[Intel-gfx] [RFC 39/60] drm/i915: setup the LMEM region

[Matthew Auld]

Hook up the LMEM region. Addresses will start from zero, and for CPU
access we get LMEM_BAR which is just a 1:1 mapping of said region.

Based on a patch from Michel Thierry.

Cc: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h            |  3 ++
 drivers/gpu/drm/i915/intel_memory_region.c | 11 ++++++-
 drivers/gpu/drm/i915/intel_region_lmem.c   | 38 ++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_region_lmem.h   |  2 ++
 4 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 7191ebd7c13f..cebcd702d968 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -12035,6 +12035,9 @@ enum skl_power_gate {
 
 #define GEN12_GLOBAL_MOCS(i)	_MMIO(0x4000 + (i) * 4) /* Global MOCS regs */
 
+#define GEN12_LMEM_CFG_ADDR		_MMIO(0xcf58)
+#define   LMEM_ENABLE			(1 << 31)
+
 /* gamt regs */
 #define GEN8_L3_LRA_1_GPGPU _MMIO(0x4dd4)
 #define   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_BDW  0x67F1427F /* max/min for LRA1/2 */
diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
index 609a65935c98..1e9f52feec59 100644
--- a/drivers/gpu/drm/i915/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/intel_memory_region.c
@@ -297,7 +297,16 @@ int intel_memory_regions_hw_probe(struct drm_i915_private *i915)
 			mem = i915_gem_stolen_setup(i915);
 			break;
 		case INTEL_MEMORY_LOCAL:
-			mem = intel_setup_fake_lmem(i915);
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+			if (IS_ENABLED(CONFIG_DRM_I915_UNSTABLE_FAKE_LMEM)) {
+				if (INTEL_GEN(i915) >= 9 && i915_selftest.live < 0 &&
+				    i915->params.fake_lmem_start)
+					mem = intel_setup_fake_lmem(i915);
+			}
+#endif
+
+			if (IS_ERR(mem))
+				mem = i915_gem_setup_lmem(i915);
 			break;
 		}
 
diff --git a/drivers/gpu/drm/i915/intel_region_lmem.c b/drivers/gpu/drm/i915/intel_region_lmem.c
index 40d8f1a95df6..e98582c76de1 100644
--- a/drivers/gpu/drm/i915/intel_region_lmem.c
+++ b/drivers/gpu/drm/i915/intel_region_lmem.c
@@ -136,3 +136,41 @@ intel_setup_fake_lmem(struct drm_i915_private *i915)
 
 	return mem;
 }
+
+static struct intel_memory_region *
+setup_lmem(struct drm_i915_private *dev_priv)
+{
+	struct pci_dev *pdev = dev_priv->drm.pdev;
+	struct intel_memory_region *mem;
+	resource_size_t io_start;
+	resource_size_t size;
+
+	/* Enables Local Memory functionality in GAM */
+	I915_WRITE(GEN12_LMEM_CFG_ADDR, I915_READ(GEN12_LMEM_CFG_ADDR) | LMEM_ENABLE);
+
+	io_start = pci_resource_start(pdev, 2);
+	size = pci_resource_len(pdev, 2);
+
+	mem = intel_memory_region_create(dev_priv,
+					 0,
+					 size,
+					 I915_GTT_PAGE_SIZE_4K,
+					 io_start,
+					 &intel_region_lmem_ops);
+	if (!IS_ERR(mem)) {
+		DRM_INFO("Intel graphics LMEM: %pR\n", &mem->region);
+		DRM_INFO("Intel graphics LMEM IO start: %llx\n",
+			 (u64)mem->io_start);
+		DRM_INFO("Intel graphics LMEM size: %llx\n",
+			 (u64)size);
+	}
+
+	return mem;
+}
+
+struct intel_memory_region *
+i915_gem_setup_lmem(struct drm_i915_private *i915)
+{
+	return setup_lmem(i915);
+}
+
diff --git a/drivers/gpu/drm/i915/intel_region_lmem.h b/drivers/gpu/drm/i915/intel_region_lmem.h
index 213def7c7b8a..054e729035c1 100644
--- a/drivers/gpu/drm/i915/intel_region_lmem.h
+++ b/drivers/gpu/drm/i915/intel_region_lmem.h
@@ -10,6 +10,8 @@ struct drm_i915_private;
 
 extern const struct intel_memory_region_ops intel_region_lmem_ops;
 
+struct intel_memory_region *i915_gem_setup_lmem(struct drm_i915_private *i915);
+
 struct intel_memory_region *
 intel_setup_fake_lmem(struct drm_i915_private *i915);
 
-- 
2.26.2