[Intel-gfx] [PATCH i-g-t v3 01/11] lib/i915/gem_mman: add FIXED mmap mode

Matthew Auld
2021-07-30T08:53:59Z

We need this for discrete.

v2(Ashutosh):
- use the new i915_drm_local.h infrastructure, and drop the LOCAL prefix

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ramalingam C <ramalingam.c@intel.com>
---
lib/i915/gem_mman.c | 36 ++++++++++++++++++++++++++++++++++++
lib/i915/gem_mman.h | 4 ++++
lib/i915/i915_drm_local.h | 2 ++
3 files changed, 42 insertions(+)

diff --git a/lib/i915/gem_mman.c b/lib/i915/gem_mman.c
index 4b4f2114..11df0d76 100644
--- a/lib/i915/gem_mman.c
+++ b/lib/i915/gem_mman.c
@@ -27,6 +27,7 @@
#include <errno.h>

#include "igt_core.h"
+#include "igt_gt.h"
#include "igt_device.h"
#include "ioctl_wrappers.h"
#include "intel_chipset.h"
@@ -497,6 +498,41 @@ void *gem_mmap_offset__cpu(int fd, uint32_t handle, uint64_t offset,
return ptr;
}

+void *__gem_mmap_offset__fixed(int fd, uint32_t handle, uint64_t offset,
+ uint64_t size, unsigned prot)
+{
+ return __gem_mmap_offset(fd, handle, offset, size, prot,
+ I915_MMAP_OFFSET_FIXED);
+}
+
+/**
+ * gem_mmap_offset__fixed: Used to mmap objects on discrete platforms
+ * @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()
+ *
+ * Like __gem_mmap_offset__fixed() except we assert on failure.
+ *
+ * For discrete the caching attributes for the pages are fixed at allocation
+ * time, and can't be changed. The FIXED mode will simply use the same caching *
+ * mode of the allocated pages. This mode will always be coherent with GPU
+ * access.
+ *
+ * On non-discrete platforms this mode is not supported.
+ *
+ * Returns: A pointer to the created memory mapping
+ */
+void *gem_mmap_offset__fixed(int fd, uint32_t handle, uint64_t offset,
+ uint64_t size, unsigned prot)
+{
+ void *ptr = __gem_mmap_offset__fixed(fd, handle, offset, size, prot);
+
+ igt_assert(ptr);
+ return ptr;
+}
+
/**
* __gem_mmap__cpu_coherent:
* @fd: open i915 drm file descriptor
diff --git a/lib/i915/gem_mman.h b/lib/i915/gem_mman.h
index 5695d2ad..290c997d 100644
--- a/lib/i915/gem_mman.h
+++ b/lib/i915/gem_mman.h
@@ -37,6 +37,8 @@ bool gem_mmap_offset__has_wc(int fd);
void *gem_mmap__wc(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned prot);
void *gem_mmap_offset__wc(int fd, uint32_t handle, uint64_t offset,
uint64_t size, unsigned prot);
+void *gem_mmap_offset__fixed(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,
@@ -54,6 +56,8 @@ void *__gem_mmap_offset__cpu(int fd, uint32_t handle, uint64_t offset,
void *__gem_mmap__wc(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned prot);
void *__gem_mmap_offset__wc(int fd, uint32_t handle, uint64_t offset,
uint64_t size, unsigned prot);
+void *__gem_mmap_offset__fixed(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_offset(int fd, uint32_t handle, uint64_t offset, uint64_t size,
diff --git a/lib/i915/i915_drm_local.h b/lib/i915/i915_drm_local.h
index dd646aed..0e3cef81 100644
--- a/lib/i915/i915_drm_local.h
+++ b/lib/i915/i915_drm_local.h
@@ -20,6 +20,8 @@ extern "C" {
* clean these up when kernel uapi headers are sync'd.
*/

+#define I915_MMAP_OFFSET_FIXED 4
+
#if defined(__cplusplus)
}
#endif