[EXTERNAL] Re: [PATCH v5 08/17] drm/imagination: Add GEM and VM related code
Danilo Krummrich
dakr at redhat.com
Mon Aug 21 11:05:35 UTC 2023
On 8/21/23 10:30, Donald Robson wrote:
> Hi Danilo,
> Thanks for the feedback. On the subject of locking, I have dma_resv locking
> in another branch where I'm trying to enable bind queues, but I didn't think
> I needed locking for the single, synchronous operations seen here. Would a
> mutex on the gem object wrapper suffice?
The reason you need to either acquire the dma-resv lock or a driver
specific lock for drm_gpuva_link() and drm_gpuva_unlink() is that you
probably iterate the linked drm_gpuvas somewhere else, typically from a
ttm_device_funcs.move callback to unmap mappings when their backing GEM
objects are evicted. If you handle that a different way and never
iterate linked drm_gpuvas, you can probably omit drm_gpuva_(un)link()
entirely.
> Thanks,
> Donald
> On Fri, 2023-08-18 at 17:30 +0200, Danilo Krummrich wrote:
>>
>> Hi Sarah,
>>
>> On Wed, Aug 16, 2023 at 09:25:23AM +0100, Sarah Walker wrote:
>>> Add a GEM implementation based on drm_gem_shmem, and support code for the
>>> PowerVR GPU MMU. The GPU VA manager is used for address space management.
>>>
>>> Changes since v4:
>>> - Correct sync function in vmap/vunmap function documentation
>>> - Update for upstream GPU VA manager
>>> - Fix missing frees when unmapping drm_gpuva objects
>>> - Always zero GEM BOs on creation
>>>
>>> Changes since v3:
>>> - Split MMU and VM code
>>> - Register page table allocations with kmemleak
>>> - Use drm_dev_{enter,exit}
>>>
>>> Changes since v2:
>>> - Use GPU VA manager
>>> - Use drm_gem_shmem
>>>
>>> Co-developed-by: Matt Coster <matt.coster at imgtec.com>
>>> Signed-off-by: Matt Coster <matt.coster at imgtec.com>
>>> Co-developed-by: Donald Robson <donald.robson at imgtec.com>
>>> Signed-off-by: Donald Robson <donald.robson at imgtec.com>
>>> Signed-off-by: Sarah Walker <sarah.walker at imgtec.com>
>>> ---
>>> drivers/gpu/drm/imagination/Makefile | 5 +-
>>> drivers/gpu/drm/imagination/pvr_device.c | 23 +-
>>> drivers/gpu/drm/imagination/pvr_device.h | 18 +
>>> drivers/gpu/drm/imagination/pvr_drv.c | 302 ++-
>>> drivers/gpu/drm/imagination/pvr_gem.c | 396 ++++
>>> drivers/gpu/drm/imagination/pvr_gem.h | 177 ++
>>> drivers/gpu/drm/imagination/pvr_mmu.c | 2487 ++++++++++++++++++++++
>>> drivers/gpu/drm/imagination/pvr_mmu.h | 108 +
>>> drivers/gpu/drm/imagination/pvr_vm.c | 890 ++++++++
>>> drivers/gpu/drm/imagination/pvr_vm.h | 60 +
>>> 10 files changed, 4455 insertions(+), 11 deletions(-)
>>> create mode 100644 drivers/gpu/drm/imagination/pvr_gem.c
>>> create mode 100644 drivers/gpu/drm/imagination/pvr_gem.h
>>> create mode 100644 drivers/gpu/drm/imagination/pvr_mmu.c
>>> create mode 100644 drivers/gpu/drm/imagination/pvr_mmu.h
>>> create mode 100644 drivers/gpu/drm/imagination/pvr_vm.c
>>> create mode 100644 drivers/gpu/drm/imagination/pvr_vm.h
>>
>> <snip>
>>
>>> diff --git a/drivers/gpu/drm/imagination/pvr_vm.c b/drivers/gpu/drm/imagination/pvr_vm.c
>>> new file mode 100644
>>> index 000000000000..616fad3a3325
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/imagination/pvr_vm.c
>>> @@ -0,0 +1,890 @@
>>> +// SPDX-License-Identifier: GPL-2.0 OR MIT
>>> +/* Copyright (c) 2023 Imagination Technologies Ltd. */
>>> +
>>> +#include "pvr_vm.h"
>>> +
>>> +#include "pvr_device.h"
>>> +#include "pvr_drv.h"
>>> +#include "pvr_gem.h"
>>> +#include "pvr_mmu.h"
>>> +#include "pvr_rogue_fwif.h"
>>> +#include "pvr_rogue_heap_config.h"
>>> +
>>> +#include <drm/drm_gem.h>
>>> +#include <drm/drm_gpuva_mgr.h>
>>> +
>>> +#include <linux/container_of.h>
>>> +#include <linux/err.h>
>>> +#include <linux/errno.h>
>>> +#include <linux/gfp_types.h>
>>> +#include <linux/kref.h>
>>> +#include <linux/mutex.h>
>>> +#include <linux/stddef.h>
>>> +
>>> +/**
>>> + * DOC: Memory context
>>> + *
>>> + * This is the "top level" datatype in the VM code. It's exposed in the public
>>> + * API as an opaque handle.
>>> + */
>>> +
>>> +/**
>>> + * struct pvr_vm_context - Context type which encapsulates an entire page table
>>> + * tree structure.
>>> + * @pvr_dev: The PowerVR device to which this context is bound.
>>> + *
>>> + * This binding is immutable for the life of the context.
>>> + * @mmu_ctx: The context for binding to physical memory.
>>> + * @gpuva_mgr: GPUVA manager object associated with this context.
>>> + * @lock: Global lock on this entire structure of page tables.
>>> + * @fw_mem_ctx_obj: Firmware object representing firmware memory context.
>>> + * @ref_count: Reference count of object.
>>> + */
>>> +struct pvr_vm_context {
>>> + struct pvr_device *pvr_dev;
>>> + struct pvr_mmu_context *mmu_ctx;
>>> + struct drm_gpuva_manager gpuva_mgr;
>>> + struct mutex lock;
>>> + struct pvr_fw_object *fw_mem_ctx_obj;
>>> + struct kref ref_count;
>>> +};
>>> +
>>> +/**
>>> + * pvr_vm_get_page_table_root_addr() - Get the DMA address of the root of the
>>> + * page table structure behind a VM context.
>>> + * @vm_ctx: Target VM context.
>>> + */
>>> +dma_addr_t pvr_vm_get_page_table_root_addr(struct pvr_vm_context *vm_ctx)
>>> +{
>>> + return pvr_mmu_get_root_table_dma_addr(vm_ctx->mmu_ctx);
>>> +}
>>> +
>>> +/**
>>> + * DOC: Memory mappings
>>> + */
>>> +
>>> +/**
>>> + * pvr_vm_gpuva_mapping_init() - Setup a mapping object with the specified
>>> + * parameters ready for mapping using pvr_vm_gpuva_mapping_map().
>>> + * @va: Pointer to drm_gpuva mapping object.
>>> + * @device_addr: Device-virtual address at the start of the mapping.
>>> + * @size: Size of the desired mapping.
>>> + * @pvr_obj: Target PowerVR memory object.
>>> + * @pvr_obj_offset: Offset into @pvr_obj to begin mapping from.
>>> + *
>>> + * Some parameters of this function are unchecked. It is therefore the callers
>>> + * responsibility to ensure certain constraints are met. Specifically:
>>> + *
>>> + * * @pvr_obj_offset must be less than the size of @pvr_obj,
>>> + * * The sum of @pvr_obj_offset and @size must be less than or equal to the
>>> + * size of @pvr_obj,
>>> + * * The range specified by @pvr_obj_offset and @size (the "CPU range") must be
>>> + * CPU page-aligned both in start position and size, and
>>> + * * The range specified by @device_addr and @size (the "device range") must be
>>> + * device page-aligned both in start position and size.
>>> + *
>>> + * Furthermore, it is up to the caller to make sure that a reference to @pvr_obj
>>> + * is taken prior to mapping @va with the drm_gpuva_manager.
>>> + */
>>> +static void
>>> +pvr_vm_gpuva_mapping_init(struct drm_gpuva *va, u64 device_addr, u64 size,
>>> + struct pvr_gem_object *pvr_obj, u64 pvr_obj_offset)
>>
>> There's already drm_gpuva_init() doing the same thing.
>>
>>> +{
>>> + va->va.addr = device_addr;
>>> + va->va.range = size;
>>> + va->gem.obj = gem_from_pvr_gem(pvr_obj);
>>> + va->gem.offset = pvr_obj_offset;
>>> +}
>>> +
>>> +struct pvr_vm_gpuva_op_ctx {
>>> + struct pvr_vm_context *vm_ctx;
>>> + struct pvr_mmu_op_context *mmu_op_ctx;
>>> + struct drm_gpuva *new_va, *prev_va, *next_va;
>>> +};
>>> +
>>> +/**
>>> + * pvr_vm_gpuva_map() - Insert a mapping into a memory context.
>>> + * @op: gpuva op containing the remap details.
>>> + * @op_ctx: Operation context.
>>> + *
>>> + * Context: Called by drm_gpuva_sm_map following a successful mapping while
>>> + * @op_ctx.vm_ctx mutex is held.
>>> + *
>>> + * Return:
>>> + * * 0 on success, or
>>> + * * Any error returned by pvr_mmu_map().
>>> + */
>>> +static int
>>> +pvr_vm_gpuva_map(struct drm_gpuva_op *op, void *op_ctx)
>>> +{
>>> + struct pvr_gem_object *pvr_gem = gem_to_pvr_gem(op->map.gem.obj);
>>> + struct pvr_vm_gpuva_op_ctx *ctx = op_ctx;
>>> + int err;
>>> +
>>> + if ((op->map.gem.offset | op->map.va.range) & ~PVR_DEVICE_PAGE_MASK)
>>> + return -EINVAL;
>>> +
>>> + err = pvr_mmu_map(ctx->mmu_op_ctx, op->map.va.range, pvr_gem->flags,
>>> + op->map.va.addr);
>>> + if (err)
>>> + return err;
>>> +
>>> + pvr_vm_gpuva_mapping_init(ctx->new_va, op->map.va.addr,
>>> + op->map.va.range, pvr_gem, op->map.gem.offset);
>>> +
>>> + drm_gpuva_map(&ctx->vm_ctx->gpuva_mgr, ctx->new_va, &op->map);
>>
>> drm_gpuva_map() does use drm_gpuva_init_from_op() internally, hence the extra
>> call to pvr_vm_gpuva_mapping_init() should be unnecessary.
>>
>>> + drm_gpuva_link(ctx->new_va);
>>
>> How is this protected?
>>
>> drm_gpuva_link() and drm_gpuva_unlink() require either the dma_resv lock of the
>> corresponding GEM object being held or, alternatively, the driver specific lock
>> indicated via drm_gem_gpuva_set_lock().
>>
>>> + ctx->new_va = NULL;
>>> +
>>> + /*
>>> + * Increment the refcount on the underlying physical memory resource
>>> + * to prevent de-allocation while the mapping exists.
>>> + */
>>> + pvr_gem_object_get(pvr_gem);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * pvr_vm_gpuva_unmap() - Remove a mapping from a memory context.
>>> + * @op: gpuva op containing the unmap details.
>>> + * @op_ctx: Operation context.
>>> + *
>>> + * Context: Called by drm_gpuva_sm_unmap following a successful unmapping while
>>> + * @op_ctx.vm_ctx mutex is held.
>>> + *
>>> + * Return:
>>> + * * 0 on success, or
>>> + * * Any error returned by pvr_mmu_unmap().
>>> + */
>>> +static int
>>> +pvr_vm_gpuva_unmap(struct drm_gpuva_op *op, void *op_ctx)
>>> +{
>>> + struct pvr_gem_object *pvr_gem = gem_to_pvr_gem(op->unmap.va->gem.obj);
>>> + struct pvr_vm_gpuva_op_ctx *ctx = op_ctx;
>>> +
>>> + int err = pvr_mmu_unmap(ctx->mmu_op_ctx, op->unmap.va->va.addr,
>>> + op->unmap.va->va.range);
>>> +
>>> + if (err)
>>> + return err;
>>> +
>>> + drm_gpuva_unmap(&op->unmap);
>>> + drm_gpuva_unlink(op->unmap.va);
>>> + kfree(op->unmap.va);
>>> +
>>> + pvr_gem_object_put(pvr_gem);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * pvr_vm_gpuva_remap() - Remap a mapping within a memory context.
>>> + * @op: gpuva op containing the remap details.
>>> + * @op_ctx: Operation context.
>>> + *
>>> + * Context: Called by either drm_gpuva_sm_map or drm_gpuva_sm_unmap when a
>>> + * mapping or unmapping operation causes a region to be split. The
>>> + * @op_ctx.vm_ctx mutex is held.
>>> + *
>>> + * Return:
>>> + * * 0 on success, or
>>> + * * Any error returned by pvr_vm_gpuva_unmap() or pvr_vm_gpuva_unmap().
>>> + */
>>> +static int
>>> +pvr_vm_gpuva_remap(struct drm_gpuva_op *op, void *op_ctx)
>>> +{
>>> + struct pvr_vm_gpuva_op_ctx *ctx = op_ctx;
>>> +
>>> + if (op->remap.unmap) {
>>
>> You can omit this check, remap operations always contain a valid unmap
>> operation. However, you might want to know whether the remap operation was
>> generated due to a call to drm_gpuva_sm_map() or drm_gpuva_sm_unmap(), since for
>> the latter you might want to free page table structures.
>>
>>> + const u64 va_start = op->remap.prev ?
>>> + op->remap.prev->va.addr + op->remap.prev->va.range :
>>> + op->remap.unmap->va->va.addr;
>>> + const u64 va_end = op->remap.next ?
>>> + op->remap.next->va.addr :
>>> + op->remap.unmap->va->va.addr + op->remap.unmap->va->va.range;
>>
>> This seems to be a common calculation for drivers, it is probably worth to come
>> up with a helper, something like
>> drm_gpuva_op_unmap_range(struct drm_gpuva_op *op, u64 *addr, u64 *range).
>>
>>> +
>>> + int err = pvr_mmu_unmap(ctx->mmu_op_ctx, va_start,
>>> + va_end - va_start);
>>> +
>>> + if (err)
>>> + return err;
>>> + }
>>> +
>>> + if (op->remap.prev)
>>> + pvr_vm_gpuva_mapping_init(ctx->prev_va, op->remap.prev->va.addr,
>>> + op->remap.prev->va.range,
>>> + gem_to_pvr_gem(op->remap.prev->gem.obj),
>>> + op->remap.prev->gem.offset);
>>> +
>>> + if (op->remap.next)
>>> + pvr_vm_gpuva_mapping_init(ctx->next_va, op->remap.next->va.addr,
>>> + op->remap.next->va.range,
>>> + gem_to_pvr_gem(op->remap.next->gem.obj),
>>> + op->remap.next->gem.offset);
>>> +
>>> + /* No actual remap required: the page table tree depth is fixed to 3,
>>> + * and we use 4k page table entries only for now.
>>> + */
>>> + drm_gpuva_remap(ctx->prev_va, ctx->next_va, &op->remap);
>>
>> As above, drm_gpuva_remap() does use drm_gpuva_init_from_op() internally, hence
>> the extra call to pvr_vm_gpuva_mapping_init() should be unnecessary.
>>
>>> +
>>> + if (op->remap.prev) {
>>> + pvr_gem_object_get(gem_to_pvr_gem(ctx->prev_va->gem.obj));
>>> + drm_gpuva_link(ctx->prev_va);
>>> + ctx->prev_va = NULL;
>>> + }
>>> +
>>> + if (op->remap.next) {
>>> + pvr_gem_object_get(gem_to_pvr_gem(ctx->next_va->gem.obj));
>>> + drm_gpuva_link(ctx->next_va);
>>> + ctx->next_va = NULL;
>>> + }
>>> +
>>> + if (op->remap.unmap) {
>>
>> As above, no need for this check.
>>
>> - Danilo
>>
>>> + struct pvr_gem_object *pvr_gem = gem_to_pvr_gem(op->remap.unmap->va->gem.obj);
>>> +
>>> + drm_gpuva_unlink(op->unmap.va);
>>> + kfree(op->unmap.va);
>>> +
>>> + pvr_gem_object_put(pvr_gem);
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/*
>>> + * Public API
>>> + *
>>> + * For an overview of these functions, see *DOC: Public API* in "pvr_vm.h".
>>> + */
>>> +
>>> +/**
>>> + * pvr_device_addr_is_valid() - Tests whether a device-virtual address
>>> + * is valid.
>>> + * @device_addr: Virtual device address to test.
>>> + *
>>> + * Return:
>>> + * * %true if @device_addr is within the valid range for a device page
>>> + * table and is aligned to the device page size, or
>>> + * * %false otherwise.
>>> + */
>>> +bool
>>> +pvr_device_addr_is_valid(u64 device_addr)
>>> +{
>>> + return (device_addr & ~PVR_PAGE_TABLE_ADDR_MASK) == 0 &&
>>> + (device_addr & ~PVR_DEVICE_PAGE_MASK) == 0;
>>> +}
>>> +
>>> +/**
>>> + * pvr_device_addr_and_size_are_valid() - Tests whether a device-virtual
>>> + * address and associated size are both valid.
>>> + * @device_addr: Virtual device address to test.
>>> + * @size: Size of the range based at @device_addr to test.
>>> + *
>>> + * Calling pvr_device_addr_is_valid() twice (once on @size, and again on
>>> + * @device_addr + @size) to verify a device-virtual address range initially
>>> + * seems intuitive, but it produces a false-negative when the address range
>>> + * is right at the end of device-virtual address space.
>>> + *
>>> + * This function catches that corner case, as well as checking that
>>> + * @size is non-zero.
>>> + *
>>> + * Return:
>>> + * * %true if @device_addr is device page aligned; @size is device page
>>> + * aligned; the range specified by @device_addr and @size is within the
>>> + * bounds of the device-virtual address space, and @size is non-zero, or
>>> + * * %false otherwise.
>>> + */
>>> +bool
>>> +pvr_device_addr_and_size_are_valid(u64 device_addr, u64 size)
>>> +{
>>> + return pvr_device_addr_is_valid(device_addr) &&
>>> + size != 0 && (size & ~PVR_DEVICE_PAGE_MASK) == 0 &&
>>> + (device_addr + size <= PVR_PAGE_TABLE_ADDR_SPACE_SIZE);
>>> +}
>>> +
>>> +static const struct drm_gpuva_fn_ops pvr_vm_gpuva_ops = {
>>> + .sm_step_map = pvr_vm_gpuva_map,
>>> + .sm_step_remap = pvr_vm_gpuva_remap,
>>> + .sm_step_unmap = pvr_vm_gpuva_unmap,
>>> +};
>>> +
>>> +/**
>>> + * pvr_vm_create_context() - Create a new VM context.
>>> + * @pvr_dev: Target PowerVR device.
>>> + * @is_userspace_context: %true if this context is for userspace. This will
>>> + * create a firmware memory context for the VM context
>>> + * and disable warnings when tearing down mappings.
>>> + *
>>> + * Return:
>>> + * * A handle to the newly-minted VM context on success,
>>> + * * -%EINVAL if the feature "virtual address space bits" on @pvr_dev is
>>> + * missing or has an unsupported value,
>>> + * * -%ENOMEM if allocation of the structure behind the opaque handle fails,
>>> + * or
>>> + * * Any error encountered while setting up internal structures.
>>> + */
>>> +struct pvr_vm_context *
>>> +pvr_vm_create_context(struct pvr_device *pvr_dev, bool is_userspace_context)
>>> +{
>>> + struct drm_device *drm_dev = from_pvr_device(pvr_dev);
>>> +
>>> + struct pvr_vm_context *vm_ctx;
>>> + u16 device_addr_bits;
>>> +
>>> + int err;
>>> +
>>> + err = PVR_FEATURE_VALUE(pvr_dev, virtual_address_space_bits,
>>> + &device_addr_bits);
>>> + if (err) {
>>> + drm_err(drm_dev,
>>> + "Failed to get device virtual address space bits\n");
>>> + return ERR_PTR(err);
>>> + }
>>> +
>>> + if (device_addr_bits != PVR_PAGE_TABLE_ADDR_BITS) {
>>> + drm_err(drm_dev,
>>> + "Device has unsupported virtual address space size\n");
>>> + return ERR_PTR(-EINVAL);
>>> + }
>>> +
>>> + vm_ctx = kzalloc(sizeof(*vm_ctx), GFP_KERNEL);
>>> + if (!vm_ctx)
>>> + return ERR_PTR(-ENOMEM);
>>> +
>>> + vm_ctx->pvr_dev = pvr_dev;
>>> + kref_init(&vm_ctx->ref_count);
>>> + mutex_init(&vm_ctx->lock);
>>> +
>>> + drm_gpuva_manager_init(&vm_ctx->gpuva_mgr,
>>> + is_userspace_context ? "PowerVR-user-VM" : "PowerVR-FW-VM",
>>> + 0, 1ULL << device_addr_bits, 0, 0, &pvr_vm_gpuva_ops);
>>> +
>>> + vm_ctx->mmu_ctx = pvr_mmu_context_create(pvr_dev);
>>> + err = PTR_ERR_OR_ZERO(&vm_ctx->mmu_ctx);
>>> + if (err) {
>>> + vm_ctx->mmu_ctx = NULL;
>>> + goto err_put_ctx;
>>> + }
>>> +
>>> + if (is_userspace_context) {
>>> + /* TODO: Create FW mem context */
>>> + err = -ENODEV;
>>> + goto err_put_ctx;
>>> + }
>>> +
>>> + return vm_ctx;
>>> +
>>> +err_put_ctx:
>>> + pvr_vm_context_put(vm_ctx);
>>> +
>>> + return ERR_PTR(err);
>>> +}
>>> +
>>> +/**
>>> + * pvr_vm_context_release() - Teardown a VM context.
>>> + * @ref_count: Pointer to reference counter of the VM context.
>>> + *
>>> + * This function ensures that no mappings are left dangling by unmapping them
>>> + * all in order of ascending device-virtual address.
>>> + */
>>> +static void
>>> +pvr_vm_context_release(struct kref *ref_count)
>>> +{
>>> + struct pvr_vm_context *vm_ctx =
>>> + container_of(ref_count, struct pvr_vm_context, ref_count);
>>> +
>>> + /* TODO: Destroy FW mem context */
>>> + WARN_ON(vm_ctx->fw_mem_ctx_obj);
>>> +
>>> + WARN_ON(pvr_vm_unmap(vm_ctx, vm_ctx->gpuva_mgr.mm_start,
>>> + vm_ctx->gpuva_mgr.mm_range));
>>> +
>>> + drm_gpuva_manager_destroy(&vm_ctx->gpuva_mgr);
>>> + pvr_mmu_context_destroy(vm_ctx->mmu_ctx);
>>> + mutex_destroy(&vm_ctx->lock);
>>> +
>>> + kfree(vm_ctx);
>>> +}
>>> +
>>> +/**
>>> + * pvr_vm_context_lookup() - Look up VM context from handle
>>> + * @pvr_file: Pointer to pvr_file structure.
>>> + * @handle: Object handle.
>>> + *
>>> + * Takes reference on VM context object. Call pvr_vm_context_put() to release.
>>> + *
>>> + * Returns:
>>> + * * The requested object on success, or
>>> + * * %NULL on failure (object does not exist in list, or is not a VM context)
>>> + */
>>> +struct pvr_vm_context *
>>> +pvr_vm_context_lookup(struct pvr_file *pvr_file, u32 handle)
>>> +{
>>> + struct pvr_vm_context *vm_ctx;
>>> +
>>> + xa_lock(&pvr_file->vm_ctx_handles);
>>> + vm_ctx = xa_load(&pvr_file->vm_ctx_handles, handle);
>>> + if (vm_ctx)
>>> + kref_get(&vm_ctx->ref_count);
>>> +
>>> + xa_unlock(&pvr_file->vm_ctx_handles);
>>> +
>>> + return vm_ctx;
>>> +}
>>> +
>>> +/**
>>> + * pvr_vm_context_put() - Release a reference on a VM context
>>> + * @vm_ctx: Target VM context.
>>> + *
>>> + * Returns:
>>> + * * %true if the VM context was destroyed, or
>>> + * * %false if there are any references still remaining.
>>> + */
>>> +bool
>>> +pvr_vm_context_put(struct pvr_vm_context *vm_ctx)
>>> +{
>>> + WARN_ON(!vm_ctx);
>>> +
>>> + if (vm_ctx)
>>> + return kref_put(&vm_ctx->ref_count, pvr_vm_context_release);
>>> +
>>> + return true;
>>> +}
>>> +
>>> +/**
>>> + * pvr_destroy_vm_contexts_for_file: Destroy any VM contexts associated with the
>>> + * given file.
>>> + * @pvr_file: Pointer to pvr_file structure.
>>> + *
>>> + * Removes all vm_contexts associated with @pvr_file from the device VM context
>>> + * list and drops initial references. vm_contexts will then be destroyed once
>>> + * all outstanding references are dropped.
>>> + */
>>> +void pvr_destroy_vm_contexts_for_file(struct pvr_file *pvr_file)
>>> +{
>>> + struct pvr_vm_context *vm_ctx;
>>> + unsigned long handle;
>>> +
>>> + xa_for_each(&pvr_file->vm_ctx_handles, handle, vm_ctx) {
>>> + /* vm_ctx is not used here because that would create a race with xa_erase */
>>> + pvr_vm_context_put(xa_erase(&pvr_file->vm_ctx_handles, handle));
>>> + }
>>> +}
>>> +
>>> +/**
>>> + * pvr_vm_map() - Map a section of physical memory into a section of device-virtual memory.
>>> + * @vm_ctx: Target VM context.
>>> + * @pvr_obj: Target PowerVR memory object.
>>> + * @pvr_obj_offset: Offset into @pvr_obj to map from.
>>> + * @device_addr: Virtual device address at the start of the requested mapping.
>>> + * @size: Size of the requested mapping.
>>> + *
>>> + * No handle is returned to represent the mapping. Instead, callers should
>>> + * remember @device_addr and use that as a handle.
>>> + *
>>> + * Return:
>>> + * * 0 on success,
>>> + * * -%EINVAL if @device_addr is not a valid page-aligned device-virtual
>>> + * address; the region specified by @pvr_obj_offset and @size does not fall
>>> + * entirely within @pvr_obj, or any part of the specified region of @pvr_obj
>>> + * is not device-virtual page-aligned,
>>> + * * Any error encountered while performing internal operations required to
>>> + * destroy the mapping (returned from pvr_vm_gpuva_map or
>>> + * pvr_vm_gpuva_remap).
>>> + */
>>> +int
>>> +pvr_vm_map(struct pvr_vm_context *vm_ctx,
>>> + struct pvr_gem_object *pvr_obj, u64 pvr_obj_offset,
>>> + u64 device_addr, u64 size)
>>> +{
>>> + const size_t pvr_obj_size = pvr_gem_object_size(pvr_obj);
>>> + struct pvr_vm_gpuva_op_ctx op_ctx = { .vm_ctx = vm_ctx };
>>> + struct sg_table *sgt;
>>> + int err;
>>> +
>>> + if (!pvr_device_addr_and_size_are_valid(device_addr, size) ||
>>> + pvr_obj_offset & ~PAGE_MASK || size & ~PAGE_MASK ||
>>> + pvr_obj_offset + size > pvr_obj_size ||
>>> + pvr_obj_offset > pvr_obj_size) {
>>> + return -EINVAL;
>>> + }
>>> +
>>> + op_ctx.new_va = kzalloc(sizeof(*op_ctx.new_va), GFP_KERNEL);
>>> + op_ctx.prev_va = kzalloc(sizeof(*op_ctx.prev_va), GFP_KERNEL);
>>> + op_ctx.next_va = kzalloc(sizeof(*op_ctx.next_va), GFP_KERNEL);
>>> + if (!op_ctx.new_va || !op_ctx.prev_va || !op_ctx.next_va) {
>>> + err = -ENOMEM;
>>> + goto out_free;
>>> + }
>>> +
>>> + sgt = pvr_gem_object_get_pages_sgt(pvr_obj);
>>> + err = PTR_ERR_OR_ZERO(sgt);
>>> + if (err)
>>> + goto out_free;
>>> +
>>> + op_ctx.mmu_op_ctx = pvr_mmu_op_context_create(vm_ctx->mmu_ctx, sgt,
>>> + pvr_obj_offset, size);
>>> + err = PTR_ERR_OR_ZERO(op_ctx.mmu_op_ctx);
>>> + if (err) {
>>> + op_ctx.mmu_op_ctx = NULL;
>>> + goto out_mmu_op_ctx_destroy;
>>> + }
>>> +
>>> + mutex_lock(&vm_ctx->lock);
>>> + err = drm_gpuva_sm_map(&vm_ctx->gpuva_mgr, &op_ctx, device_addr, size,
>>> + gem_from_pvr_gem(pvr_obj), pvr_obj_offset);
>>> + mutex_unlock(&vm_ctx->lock);
>>> +
>>> +out_mmu_op_ctx_destroy:
>>> + pvr_mmu_op_context_destroy(op_ctx.mmu_op_ctx);
>>> +
>>> +out_free:
>>> + kfree(op_ctx.next_va);
>>> + kfree(op_ctx.prev_va);
>>> + kfree(op_ctx.new_va);
>>> +
>>> + return err;
>>> +}
>>> +
>>> +/**
>>> + * pvr_vm_unmap() - Unmap an already mapped section of device-virtual memory.
>>> + * @vm_ctx: Target VM context.
>>> + * @device_addr: Virtual device address at the start of the target mapping.
>>> + * @size: Size of the target mapping.
>>> + *
>>> + * Return:
>>> + * * 0 on success,
>>> + * * -%EINVAL if @device_addr is not a valid page-aligned device-virtual
>>> + * address,
>>> + * * Any error encountered while performing internal operations required to
>>> + * destroy the mapping (returned from pvr_vm_gpuva_unmap or
>>> + * pvr_vm_gpuva_remap).
>>> + */
>>> +int
>>> +pvr_vm_unmap(struct pvr_vm_context *vm_ctx, u64 device_addr, u64 size)
>>> +{
>>> + struct pvr_vm_gpuva_op_ctx op_ctx = { .vm_ctx = vm_ctx };
>>> + int err;
>>> +
>>> + if (!pvr_device_addr_and_size_are_valid(device_addr, size))
>>> + return -EINVAL;
>>> +
>>> + op_ctx.prev_va = kzalloc(sizeof(*op_ctx.prev_va), GFP_KERNEL);
>>> + op_ctx.next_va = kzalloc(sizeof(*op_ctx.next_va), GFP_KERNEL);
>>> + if (!op_ctx.prev_va || !op_ctx.next_va) {
>>> + err = -ENOMEM;
>>> + goto out;
>>> + }
>>> +
>>> + op_ctx.mmu_op_ctx =
>>> + pvr_mmu_op_context_create(vm_ctx->mmu_ctx, NULL, 0, 0);
>>> + err = PTR_ERR_OR_ZERO(op_ctx.mmu_op_ctx);
>>> + if (err) {
>>> + op_ctx.mmu_op_ctx = NULL;
>>> + goto out;
>>> + }
>>> +
>>> + mutex_lock(&vm_ctx->lock);
>>> + err = drm_gpuva_sm_unmap(&vm_ctx->gpuva_mgr, &op_ctx, device_addr, size);
>>> + mutex_unlock(&vm_ctx->lock);
>>> +
>>> +out:
>>> + pvr_mmu_op_context_destroy(op_ctx.mmu_op_ctx);
>>> + kfree(op_ctx.next_va);
>>> + kfree(op_ctx.prev_va);
>>> +
>>> + return err;
>>> +}
>>> +
>>> +/*
>>> + * Static data areas are determined by firmware.
>>> + *
>>> + * When adding a new static data area you will also need to update the reserved_size field for the
>>> + * heap in pvr_heaps[].
>>> + */
>>> +static const struct drm_pvr_static_data_area static_data_areas[] = {
>>> + {
>>> + .area_usage = DRM_PVR_STATIC_DATA_AREA_FENCE,
>>> + .location_heap_id = DRM_PVR_HEAP_GENERAL,
>>> + .offset = 0,
>>> + .size = 128,
>>> + },
>>> + {
>>> + .area_usage = DRM_PVR_STATIC_DATA_AREA_YUV_CSC,
>>> + .location_heap_id = DRM_PVR_HEAP_GENERAL,
>>> + .offset = 128,
>>> + .size = 1024,
>>> + },
>>> + {
>>> + .area_usage = DRM_PVR_STATIC_DATA_AREA_VDM_SYNC,
>>> + .location_heap_id = DRM_PVR_HEAP_PDS_CODE_DATA,
>>> + .offset = 0,
>>> + .size = 128,
>>> + },
>>> + {
>>> + .area_usage = DRM_PVR_STATIC_DATA_AREA_EOT,
>>> + .location_heap_id = DRM_PVR_HEAP_PDS_CODE_DATA,
>>> + .offset = 128,
>>> + .size = 128,
>>> + },
>>> + {
>>> + .area_usage = DRM_PVR_STATIC_DATA_AREA_VDM_SYNC,
>>> + .location_heap_id = DRM_PVR_HEAP_USC_CODE,
>>> + .offset = 0,
>>> + .size = 128,
>>> + },
>>> +};
>>> +
>>> +#define GET_RESERVED_SIZE(last_offset, last_size) round_up((last_offset) + (last_size), PAGE_SIZE)
>>> +
>>> +/*
>>> + * The values given to GET_RESERVED_SIZE() are taken from the last entry in the corresponding
>>> + * static data area for each heap.
>>> + */
>>> +static const struct drm_pvr_heap pvr_heaps[] = {
>>> + [DRM_PVR_HEAP_GENERAL] = {
>>> + .base = ROGUE_GENERAL_HEAP_BASE,
>>> + .size = ROGUE_GENERAL_HEAP_SIZE,
>>> + .flags = 0,
>>> + .page_size_log2 = PVR_DEVICE_PAGE_SHIFT,
>>> + },
>>> + [DRM_PVR_HEAP_PDS_CODE_DATA] = {
>>> + .base = ROGUE_PDSCODEDATA_HEAP_BASE,
>>> + .size = ROGUE_PDSCODEDATA_HEAP_SIZE,
>>> + .flags = 0,
>>> + .page_size_log2 = PVR_DEVICE_PAGE_SHIFT,
>>> + },
>>> + [DRM_PVR_HEAP_USC_CODE] = {
>>> + .base = ROGUE_USCCODE_HEAP_BASE,
>>> + .size = ROGUE_USCCODE_HEAP_SIZE,
>>> + .flags = 0,
>>> + .page_size_log2 = PVR_DEVICE_PAGE_SHIFT,
>>> + },
>>> + [DRM_PVR_HEAP_RGNHDR] = {
>>> + .base = ROGUE_RGNHDR_HEAP_BASE,
>>> + .size = ROGUE_RGNHDR_HEAP_SIZE,
>>> + .flags = 0,
>>> + .page_size_log2 = PVR_DEVICE_PAGE_SHIFT,
>>> + },
>>> + [DRM_PVR_HEAP_VIS_TEST] = {
>>> + .base = ROGUE_VISTEST_HEAP_BASE,
>>> + .size = ROGUE_VISTEST_HEAP_SIZE,
>>> + .flags = 0,
>>> + .page_size_log2 = PVR_DEVICE_PAGE_SHIFT,
>>> + },
>>> + [DRM_PVR_HEAP_TRANSFER_FRAG] = {
>>> + .base = ROGUE_TRANSFER_FRAG_HEAP_BASE,
>>> + .size = ROGUE_TRANSFER_FRAG_HEAP_SIZE,
>>> + .flags = 0,
>>> + .page_size_log2 = PVR_DEVICE_PAGE_SHIFT,
>>> + },
>>> +};
>>> +
>>> +int
>>> +pvr_static_data_areas_get(const struct pvr_device *pvr_dev,
>>> + struct drm_pvr_ioctl_dev_query_args *args)
>>> +{
>>> + struct drm_pvr_dev_query_static_data_areas query = {0};
>>> + int err;
>>> +
>>> + if (!args->pointer) {
>>> + args->size = sizeof(struct drm_pvr_dev_query_static_data_areas);
>>> + return 0;
>>> + }
>>> +
>>> + err = PVR_UOBJ_GET(query, args->size, args->pointer);
>>> + if (err < 0)
>>> + return err;
>>> +
>>> + if (!query.static_data_areas.array) {
>>> + query.static_data_areas.count = ARRAY_SIZE(static_data_areas);
>>> + query.static_data_areas.stride = sizeof(struct drm_pvr_static_data_area);
>>> + goto copy_out;
>>> + }
>>> +
>>> + if (query.static_data_areas.count > ARRAY_SIZE(static_data_areas))
>>> + query.static_data_areas.count = ARRAY_SIZE(static_data_areas);
>>> +
>>> + err = PVR_UOBJ_SET_ARRAY(&query.static_data_areas, static_data_areas);
>>> + if (err < 0)
>>> + return err;
>>> +
>>> +copy_out:
>>> + err = PVR_UOBJ_SET(args->pointer, args->size, query);
>>> + if (err < 0)
>>> + return err;
>>> +
>>> + args->size = sizeof(query);
>>> + return 0;
>>> +}
>>> +
>>> +int
>>> +pvr_heap_info_get(const struct pvr_device *pvr_dev,
>>> + struct drm_pvr_ioctl_dev_query_args *args)
>>> +{
>>> + struct drm_pvr_dev_query_heap_info query = {0};
>>> + u64 dest;
>>> + int err;
>>> +
>>> + if (!args->pointer) {
>>> + args->size = sizeof(struct drm_pvr_dev_query_heap_info);
>>> + return 0;
>>> + }
>>> +
>>> + err = PVR_UOBJ_GET(query, args->size, args->pointer);
>>> + if (err < 0)
>>> + return err;
>>> +
>>> + if (!query.heaps.array) {
>>> + query.heaps.count = ARRAY_SIZE(pvr_heaps);
>>> + query.heaps.stride = sizeof(struct drm_pvr_heap);
>>> + goto copy_out;
>>> + }
>>> +
>>> + if (query.heaps.count > ARRAY_SIZE(pvr_heaps))
>>> + query.heaps.count = ARRAY_SIZE(pvr_heaps);
>>> +
>>> + /* Region header heap is only present if BRN63142 is present. */
>>> + dest = query.heaps.array;
>>> + for (size_t i = 0; i < query.heaps.count; i++) {
>>> + struct drm_pvr_heap heap = pvr_heaps[i];
>>> +
>>> + if (i == DRM_PVR_HEAP_RGNHDR && !PVR_HAS_QUIRK(pvr_dev, 63142))
>>> + heap.size = 0;
>>> +
>>> + err = PVR_UOBJ_SET(dest, query.heaps.stride, heap);
>>> + if (err < 0)
>>> + return err;
>>> +
>>> + dest += query.heaps.stride;
>>> + }
>>> +
>>> +copy_out:
>>> + err = PVR_UOBJ_SET(args->pointer, args->size, query);
>>> + if (err < 0)
>>> + return err;
>>> +
>>> + args->size = sizeof(query);
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * pvr_heap_contains_range() - Determine if a given heap contains the specified
>>> + * device-virtual address range.
>>> + * @pvr_heap: Target heap.
>>> + * @start: Inclusive start of the target range.
>>> + * @end: Inclusive end of the target range.
>>> + *
>>> + * It is an error to call this function with values of @start and @end that do
>>> + * not satisfy the condition @start <= @end.
>>> + */
>>> +static __always_inline bool
>>> +pvr_heap_contains_range(const struct drm_pvr_heap *pvr_heap, u64 start, u64 end)
>>> +{
>>> + return pvr_heap->base <= start && end < pvr_heap->base + pvr_heap->size;
>>> +}
>>> +
>>> +/**
>>> + * pvr_find_heap_containing() - Find a heap which contains the specified
>>> + * device-virtual address range.
>>> + * @pvr_dev: Target PowerVR device.
>>> + * @start: Start of the target range.
>>> + * @size: Size of the target range.
>>> + *
>>> + * Return:
>>> + * * A pointer to a constant instance of struct drm_pvr_heap representing the
>>> + * heap containing the entire range specified by @start and @size on
>>> + * success, or
>>> + * * %NULL if no such heap exists.
>>> + */
>>> +const struct drm_pvr_heap *
>>> +pvr_find_heap_containing(struct pvr_device *pvr_dev, u64 start, u64 size)
>>> +{
>>> + u64 end;
>>> +
>>> + if (check_add_overflow(start, size - 1, &end))
>>> + return NULL;
>>> +
>>> + /*
>>> + * There are no guarantees about the order of address ranges in
>>> + * &pvr_heaps, so iterate over the entire array for a heap whose
>>> + * range completely encompasses the given range.
>>> + */
>>> + for (u32 heap_id = 0; heap_id < ARRAY_SIZE(pvr_heaps); heap_id++) {
>>> + /* Filter heaps that present only with an associated quirk */
>>> + if (heap_id == DRM_PVR_HEAP_RGNHDR &&
>>> + !PVR_HAS_QUIRK(pvr_dev, 63142)) {
>>> + continue;
>>> + }
>>> +
>>> + if (pvr_heap_contains_range(&pvr_heaps[heap_id], start, end))
>>> + return &pvr_heaps[heap_id];
>>> + }
>>> +
>>> + return NULL;
>>> +}
>>> +
>>> +/**
>>> + * pvr_vm_find_gem_object() - Look up a buffer object from a given
>>> + * device-virtual address.
>>> + * @vm_ctx: [IN] Target VM context.
>>> + * @device_addr: [IN] Virtual device address at the start of the required
>>> + * object.
>>> + * @mapped_offset_out: [OUT] Pointer to location to write offset of the start
>>> + * of the mapped region within the buffer object. May be
>>> + * %NULL if this information is not required.
>>> + * @mapped_size_out: [OUT] Pointer to location to write size of the mapped
>>> + * region. May be %NULL if this information is not required.
>>> + *
>>> + * If successful, a reference will be taken on the buffer object. The caller
>>> + * must drop the reference with pvr_gem_object_put().
>>> + *
>>> + * Return:
>>> + * * The PowerVR buffer object mapped at @device_addr if one exists, or
>>> + * * %NULL otherwise.
>>> + */
>>> +struct pvr_gem_object *
>>> +pvr_vm_find_gem_object(struct pvr_vm_context *vm_ctx, u64 device_addr,
>>> + u64 *mapped_offset_out, u64 *mapped_size_out)
>>> +{
>>> + struct pvr_gem_object *pvr_obj;
>>> + struct drm_gpuva *va;
>>> +
>>> + mutex_lock(&vm_ctx->lock);
>>> +
>>> + va = drm_gpuva_find_first(&vm_ctx->gpuva_mgr, device_addr, 1);
>>> + if (!va)
>>> + goto err_unlock;
>>> +
>>> + pvr_obj = gem_to_pvr_gem(va->gem.obj);
>>> + pvr_gem_object_get(pvr_obj);
>>> +
>>> + if (mapped_offset_out)
>>> + *mapped_offset_out = va->gem.offset;
>>> + if (mapped_size_out)
>>> + *mapped_size_out = va->va.range;
>>> +
>>> + mutex_unlock(&vm_ctx->lock);
>>> +
>>> + return pvr_obj;
>>> +
>>> +err_unlock:
>>> + mutex_unlock(&vm_ctx->lock);
>>> +
>>> + return NULL;
>>> +}
>>> +
>>> +/**
>>> + * pvr_vm_get_fw_mem_context: Get object representing firmware memory context
>>> + * @vm_ctx: Target VM context.
>>> + *
>>> + * Returns:
>>> + * * FW object representing firmware memory context, or
>>> + * * %NULL if this VM context does not have a firmware memory context.
>>> + */
>>> +struct pvr_fw_object *
>>> +pvr_vm_get_fw_mem_context(struct pvr_vm_context *vm_ctx)
>>> +{
>>> + return vm_ctx->fw_mem_ctx_obj;
>>> +}
>>> diff --git a/drivers/gpu/drm/imagination/pvr_vm.h b/drivers/gpu/drm/imagination/pvr_vm.h
>>> new file mode 100644
>>> index 000000000000..b98bc3981807
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/imagination/pvr_vm.h
>>> @@ -0,0 +1,60 @@
>>> +/* SPDX-License-Identifier: GPL-2.0 OR MIT */
>>> +/* Copyright (c) 2023 Imagination Technologies Ltd. */
>>> +
>>> +#ifndef PVR_VM_H
>>> +#define PVR_VM_H
>>> +
>>> +#include "pvr_rogue_mmu_defs.h"
>>> +
>>> +#include <uapi/drm/pvr_drm.h>
>>> +
>>> +#include <linux/types.h>
>>> +
>>> +/* Forward declaration from "pvr_device.h" */
>>> +struct pvr_device;
>>> +struct pvr_file;
>>> +
>>> +/* Forward declaration from "pvr_gem.h" */
>>> +struct pvr_gem_object;
>>> +
>>> +/* Forward declaration from "pvr_vm.c" */
>>> +struct pvr_vm_context;
>>> +
>>> +/* Forward declaration from <uapi/drm/pvr_drm.h> */
>>> +struct drm_pvr_ioctl_get_heap_info_args;
>>> +
>>> +/* Functions defined in pvr_vm.c */
>>> +
>>> +bool pvr_device_addr_is_valid(u64 device_addr);
>>> +bool pvr_device_addr_and_size_are_valid(u64 device_addr, u64 size);
>>> +
>>> +struct pvr_vm_context *pvr_vm_create_context(struct pvr_device *pvr_dev,
>>> + bool is_userspace_context);
>>> +
>>> +int pvr_vm_map(struct pvr_vm_context *vm_ctx,
>>> + struct pvr_gem_object *pvr_obj, u64 pvr_obj_offset,
>>> + u64 device_addr, u64 size);
>>> +int pvr_vm_unmap(struct pvr_vm_context *vm_ctx, u64 device_addr, u64 size);
>>> +
>>> +dma_addr_t pvr_vm_get_page_table_root_addr(struct pvr_vm_context *vm_ctx);
>>> +
>>> +int pvr_static_data_areas_get(const struct pvr_device *pvr_dev,
>>> + struct drm_pvr_ioctl_dev_query_args *args);
>>> +int pvr_heap_info_get(const struct pvr_device *pvr_dev,
>>> + struct drm_pvr_ioctl_dev_query_args *args);
>>> +const struct drm_pvr_heap *pvr_find_heap_containing(struct pvr_device *pvr_dev,
>>> + u64 addr, u64 size);
>>> +
>>> +struct pvr_gem_object *pvr_vm_find_gem_object(struct pvr_vm_context *vm_ctx,
>>> + u64 device_addr,
>>> + u64 *mapped_offset_out,
>>> + u64 *mapped_size_out);
>>> +
>>> +struct pvr_fw_object *
>>> +pvr_vm_get_fw_mem_context(struct pvr_vm_context *vm_ctx);
>>> +
>>> +struct pvr_vm_context *pvr_vm_context_lookup(struct pvr_file *pvr_file, u32 handle);
>>> +bool pvr_vm_context_put(struct pvr_vm_context *vm_ctx);
>>> +void pvr_destroy_vm_contexts_for_file(struct pvr_file *pvr_file);
>>> +
>>> +#endif /* PVR_VM_H */
>>> --
>>> 2.41.0
>>>
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