQ command";
>> +       }
>> +}
>> +
>> +static int ivpu_mmu_config_check(struct ivpu_device *vdev)
>> +{
>> +       u32 val_ref;
>> +       u32 val;
>> +
>> +       if (ivpu_is_simics(vdev))
>> +               val_ref = IVPU_MMU_IDR0_REF_SIMICS;
>> +       else
>> +               val_ref = IVPU_MMU_IDR0_REF;
>> +
>> +       val = REGV_RD32(MTL_VPU_HOST_MMU_IDR0);
>> +       if (val != val_ref)
>> +               ivpu_err(vdev, "IDR0 0x%x != IDR0_REF 0x%x\n", val, val_ref);
> What's the meaning of printing an error if this function always returns 0 ?
> Do you count on the user to look at dmesg ?

No meaning, I will change this and all other output to ivpu_dbg().

>> +
>> +       val = REGV_RD32(MTL_VPU_HOST_MMU_IDR1);
>> +       if (val != IVPU_MMU_IDR1_REF)
>> +               ivpu_warn(vdev, "IDR1 0x%x != IDR1_REF 0x%x\n", val, IVPU_MMU_IDR1_REF);
>> +
>> +       val = REGV_RD32(MTL_VPU_HOST_MMU_IDR3);
>> +       if (val != IVPU_MMU_IDR3_REF)
>> +               ivpu_warn(vdev, "IDR3 0x%x != IDR3_REF 0x%x\n", val, IVPU_MMU_IDR3_REF);
>> +
>> +       if (ivpu_is_simics(vdev))
>> +               val_ref = IVPU_MMU_IDR5_REF_SIMICS;
>> +       else if (ivpu_is_fpga(vdev))
>> +               val_ref = IVPU_MMU_IDR5_REF_FPGA;
>> +       else
>> +               val_ref = IVPU_MMU_IDR5_REF;
>> +
>> +       val = REGV_RD32(MTL_VPU_HOST_MMU_IDR5);
>> +       if (val != val_ref)
>> +               ivpu_dbg(vdev, MMU, "IDR5 0x%x != IDR5_REF 0x%x\n", val, val_ref);
>> +
>> +       return 0;
> Why not define this function as void if it always returns 0 ?

Yeah, it should be void.

>> +}
>> +
>> +static int ivpu_mmu_cdtab_alloc(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +       struct ivpu_mmu_cdtab *cdtab = &mmu->cdtab;
>> +       size_t size = IVPU_MMU_CDTAB_ENT_COUNT * IVPU_MMU_CDTAB_ENT_SIZE;
>> +
>> +       cdtab->base = dmam_alloc_coherent(vdev->drm.dev, size, &cdtab->dma, GFP_KERNEL);
>> +       if (!cdtab->base)
>> +               return -ENOMEM;
>> +
>> +       ivpu_dbg(vdev, MMU, "CDTAB alloc: dma=%pad size=%zu\n", &cdtab->dma, size);
>> +
>> +       return 0;
>> +}
>> +
>> +static int ivpu_mmu_strtab_alloc(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +       struct ivpu_mmu_strtab *strtab = &mmu->strtab;
>> +       size_t size = IVPU_MMU_STRTAB_ENT_COUNT * IVPU_MMU_STRTAB_ENT_SIZE;
>> +
>> +       strtab->base = dmam_alloc_coherent(vdev->drm.dev, size, &strtab->dma, GFP_KERNEL);
>> +       if (!strtab->base)
>> +               return -ENOMEM;
>> +
>> +       strtab->base_cfg = IVPU_MMU_STRTAB_CFG;
>> +       strtab->dma_q = IVPU_MMU_STRTAB_BASE_RA;
>> +       strtab->dma_q |= strtab->dma & IVPU_MMU_STRTAB_BASE_ADDR_MASK;
>> +
>> +       ivpu_dbg(vdev, MMU, "STRTAB alloc: dma=%pad dma_q=%pad size=%zu\n",
>> +                &strtab->dma, &strtab->dma_q, size);
>> +
>> +       return 0;
>> +}
>> +
>> +static int ivpu_mmu_cmdq_alloc(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +       struct ivpu_mmu_queue *q = &mmu->cmdq;
>> +
>> +       q->base = dmam_alloc_coherent(vdev->drm.dev, IVPU_MMU_CMDQ_SIZE, &q->dma, GFP_KERNEL);
>> +       if (!q->base)
>> +               return -ENOMEM;
>> +
>> +       q->dma_q = IVPU_MMU_Q_BASE_RWA;
>> +       q->dma_q |= q->dma & IVPU_MMU_Q_BASE_ADDR_MASK;
>> +       q->dma_q |= IVPU_MMU_Q_COUNT_LOG2;
>> +
>> +       ivpu_dbg(vdev, MMU, "CMDQ alloc: dma=%pad dma_q=%pad size=%u\n",
>> +                &q->dma, &q->dma_q, IVPU_MMU_CMDQ_SIZE);
>> +
>> +       return 0;
>> +}
>> +
>> +static int ivpu_mmu_evtq_alloc(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +       struct ivpu_mmu_queue *q = &mmu->evtq;
>> +
>> +       q->base = dmam_alloc_coherent(vdev->drm.dev, IVPU_MMU_EVTQ_SIZE, &q->dma, GFP_KERNEL);
>> +       if (!q->base)
>> +               return -ENOMEM;
>> +
>> +       q->dma_q = IVPU_MMU_Q_BASE_RWA;
>> +       q->dma_q |= q->dma & IVPU_MMU_Q_BASE_ADDR_MASK;
>> +       q->dma_q |= IVPU_MMU_Q_COUNT_LOG2;
>> +
>> +       ivpu_dbg(vdev, MMU, "EVTQ alloc: dma=%pad dma_q=%pad size=%u\n",
>> +                &q->dma, &q->dma_q, IVPU_MMU_EVTQ_SIZE);
>> +
>> +       return 0;
>> +}
>> +
>> +static int ivpu_mmu_structs_alloc(struct ivpu_device *vdev)
>> +{
>> +       int ret;
>> +
>> +       ret = ivpu_mmu_cdtab_alloc(vdev);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to allocate cdtab: %d\n", ret);
>> +               return ret;
>> +       }
>> +
>> +       ret = ivpu_mmu_strtab_alloc(vdev);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to allocate strtab: %d\n", ret);
>> +               return ret;
>> +       }
>> +
>> +       ret = ivpu_mmu_cmdq_alloc(vdev);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to allocate cmdq: %d\n", ret);
>> +               return ret;
>> +       }
>> +
>> +       ret = ivpu_mmu_evtq_alloc(vdev);
>> +       if (ret)
>> +               ivpu_err(vdev, "Failed to allocate evtq: %d\n", ret);
>> +
>> +       return ret;
>> +}
>> +
>> +static int ivpu_mmu_reg_write(struct ivpu_device *vdev, u32 reg, u32 val)
>> +{
>> +       u32 reg_ack = reg + 4; /* ACK register is 4B after base register */
>> +       u32 val_ack;
>> +       int ret;
>> +
>> +       REGV_WR32(reg, val);
>> +
>> +       ret = REGV_POLL(reg_ack, val_ack, (val == val_ack), IVPU_MMU_REG_TIMEOUT_US);
>> +       if (ret)
>> +               ivpu_err(vdev, "Failed to write register 0x%x\n", reg);
>> +
>> +       return ret;
>> +}
>> +
>> +static int ivpu_mmu_irqs_setup(struct ivpu_device *vdev)
>> +{
>> +       u32 irq_ctrl = IVPU_MMU_IRQ_EVTQ_EN | IVPU_MMU_IRQ_GERROR_EN;
>> +       int ret;
>> +
>> +       ret = ivpu_mmu_reg_write(vdev, MTL_VPU_HOST_MMU_IRQ_CTRL, 0);
>> +       if (ret)
>> +               return ret;
>> +
>> +       return ivpu_mmu_reg_write(vdev, MTL_VPU_HOST_MMU_IRQ_CTRL, irq_ctrl);
>> +}
>> +
>> +static int ivpu_mmu_cmdq_wait_for_cons(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_queue *cmdq = &vdev->mmu->cmdq;
>> +
>> +       return REGV_POLL(MTL_VPU_HOST_MMU_CMDQ_CONS, cmdq->cons, (cmdq->prod == cmdq->cons),
>> +                        IVPU_MMU_QUEUE_TIMEOUT_US);
>> +}
>> +
>> +static int ivpu_mmu_cmdq_cmd_write(struct ivpu_device *vdev, const char *name, u64 data0, u64 data1)
>> +{
>> +       struct ivpu_mmu_queue *q = &vdev->mmu->cmdq;
>> +       u64 *queue_buffer = q->base;
>> +       int idx = IVPU_MMU_Q_IDX(q->prod) * (IVPU_MMU_CMDQ_CMD_SIZE / sizeof(*queue_buffer));
>> +
>> +       if (!CIRC_SPACE(IVPU_MMU_Q_IDX(q->prod), IVPU_MMU_Q_IDX(q->cons), IVPU_MMU_Q_COUNT)) {
>> +               ivpu_err(vdev, "Failed to write MMU CMD %s\n", name);
>> +               return -EBUSY;
>> +       }
>> +
>> +       queue_buffer[idx] = data0;
>> +       queue_buffer[idx + 1] = data1;
>> +       q->prod = (q->prod + 1) & IVPU_MMU_Q_WRAP_MASK;
>> +
>> +       ivpu_dbg(vdev, MMU, "CMD write: %s data: 0x%llx 0x%llx\n", name, data0, data1);
>> +
>> +       return 0;
>> +}
>> +
>> +static int ivpu_mmu_cmdq_sync(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_queue *q = &vdev->mmu->cmdq;
>> +       u64 val;
>> +       int ret;
>> +
>> +       val = FIELD_PREP(IVPU_MMU_CMD_OPCODE, CMD_SYNC) |
>> +             FIELD_PREP(IVPU_MMU_CMD_SYNC_0_CS, 0x2) |
>> +             FIELD_PREP(IVPU_MMU_CMD_SYNC_0_MSH, 0x3) |
>> +             FIELD_PREP(IVPU_MMU_CMD_SYNC_0_MSI_ATTR, 0xf);
>> +
>> +       ret = ivpu_mmu_cmdq_cmd_write(vdev, "SYNC", val, 0);
>> +       if (ret)
>> +               return ret;
>> +
>> +       clflush_cache_range(q->base, IVPU_MMU_CMDQ_SIZE);
> Why do you need this call ? Not just here, in all the places in the driver.
> This is not a function call that is commonly seen in PCI drivers...

It flushes CPU caches to DDR.
We need this call for MMU page tables as they are allocated as cached and 
VPU doesn't snoop them for performance reasons.
In future we may allocate the page tables as write-combined and replace clfushes with a single wmb().
I will add this to TODO.

>> +       REGV_WR32(MTL_VPU_HOST_MMU_CMDQ_PROD, q->prod);
>> +
>> +       ret = ivpu_mmu_cmdq_wait_for_cons(vdev);
>> +       if (ret)
>> +               ivpu_err(vdev, "Timed out waiting for consumer: %d\n", ret);
>> +
>> +       return ret;
>> +}
>> +
>> +static int ivpu_mmu_cmdq_write_cfgi_all(struct ivpu_device *vdev)
>> +{
>> +       u64 data0 = FIELD_PREP(IVPU_MMU_CMD_OPCODE, CMD_CFGI_ALL);
>> +       u64 data1 = FIELD_PREP(IVPU_MMU_CMD_CFGI_1_RANGE, 0x1f);
>> +
>> +       return ivpu_mmu_cmdq_cmd_write(vdev, "CFGI_ALL", data0, data1);
>> +}
>> +
>> +static int ivpu_mmu_cmdq_write_tlbi_nh_asid(struct ivpu_device *vdev, u16 ssid)
>> +{
>> +       u64 val = FIELD_PREP(IVPU_MMU_CMD_OPCODE, CMD_TLBI_NH_ASID) |
>> +                 FIELD_PREP(IVPU_MMU_CMD_TLBI_0_ASID, ssid);
>> +
>> +       return ivpu_mmu_cmdq_cmd_write(vdev, "TLBI_NH_ASID", val, 0);
>> +}
>> +
>> +static int ivpu_mmu_cmdq_write_tlbi_nsnh_all(struct ivpu_device *vdev)
>> +{
>> +       u64 val = FIELD_PREP(IVPU_MMU_CMD_OPCODE, CMD_TLBI_NSNH_ALL);
>> +
>> +       return ivpu_mmu_cmdq_cmd_write(vdev, "TLBI_NSNH_ALL", val, 0);
>> +}
>> +
>> +static int ivpu_mmu_reset(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +       u32 val;
>> +       int ret;
>> +
>> +       memset(mmu->cmdq.base, 0, IVPU_MMU_CMDQ_SIZE);
>> +       clflush_cache_range(mmu->cmdq.base, IVPU_MMU_CMDQ_SIZE);
>> +       mmu->cmdq.prod = 0;
>> +       mmu->cmdq.cons = 0;
>> +
>> +       memset(mmu->evtq.base, 0, IVPU_MMU_EVTQ_SIZE);
>> +       clflush_cache_range(mmu->evtq.base, IVPU_MMU_EVTQ_SIZE);
>> +       mmu->evtq.prod = 0;
>> +       mmu->evtq.cons = 0;
>> +
>> +       ret = ivpu_mmu_reg_write(vdev, MTL_VPU_HOST_MMU_CR0, 0);
>> +       if (ret)
>> +               return ret;
>> +
>> +       val = FIELD_PREP(IVPU_MMU_CR1_TABLE_SH, IVPU_MMU_SH_ISH) |
>> +             FIELD_PREP(IVPU_MMU_CR1_TABLE_OC, IVPU_MMU_CACHE_WB) |
>> +             FIELD_PREP(IVPU_MMU_CR1_TABLE_IC, IVPU_MMU_CACHE_WB) |
>> +             FIELD_PREP(IVPU_MMU_CR1_QUEUE_SH, IVPU_MMU_SH_ISH) |
>> +             FIELD_PREP(IVPU_MMU_CR1_QUEUE_OC, IVPU_MMU_CACHE_WB) |
>> +             FIELD_PREP(IVPU_MMU_CR1_QUEUE_IC, IVPU_MMU_CACHE_WB);
>> +       REGV_WR32(MTL_VPU_HOST_MMU_CR1, val);
>> +
>> +       REGV_WR64(MTL_VPU_HOST_MMU_STRTAB_BASE, mmu->strtab.dma_q);
>> +       REGV_WR32(MTL_VPU_HOST_MMU_STRTAB_BASE_CFG, mmu->strtab.base_cfg);
>> +
>> +       REGV_WR64(MTL_VPU_HOST_MMU_CMDQ_BASE, mmu->cmdq.dma_q);
>> +       REGV_WR32(MTL_VPU_HOST_MMU_CMDQ_PROD, 0);
>> +       REGV_WR32(MTL_VPU_HOST_MMU_CMDQ_CONS, 0);
>> +
>> +       val = IVPU_MMU_CR0_CMDQEN;
>> +       ret = ivpu_mmu_reg_write(vdev, MTL_VPU_HOST_MMU_CR0, val);
>> +       if (ret)
>> +               return ret;
>> +
>> +       ret = ivpu_mmu_cmdq_write_cfgi_all(vdev);
>> +       if (ret)
>> +               return ret;
>> +
>> +       ret = ivpu_mmu_cmdq_write_tlbi_nsnh_all(vdev);
>> +       if (ret)
>> +               return ret;
>> +
>> +       ret = ivpu_mmu_cmdq_sync(vdev);
>> +       if (ret)
>> +               return ret;
>> +
>> +       REGV_WR64(MTL_VPU_HOST_MMU_EVTQ_BASE, mmu->evtq.dma_q);
>> +       REGV_WR32(MTL_VPU_HOST_MMU_EVTQ_PROD_SEC, 0);
>> +       REGV_WR32(MTL_VPU_HOST_MMU_EVTQ_CONS_SEC, 0);
>> +
>> +       val |= IVPU_MMU_CR0_EVTQEN;
>> +       ret = ivpu_mmu_reg_write(vdev, MTL_VPU_HOST_MMU_CR0, val);
>> +       if (ret)
>> +               return ret;
>> +
>> +       val |= IVPU_MMU_CR0_ATSCHK;
>> +       ret = ivpu_mmu_reg_write(vdev, MTL_VPU_HOST_MMU_CR0, val);
>> +       if (ret)
>> +               return ret;
>> +
>> +       ret = ivpu_mmu_irqs_setup(vdev);
>> +       if (ret)
>> +               return ret;
>> +
>> +       val |= IVPU_MMU_CR0_SMMUEN;
>> +       return ivpu_mmu_reg_write(vdev, MTL_VPU_HOST_MMU_CR0, val);
>> +}
>> +
>> +static void ivpu_mmu_strtab_link_cd(struct ivpu_device *vdev, u32 sid)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +       struct ivpu_mmu_strtab *strtab = &mmu->strtab;
>> +       struct ivpu_mmu_cdtab *cdtab = &mmu->cdtab;
>> +       u64 *entry = strtab->base + (sid * IVPU_MMU_STRTAB_ENT_SIZE);
>> +       u64 str[2];
>> +
>> +       str[0] = FIELD_PREP(IVPU_MMU_STE_0_CFG, IVPU_MMU_STE_0_CFG_S1_TRANS) |
>> +                FIELD_PREP(IVPU_MMU_STE_0_S1CDMAX, IVPU_MMU_CDTAB_ENT_COUNT_LOG2) |
>> +                FIELD_PREP(IVPU_MMU_STE_0_S1FMT, IVPU_MMU_STE_0_S1FMT_LINEAR) |
>> +                IVPU_MMU_STE_0_V |
>> +                (cdtab->dma & IVPU_MMU_STE_0_S1CTXPTR_MASK);
>> +
>> +       str[1] = FIELD_PREP(IVPU_MMU_STE_1_S1DSS, IVPU_MMU_STE_1_S1DSS_TERMINATE) |
>> +                FIELD_PREP(IVPU_MMU_STE_1_S1CIR, IVPU_MMU_STE_1_S1C_CACHE_NC) |
>> +                FIELD_PREP(IVPU_MMU_STE_1_S1COR, IVPU_MMU_STE_1_S1C_CACHE_NC) |
>> +                FIELD_PREP(IVPU_MMU_STE_1_S1CSH, IVPU_MMU_SH_NSH) |
>> +                FIELD_PREP(IVPU_MMU_STE_1_PRIVCFG, IVPU_MMU_STE_1_PRIVCFG_UNPRIV) |
>> +                FIELD_PREP(IVPU_MMU_STE_1_INSTCFG, IVPU_MMU_STE_1_INSTCFG_DATA) |
>> +                FIELD_PREP(IVPU_MMU_STE_1_STRW, IVPU_MMU_STE_1_STRW_NSEL1) |
>> +                FIELD_PREP(IVPU_MMU_STE_1_CONT, IVPU_MMU_STRTAB_CFG_LOG2SIZE) |
>> +                IVPU_MMU_STE_1_MEV |
>> +                IVPU_MMU_STE_1_S1STALLD;
>> +
>> +       WRITE_ONCE(entry[1], str[1]);
>> +       WRITE_ONCE(entry[0], str[0]);
>> +
>> +       clflush_cache_range(entry, IVPU_MMU_STRTAB_ENT_SIZE);
>> +
>> +       ivpu_dbg(vdev, MMU, "STRTAB write entry (SSID=%u): 0x%llx, 0x%llx\n", sid, str[0], str[1]);
>> +}
>> +
>> +static int ivpu_mmu_strtab_init(struct ivpu_device *vdev)
>> +{
>> +       ivpu_mmu_strtab_link_cd(vdev, IVPU_MMU_STREAM_ID0);
>> +       ivpu_mmu_strtab_link_cd(vdev, IVPU_MMU_STREAM_ID3);
>> +
>> +       return 0;
>> +}
>> +
>> +int ivpu_mmu_invalidate_tlb(struct ivpu_device *vdev, u16 ssid)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +       int ret;
>> +
>> +       ret = mutex_lock_interruptible(&mmu->lock);
>> +       if (ret)
>> +               return ret;
>> +
>> +       if (!mmu->on) {
>> +               ret = 0;
>> +               goto unlock;
>> +       }
> Is this check really necessary ? Or is it for debug/bringup cases ?
> Excluding debug/bringup, I would imagine that the code should never
> reach tlb invalidation if MMU is not enabled.

We check here if MMU is enabled to protect against reset/recovery/autosuspend which may happen at any time.

> Also, from using mutex_lock_interruptible I infer that we only get to
> this function within a process context.
> And afaics, mmu enable/disable happens on device init/fini, where no
> user process exists...

ivpu_mmu_invalidate_tlb() is called at the end of ivpu_mmu_context_map(),
which is called from submit IOCTL to prapare buffers for the VPU, so it is executed
from process context, hence *_interruptible.

>> +
>> +       ret = ivpu_mmu_cmdq_write_tlbi_nh_asid(vdev, ssid);
>> +       if (ret)
>> +               goto unlock;
>> +
>> +       ret = ivpu_mmu_cmdq_sync(vdev);
>> +unlock:
>> +       mutex_unlock(&mmu->lock);
>> +       return ret;
>> +}
>> +
>> +static int ivpu_mmu_cd_add(struct ivpu_device *vdev, u32 ssid, u64 cd_dma)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +       struct ivpu_mmu_cdtab *cdtab = &mmu->cdtab;
>> +       u64 *entry;
>> +       u64 cd[4];
>> +       int ret;
>> +
>> +       if (ssid > IVPU_MMU_CDTAB_ENT_COUNT)
>> +               return -EINVAL;
>> +
>> +       ret = mutex_lock_interruptible(&mmu->lock);
> Why is this entire function protected by mmu lock ?
> afaics, you prepare a context descriptor in system memory, and that
> descriptor is single per context and every context has its own
> location inside the cdtab->base (based on ssid).
> Which concurrency are you protecting against ?
> 
> And if there is no concurrency, I would expect to get the lock only
> before calling ivpu_mmu_cmdq_write_cfgi_all()

Yes, good point. I will move the lock before ivpu_mmu_cmdq_write_cfgi_all().

>> +       if (ret)
>> +               return ret;
>> +
>> +       entry = cdtab->base + (ssid * IVPU_MMU_CDTAB_ENT_SIZE);
>> +
>> +       if (cd_dma != 0) {
>> +               cd[0] = FIELD_PREP(IVPU_MMU_CD_0_TCR_T0SZ, 26) |
>> +                       FIELD_PREP(IVPU_MMU_CD_0_TCR_TG0, 0) |
>> +                       FIELD_PREP(IVPU_MMU_CD_0_TCR_IRGN0, 0) |
>> +                       FIELD_PREP(IVPU_MMU_CD_0_TCR_ORGN0, 0) |
>> +                       FIELD_PREP(IVPU_MMU_CD_0_TCR_SH0, 0) |
>> +                       FIELD_PREP(IVPU_MMU_CD_0_TCR_IPS, 3) |
>> +                       FIELD_PREP(IVPU_MMU_CD_0_ASID, ssid) |
>> +                       IVPU_MMU_CD_0_TCR_EPD1 |
>> +                       IVPU_MMU_CD_0_AA64 |
>> +                       IVPU_MMU_CD_0_R |
>> +                       IVPU_MMU_CD_0_A |
>> +                       IVPU_MMU_CD_0_ASET |
>> +                       IVPU_MMU_CD_0_V;
>> +               cd[1] = cd_dma & IVPU_MMU_CD_1_TTB0_MASK;
>> +               cd[2] = 0;
>> +               cd[3] = 0x0000000000007444;
>> +       } else {
>> +               memset(cd, 0, sizeof(cd));
>> +       }
>> +
>> +       WRITE_ONCE(entry[1], cd[1]);
>> +       WRITE_ONCE(entry[2], cd[2]);
>> +       WRITE_ONCE(entry[3], cd[3]);
>> +       WRITE_ONCE(entry[0], cd[0]);
>> +
>> +       clflush_cache_range(entry, IVPU_MMU_CDTAB_ENT_SIZE);
>> +
>> +       ivpu_dbg(vdev, MMU, "CDTAB %s entry (SSID=%u, dma=%pad): 0x%llx, 0x%llx, 0x%llx, 0x%llx\n",
>> +                cd_dma ? "write" : "clear", ssid, &cd_dma, cd[0], cd[1], cd[2], cd[3]);
>> +
>> +       if (!mmu->on) {
>> +               ret = 0;
>> +               goto unlock;
>> +       }
>> +
>> +       ret = ivpu_mmu_cmdq_write_cfgi_all(vdev);
>> +       if (ret)
>> +               goto unlock;
>> +
>> +       ret = ivpu_mmu_cmdq_sync(vdev);
>> +unlock:
>> +       mutex_unlock(&mmu->lock);
>> +       return ret;
>> +}
>> +
>> +static int ivpu_mmu_cd_add_gbl(struct ivpu_device *vdev)
>> +{
>> +       int ret;
>> +
>> +       ret = ivpu_mmu_cd_add(vdev, 0, vdev->gctx.pgtable.pgd_dma);
>> +       if (ret)
>> +               ivpu_err(vdev, "Failed to add global CD entry: %d\n", ret);
>> +
>> +       return ret;
>> +}
>> +
>> +static int ivpu_mmu_cd_add_user(struct ivpu_device *vdev, u32 ssid, dma_addr_t cd_dma)
>> +{
>> +       int ret;
>> +
>> +       if (ssid == 0) {
>> +               ivpu_err(vdev, "Invalid SSID: %u\n", ssid);
>> +               return -EINVAL;
>> +       }
>> +
>> +       ret = ivpu_mmu_cd_add(vdev, ssid, cd_dma);
>> +       if (ret)
>> +               ivpu_err(vdev, "Failed to add CD entry SSID=%u: %d\n", ssid, ret);
>> +
>> +       return ret;
>> +}
>> +
>> +int ivpu_mmu_init(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +       int ret;
>> +
>> +       ivpu_dbg(vdev, MMU, "Init..\n");
>> +
>> +       drmm_mutex_init(&vdev->drm, &mmu->lock);
>> +
>> +       ret = ivpu_mmu_config_check(vdev);
>> +       if (ret)
>> +               return ret;
> See my comments in ivpu_mmu_config_check(). This check is useless

OK

>> +
>> +       ret = ivpu_mmu_structs_alloc(vdev);
>> +       if (ret)
>> +               return ret;
>> +
>> +       ret = ivpu_mmu_strtab_init(vdev);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to initialize strtab: %d\n", ret);
>> +               return ret;
>> +       }
>> +
>> +       ret = ivpu_mmu_cd_add_gbl(vdev);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to initialize strtab: %d\n", ret);
>> +               return ret;
>> +       }
>> +
>> +       ret = ivpu_mmu_enable(vdev);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to resume MMU: %d\n", ret);
>> +               return ret;
>> +       }
>> +
>> +       ivpu_dbg(vdev, MMU, "Init done\n");
>> +
>> +       return 0;
>> +}
>> +
>> +int ivpu_mmu_enable(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +       int ret;
>> +
>> +       mutex_lock(&mmu->lock);
>> +
>> +       mmu->on = true;
>> +
>> +       ret = ivpu_mmu_reset(vdev);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to reset MMU: %d\n", ret);
>> +               goto err;
>> +       }
>> +
>> +       ret = ivpu_mmu_cmdq_write_cfgi_all(vdev);
>> +       if (ret)
>> +               goto err;
>> +
>> +       ret = ivpu_mmu_cmdq_write_tlbi_nsnh_all(vdev);
>> +       if (ret)
>> +               goto err;
>> +
>> +       ret = ivpu_mmu_cmdq_sync(vdev);
>> +       if (ret)
>> +               goto err;
>> +
>> +       mutex_unlock(&mmu->lock);
>> +
>> +       return 0;
>> +err:
>> +       mmu->on = false;
>> +       mutex_unlock(&mmu->lock);
>> +       return ret;
>> +}
>> +
>> +void ivpu_mmu_disable(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_info *mmu = vdev->mmu;
>> +
>> +       mutex_lock(&mmu->lock);
>> +       mmu->on = false;
>> +       mutex_unlock(&mmu->lock);
>> +}
>> +
>> +static void ivpu_mmu_dump_event(struct ivpu_device *vdev, u32 *event)
>> +{
>> +       u32 ssid = FIELD_GET(IVPU_MMU_EVT_SSID_MASK, event[0]);
>> +       u32 op = FIELD_GET(IVPU_MMU_EVT_OP_MASK, event[0]);
>> +       u64 fetch_addr = ((u64)event[7]) << 32 | event[6];
>> +       u64 in_addr = ((u64)event[5]) << 32 | event[4];
>> +       u32 sid = event[1];
>> +
>> +       ivpu_err(vdev, "MMU EVTQ: 0x%x (%s) SSID: %d SID: %d, e[2] %08x, e[3] %08x, in addr: 0x%llx, fetch addr: 0x%llx\n",
>> +                op, ivpu_mmu_event_to_str(op), ssid, sid, event[2], event[3], in_addr, fetch_addr);
>> +}
>> +
>> +static u32 *ivpu_mmu_get_event(struct ivpu_device *vdev)
>> +{
>> +       struct ivpu_mmu_queue *evtq = &vdev->mmu->evtq;
>> +       u32 idx = IVPU_MMU_Q_IDX(evtq->cons);
>> +       u32 *evt = evtq->base + (idx * IVPU_MMU_EVTQ_CMD_SIZE);
>> +
>> +       evtq->prod = REGV_RD32(MTL_VPU_HOST_MMU_EVTQ_PROD_SEC);
>> +       if (!CIRC_CNT(IVPU_MMU_Q_IDX(evtq->prod), IVPU_MMU_Q_IDX(evtq->cons), IVPU_MMU_Q_COUNT))
>> +               return NULL;
>> +
>> +       clflush_cache_range(evt, IVPU_MMU_EVTQ_CMD_SIZE);
>> +
>> +       evtq->cons = (evtq->cons + 1) & IVPU_MMU_Q_WRAP_MASK;
>> +       REGV_WR32(MTL_VPU_HOST_MMU_EVTQ_CONS_SEC, evtq->cons);
>> +
>> +       return evt;
>> +}
>> +
>> +void ivpu_mmu_irq_evtq_handler(struct ivpu_device *vdev)
>> +{
>> +       u32 *event;
>> +       u32 ssid;
>> +
>> +       ivpu_dbg(vdev, IRQ, "MMU event queue\n");
>> +
>> +       while ((event = ivpu_mmu_get_event(vdev)) != NULL)
>> +               ivpu_mmu_dump_event(vdev, event);
> This is done in irq context, correct ? Is there some protection
> against endless (or very large number) stream of events (can be real
> thing or just f/w bug) ?

I will add protection here.

>> +}
>> +
>> +void ivpu_mmu_irq_gerr_handler(struct ivpu_device *vdev)
>> +{
>> +       u32 gerror_val, gerrorn_val, active;
>> +
>> +       ivpu_dbg(vdev, IRQ, "MMU error\n");
>> +
>> +       gerror_val = REGV_RD32(MTL_VPU_HOST_MMU_GERROR);
>> +       gerrorn_val = REGV_RD32(MTL_VPU_HOST_MMU_GERRORN);
>> +
>> +       active = gerror_val ^ gerrorn_val;
>> +       if (!(active & IVPU_MMU_GERROR_ERR_MASK))
>> +               return;
>> +
>> +       if (REG_TEST_FLD(MTL_VPU_HOST_MMU_GERROR, MSI_ABT, active))
>> +               ivpu_warn_ratelimited(vdev, "MMU MSI ABT write aborted\n");
>> +
>> +       if (REG_TEST_FLD(MTL_VPU_HOST_MMU_GERROR, MSI_PRIQ_ABT, active))
>> +               ivpu_warn_ratelimited(vdev, "MMU PRIQ MSI ABT write aborted\n");
>> +
>> +       if (REG_TEST_FLD(MTL_VPU_HOST_MMU_GERROR, MSI_EVTQ_ABT, active))
>> +               ivpu_warn_ratelimited(vdev, "MMU EVTQ MSI ABT write aborted\n");
>> +
>> +       if (REG_TEST_FLD(MTL_VPU_HOST_MMU_GERROR, MSI_CMDQ_ABT, active))
>> +               ivpu_warn_ratelimited(vdev, "MMU CMDQ MSI ABT write aborted\n");
>> +
>> +       if (REG_TEST_FLD(MTL_VPU_HOST_MMU_GERROR, PRIQ_ABT, active))
>> +               ivpu_err_ratelimited(vdev, "MMU PRIQ write aborted\n");
>> +
>> +       if (REG_TEST_FLD(MTL_VPU_HOST_MMU_GERROR, EVTQ_ABT, active))
>> +               ivpu_err_ratelimited(vdev, "MMU EVTQ write aborted\n");
>> +
>> +       if (REG_TEST_FLD(MTL_VPU_HOST_MMU_GERROR, CMDQ, active))
>> +               ivpu_err_ratelimited(vdev, "MMU CMDQ write aborted\n");
>> +
>> +       REGV_WR32(MTL_VPU_HOST_MMU_GERRORN, gerror_val);
>> +}
>> +
>> +int ivpu_mmu_set_pgtable(struct ivpu_device *vdev, int ssid, struct ivpu_mmu_pgtable *pgtable)
>> +{
>> +       return ivpu_mmu_cd_add_user(vdev, ssid, pgtable->pgd_dma);
>> +}
>> +
>> +void ivpu_mmu_clear_pgtable(struct ivpu_device *vdev, int ssid)
>> +{
>> +       ivpu_mmu_cd_add_user(vdev, ssid, 0); /* 0 will clear CD entry */
>> +}
>> diff --git a/drivers/accel/ivpu/ivpu_mmu.h b/drivers/accel/ivpu/ivpu_mmu.h
>> new file mode 100644
>> index 000000000000..466d698c7142
>> --- /dev/null
>> +++ b/drivers/accel/ivpu/ivpu_mmu.h
>> @@ -0,0 +1,50 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (C) 2020-2022 Intel Corporation
>> + */
>> +
>> +#ifndef __IVPU_MMU_H__
>> +#define __IVPU_MMU_H__
>> +
>> +struct ivpu_device;
>> +
>> +struct ivpu_mmu_cdtab {
>> +       void *base;
>> +       dma_addr_t dma;
>> +};
>> +
>> +struct ivpu_mmu_strtab {
>> +       void *base;
>> +       dma_addr_t dma;
>> +       u64 dma_q;
>> +       u32 base_cfg;
>> +};
>> +
>> +struct ivpu_mmu_queue {
>> +       void *base;
>> +       dma_addr_t dma;
>> +       u64 dma_q;
>> +       u32 prod;
>> +       u32 cons;
>> +};
>> +
>> +struct ivpu_mmu_info {
>> +       struct mutex lock; /* Protects cdtab, strtab, cmdq, on */
>> +       struct ivpu_mmu_cdtab cdtab;
>> +       struct ivpu_mmu_strtab strtab;
>> +       struct ivpu_mmu_queue cmdq;
>> +       struct ivpu_mmu_queue evtq;
>> +       bool on;
>> +};
>> +
>> +int ivpu_mmu_init(struct ivpu_device *vdev);
>> +void ivpu_mmu_disable(struct ivpu_device *vdev);
>> +int ivpu_mmu_enable(struct ivpu_device *vdev);
>> +int ivpu_mmu_set_pgtable(struct ivpu_device *vdev, int ssid, struct ivpu_mmu_pgtable *pgtable);
>> +void ivpu_mmu_clear_pgtable(struct ivpu_device *vdev, int ssid);
>> +int ivpu_mmu_invalidate_tlb(struct ivpu_device *vdev, u16 ssid);
>> +
>> +void ivpu_mmu_irq_evtq_handler(struct ivpu_device *vdev);
>> +void ivpu_mmu_irq_gerr_handler(struct ivpu_device *vdev);
>> +
>> +#endif /* __IVPU_MMU_H__ */
>> diff --git a/drivers/accel/ivpu/ivpu_mmu_context.c b/drivers/accel/ivpu/ivpu_mmu_context.c
>> new file mode 100644
>> index 000000000000..eb25e613bb90
>> --- /dev/null
>> +++ b/drivers/accel/ivpu/ivpu_mmu_context.c
>> @@ -0,0 +1,385 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (C) 2020-2022 Intel Corporation
>> + */
>> +
>> +#include <linux/bitfield.h>
>> +#include <linux/highmem.h>
>> +
>> +#include "ivpu_drv.h"
>> +#include "ivpu_hw.h"
>> +#include "ivpu_mmu.h"
>> +#include "ivpu_mmu_context.h"
>> +
>> +#define IVPU_MMU_PGD_INDEX_MASK          GENMASK(38, 30)
>> +#define IVPU_MMU_PMD_INDEX_MASK          GENMASK(29, 21)
>> +#define IVPU_MMU_PTE_INDEX_MASK          GENMASK(20, 12)
>> +#define IVPU_MMU_ENTRY_FLAGS_MASK        GENMASK(11, 0)
>> +#define IVPU_MMU_ENTRY_FLAG_NG           BIT(11)
>> +#define IVPU_MMU_ENTRY_FLAG_AF           BIT(10)
>> +#define IVPU_MMU_ENTRY_FLAG_USER         BIT(6)
>> +#define IVPU_MMU_ENTRY_FLAG_LLC_COHERENT BIT(2)
>> +#define IVPU_MMU_ENTRY_FLAG_TYPE_PAGE    BIT(1)
>> +#define IVPU_MMU_ENTRY_FLAG_VALID        BIT(0)
>> +
>> +#define IVPU_MMU_PAGE_SIZE    SZ_4K
>> +#define IVPU_MMU_PTE_MAP_SIZE (IVPU_MMU_PGTABLE_ENTRIES * IVPU_MMU_PAGE_SIZE)
>> +#define IVPU_MMU_PMD_MAP_SIZE (IVPU_MMU_PGTABLE_ENTRIES * IVPU_MMU_PTE_MAP_SIZE)
>> +#define IVPU_MMU_PGTABLE_SIZE (IVPU_MMU_PGTABLE_ENTRIES * sizeof(u64))
>> +
>> +#define IVPU_MMU_DUMMY_ADDRESS 0xdeadb000
>> +#define IVPU_MMU_ENTRY_VALID   (IVPU_MMU_ENTRY_FLAG_TYPE_PAGE | IVPU_MMU_ENTRY_FLAG_VALID)
>> +#define IVPU_MMU_ENTRY_INVALID (IVPU_MMU_DUMMY_ADDRESS & ~IVPU_MMU_ENTRY_FLAGS_MASK)
>> +#define IVPU_MMU_ENTRY_MAPPED  (IVPU_MMU_ENTRY_FLAG_AF | IVPU_MMU_ENTRY_FLAG_USER | \
>> +                               IVPU_MMU_ENTRY_FLAG_NG | IVPU_MMU_ENTRY_VALID)
>> +
>> +static int ivpu_mmu_pgtable_init(struct ivpu_device *vdev, struct ivpu_mmu_pgtable *pgtable)
>> +{
>> +       dma_addr_t pgd_dma;
>> +       u64 *pgd;
>> +
>> +       pgd = dma_alloc_wc(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, &pgd_dma, GFP_KERNEL);
>> +       if (!pgd)
>> +               return -ENOMEM;
>> +
>> +       pgtable->pgd = pgd;
>> +       pgtable->pgd_dma = pgd_dma;
>> +
>> +       return 0;
>> +}
>> +
>> +static void ivpu_mmu_pgtable_free(struct ivpu_device *vdev, struct ivpu_mmu_pgtable *pgtable)
>> +{
>> +       int pgd_index, pmd_index;
>> +
>> +       for (pgd_index = 0; pgd_index < IVPU_MMU_PGTABLE_ENTRIES; ++pgd_index) {
>> +               u64 **pmd_entries = pgtable->pgd_cpu_entries[pgd_index];
>> +               u64 *pmd = pgtable->pgd_entries[pgd_index];
>> +
>> +               if (!pmd_entries)
>> +                       continue;
>> +
>> +               for (pmd_index = 0; pmd_index < IVPU_MMU_PGTABLE_ENTRIES; ++pmd_index) {
>> +                       if (pmd_entries[pmd_index])
>> +                               dma_free_wc(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE,
>> +                                           pmd_entries[pmd_index],
>> +                                           pmd[pmd_index] & ~IVPU_MMU_ENTRY_FLAGS_MASK);
>> +               }
>> +
>> +               kfree(pmd_entries);
>> +               dma_free_wc(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, pgtable->pgd_entries[pgd_index],
>> +                           pgtable->pgd[pgd_index] & ~IVPU_MMU_ENTRY_FLAGS_MASK);
>> +       }
>> +
>> +       dma_free_wc(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, pgtable->pgd,
>> +                   pgtable->pgd_dma & ~IVPU_MMU_ENTRY_FLAGS_MASK);
>> +}
>> +
>> +static u64*
>> +ivpu_mmu_ensure_pmd(struct ivpu_device *vdev, struct ivpu_mmu_pgtable *pgtable, u64 pgd_index)
>> +{
>> +       u64 **pmd_entries;
>> +       dma_addr_t pmd_dma;
>> +       u64 *pmd;
>> +
>> +       if (pgtable->pgd_entries[pgd_index])
>> +               return pgtable->pgd_entries[pgd_index];
>> +
>> +       pmd = dma_alloc_wc(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, &pmd_dma, GFP_KERNEL);
>> +       if (!pmd)
>> +               return NULL;
>> +
>> +       pmd_entries = kzalloc(IVPU_MMU_PGTABLE_SIZE, GFP_KERNEL);
>> +       if (!pmd_entries)
>> +               goto err_free_pgd;
>> +
>> +       pgtable->pgd_entries[pgd_index] = pmd;
>> +       pgtable->pgd_cpu_entries[pgd_index] = pmd_entries;
>> +       pgtable->pgd[pgd_index] = pmd_dma | IVPU_MMU_ENTRY_VALID;
>> +
>> +       return pmd;
>> +
>> +err_free_pgd:
>> +       dma_free_wc(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, pmd, pmd_dma);
>> +       return NULL;
>> +}
>> +
>> +static u64*
>> +ivpu_mmu_ensure_pte(struct ivpu_device *vdev, struct ivpu_mmu_pgtable *pgtable,
>> +                   int pgd_index, int pmd_index)
>> +{
>> +       dma_addr_t pte_dma;
>> +       u64 *pte;
>> +
>> +       if (pgtable->pgd_cpu_entries[pgd_index][pmd_index])
>> +               return pgtable->pgd_cpu_entries[pgd_index][pmd_index];
>> +
>> +       pte = dma_alloc_wc(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, &pte_dma, GFP_KERNEL);
>> +       if (!pte)
>> +               return NULL;
>> +
>> +       pgtable->pgd_cpu_entries[pgd_index][pmd_index] = pte;
>> +       pgtable->pgd_entries[pgd_index][pmd_index] = pte_dma | IVPU_MMU_ENTRY_VALID;
>> +
>> +       return pte;
>> +}
>> +
>> +static int
>> +ivpu_mmu_context_map_page(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx,
>> +                         u64 vpu_addr, dma_addr_t dma_addr, int prot)
>> +{
>> +       u64 *pte;
>> +       int pgd_index = FIELD_GET(IVPU_MMU_PGD_INDEX_MASK, vpu_addr);
>> +       int pmd_index = FIELD_GET(IVPU_MMU_PMD_INDEX_MASK, vpu_addr);
>> +       int pte_index = FIELD_GET(IVPU_MMU_PTE_INDEX_MASK, vpu_addr);
>> +
>> +       /* Allocate PMD - second level page table if needed */
>> +       if (!ivpu_mmu_ensure_pmd(vdev, &ctx->pgtable, pgd_index))
>> +               return -ENOMEM;
>> +
>> +       /* Allocate PTE - third level page table if needed */
>> +       pte = ivpu_mmu_ensure_pte(vdev, &ctx->pgtable, pgd_index, pmd_index);
>> +       if (!pte)
>> +               return -ENOMEM;
>> +
>> +       /* Update PTE - third level page table with DMA address */
>> +       pte[pte_index] = dma_addr | prot;
>> +
>> +       return 0;
>> +}
>> +
>> +static void ivpu_mmu_context_unmap_page(struct ivpu_mmu_context *ctx, u64 vpu_addr)
>> +{
>> +       int pgd_index = FIELD_GET(IVPU_MMU_PGD_INDEX_MASK, vpu_addr);
>> +       int pmd_index = FIELD_GET(IVPU_MMU_PMD_INDEX_MASK, vpu_addr);
>> +       int pte_index = FIELD_GET(IVPU_MMU_PTE_INDEX_MASK, vpu_addr);
>> +
>> +       /* Update PTE with dummy physical address and clear flags */
>> +       ctx->pgtable.pgd_cpu_entries[pgd_index][pmd_index][pte_index] = IVPU_MMU_ENTRY_INVALID;
>> +}
>> +
>> +static void
>> +ivpu_mmu_context_flush_page_tables(struct ivpu_mmu_context *ctx, u64 vpu_addr, size_t size)
>> +{
>> +       u64 end_addr = vpu_addr + size;
>> +       u64 *pgd = ctx->pgtable.pgd;
>> +
>> +       /* Align to PMD entry (2 MB) */
>> +       vpu_addr &= ~(IVPU_MMU_PTE_MAP_SIZE - 1);
>> +
>> +       while (vpu_addr < end_addr) {
>> +               int pgd_index = FIELD_GET(IVPU_MMU_PGD_INDEX_MASK, vpu_addr);
>> +               u64 pmd_end = (pgd_index + 1) * (u64)IVPU_MMU_PMD_MAP_SIZE;
>> +               u64 *pmd = ctx->pgtable.pgd_entries[pgd_index];
>> +
>> +               while (vpu_addr < end_addr && vpu_addr < pmd_end) {
>> +                       int pmd_index = FIELD_GET(IVPU_MMU_PMD_INDEX_MASK, vpu_addr);
>> +                       u64 *pte = ctx->pgtable.pgd_cpu_entries[pgd_index][pmd_index];
>> +
>> +                       clflush_cache_range(pte, IVPU_MMU_PGTABLE_SIZE);
>> +                       vpu_addr += IVPU_MMU_PTE_MAP_SIZE;
>> +               }
>> +               clflush_cache_range(pmd, IVPU_MMU_PGTABLE_SIZE);
>> +       }
>> +       clflush_cache_range(pgd, IVPU_MMU_PGTABLE_SIZE);
>> +}
>> +
>> +static int
>> +ivpu_mmu_context_map_pages(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx,
>> +                          u64 vpu_addr, dma_addr_t dma_addr, size_t size, int prot)
>> +{
>> +       while (size) {
>> +               int ret = ivpu_mmu_context_map_page(vdev, ctx, vpu_addr, dma_addr, prot);
>> +
>> +               if (ret)
>> +                       return ret;
>> +
>> +               vpu_addr += IVPU_MMU_PAGE_SIZE;
>> +               dma_addr += IVPU_MMU_PAGE_SIZE;
>> +               size -= IVPU_MMU_PAGE_SIZE;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static void ivpu_mmu_context_unmap_pages(struct ivpu_mmu_context *ctx, u64 vpu_addr, size_t size)
>> +{
>> +       while (size) {
>> +               ivpu_mmu_context_unmap_page(ctx, vpu_addr);
>> +               vpu_addr += IVPU_MMU_PAGE_SIZE;
>> +               size -= IVPU_MMU_PAGE_SIZE;
>> +       }
>> +}
>> +
>> +int
>> +ivpu_mmu_context_map_sgt(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx,
>> +                        u64 vpu_addr, struct sg_table *sgt,  bool llc_coherent)
>> +{
> Hard to review these functions as the callers are not in this patch
> AND there is documenation on the function.

Yeah, I know, it is not that easy but I think that separate patches
are still better then one giant patch with the whole driver.

>> +       struct scatterlist *sg;
>> +       int prot;
>> +       int ret;
>> +       u64 i;
>> +
>> +       if (!IS_ALIGNED(vpu_addr, IVPU_MMU_PAGE_SIZE))
>> +               return -EINVAL;
>> +       /*
>> +        * VPU is only 32 bit, but DMA engine is 38 bit
>> +        * Ranges < 2 GB are reserved for VPU internal registers
>> +        * Limit range to 8 GB
>> +        */
>> +       if (vpu_addr < SZ_2G || vpu_addr > SZ_8G)
>> +               return -EINVAL;
>> +
>> +       prot = IVPU_MMU_ENTRY_MAPPED;
>> +       if (llc_coherent)
>> +               prot |= IVPU_MMU_ENTRY_FLAG_LLC_COHERENT;
>> +
>> +       mutex_lock(&ctx->lock);
>> +
>> +       for_each_sgtable_dma_sg(sgt, sg, i) {
>> +               u64 dma_addr = sg_dma_address(sg) - sg->offset;
>> +               size_t size = sg_dma_len(sg) + sg->offset;
>> +
>> +               ret = ivpu_mmu_context_map_pages(vdev, ctx, vpu_addr, dma_addr, size, prot);
>> +               if (ret) {
>> +                       ivpu_err(vdev, "Failed to map context pages\n");
>> +                       mutex_unlock(&ctx->lock);
>> +                       return ret;
>> +               }
>> +               ivpu_mmu_context_flush_page_tables(ctx, vpu_addr, size);
>> +               vpu_addr += size;
>> +       }
>> +
>> +       mutex_unlock(&ctx->lock);
>> +
>> +       ret = ivpu_mmu_invalidate_tlb(vdev, ctx->id);
>> +       if (ret)
>> +               ivpu_err(vdev, "Failed to invalidate TLB for ctx %u: %d\n", ctx->id, ret);
>> +       return ret;
>> +}
>> +
>> +void
>> +ivpu_mmu_context_unmap_sgt(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx,
>> +                          u64 vpu_addr, struct sg_table *sgt)
>> +{
>> +       struct scatterlist *sg;
>> +       int ret;
>> +       u64 i;
>> +
>> +       if (!IS_ALIGNED(vpu_addr, IVPU_MMU_PAGE_SIZE))
>> +               ivpu_warn(vdev, "Unaligned vpu_addr: 0x%llx\n", vpu_addr);
>> +
>> +       mutex_lock(&ctx->lock);
>> +
>> +       for_each_sgtable_dma_sg(sgt, sg, i) {
>> +               size_t size = sg_dma_len(sg) + sg->offset;
>> +
>> +               ivpu_mmu_context_unmap_pages(ctx, vpu_addr, size);
>> +               ivpu_mmu_context_flush_page_tables(ctx, vpu_addr, size);
>> +               vpu_addr += size;
>> +       }
>> +
>> +       mutex_unlock(&ctx->lock);
>> +
>> +       ret = ivpu_mmu_invalidate_tlb(vdev, ctx->id);
>> +       if (ret)
>> +               ivpu_warn(vdev, "Failed to invalidate TLB for ctx %u: %d\n", ctx->id, ret);
>> +}
>> +
>> +int
>> +ivpu_mmu_context_insert_node_locked(struct ivpu_mmu_context *ctx,
>> +                                   const struct ivpu_addr_range *range,
>> +                                   u64 size, struct drm_mm_node *node)
>> +{
>> +       lockdep_assert_held(&ctx->lock);
>> +
>> +       return drm_mm_insert_node_in_range(&ctx->mm, node, size, IVPU_MMU_PAGE_SIZE,
>> +                                         0, range->start, range->end, DRM_MM_INSERT_BEST);
>> +}
>> +
>> +void
>> +ivpu_mmu_context_remove_node_locked(struct ivpu_mmu_context *ctx, struct drm_mm_node *node)
>> +{
>> +       lockdep_assert_held(&ctx->lock);
>> +
>> +       drm_mm_remove_node(node);
>> +}
>> +
>> +static int
>> +ivpu_mmu_context_init(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx, u32 context_id)
>> +{
>> +       u64 start, end;
>> +       int ret;
>> +
>> +       mutex_init(&ctx->lock);
>> +       INIT_LIST_HEAD(&ctx->bo_list);
>> +
>> +       ret = ivpu_mmu_pgtable_init(vdev, &ctx->pgtable);
>> +       if (ret)
>> +               return ret;
>> +
>> +       if (!context_id) {
>> +               start = vdev->hw->ranges.global_low.start;
>> +               end = vdev->hw->ranges.global_high.end;
>> +       } else {
>> +               start = vdev->hw->ranges.user_low.start;
>> +               end = vdev->hw->ranges.user_high.end;
>> +       }
>> +
>> +       drm_mm_init(&ctx->mm, start, end - start);
>> +       ctx->id = context_id;
>> +
>> +       return 0;
>> +}
>> +
>> +static void ivpu_mmu_context_fini(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx)
>> +{
>> +       drm_WARN_ON(&vdev->drm, !ctx->pgtable.pgd);
>> +
>> +       mutex_destroy(&ctx->lock);
>> +       ivpu_mmu_pgtable_free(vdev, &ctx->pgtable);
>> +       drm_mm_takedown(&ctx->mm);
>> +}
>> +
>> +int ivpu_mmu_global_context_init(struct ivpu_device *vdev)
>> +{
>> +       return ivpu_mmu_context_init(vdev, &vdev->gctx, IVPU_GLOBAL_CONTEXT_MMU_SSID);
>> +}
>> +
>> +void ivpu_mmu_global_context_fini(struct ivpu_device *vdev)
>> +{
>> +       return ivpu_mmu_context_fini(vdev, &vdev->gctx);
>> +}
>> +
>> +int ivpu_mmu_user_context_init(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx, u32 ctx_id)
>> +{
>> +       int ret;
>> +
>> +       drm_WARN_ON(&vdev->drm, !ctx_id);
>> +
>> +       ret = ivpu_mmu_context_init(vdev, ctx, ctx_id);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to initialize context: %d\n", ret);
>> +               return ret;
>> +       }
>> +
>> +       ret = ivpu_mmu_set_pgtable(vdev, ctx_id, &ctx->pgtable);
>> +       if (ret) {
>> +               ivpu_err(vdev, "Failed to set page table: %d\n", ret);
>> +               goto err_context_fini;
>> +       }
>> +
>> +       return 0;
>> +
>> +err_context_fini:
>> +       ivpu_mmu_context_fini(vdev, ctx);
>> +       return ret;
>> +}
>> +
>> +void ivpu_mmu_user_context_fini(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx)
>> +{
>> +       drm_WARN_ON(&vdev->drm, !ctx->id);
>> +
>> +       ivpu_mmu_clear_pgtable(vdev, ctx->id);
>> +       ivpu_mmu_context_fini(vdev, ctx);
>> +}
>> diff --git a/drivers/accel/ivpu/ivpu_mmu_context.h b/drivers/accel/ivpu/ivpu_mmu_context.h
>> new file mode 100644
>> index 000000000000..a358de65a30d
>> --- /dev/null
>> +++ b/drivers/accel/ivpu/ivpu_mmu_context.h
>> @@ -0,0 +1,49 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (C) 2020-2022 Intel Corporation
>> + */
>> +
>> +#ifndef __IVPU_MMU_CONTEXT_H__
>> +#define __IVPU_MMU_CONTEXT_H__
>> +
>> +#include <drm/drm_mm.h>
>> +
>> +struct ivpu_device;
>> +struct ivpu_file_priv;
>> +struct ivpu_addr_range;
>> +
>> +#define IVPU_MMU_PGTABLE_ENTRIES       512
>> +
>> +struct ivpu_mmu_pgtable {
>> +       u64             **pgd_cpu_entries[IVPU_MMU_PGTABLE_ENTRIES];
>> +       u64             *pgd_entries[IVPU_MMU_PGTABLE_ENTRIES];
>> +       u64             *pgd;
>> +       dma_addr_t      pgd_dma;
>> +};
>> +
>> +struct ivpu_mmu_context {
>> +       struct mutex lock; /* protects: mm, pgtable, bo_list */
>> +       struct drm_mm mm;
>> +       struct ivpu_mmu_pgtable pgtable;
>> +       struct list_head bo_list;
>> +       u32 id;
>> +};
>> +
>> +int ivpu_mmu_global_context_init(struct ivpu_device *vdev);
>> +void ivpu_mmu_global_context_fini(struct ivpu_device *vdev);
>> +
>> +int ivpu_mmu_user_context_init(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx, u32 ctx_id);
>> +void ivpu_mmu_user_context_fini(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx);
>> +
>> +int ivpu_mmu_context_insert_node_locked(struct ivpu_mmu_context *ctx,
>> +                                       const struct ivpu_addr_range *range,
>> +                                       u64 size, struct drm_mm_node *node);
>> +void ivpu_mmu_context_remove_node_locked(struct ivpu_mmu_context *ctx,
>> +                                        struct drm_mm_node *node);
>> +
>> +int ivpu_mmu_context_map_sgt(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx,
>> +                            u64 vpu_addr, struct sg_table *sgt, bool llc_coherent);
>> +void ivpu_mmu_context_unmap_sgt(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx,
>> +                               u64 vpu_addr, struct sg_table *sgt);
>> +
>> +#endif /* __IVPU_MMU_CONTEXT_H__ */
>> diff --git a/include/uapi/drm/ivpu_drm.h b/include/uapi/drm/ivpu_drm.h
>> index 922cbf30ce34..fc97ce215e79 100644
>> --- a/include/uapi/drm/ivpu_drm.h
>> +++ b/include/uapi/drm/ivpu_drm.h
>> @@ -38,6 +38,7 @@ extern "C" {
>>  #define DRM_IVPU_PARAM_NUM_CONTEXTS        4
>>  #define DRM_IVPU_PARAM_CONTEXT_BASE_ADDRESS 5
>>  #define DRM_IVPU_PARAM_CONTEXT_PRIORITY            6
>> +#define DRM_IVPU_PARAM_CONTEXT_ID          7
>>
>>  #define DRM_IVPU_PLATFORM_TYPE_SILICON     0
>>
>> @@ -78,6 +79,9 @@ struct drm_ivpu_param {
>>          * Value of current context scheduling priority (read-write).
>>          * See DRM_IVPU_CONTEXT_PRIORITY_* for possible values.
>>          *
>> +        * %DRM_IVPU_PARAM_CONTEXT_ID:
>> +        * Current context ID, always greater than 0 (read-only)
>> +        *
>>          */
>>         __u32 param;
>>
>> --
>> 2.34.1

Regards,
Jacek



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