drm/radeon/kms: fix a regression on r7xx AGP due to the HDP flush fix

commit: 812d046915f48236657f02c06d7dc47140e9ceda
drm/radeon/kms/r7xx: add workaround for hw issue with HDP flush
breaks on AGP boards since there is no VRAM gart table.

This patch fixes the issue by creating a VRAM scratch page so that
can be used on both AGP and PCIE.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=29834

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 59 insertions, 1 deletions

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index d0ebae9dde25..aee8376216a2 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -3541,7 +3541,7 @@ void r600_ioctl_wait_idle(struct radeon_device *rdev, struct radeon_bo *bo)
          * rather than write to HDP_REG_COHERENCY_FLUSH_CNTL
          */
         if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740)) {
-                void __iomem *ptr = (void *)rdev->gart.table.vram.ptr;
+                void __iomem *ptr = (void *)rdev->vram_scratch.ptr;
                 u32 tmp;
 
                 WREG32(HDP_DEBUG1, 0);
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 3dfcfa3ca425..e90d9e3765b4 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -1013,6 +1013,11 @@ int radeon_gem_set_tiling_ioctl(struct drm_device *dev, void *data,
 int radeon_gem_get_tiling_ioctl(struct drm_device *dev, void *data,
                                 struct drm_file *filp);
 
+/* VRAM scratch page for HDP bug */
+struct r700_vram_scratch {
+        struct radeon_bo                *robj;
+        volatile uint32_t               *ptr;
+};
 
 /*
  * Core structure, functions and helpers.
@@ -1079,6 +1084,7 @@ struct radeon_device {
         const struct firmware *pfp_fw;  /* r6/700 PFP firmware */
         const struct firmware *rlc_fw;  /* r6/700 RLC firmware */
         struct r600_blit r600_blit;
+        struct r700_vram_scratch vram_scratch;
         int msi_enabled; /* msi enabled */
         struct r600_ih ih; /* r6/700 interrupt ring */
         struct workqueue_struct *wq;
diff --git a/drivers/gpu/drm/radeon/rv770.c b/drivers/gpu/drm/radeon/rv770.c
index f1c796810117..a84e38643788 100644
--- a/drivers/gpu/drm/radeon/rv770.c
+++ b/drivers/gpu/drm/radeon/rv770.c
@@ -905,6 +905,54 @@ static void rv770_gpu_init(struct radeon_device *rdev)
 
 }
 
+static int rv770_vram_scratch_init(struct radeon_device *rdev)
+{
+        int r;
+        u64 gpu_addr;
+
+        if (rdev->vram_scratch.robj == NULL) {
+                r = radeon_bo_create(rdev, NULL, RADEON_GPU_PAGE_SIZE,
+                                        true, RADEON_GEM_DOMAIN_VRAM,
+                                        &rdev->vram_scratch.robj);
+                if (r) {
+                        return r;
+                }
+        }
+
+        r = radeon_bo_reserve(rdev->vram_scratch.robj, false);
+        if (unlikely(r != 0))
+                return r;
+        r = radeon_bo_pin(rdev->vram_scratch.robj,
+                          RADEON_GEM_DOMAIN_VRAM, &gpu_addr);
+        if (r) {
+                radeon_bo_unreserve(rdev->vram_scratch.robj);
+                return r;
+        }
+        r = radeon_bo_kmap(rdev->vram_scratch.robj,
+                                (void **)&rdev->vram_scratch.ptr);
+        if (r)
+                radeon_bo_unpin(rdev->vram_scratch.robj);
+        radeon_bo_unreserve(rdev->vram_scratch.robj);
+
+        return r;
+}
+
+static void rv770_vram_scratch_fini(struct radeon_device *rdev)
+{
+        int r;
+
+        if (rdev->vram_scratch.robj == NULL) {
+                return;
+        }
+        r = radeon_bo_reserve(rdev->vram_scratch.robj, false);
+        if (likely(r == 0)) {
+                radeon_bo_kunmap(rdev->vram_scratch.robj);
+                radeon_bo_unpin(rdev->vram_scratch.robj);
+                radeon_bo_unreserve(rdev->vram_scratch.robj);
+        }
+        radeon_bo_unref(&rdev->vram_scratch.robj);
+}
+
 int rv770_mc_init(struct radeon_device *rdev)
 {
         u32 tmp;
@@ -970,6 +1018,9 @@ static int rv770_startup(struct radeon_device *rdev)
                 if (r)
                         return r;
         }
+        r = rv770_vram_scratch_init(rdev);
+        if (r)
+                return r;
         rv770_gpu_init(rdev);
         r = r600_blit_init(rdev);
         if (r) {
@@ -1195,6 +1246,7 @@ void rv770_fini(struct radeon_device *rdev)
         r600_irq_fini(rdev);
         radeon_irq_kms_fini(rdev);
         rv770_pcie_gart_fini(rdev);
+        rv770_vram_scratch_fini(rdev);
         radeon_gem_fini(rdev);
         radeon_fence_driver_fini(rdev);
         radeon_clocks_fini(rdev);