From: Imre Deak imre.deak@intel.com
On DG1 A0/B0 steppings the first 1MB of local memory must be reserved. One reason for this is that the 0xA0000-0xB0000 range is not accessible by the display, probably since this region is redirected to another memory location for legacy VGA compatibility.
BSpec: 50586 Testcase: igt/kms_big_fb/linear-64bpp-rotate-0 Signed-off-by: Imre Deak imre.deak@intel.com --- drivers/gpu/drm/i915/intel_region_lmem.c | 52 ++++++++++++++++++++++++ 1 file changed, 52 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_region_lmem.c b/drivers/gpu/drm/i915/intel_region_lmem.c index 939cf0d195a5..eafef7034680 100644 --- a/drivers/gpu/drm/i915/intel_region_lmem.c +++ b/drivers/gpu/drm/i915/intel_region_lmem.c @@ -137,6 +137,48 @@ intel_setup_fake_lmem(struct drm_i915_private *i915) return mem; }
+static void get_legacy_lowmem_region(struct intel_uncore *uncore, + u64 *start, u32 *size) +{ + *start = 0; + *size = 0; + + if (!IS_DG1_REVID(uncore->i915, DG1_REVID_A0, DG1_REVID_B0)) + return; + + *size = SZ_1M; + + DRM_DEBUG_DRIVER("LMEM: reserved legacy low-memory [0x%llx-0x%llx]\n", + *start, *start + *size); +} + +static int reserve_lowmem_region(struct intel_uncore *uncore, + struct intel_memory_region *mem) +{ + u64 reserve_start; + u64 reserve_end; + u64 region_start; + u32 region_size; + int ret; + + get_legacy_lowmem_region(uncore, ®ion_start, ®ion_size); + reserve_start = region_start; + reserve_end = region_start + region_size; + + if (!reserve_end) + return 0; + + DRM_INFO("LMEM: reserving low-memory region [0x%llx-0x%llx]\n", + reserve_start, reserve_end); + ret = i915_buddy_alloc_range(&mem->mm, &mem->reserved, + reserve_start, + reserve_end - reserve_start); + if (ret) + DRM_ERROR("LMEM: reserving low memory region failed\n"); + + return ret; +} + static struct intel_memory_region * setup_lmem(struct drm_i915_private *dev_priv) { @@ -160,6 +202,16 @@ setup_lmem(struct drm_i915_private *dev_priv) I915_GTT_PAGE_SIZE_4K, io_start, &intel_region_lmem_ops); + if (!IS_ERR(mem)) { + int err; + + err = reserve_lowmem_region(uncore, mem); + if (err) { + intel_memory_region_put(mem); + return ERR_PTR(err); + } + } + if (!IS_ERR(mem)) { DRM_INFO("Intel graphics LMEM: %pR\n", &mem->region); DRM_INFO("Intel graphics LMEM IO start: %llx\n",