Re: [PATCH] drm/exynos: simplify DMA mapping
Hi Andrzej,
On 2018-09-21 10:58, Andrzej Hajda wrote:
> Moving DMA mapping creation to drm_iommu_attach_device allows to avoid
> looping through all components and maintaining DMA device flags.
>
> Signed-off-by: Andrzej Hajda
> ---
> drivers/gpu/drm/exynos/exynos_drm_drv.c | 50 +++
> drivers/gpu/drm/exynos/exynos_drm_iommu.c | 13 +-
I like simplification, but this one is a bit too invasive. It breaks
Exynos DRM when IOMMU support is disabled (dma_dev won't be set in such
case).
> 2 files changed, 17 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c
> b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> index b599f74692e5..c83437d8a595 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> @@ -197,8 +197,7 @@ struct exynos_drm_driver_info {
>
> #define DRM_COMPONENT_DRIVERBIT(0) /* supports component framework
> */
> #define DRM_VIRTUAL_DEVICE BIT(1) /* create virtual platform device */
> -#define DRM_DMA_DEVICE BIT(2) /* can be used for dma
> allocations */
> -#define DRM_FIMC_DEVICE BIT(3) /* devices shared with V4L2
> subsystem */
> +#define DRM_FIMC_DEVICE BIT(2) /* devices shared with V4L2
> subsystem */
>
> #define DRV_PTR(drv, cond) (IS_ENABLED(cond) ? : NULL)
>
> @@ -209,16 +208,16 @@ struct exynos_drm_driver_info {
> static struct exynos_drm_driver_info exynos_drm_drivers[] = {
> {
> DRV_PTR(fimd_driver, CONFIG_DRM_EXYNOS_FIMD),
> - DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
> + DRM_COMPONENT_DRIVER
> }, {
> DRV_PTR(exynos5433_decon_driver, CONFIG_DRM_EXYNOS5433_DECON),
> - DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
> + DRM_COMPONENT_DRIVER
> }, {
> DRV_PTR(decon_driver, CONFIG_DRM_EXYNOS7_DECON),
> - DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
> + DRM_COMPONENT_DRIVER
> }, {
> DRV_PTR(mixer_driver, CONFIG_DRM_EXYNOS_MIXER),
> - DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
> + DRM_COMPONENT_DRIVER
> }, {
> DRV_PTR(mic_driver, CONFIG_DRM_EXYNOS_MIC),
> DRM_COMPONENT_DRIVER
> @@ -289,27 +288,6 @@ static struct component_match
> *exynos_drm_match_add(struct device *dev)
> return match ?: ERR_PTR(-ENODEV);
> }
>
> -static struct device *exynos_drm_get_dma_device(void)
> -{
> - int i;
> -
> - for (i = 0; i < ARRAY_SIZE(exynos_drm_drivers); ++i) {
> - struct exynos_drm_driver_info *info = _drm_drivers[i];
> - struct device *dev;
> -
> - if (!info->driver || !(info->flags & DRM_DMA_DEVICE))
> - continue;
> -
> - while ((dev = bus_find_device(_bus_type, NULL,
> - >driver->driver,
> - (void *)platform_bus_type.match))) {
> - put_device(dev);
> - return dev;
> - }
> - }
> - return NULL;
> -}
> -
> static int exynos_drm_bind(struct device *dev)
> {
> struct exynos_drm_private *private;
> @@ -334,23 +312,6 @@ static int exynos_drm_bind(struct device *dev)
> dev_set_drvdata(dev, drm);
> drm->dev_private = (void *)private;
>
> - /* the first real CRTC device is used for all dma mapping operations */
> - private->dma_dev = exynos_drm_get_dma_device();
> - if (!private->dma_dev) {
> - DRM_ERROR("no device found for DMA mapping operations.\n");
> - ret = -ENODEV;
> - goto err_free_private;
> - }
> - DRM_INFO("Exynos DRM: using %s device for DMA mapping operations\n",
> - dev_name(private->dma_dev));
> -
> - /* create common IOMMU mapping for all devices attached to Exynos DRM */
> - ret = drm_create_iommu_mapping(drm);
> - if (ret < 0) {
> - DRM_ERROR("failed to create iommu mapping.\n");
> - goto err_free_private;
> - }
> -
> drm_mode_config_init(drm);
>
> exynos_drm_mode_config_init(drm);
> @@ -408,7 +369,6 @@ static int exynos_drm_bind(struct device *dev)
> err_mode_config_cleanup:
> drm_mode_config_cleanup(drm);
> drm_release_iommu_mapping(drm);
> -err_free_private:
> kfree(private);
> err_free_drm:
> drm_dev_put(drm);
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.c
> b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
> index 0f373702414e..bb8b800a9fba 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_iommu.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
> @@ -75,7 +75,18 @@ int drm_iommu_attach_device(struct drm_device *drm_dev,
> struct exynos_drm_private *priv = drm_dev->dev_private;
> int ret;
>
> - if (get_dma_ops(priv->dma_dev) != get_dma_ops(subdrv_dev)) {
> + if (!priv->dma_dev) {
> +
[PATCH] drm/exynos: simplify DMA mapping
Moving DMA mapping creation to drm_iommu_attach_device allows to avoid
looping through all components and maintaining DMA device flags.
Signed-off-by: Andrzej Hajda
---
drivers/gpu/drm/exynos/exynos_drm_drv.c | 50 +++
drivers/gpu/drm/exynos/exynos_drm_iommu.c | 13 +-
2 files changed, 17 insertions(+), 46 deletions(-)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c
b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index b599f74692e5..c83437d8a595 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -197,8 +197,7 @@ struct exynos_drm_driver_info {
#define DRM_COMPONENT_DRIVER BIT(0) /* supports component framework */
#define DRM_VIRTUAL_DEVICE BIT(1) /* create virtual platform device */
-#define DRM_DMA_DEVICE BIT(2) /* can be used for dma allocations */
-#define DRM_FIMC_DEVICEBIT(3) /* devices shared with V4L2
subsystem */
+#define DRM_FIMC_DEVICEBIT(2) /* devices shared with V4L2
subsystem */
#define DRV_PTR(drv, cond) (IS_ENABLED(cond) ? : NULL)
@@ -209,16 +208,16 @@ struct exynos_drm_driver_info {
static struct exynos_drm_driver_info exynos_drm_drivers[] = {
{
DRV_PTR(fimd_driver, CONFIG_DRM_EXYNOS_FIMD),
- DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
+ DRM_COMPONENT_DRIVER
}, {
DRV_PTR(exynos5433_decon_driver, CONFIG_DRM_EXYNOS5433_DECON),
- DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
+ DRM_COMPONENT_DRIVER
}, {
DRV_PTR(decon_driver, CONFIG_DRM_EXYNOS7_DECON),
- DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
+ DRM_COMPONENT_DRIVER
}, {
DRV_PTR(mixer_driver, CONFIG_DRM_EXYNOS_MIXER),
- DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
+ DRM_COMPONENT_DRIVER
}, {
DRV_PTR(mic_driver, CONFIG_DRM_EXYNOS_MIC),
DRM_COMPONENT_DRIVER
@@ -289,27 +288,6 @@ static struct component_match *exynos_drm_match_add(struct
device *dev)
return match ?: ERR_PTR(-ENODEV);
}
-static struct device *exynos_drm_get_dma_device(void)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(exynos_drm_drivers); ++i) {
- struct exynos_drm_driver_info *info = _drm_drivers[i];
- struct device *dev;
-
- if (!info->driver || !(info->flags & DRM_DMA_DEVICE))
- continue;
-
- while ((dev = bus_find_device(_bus_type, NULL,
- >driver->driver,
- (void *)platform_bus_type.match))) {
- put_device(dev);
- return dev;
- }
- }
- return NULL;
-}
-
static int exynos_drm_bind(struct device *dev)
{
struct exynos_drm_private *private;
@@ -334,23 +312,6 @@ static int exynos_drm_bind(struct device *dev)
dev_set_drvdata(dev, drm);
drm->dev_private = (void *)private;
- /* the first real CRTC device is used for all dma mapping operations */
- private->dma_dev = exynos_drm_get_dma_device();
- if (!private->dma_dev) {
- DRM_ERROR("no device found for DMA mapping operations.\n");
- ret = -ENODEV;
- goto err_free_private;
- }
- DRM_INFO("Exynos DRM: using %s device for DMA mapping operations\n",
-dev_name(private->dma_dev));
-
- /* create common IOMMU mapping for all devices attached to Exynos DRM */
- ret = drm_create_iommu_mapping(drm);
- if (ret < 0) {
- DRM_ERROR("failed to create iommu mapping.\n");
- goto err_free_private;
- }
-
drm_mode_config_init(drm);
exynos_drm_mode_config_init(drm);
@@ -408,7 +369,6 @@ static int exynos_drm_bind(struct device *dev)
err_mode_config_cleanup:
drm_mode_config_cleanup(drm);
drm_release_iommu_mapping(drm);
-err_free_private:
kfree(private);
err_free_drm:
drm_dev_put(drm);
diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.c
b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
index 0f373702414e..bb8b800a9fba 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_iommu.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
@@ -75,7 +75,18 @@ int drm_iommu_attach_device(struct drm_device *drm_dev,
struct exynos_drm_private *priv = drm_dev->dev_private;
int ret;
- if (get_dma_ops(priv->dma_dev) != get_dma_ops(subdrv_dev)) {
+ if (!priv->dma_dev) {
+ priv->dma_dev = subdrv_dev;
+ DRM_INFO("Exynos DRM: using %s device for DMA mapping
operations\n",
+dev_name(subdrv_dev));
+ /* create common IOMMU mapping for all Exynos DRM devices */
+ ret = drm_create_iommu_mapping(drm_dev);
+ if (ret < 0) {
+
