Re: [PATCH 14/18] drm/exynos: Consolidate IOMMU mapping code

Marek Szyprowski
2020-09-18T14:30:51Z

Hi Robin,

On 20.08.2020 17:08, Robin Murphy wrote:
> Now that arch/arm is wired up for default domains and iommu-dma, we can
> consolidate the shared mapping code onto the generic IOMMU API version,
> and retire the arch-specific implementation.
>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>
> ---
> This is a cheeky revert of 07dc3678bacc ("drm/exynos: Fix cleanup of
> IOMMU related objects"), plus removal of the remaining arm_iommu_*
> references on top.

I have one more suggestion to this patch. Please rename
exynos_drm_private->mapping to exynos_drm_private->domain and change its
type from "void *" to "struct iommu_domain *". The "void *" was there to
support both old-ARM and ARM64 IOMMU/DMA-mapping frameworks, but now we
can use the proper pointer types.

> ---
> drivers/gpu/drm/exynos/exynos5433_drm_decon.c | 5 +-
> drivers/gpu/drm/exynos/exynos7_drm_decon.c | 5 +-
> drivers/gpu/drm/exynos/exynos_drm_dma.c | 61 +++----------------
> drivers/gpu/drm/exynos/exynos_drm_drv.h | 6 +-
> drivers/gpu/drm/exynos/exynos_drm_fimc.c | 5 +-
> drivers/gpu/drm/exynos/exynos_drm_fimd.c | 5 +-
> drivers/gpu/drm/exynos/exynos_drm_g2d.c | 5 +-
> drivers/gpu/drm/exynos/exynos_drm_gsc.c | 5 +-
> drivers/gpu/drm/exynos/exynos_drm_rotator.c | 5 +-
> drivers/gpu/drm/exynos/exynos_drm_scaler.c | 6 +-
> drivers/gpu/drm/exynos/exynos_mixer.c | 7 +--
> 11 files changed, 29 insertions(+), 86 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos5433_drm_decon.c b/drivers/gpu/drm/exynos/exynos5433_drm_decon.c
> index 1f79bc2a881e..8428ae12dfa5 100644
> --- a/drivers/gpu/drm/exynos/exynos5433_drm_decon.c
> +++ b/drivers/gpu/drm/exynos/exynos5433_drm_decon.c
> @@ -55,7 +55,6 @@ static const char * const decon_clks_name[] = {
> struct decon_context {
> struct device *dev;
> struct drm_device *drm_dev;
> - void *dma_priv;
> struct exynos_drm_crtc *crtc;
> struct exynos_drm_plane planes[WINDOWS_NR];
> struct exynos_drm_plane_config configs[WINDOWS_NR];
> @@ -645,7 +644,7 @@ static int decon_bind(struct device *dev, struct device *master, void *data)
>
> decon_clear_channels(ctx->crtc);
>
> - return exynos_drm_register_dma(drm_dev, dev, &ctx->dma_priv);
> + return exynos_drm_register_dma(drm_dev, dev);
> }
>
> static void decon_unbind(struct device *dev, struct device *master, void *data)
> @@ -655,7 +654,7 @@ static void decon_unbind(struct device *dev, struct device *master, void *data)
> decon_atomic_disable(ctx->crtc);
>
> /* detach this sub driver from iommu mapping if supported. */
> - exynos_drm_unregister_dma(ctx->drm_dev, ctx->dev, &ctx->dma_priv);
> + exynos_drm_unregister_dma(ctx->drm_dev, ctx->dev);
> }
>
> static const struct component_ops decon_component_ops = {
> diff --git a/drivers/gpu/drm/exynos/exynos7_drm_decon.c b/drivers/gpu/drm/exynos/exynos7_drm_decon.c
> index f2d87a7445c7..e7b58097ccdc 100644
> --- a/drivers/gpu/drm/exynos/exynos7_drm_decon.c
> +++ b/drivers/gpu/drm/exynos/exynos7_drm_decon.c
> @@ -40,7 +40,6 @@
> struct decon_context {
> struct device *dev;
> struct drm_device *drm_dev;
> - void *dma_priv;
> struct exynos_drm_crtc *crtc;
> struct exynos_drm_plane planes[WINDOWS_NR];
> struct exynos_drm_plane_config configs[WINDOWS_NR];
> @@ -128,13 +127,13 @@ static int decon_ctx_initialize(struct decon_context *ctx,
>
> decon_clear_channels(ctx->crtc);
>
> - return exynos_drm_register_dma(drm_dev, ctx->dev, &ctx->dma_priv);
> + return exynos_drm_register_dma(drm_dev, ctx->dev);
> }
>
> static void decon_ctx_remove(struct decon_context *ctx)
> {
> /* detach this sub driver from iommu mapping if supported. */
> - exynos_drm_unregister_dma(ctx->drm_dev, ctx->dev, &ctx->dma_priv);
> + exynos_drm_unregister_dma(ctx->drm_dev, ctx->dev);
> }
>
> static u32 decon_calc_clkdiv(struct decon_context *ctx,
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dma.c b/drivers/gpu/drm/exynos/exynos_drm_dma.c
> index 58b89ec11b0e..fd5f9bcf1857 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_dma.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_dma.c
> @@ -14,19 +14,6 @@
>
> #include "exynos_drm_drv.h"
>
> -#if defined(CONFIG_ARM_DMA_USE_IOMMU)
> -#include <asm/dma-iommu.h>
> -#else
> -#define arm_iommu_create_mapping(...) ({ NULL; })
> -#define arm_iommu_attach_device(...) ({ -ENODEV; })
> -#define arm_iommu_release_mapping(...) ({ })
> -#define arm_iommu_detach_device(...) ({ })
> -#define to_dma_iommu_mapping(dev) NULL
> -#endif
> -
> -#if !defined(CONFIG_IOMMU_DMA)
> -#define iommu_dma_init_domain(...) ({ -EINVAL; })
> -#endif
>
> #define EXYNOS_DEV_ADDR_START 0x20000000
> #define EXYNOS_DEV_ADDR_SIZE 0x40000000
> @@ -58,7 +45,7 @@ static inline void clear_dma_max_seg_size(struct device *dev)
> * mapping.
> */
> static int drm_iommu_attach_device(struct drm_device *drm_dev,
> - struct device *subdrv_dev, void **dma_priv)
> + struct device *subdrv_dev)
> {
> struct exynos_drm_private *priv = drm_dev->dev_private;
> int ret = 0;
> @@ -73,22 +60,7 @@ static int drm_iommu_attach_device(struct drm_device *drm_dev,
> if (ret)
> return ret;
>
> - if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) {
> - /*
> - * Keep the original DMA mapping of the sub-device and
> - * restore it on Exynos DRM detach, otherwise the DMA
> - * framework considers it as IOMMU-less during the next
> - * probe (in case of deferred probe or modular build)
> - */
> - *dma_priv = to_dma_iommu_mapping(subdrv_dev);
> - if (*dma_priv)
> - arm_iommu_detach_device(subdrv_dev);
> -
> - ret = arm_iommu_attach_device(subdrv_dev, priv->mapping);
> - } else if (IS_ENABLED(CONFIG_IOMMU_DMA)) {
> - ret = iommu_attach_device(priv->mapping, subdrv_dev);
> - }
> -
> + ret = iommu_attach_device(priv->mapping, subdrv_dev);
> if (ret)
> clear_dma_max_seg_size(subdrv_dev);
>
> @@ -105,21 +77,15 @@ static int drm_iommu_attach_device(struct drm_device *drm_dev,
> * mapping
> */
> static void drm_iommu_detach_device(struct drm_device *drm_dev,
> - struct device *subdrv_dev, void **dma_priv)
> + struct device *subdrv_dev)
> {
> struct exynos_drm_private *priv = drm_dev->dev_private;
>
> - if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) {
> - arm_iommu_detach_device(subdrv_dev);
> - arm_iommu_attach_device(subdrv_dev, *dma_priv);
> - } else if (IS_ENABLED(CONFIG_IOMMU_DMA))
> - iommu_detach_device(priv->mapping, subdrv_dev);
> -
> + iommu_detach_device(priv->mapping, subdrv_dev);
> clear_dma_max_seg_size(subdrv_dev);
> }
>
> -int exynos_drm_register_dma(struct drm_device *drm, struct device *dev,
> - void **dma_priv)
> +int exynos_drm_register_dma(struct drm_device *drm, struct device *dev)
> {
> struct exynos_drm_private *priv = drm->dev_private;
>
> @@ -133,27 +99,20 @@ int exynos_drm_register_dma(struct drm_device *drm, struct device *dev,
> return 0;
>
> if (!priv->mapping) {
> - void *mapping;
> -
> - if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))
> - mapping = arm_iommu_create_mapping(&platform_bus_type,
> - EXYNOS_DEV_ADDR_START, EXYNOS_DEV_ADDR_SIZE);
> - else if (IS_ENABLED(CONFIG_IOMMU_DMA))
> - mapping = iommu_get_domain_for_dev(priv->dma_dev);
> + void *mapping = iommu_get_domain_for_dev(priv->dma_dev);
>
> if (IS_ERR(mapping))
> return PTR_ERR(mapping);
> priv->mapping = mapping;
> }
>
> - return drm_iommu_attach_device(drm, dev, dma_priv);
> + return drm_iommu_attach_device(drm, dev);
> }
>
> -void exynos_drm_unregister_dma(struct drm_device *drm, struct device *dev,
> - void **dma_priv)
> +void exynos_drm_unregister_dma(struct drm_device *drm, struct device *dev)
> {
> if (IS_ENABLED(CONFIG_EXYNOS_IOMMU))
> - drm_iommu_detach_device(drm, dev, dma_priv);
> + drm_iommu_detach_device(drm, dev);
> }
>
> void exynos_drm_cleanup_dma(struct drm_device *drm)
> @@ -163,7 +122,5 @@ void exynos_drm_cleanup_dma(struct drm_device *drm)
> if (!IS_ENABLED(CONFIG_EXYNOS_IOMMU))
> return;
>
> - arm_iommu_release_mapping(priv->mapping);
> - priv->mapping = NULL;
> priv->dma_dev = NULL;
> }
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
> index 6ae9056e7a18..d4d21d8cfb90 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
> +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
> @@ -223,10 +223,8 @@ static inline bool is_drm_iommu_supported(struct drm_device *drm_dev)
> return priv->mapping ? true : false;
> }
>
> -int exynos_drm_register_dma(struct drm_device *drm, struct device *dev,
> - void **dma_priv);
> -void exynos_drm_unregister_dma(struct drm_device *drm, struct device *dev,
> - void **dma_priv);
> +int exynos_drm_register_dma(struct drm_device *drm, struct device *dev);
> +void exynos_drm_unregister_dma(struct drm_device *drm, struct device *dev);
> void exynos_drm_cleanup_dma(struct drm_device *drm);
>
> #ifdef CONFIG_DRM_EXYNOS_DPI
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimc.c b/drivers/gpu/drm/exynos/exynos_drm_fimc.c
> index 29ab8be8604c..8ea2e1d77802 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fimc.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fimc.c
> @@ -97,7 +97,6 @@ struct fimc_scaler {
> struct fimc_context {
> struct exynos_drm_ipp ipp;
> struct drm_device *drm_dev;
> - void *dma_priv;
> struct device *dev;
> struct exynos_drm_ipp_task *task;
> struct exynos_drm_ipp_formats *formats;
> @@ -1134,7 +1133,7 @@ static int fimc_bind(struct device *dev, struct device *master, void *data)
>
> ctx->drm_dev = drm_dev;
> ipp->drm_dev = drm_dev;
> - exynos_drm_register_dma(drm_dev, dev, &ctx->dma_priv);
> + exynos_drm_register_dma(drm_dev, dev);
>
> exynos_drm_ipp_register(dev, ipp, &ipp_funcs,
> DRM_EXYNOS_IPP_CAP_CROP | DRM_EXYNOS_IPP_CAP_ROTATE |
> @@ -1154,7 +1153,7 @@ static void fimc_unbind(struct device *dev, struct device *master,
> struct exynos_drm_ipp *ipp = &ctx->ipp;
>
> exynos_drm_ipp_unregister(dev, ipp);
> - exynos_drm_unregister_dma(drm_dev, dev, &ctx->dma_priv);
> + exynos_drm_unregister_dma(drm_dev, dev);
> }
>
> static const struct component_ops fimc_component_ops = {
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> index bb67cad8371f..21aec38702fc 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> @@ -167,7 +167,6 @@ static struct fimd_driver_data exynos5420_fimd_driver_data = {
> struct fimd_context {
> struct device *dev;
> struct drm_device *drm_dev;
> - void *dma_priv;
> struct exynos_drm_crtc *crtc;
> struct exynos_drm_plane planes[WINDOWS_NR];
> struct exynos_drm_plane_config configs[WINDOWS_NR];
> @@ -1091,7 +1090,7 @@ static int fimd_bind(struct device *dev, struct device *master, void *data)
> if (is_drm_iommu_supported(drm_dev))
> fimd_clear_channels(ctx->crtc);
>
> - return exynos_drm_register_dma(drm_dev, dev, &ctx->dma_priv);
> + return exynos_drm_register_dma(drm_dev, dev);
> }
>
> static void fimd_unbind(struct device *dev, struct device *master,
> @@ -1101,7 +1100,7 @@ static void fimd_unbind(struct device *dev, struct device *master,
>
> fimd_atomic_disable(ctx->crtc);
>
> - exynos_drm_unregister_dma(ctx->drm_dev, ctx->dev, &ctx->dma_priv);
> + exynos_drm_unregister_dma(ctx->drm_dev, ctx->dev);
>
> if (ctx->encoder)
> exynos_dpi_remove(ctx->encoder);
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
> index 03be31427181..256ceafd9945 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
> @@ -232,7 +232,6 @@ struct g2d_runqueue_node {
>
> struct g2d_data {
> struct device *dev;
> - void *dma_priv;
> struct clk *gate_clk;
> void __iomem *regs;
> int irq;
> @@ -1410,7 +1409,7 @@ static int g2d_bind(struct device *dev, struct device *master, void *data)
> return ret;
> }
>
> - ret = exynos_drm_register_dma(drm_dev, dev, &g2d->dma_priv);
> + ret = exynos_drm_register_dma(drm_dev, dev);
> if (ret < 0) {
> dev_err(dev, "failed to enable iommu.\n");
> g2d_fini_cmdlist(g2d);
> @@ -1435,7 +1434,7 @@ static void g2d_unbind(struct device *dev, struct device *master, void *data)
> priv->g2d_dev = NULL;
>
> cancel_work_sync(&g2d->runqueue_work);
> - exynos_drm_unregister_dma(g2d->drm_dev, dev, &g2d->dma_priv);
> + exynos_drm_unregister_dma(g2d->drm_dev, dev);
> }
>
> static const struct component_ops g2d_component_ops = {
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gsc.c b/drivers/gpu/drm/exynos/exynos_drm_gsc.c
> index 45e9aee8366a..88b6fcaa20be 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gsc.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gsc.c
> @@ -97,7 +97,6 @@ struct gsc_scaler {
> struct gsc_context {
> struct exynos_drm_ipp ipp;
> struct drm_device *drm_dev;
> - void *dma_priv;
> struct device *dev;
> struct exynos_drm_ipp_task *task;
> struct exynos_drm_ipp_formats *formats;
> @@ -1170,7 +1169,7 @@ static int gsc_bind(struct device *dev, struct device *master, void *data)
>
> ctx->drm_dev = drm_dev;
> ctx->drm_dev = drm_dev;
> - exynos_drm_register_dma(drm_dev, dev, &ctx->dma_priv);
> + exynos_drm_register_dma(drm_dev, dev);
>
> exynos_drm_ipp_register(dev, ipp, &ipp_funcs,
> DRM_EXYNOS_IPP_CAP_CROP | DRM_EXYNOS_IPP_CAP_ROTATE |
> @@ -1190,7 +1189,7 @@ static void gsc_unbind(struct device *dev, struct device *master,
> struct exynos_drm_ipp *ipp = &ctx->ipp;
>
> exynos_drm_ipp_unregister(dev, ipp);
> - exynos_drm_unregister_dma(drm_dev, dev, &ctx->dma_priv);
> + exynos_drm_unregister_dma(drm_dev, dev);
> }
>
> static const struct component_ops gsc_component_ops = {
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_rotator.c b/drivers/gpu/drm/exynos/exynos_drm_rotator.c
> index 2d94afba031e..f22fa0d2621a 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_rotator.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_rotator.c
> @@ -56,7 +56,6 @@ struct rot_variant {
> struct rot_context {
> struct exynos_drm_ipp ipp;
> struct drm_device *drm_dev;
> - void *dma_priv;
> struct device *dev;
> void __iomem *regs;
> struct clk *clock;
> @@ -244,7 +243,7 @@ static int rotator_bind(struct device *dev, struct device *master, void *data)
>
> rot->drm_dev = drm_dev;
> ipp->drm_dev = drm_dev;
> - exynos_drm_register_dma(drm_dev, dev, &rot->dma_priv);
> + exynos_drm_register_dma(drm_dev, dev);
>
> exynos_drm_ipp_register(dev, ipp, &ipp_funcs,
> DRM_EXYNOS_IPP_CAP_CROP | DRM_EXYNOS_IPP_CAP_ROTATE,
> @@ -262,7 +261,7 @@ static void rotator_unbind(struct device *dev, struct device *master,
> struct exynos_drm_ipp *ipp = &rot->ipp;
>
> exynos_drm_ipp_unregister(dev, ipp);
> - exynos_drm_unregister_dma(rot->drm_dev, rot->dev, &rot->dma_priv);
> + exynos_drm_unregister_dma(rot->drm_dev, rot->dev);
> }
>
> static const struct component_ops rotator_component_ops = {
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_scaler.c b/drivers/gpu/drm/exynos/exynos_drm_scaler.c
> index ce1857138f89..0c560566bd2e 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_scaler.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_scaler.c
> @@ -39,7 +39,6 @@ struct scaler_data {
> struct scaler_context {
> struct exynos_drm_ipp ipp;
> struct drm_device *drm_dev;
> - void *dma_priv;
> struct device *dev;
> void __iomem *regs;
> struct clk *clock[SCALER_MAX_CLK];
> @@ -451,7 +450,7 @@ static int scaler_bind(struct device *dev, struct device *master, void *data)
>
> scaler->drm_dev = drm_dev;
> ipp->drm_dev = drm_dev;
> - exynos_drm_register_dma(drm_dev, dev, &scaler->dma_priv);
> + exynos_drm_register_dma(drm_dev, dev);
>
> exynos_drm_ipp_register(dev, ipp, &ipp_funcs,
> DRM_EXYNOS_IPP_CAP_CROP | DRM_EXYNOS_IPP_CAP_ROTATE |
> @@ -471,8 +470,7 @@ static void scaler_unbind(struct device *dev, struct device *master,
> struct exynos_drm_ipp *ipp = &scaler->ipp;
>
> exynos_drm_ipp_unregister(dev, ipp);
> - exynos_drm_unregister_dma(scaler->drm_dev, scaler->dev,
> - &scaler->dma_priv);
> + exynos_drm_unregister_dma(scaler->drm_dev, scaler->dev);
> }
>
> static const struct component_ops scaler_component_ops = {
> diff --git a/drivers/gpu/drm/exynos/exynos_mixer.c b/drivers/gpu/drm/exynos/exynos_mixer.c
> index af192e5a16ef..18972e605c5d 100644
> --- a/drivers/gpu/drm/exynos/exynos_mixer.c
> +++ b/drivers/gpu/drm/exynos/exynos_mixer.c
> @@ -94,7 +94,6 @@ struct mixer_context {
> struct platform_device *pdev;
> struct device *dev;
> struct drm_device *drm_dev;
> - void *dma_priv;
> struct exynos_drm_crtc *crtc;
> struct exynos_drm_plane planes[MIXER_WIN_NR];
> unsigned long flags;
> @@ -895,14 +894,12 @@ static int mixer_initialize(struct mixer_context *mixer_ctx,
> }
> }
>
> - return exynos_drm_register_dma(drm_dev, mixer_ctx->dev,
> - &mixer_ctx->dma_priv);
> + return exynos_drm_register_dma(drm_dev, mixer_ctx->dev);
> }
>
> static void mixer_ctx_remove(struct mixer_context *mixer_ctx)
> {
> - exynos_drm_unregister_dma(mixer_ctx->drm_dev, mixer_ctx->dev,
> - &mixer_ctx->dma_priv);
> + exynos_drm_unregister_dma(mixer_ctx->drm_dev, mixer_ctx->dev);
> }
>
> static int mixer_enable_vblank(struct exynos_drm_crtc *crtc)

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland