[igt-dev] [PATCH i-g-t v3 3/4] lib/ioctl_wrapper: Implement __gem_mmap

Lukasz Kalamarz
2019-01-11T16:19:14Z

Previous implementation of __gem_mmap__cpu and __gem_mmap_wc only
differ with setting proper flag for caching. This patch implement
__gem_mmap, which merge those two functions into one.
v2: Reordered and splited this patch into two separete patches
v3: Dropped unnecessary check

Signed-off-by: Lukasz Kalamarz <lukasz.kalamarz@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Katarzyna Dec <katarzyna.dec@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
---
lib/ioctl_wrappers.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)

diff --git a/lib/ioctl_wrappers.c b/lib/ioctl_wrappers.c
index f71f0e32..e9225da0 100644
--- a/lib/ioctl_wrappers.c
+++ b/lib/ioctl_wrappers.c
@@ -736,6 +736,42 @@ bool gem_mmap__has_wc(int fd)
return has_wc > 0;
}

+/**
+ * __gem_mmap:
+ * @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()
+ * @flags: flags used to determine caching
+ *
+ * This functions wraps up procedure to establish a memory mapping through
+ * direct cpu access, bypassing the gpu (valid for wc == false). For wc == true
+ * it also bypass cpu caches completely and GTT system agent (i.e. there is no
+ * automatic tiling of the mmapping through the fence registers).
+ *
+ * Returns: A pointer to the created memory mapping, NULL on failure.
+ */
+static void
+*__gem_mmap(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned int prot, uint64_t flags)
+{
+ struct drm_i915_gem_mmap arg;
+
+ memset(&arg, 0, sizeof(arg));
+ arg.handle = handle;
+ arg.offset = offset;
+ arg.size = size;
+ arg.flags = flags;
+
+ if (igt_ioctl(fd, DRM_IOCTL_I915_GEM_MMAP, &arg))
+ return NULL;
+
+ VG(VALGRIND_MAKE_MEM_DEFINED(from_user_pointer(arg.addr_ptr), arg.size));
+
+ errno = 0;
+ return from_user_pointer(arg.addr_ptr);
+}
+
/**
* __gem_mmap__wc:
* @fd: open i915 drm file descriptor
--
2.17.2