[PATCH v3 31/37] drm/i915/lmem: add helper to get CPU accessible offset

Matthew Auld
2019-08-09T22:26:37Z

From: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>

LMEM can be accessed by the CPU through a BAR. The mapping itself should
be 1:1.

Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_lmem.c | 16 ++++++++++++++++
drivers/gpu/drm/i915/gem/i915_gem_lmem.h | 3 +++
2 files changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
index f00078ac331e..8d0251af5dfc 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
@@ -225,6 +225,22 @@ void __iomem *i915_gem_object_lmem_io_map(struct drm_i915_gem_object *obj,
return io_mapping_map_wc(&obj->mm.region->iomap, offset, size);
}

+resource_size_t i915_gem_object_lmem_io_offset(struct drm_i915_gem_object *obj,
+ unsigned long n)
+{
+ struct intel_memory_region *mem = obj->mm.region;
+ dma_addr_t daddr;
+
+ /*
+ * XXX: It's not a dma address, more a device address or physical
+ * offset, so we are clearly abusing the semantics of the sg_table
+ * here, and elsewhere like in the gtt paths.
+ */
+ daddr = i915_gem_object_get_dma_address(obj, n);
+
+ return mem->io_start + daddr;
+}
+
bool i915_gem_object_is_lmem(struct drm_i915_gem_object *obj)
{
struct intel_memory_region *region = obj->mm.region;
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_lmem.h b/drivers/gpu/drm/i915/gem/i915_gem_lmem.h
index 31a6462bdbb6..43e6e715eeed 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_lmem.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_lmem.h
@@ -21,6 +21,9 @@ void __iomem *
i915_gem_object_lmem_io_map_page_atomic(struct drm_i915_gem_object *obj,
unsigned long n);

+resource_size_t i915_gem_object_lmem_io_offset(struct drm_i915_gem_object *obj,
+ unsigned long n);
+
bool i915_gem_object_is_lmem(struct drm_i915_gem_object *obj);

struct drm_i915_gem_object *