[igt-dev] [PATCH i-g-t] lib/i915/gem_mman.c: add cpu coherency mapping wrapper

Zbigniew Kempczyński
2020-01-14T05:27:32Z

For reduce code redundancy adding a wrapper for cpu memory mapping.

Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
lib/i915/gem_mman.c | 50 +++++++++++++++++++++++++++++++++++++++++++++
lib/i915/gem_mman.h | 5 +++++
2 files changed, 55 insertions(+)

diff --git a/lib/i915/gem_mman.c b/lib/i915/gem_mman.c
index c98f02ae..c034f317 100644
--- a/lib/i915/gem_mman.c
+++ b/lib/i915/gem_mman.c
@@ -470,6 +470,56 @@ void *gem_mmap_offset__cpu(int fd, uint32_t handle, uint64_t offset,
return ptr;
}

+/**
+ * __gem_mmap__cpu_coherent:
+ * @fd: open i915 drm file descriptor
+ * @handle: gem buffer object handle
+ * @offset: offset in the gem buffer of the mmap arena
+ * @size: size of the mmap arena
+ * @prot: memory protection bits as used by mmap()
+ *
+ * This function wraps up procedure to establish a memory mapping through
+ * direct cpu access.
+ */
+void *__gem_mmap__cpu_coherent(int fd, uint32_t handle, uint64_t offset,
+ uint64_t size, unsigned prot)
+{
+ void *ptr = __gem_mmap_offset__cpu(fd, handle, offset, size, prot);
+
+ if (!ptr)
+ ptr = __gem_mmap__cpu(fd, handle, offset, size, prot);
+
+ return ptr;
+}
+
+/**
+ * gem_mmap__cpu_coherent:
+ * @fd: open i915 drm file descriptor
+ * @handle: gem buffer object handle
+ * @offset: offset in the gem buffer of the mmap arena
+ * @size: size of the mmap arena
+ * @prot: memory protection bits as used by mmap()
+ *
+ * Call __gem_mmap__cpu__coherent(), asserts on fail.
+ * Offset argument passed in function call must be 0. In the future
+ * when driver will allow slice mapping of buffer object this restriction
+ * will be removed.
+ *
+ * Returns: A pointer to the created memory mapping.
+ */
+void *gem_mmap__cpu_coherent(int fd, uint32_t handle, uint64_t offset,
+ uint64_t size, unsigned prot)
+{
+ void *ptr;
+
+ igt_assert(offset == 0);
+
+ ptr = __gem_mmap__cpu_coherent(fd, handle, offset, size, prot);
+ igt_assert(ptr);
+
+ return ptr;
+}
+
bool gem_has_mappable_ggtt(int i915)
{
struct drm_i915_gem_mmap_gtt arg = {};
diff --git a/lib/i915/gem_mman.h b/lib/i915/gem_mman.h
index 7b4d6f90..2730295e 100644
--- a/lib/i915/gem_mman.h
+++ b/lib/i915/gem_mman.h
@@ -39,6 +39,9 @@ void *gem_mmap_offset__wc(int fd, uint32_t handle, uint64_t offset,
uint64_t size, unsigned prot);
void *gem_mmap__device_coherent(int fd, uint32_t handle, uint64_t offset,
uint64_t size, unsigned prot);
+void *gem_mmap__cpu_coherent(int fd, uint32_t handle, uint64_t offset,
+ uint64_t size, unsigned prot);
+
#ifndef I915_GEM_DOMAIN_WC
#define I915_GEM_DOMAIN_WC 0x80
#endif
@@ -58,6 +61,8 @@ void *__gem_mmap__device_coherent(int fd, uint32_t handle, uint64_t offset,
uint64_t size, unsigned prot);
void *__gem_mmap_offset(int fd, uint32_t handle, uint64_t offset, uint64_t size,
unsigned int prot, uint64_t flags);
+void *__gem_mmap__cpu_coherent(int fd, uint32_t handle, uint64_t offset,
+ uint64_t size, unsigned prot);

int gem_munmap(void *ptr, uint64_t size);

--
2.23.0