linux-kernel - [PATCH] drm/msm: Deprecate MSM_BO

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Date:   Mon, 13 Jun 2022 12:46:23 -0700
From:   Rob Clark <robdclark@...il.com>
To:     dri-devel@...ts.freedesktop.org
Cc:     freedreno@...ts.freedesktop.org, linux-arm-msm@...r.kernel.org,
        Rob Clark <robdclark@...omium.org>,
        Rob Clark <robdclark@...il.com>,
        Abhinav Kumar <quic_abhinavk@...cinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        Sean Paul <sean@...rly.run>, David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        linux-kernel@...r.kernel.org (open list)
Subject: [PATCH] drm/msm: Deprecate MSM_BO_UNCACHED harder

From: Rob Clark <robdclark@...omium.org>

Handle the demotion to MSM_BO_WC at the userspace ABI level, and fix
the remaining internal MSM_BO_UNCACHED user.

Signed-off-by: Rob Clark <robdclark@...omium.org>
---
 drivers/gpu/drm/msm/msm_drv.c | 13 +++++++++++++
 drivers/gpu/drm/msm/msm_gem.c |  7 +++----
 drivers/gpu/drm/msm/msm_gpu.c |  2 +-
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 57a66093e671..acc940d32ab4 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -633,12 +633,25 @@ static int msm_ioctl_gem_new(struct drm_device *dev, void *data,
 		struct drm_file *file)
 {
 	struct drm_msm_gem_new *args = data;
+	uint32_t flags = args->flags;
 
 	if (args->flags & ~MSM_BO_FLAGS) {
 		DRM_ERROR("invalid flags: %08x\n", args->flags);
 		return -EINVAL;
 	}
 
+	/*
+	 * Uncached CPU mappings are deprecated, as of:
+	 *
+	 * 9ef364432db4 ("drm/msm: deprecate MSM_BO_UNCACHED (map as writecombine instead)")
+	 *
+	 * So promote them to WC.
+	 */
+	if (flags & MSM_BO_UNCACHED) {
+		flags &= ~MSM_BO_CACHED;
+		flags |= MSM_BO_WC;
+	}
+
 	return msm_gem_new_handle(dev, file, args->size,
 			args->flags, &args->handle, NULL);
 }
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 9a73e48a3049..35845e273d81 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -129,7 +129,7 @@ static struct page **get_pages(struct drm_gem_object *obj)
 		/* For non-cached buffers, ensure the new pages are clean
 		 * because display controller, GPU, etc. are not coherent:
 		 */
-		if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
+		if (msm_obj->flags & MSM_BO_WC)
 			sync_for_device(msm_obj);
 
 		update_inactive(msm_obj);
@@ -160,7 +160,7 @@ static void put_pages(struct drm_gem_object *obj)
 			 * pages are clean because display controller,
 			 * GPU, etc. are not coherent:
 			 */
-			if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
+			if (msm_obj->flags & MSM_BO_WC)
 				sync_for_cpu(msm_obj);
 
 			sg_free_table(msm_obj->sgt);
@@ -213,7 +213,7 @@ void msm_gem_put_pages(struct drm_gem_object *obj)
 
 static pgprot_t msm_gem_pgprot(struct msm_gem_object *msm_obj, pgprot_t prot)
 {
-	if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
+	if (msm_obj->flags & MSM_BO_WC)
 		return pgprot_writecombine(prot);
 	return prot;
 }
@@ -1122,7 +1122,6 @@ static int msm_gem_new_impl(struct drm_device *dev,
 	struct msm_gem_object *msm_obj;
 
 	switch (flags & MSM_BO_CACHE_MASK) {
-	case MSM_BO_UNCACHED:
 	case MSM_BO_CACHED:
 	case MSM_BO_WC:
 		break;
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index f99292eaf529..e59a757578df 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -952,7 +952,7 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
 
 	memptrs = msm_gem_kernel_new(drm,
 		sizeof(struct msm_rbmemptrs) * nr_rings,
-		check_apriv(gpu, MSM_BO_UNCACHED), gpu->aspace, &gpu->memptrs_bo,
+		check_apriv(gpu, MSM_BO_WC), gpu->aspace, &gpu->memptrs_bo,
 		&memptrs_iova);
 
 	if (IS_ERR(memptrs)) {
-- 
2.36.1