[Intel-gfx] [RFC PATCH V4 1/4] drm/i915: add i915_ved.c to setup bridge for VED
Cheng, Yao
yao.cheng at intel.com
Wed Jan 14 18:52:27 PST 2015
+ commenters of v1~v3
Thanks,
Yao
> -----Original Message-----
> From: Sean V Kelley [mailto:seanvk at posteo.de]
> Sent: Thursday, January 8, 2015 8:35
> To: Intel-gfx at lists.freedesktop.org
> Cc: dri-devel at lists.freedesktop.org; Cheng, Yao; Sean V Kelley
> Subject: [RFC PATCH V4 1/4] drm/i915: add i915_ved.c to setup bridge for
> VED
>
> From: Yao Cheng <yao.cheng at intel.com>
>
> Setup minimum required resources during i915_driver_load:
> 1. Create a platform device to share MMIO/IRQ resources 2. Make the
> platform device child of i915 device for runtime PM.
> 3. Create IRQ chip to forward the VED irqs.
> VED driver (a standalone drm driver) probes the VED device and creates a
> new dri card on install.
> Currently only supports VED on valleyview.
> Kerneldoc is updated for i915_ved.c.
>
> v2:
> take Daniel & Jani's comments
> - extract change to new file i915_ved.c
> - add kerneldoc
> - change 'ipvr-ved' to 'ipvr-vlv-ved' for extensibility
> - unregister platdev before irq_free_desc
> - add WARN_ON(!intel_irqs_enabled) in irq init code
> - remove unnecessary trace point
> - remove unnecessary BUG_ON
>
> v3:
> take Ville's comments and VED PRIME support
> - add HAS_VED() check
> - add ved struct to make code neat
> - no need to check platform in vlv_irq_handler
> - i915_reg.h update
> - no need to kmalloc for small amount of resource
> - remove unnecessary REG resource
> - follow vlv_display_irqs_install() to implement VED mask/unmask
> - workaround nommu_map_sg issue by set dma_mask to support
> VED PRIME.
>
> v4:
> take Bob's comments
> - add more detail on the use-after-free issue description
> - mask VED irq before removing the child device
>
> Signed-off-by: Yao Cheng <yao.cheng at intel.com>
> Signed-off-by: Sean V Kelley <seanvk at posteo.de>
> ---
> Documentation/DocBook/drm.tmpl | 5 +
> drivers/gpu/drm/i915/Makefile | 3 +
> drivers/gpu/drm/i915/i915_dma.c | 11 ++ drivers/gpu/drm/i915/i915_drv.h
> | 12 ++
> drivers/gpu/drm/i915/i915_irq.c | 2 +
> drivers/gpu/drm/i915/i915_reg.h | 4 +
> drivers/gpu/drm/i915/i915_ved.c | 270
> ++++++++++++++++++++++++++++++++++++++++
> 7 files changed, 307 insertions(+)
> create mode 100644 drivers/gpu/drm/i915/i915_ved.c
>
> diff --git a/Documentation/DocBook/drm.tmpl
> b/Documentation/DocBook/drm.tmpl index 56e2a9b..9db989c 100644
> --- a/Documentation/DocBook/drm.tmpl
> +++ b/Documentation/DocBook/drm.tmpl
> @@ -3867,6 +3867,11 @@ int
> num_ioctls;</synopsis> !Fdrivers/gpu/drm/i915/i915_irq.c
> intel_runtime_pm_disable_interrupts
> !Fdrivers/gpu/drm/i915/i915_irq.c intel_runtime_pm_enable_interrupts
> </sect2>
> + <sect2>
> + <title>VED video core integration</title>
> +!Pdrivers/gpu/drm/i915/i915_ved.c VED video core integration
> +!Idrivers/gpu/drm/i915/i915_ved.c
> + </sect2>
> </sect1>
> <sect1>
> <title>Display Hardware Handling</title> diff --git
> a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index
> e4083e4..7d0bbfa 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -84,6 +84,9 @@ i915-y += dvo_ch7017.o \ i915-y += i915_dma.o \
> i915_ums.o
>
> +# VED for VLV
> +i915-y += i915_ved.o
> +
> obj-$(CONFIG_DRM_I915) += i915.o
>
> CFLAGS_i915_trace_points.o := -I$(src)
> diff --git a/drivers/gpu/drm/i915/i915_dma.c
> b/drivers/gpu/drm/i915/i915_dma.c index 887d88f..cd96618 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -828,6 +828,13 @@ int i915_driver_load(struct drm_device *dev,
> unsigned long flags)
> if (IS_GEN5(dev))
> intel_gpu_ips_init(dev_priv);
>
> + if (HAS_VED(dev)) {
> + ret = vlv_setup_ved(dev);
> + if (ret < 0) {
> + DRM_ERROR("failed to setup VED bridge: %d\n", ret);
> + }
> + }
> +
> intel_runtime_pm_enable(dev_priv);
>
> return 0;
> @@ -870,6 +877,10 @@ int i915_driver_unload(struct drm_device *dev)
> struct drm_i915_private *dev_priv = dev->dev_private;
> int ret;
>
> + if (HAS_VED(dev)) {
> + vlv_teardown_ved(dev);
> + }
> +
> ret = i915_gem_suspend(dev);
> if (ret) {
> DRM_ERROR("failed to idle hardware: %d\n", ret); diff --git
> a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 502a01b..aa39d47 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1773,6 +1773,12 @@ struct drm_i915_private {
>
> uint32_t bios_vgacntr;
>
> + /* necessary resource sharing with ved driver. */
> + struct {
> + struct platform_device *platdev;
> + int irq;
> + } ved;
> +
> /* Abstract the submission mechanism (legacy ringbuffer or execlists)
> away */
> struct {
> int (*do_execbuf)(struct drm_device *dev, struct drm_file
> *file, @@ -2305,6 +2311,7 @@ struct drm_i915_cmd_table {
> IS_BROADWELL(dev) ||
> IS_VALLEYVIEW(dev))
> #define HAS_RC6(dev) (INTEL_INFO(dev)->gen >= 6)
> #define HAS_RC6p(dev) (INTEL_INFO(dev)->gen == 6 ||
> IS_IVYBRIDGE(dev))
> +#define HAS_VED(dev) (INTEL_INFO(dev)->is_valleyview &&
> IS_GEN7(dev))
>
> #define INTEL_PCH_DEVICE_ID_MASK 0xff00
> #define INTEL_PCH_IBX_DEVICE_ID_TYPE 0x3b00
> @@ -2894,6 +2901,11 @@ void i915_restore_display_reg(struct drm_device
> *dev); void i915_setup_sysfs(struct drm_device *dev_priv); void
> i915_teardown_sysfs(struct drm_device *dev_priv);
>
> +/* i915_ved.c */
> +int vlv_setup_ved(struct drm_device *dev); void vlv_teardown_ved(struct
> +drm_device *dev); void vlv_ved_irq_handler(struct drm_device *dev);
> +
> /* intel_i2c.c */
> extern int intel_setup_gmbus(struct drm_device *dev); extern void
> intel_teardown_gmbus(struct drm_device *dev); diff --git
> a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index
> 7913a72..9837a71 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -1892,6 +1892,8 @@ static irqreturn_t valleyview_irq_handler(int irq,
> void *arg)
> snb_gt_irq_handler(dev, dev_priv, gt_iir);
> if (pm_iir)
> gen6_rps_irq_handler(dev_priv, pm_iir);
> + if (iir & VLV_VED_BLOCK_INTERRUPT)
> + vlv_ved_irq_handler(dev);
> /* Call regardless, as some status bits might not be
> * signalled in iir */
> valleyview_pipestat_irq_handler(dev, iir); diff --git
> a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 869e5ae..79d8764 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -1301,6 +1301,9 @@ enum punit_power_well { #define
> VLV_DISPLAY_BASE 0x180000 #define VLV_MIPI_BASE VLV_DISPLAY_BASE
>
> +#define VLV_VED_BASE 0x170000
> +#define VLV_VED_SIZE 0x010000
> +
> #define VLV_GU_CTL0 (VLV_DISPLAY_BASE + 0x2030)
> #define VLV_GU_CTL1 (VLV_DISPLAY_BASE + 0x2034)
> #define SCPD0 0x0209c /* 915+ only */
> @@ -1494,6 +1497,7 @@ enum punit_power_well {
> #define ILK_BSD_USER_INTERRUPT (1<<5)
>
> #define I915_PM_INTERRUPT (1<<31)
> +#define VLV_VED_BLOCK_INTERRUPT (1<<23)
> #define I915_ISP_INTERRUPT (1<<22)
> #define I915_LPE_PIPE_B_INTERRUPT (1<<21)
> #define I915_LPE_PIPE_A_INTERRUPT (1<<20)
> diff --git a/drivers/gpu/drm/i915/i915_ved.c
> b/drivers/gpu/drm/i915/i915_ved.c new file mode 100644 index
> 0000000..f8ea7be
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/i915_ved.c
> @@ -0,0 +1,270 @@
> +/*
> + * Copyright © 2014 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person
> +obtaining a
> + * copy of this software and associated documentation files (the
> +"Software"),
> + * to deal in the Software without restriction, including without
> +limitation
> + * the rights to use, copy, modify, merge, publish, distribute,
> +sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom
> +the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the
> +next
> + * paragraph) shall be included in all copies or substantial portions
> +of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> +EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> +MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
> EVENT
> +SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
> DAMAGES OR
> +OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> +ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> OTHER
> +DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + * Yao Cheng <yao.cheng at intel.com>
> + *
> + */
> +
> +#include "i915_drv.h"
> +
> +/**
> + * DOC: VED video core integration
> + *
> + * Motivation:
> + * Some platforms (e.g. valleyview) integrates a VED inside GPU to
> +extend the
> + * video decoding capability.
> + * The VED is driven by the standalone drm driver "ipvr" which covers
> +PowerVR
> + * VPUs. Since the PowerVR VPUs are also integrated by non-i915
> +platforms such
> + * as GMA500, we'd like to keep ipvr driver and i915 driver separated
> +and
> + * independent to each other. To achieve this we do the minimum work in
> +i915
> + * to setup a bridge between ipvr and i915:
> + * 1. Create a platform device to share MMIO/IRQ resources
> + * 2. Make the platform device child of i915 device for runtime PM.
> + * 3. Create IRQ chip to forward the VED irqs.
> + * ipvr driver probes the VED device and creates a new dri card on install.
> + *
> + * Threats:
> + * Due to the restriction in Linux platform device model, user need
> +manually
> + * uninstall ipvr driver before uninstalling i915 module, otherwise we
> +might
> + * run into use-after-free issues after i915 removes the platform
> +device: even
> + * though ipvr driver is released, the modules is still in "installed" status.
> + *
> + * Implementation:
> + * The MMIO/REG platform resources are created according to the
> +registers
> + * specification.
> + * When forwarding VED irqs, the flow control handler selection depends
> +on the
> + * platform, for example on valleyview handle_simple_irq is enough.
> + *
> + */
> +
> +static struct platform_device* vlv_ved_platdev_create(struct drm_device
> +*dev) {
> + int ret;
> + struct resource rsc[2] = { {0}, {0} };
> + struct platform_device *platdev;
> + u64 *dma_mask = NULL;
> + struct drm_i915_private *dev_priv = dev->dev_private;
> +
> + if (dev_priv->ved.irq < 0)
> + return ERR_PTR(-EINVAL);
> +
> + platdev = platform_device_alloc("ipvr-ved-vlv", -1);
> + if (!platdev) {
> + ret = -ENOMEM;
> + DRM_ERROR("Failed to allocate VED platform device\n");
> + goto err;
> + }
> +
> + /* to work-around check_addr in nommu_map_sg() */
> + dma_mask = kmalloc(sizeof(*platdev->dev.dma_mask),
> GFP_KERNEL);
> + if (!dma_mask) {
> + ret = -ENOMEM;
> + DRM_ERROR("Failed to allocate dma_mask\n");
> + goto err_put_dev;
> + }
> + *dma_mask = DMA_BIT_MASK(31);
> + platdev->dev.dma_mask = dma_mask;
> + platdev->dev.coherent_dma_mask = *dma_mask;
> +
> + rsc[0].start = rsc[0].end = dev_priv->ved.irq;
> + rsc[0].flags = IORESOURCE_IRQ;
> + rsc[0].name = "ipvr-ved-vlv-irq";
> +
> + rsc[1].start = pci_resource_start(dev->pdev, 0) + VLV_VED_BASE;
> + rsc[1].end = pci_resource_start(dev->pdev, 0) + VLV_VED_BASE +
> VLV_VED_SIZE;
> + rsc[1].flags = IORESOURCE_MEM;
> + rsc[1].name = "ipvr-ved-vlv-mmio";
> +
> + ret = platform_device_add_resources(platdev, rsc, 2);
> + if (ret) {
> + DRM_ERROR("Failed to add resource for VED platform
> device: %d\n", ret);
> + goto err_put_dev;
> + }
> +
> + platdev->dev.parent = dev->dev; /* for VED driver's runtime-PM */
> + ret = platform_device_add(platdev);
> + if (ret) {
> + DRM_ERROR("Failed to add VED platform device: %d\n", ret);
> + goto err_put_dev;
> + }
> +
> + return platdev;
> +err_put_dev:
> + platform_device_put(platdev);
> +err:
> + if (dma_mask)
> + kfree(dma_mask);
> + return ERR_PTR(ret);
> +}
> +
> +static void vlv_ved_platdev_destroy(struct drm_device *dev) {
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + if (dev_priv->ved.platdev) {
> + kfree(dev_priv->ved.platdev->dev.dma_mask);
> + platform_device_unregister(dev_priv->ved.platdev);
> + }
> +}
> +
> +static void vlv_ved_irq_unmask(struct irq_data *d) {
> + struct drm_device *dev = d->chip_data;
> + struct drm_i915_private *dev_priv = (struct drm_i915_private *)
> dev->dev_private;
> + unsigned long irqflags;
> + spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
> +
> + dev_priv->irq_mask &= ~VLV_VED_BLOCK_INTERRUPT;
> + I915_WRITE(VLV_IIR, VLV_VED_BLOCK_INTERRUPT);
> + I915_WRITE(VLV_IIR, VLV_VED_BLOCK_INTERRUPT);
> + I915_WRITE(VLV_IMR, dev_priv->irq_mask);
> + I915_WRITE(VLV_IER, ~dev_priv->irq_mask);
> + POSTING_READ(VLV_IER);
> +
> + spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags); }
> +
> +static void vlv_ved_irq_mask(struct irq_data *d) {
> + struct drm_device *dev = d->chip_data;
> + struct drm_i915_private *dev_priv = (struct drm_i915_private *)
> dev->dev_private;
> + unsigned long irqflags;
> + spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
> +
> + dev_priv->irq_mask |= VLV_VED_BLOCK_INTERRUPT;
> + I915_WRITE(VLV_IER, ~dev_priv->irq_mask);
> + I915_WRITE(VLV_IMR, dev_priv->irq_mask);
> + I915_WRITE(VLV_IIR, VLV_VED_BLOCK_INTERRUPT);
> + I915_WRITE(VLV_IIR, VLV_VED_BLOCK_INTERRUPT);
> + POSTING_READ(VLV_IIR);
> +
> + spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags); }
> +
> +static struct irq_chip vlv_ved_irqchip = {
> + .name = "ipvr_ved_irqchip",
> + .irq_mask = vlv_ved_irq_mask,
> + .irq_unmask = vlv_ved_irq_unmask,
> +};
> +
> +static int vlv_ved_irq_init(struct drm_device *dev, int irq) {
> + struct drm_i915_private *dev_priv = (struct drm_i915_private *)
> dev->dev_private;
> + WARN_ON(!intel_irqs_enabled(dev_priv));
> + irq_set_chip_and_handler_name(irq,
> + &vlv_ved_irqchip,
> + handle_simple_irq,
> + "ipvr_ved_vlv_irq_handler");
> + return irq_set_chip_data(irq, dev);
> +}
> +
> +/**
> + * vlv_ved_irq_handler() - forwards the VED irq
> + * @dev: the i915 drm device
> + *
> + * the VED irq is forwarded to the irq handler registered by VED driver.
> + */
> +void vlv_ved_irq_handler(struct drm_device *dev) {
> + int ret;
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + if (dev_priv->ved.irq < 0 && printk_ratelimit()) {
> + DRM_ERROR("invalid ved irq number: %d\n", dev_priv-
> >ved.irq);
> + return;
> + }
> + ret = generic_handle_irq(dev_priv->ved.irq);
> + if (ret && printk_ratelimit()) {
> + DRM_ERROR("error handling vlv ved irq: %d\n", ret);
> + }
> +}
> +
> +/**
> + * vlv_setup_ved() - setup the bridge between VED driver and i915
> + * @dev: the i915 drm device
> + *
> + * set up the minimum required resources for the bridge: irq chip,
> +platform
> + * resource and platform device. i915 device is set as parent of the
> +new
> + * platform device.
> + *
> + * Return: 0 if successful. non-zero if allocation/initialization fails
> +*/ int vlv_setup_ved(struct drm_device *dev) {
> + int ret;
> + struct drm_i915_private *dev_priv = dev->dev_private;
> +
> + dev_priv->ved.irq = irq_alloc_descs(-1, 0, 1, 0);
> + if (dev_priv->ved.irq < 0) {
> + DRM_ERROR("Failed to allocate IRQ desc: %d\n", dev_priv-
> >ved.irq);
> + ret = dev_priv->ved.irq;
> + goto err;
> + }
> +
> + ret = vlv_ved_irq_init(dev, dev_priv->ved.irq);
> + if (ret) {
> + DRM_ERROR("Failed to initialize irqchip for vlv-ved: %d\n",
> ret);
> + goto err_free_irq;
> + }
> +
> + dev_priv->ved.platdev = vlv_ved_platdev_create(dev);
> + if (IS_ERR(dev_priv->ved.platdev)) {
> + ret = PTR_ERR(dev_priv->ved.platdev);
> + DRM_ERROR("Failed to create platform device for vlv-
> ved: %d\n", ret);
> + goto err_free_irq;
> + }
> +
> + return 0;
> +err_free_irq:
> + irq_free_desc(dev_priv->ved.irq);
> +err:
> + dev_priv->ved.irq = -1;
> + dev_priv->ved.platdev = NULL;
> + return ret;
> +}
> +
> +/**
> + * vlv_teardown_ved() - destroy the bridge between VED driver and i915
> + * @dev: the i915 drm device
> + *
> + * release all the resources for VED <-> i915 bridge.
> + */
> +void vlv_teardown_ved(struct drm_device *dev) {
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + unsigned long irqflags;
> +
> + /**
> + * mask VED irq before destroying
> + */
> + spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
> + dev_priv->irq_mask |= VLV_VED_BLOCK_INTERRUPT;
> + I915_WRITE(VLV_IER, ~dev_priv->irq_mask);
> + I915_WRITE(VLV_IMR, dev_priv->irq_mask);
> + I915_WRITE(VLV_IIR, VLV_VED_BLOCK_INTERRUPT);
> + I915_WRITE(VLV_IIR, VLV_VED_BLOCK_INTERRUPT);
> + POSTING_READ(VLV_IIR);
> + spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
> +
> + vlv_ved_platdev_destroy(dev);
> + if (dev_priv->ved.irq >= 0)
> + irq_free_desc(dev_priv->ved.irq);
> +}
> --
> 2.1.0
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