[igt-dev] [PATCH i-g-t v6 4/9] lib/i915: Add mmap_offset support

Antonio Argenziano antonio.argenziano at intel.com
Thu Jun 13 21:54:43 UTC 2019


From: "Kalamarz, Lukasz" <lukasz.kalamarz at intel.com>

With recently proposed changes, IGT need to start supporting new
way of mmaping object, which will be used from now by default.
This patch modify gem_mmap_wc and gem_mmap functions to be
in sync with those changes.

v2:
	- Fix IOCTL number. (Daniele)
	- Move wrappers to new file. (Chris)

v3:
	- Use mmap IOCTL for lower level wrappers. (Chris)

v4:
	- Don't use static variables. (Chris)
	- Remember gem_ prefix. (Chris)

v5:
	- Go back to using static variables (Antonio)
	- Check mmap offset is present before mapping (Antonio)

Signed-off-by: Lukasz Kalamarz <lukasz.kalamarz at intel.com>
Cc: Janulgue Abdiel <abdiel.janulgue at intel.com>
Cc: Matthew Auld <matthew.auld at intel.com>
Cc: Michal Winiarski <michal.winiarski at intel.com>
Cc: Antonio Argenziano <antonio.argenziano at intel.com>
Cc: Daniele Spurio Ceraolo <daniele.ceraolospurio at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Antonio Argenziano <antonio.argenziano at intel.com>
---
 lib/i915/gem_mman.c | 125 ++++++++++++++++++++++++++++++++++++--------
 lib/i915/gem_mman.h |  33 ++++++++++++
 2 files changed, 137 insertions(+), 21 deletions(-)

diff --git a/lib/i915/gem_mman.c b/lib/i915/gem_mman.c
index b43ccd95..0631bf40 100644
--- a/lib/i915/gem_mman.c
+++ b/lib/i915/gem_mman.c
@@ -103,34 +103,49 @@ int gem_munmap(void *ptr, uint64_t size)
 
 bool gem_mmap__has_wc(int fd)
 {
-	struct drm_i915_getparam gp;
-	int mmap_version = -1;
-	int gtt_version = -1;
 	int has_wc = 0;
 
-	memset(&gp, 0, sizeof(gp));
-	gp.param = I915_PARAM_MMAP_GTT_VERSION;
-	gp.value = &gtt_version;
-	ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
-
-	memset(&gp, 0, sizeof(gp));
-	gp.param = I915_PARAM_MMAP_VERSION;
-	gp.value = &mmap_version;
-	ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
-
-	/* Do we have the new mmap_ioctl with DOMAIN_WC? */
-	if (mmap_version >= 1 && gtt_version >= 2) {
-		struct drm_i915_gem_mmap arg;
+	/* Do we have the new mmap_offset ioctl? */
+	if (gem_has_mmap_offset(fd)) {
+		struct local_drm_i915_gem_mmap_offset arg;
 
 		/* Does this device support wc-mmaps ? */
 		memset(&arg, 0, sizeof(arg));
 		arg.handle = gem_create(fd, 4096);
 		arg.offset = 0;
-		arg.size = 4096;
-		arg.flags = I915_MMAP_WC;
-		has_wc = igt_ioctl(fd, DRM_IOCTL_I915_GEM_MMAP, &arg) == 0;
+		arg.flags = LOCAL_I915_MMAP_OFFSET_WC;
+		has_wc = igt_ioctl(fd, LOCAL_DRM_IOCTL_I915_GEM_MMAP_OFFSET, &arg) == 0;
 		gem_close(fd, arg.handle);
+	} else {
+		struct drm_i915_getparam gp;
+		int mmap_version = -1;
+		int gtt_version = -1;
+
+		memset(&gp, 0, sizeof(gp));
+		gp.param = I915_PARAM_MMAP_GTT_VERSION;
+		gp.value = &gtt_version;
+		ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
+
+		memset(&gp, 0, sizeof(gp));
+		gp.param = I915_PARAM_MMAP_VERSION;
+		gp.value = &mmap_version;
+		ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
+
+		/* Do we have the mmap_ioctl with DOMAIN_WC? */
+		if (mmap_version >= 1 && gtt_version >= 2) {
+			struct drm_i915_gem_mmap arg;
+
+			/* Does this device support wc-mmaps ? */
+			memset(&arg, 0, sizeof(arg));
+			arg.handle = gem_create(fd, 4096);
+			arg.offset = 0;
+			arg.size = 4096;
+			arg.flags = I915_MMAP_WC;
+			has_wc = igt_ioctl(fd, DRM_IOCTL_I915_GEM_MMAP, &arg) == 0;
+			gem_close(fd, arg.handle);
+		}
 	}
+
 	errno = 0;
 
 	return has_wc > 0;
@@ -206,7 +221,12 @@ void *__gem_mmap__wc(int fd, uint32_t handle, uint64_t offset, uint64_t size, un
  */
 void *gem_mmap__wc(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned prot)
 {
-	void *ptr = __gem_mmap__wc(fd, handle, offset, size, prot);
+	void *ptr;
+
+	ptr = __gem_mmap_offset(fd, handle, offset, size, prot, LOCAL_I915_MMAP_OFFSET_WC);
+	if (!ptr)
+		ptr = __gem_mmap__wc(fd, handle, offset, size, prot);
+
 	igt_assert(ptr);
 	return ptr;
 }
@@ -243,7 +263,70 @@ void *__gem_mmap__cpu(int fd, uint32_t handle, uint64_t offset, uint64_t size, u
  */
 void *gem_mmap__cpu(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned prot)
 {
-	void *ptr = __gem_mmap__cpu(fd, handle, offset, size, prot);
+	void *ptr;
+
+	ptr = __gem_mmap_offset(fd, handle, offset, size, prot, LOCAL_I915_MMAP_OFFSET_WB);
+	if (!ptr)
+		ptr = __gem_mmap(fd, handle, offset, size, prot, 0);
+
 	igt_assert(ptr);
 	return ptr;
 }
+
+bool gem_has_mmap_offset(int fd)
+{
+	static int has_mmap_offset = -1;
+
+	if (has_mmap_offset == -1) {
+		struct drm_i915_getparam gp;
+		has_mmap_offset = 0;
+
+		memset(&gp, 0, sizeof(gp));
+		gp.param = 0x55; /* I915_PARAM_MMAP_OFFSET_VERSION */
+		gp.value = &has_mmap_offset;
+		ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
+	}
+
+	return has_mmap_offset > 0;
+}
+
+/**
+ * __gem_mmap_offset:
+ * @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
+ *
+ * Similar to __gem_mmap but use MMAP_OFFSET IOCTL.
+ *
+ * Returns: A pointer to the created memory mapping, NULL on failure.
+ */
+void
+*__gem_mmap_offset(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned int prot, uint64_t flags)
+{
+	struct local_drm_i915_gem_mmap_offset arg;
+	void *ptr;
+
+	memset(&arg, 0, sizeof(arg));
+	arg.handle = handle;
+	arg.offset = offset;
+	arg.flags = flags;
+
+	if (!gem_has_mmap_offset(fd))
+		return NULL;
+
+	if (igt_ioctl(fd, LOCAL_DRM_IOCTL_I915_GEM_MMAP_OFFSET, &arg))
+		return NULL;
+
+	ptr = mmap64(0, size, prot, MAP_SHARED, fd, arg.offset);
+
+	if (ptr == MAP_FAILED)
+		ptr = NULL;
+	else
+		errno = 0;
+
+	return ptr;
+}
+
diff --git a/lib/i915/gem_mman.h b/lib/i915/gem_mman.h
index f7242ed7..fff2ecab 100644
--- a/lib/i915/gem_mman.h
+++ b/lib/i915/gem_mman.h
@@ -51,5 +51,38 @@ int gem_munmap(void *ptr, uint64_t size);
  */
 #define gem_require_mmap_wc(fd) igt_require(gem_mmap__has_wc(fd))
 
+struct local_drm_i915_gem_mmap_offset {
+	/** Handle for the object being mapped. */
+	__u32 handle;
+	__u32 pad;
+	/**
+	 * Fake offset to use for subsequent mmap call
+	 *
+	 * This is a fixed-size type for 32/64 compatibility.
+	 */
+	__u64 offset;
+
+	/**
+	 * Flags for extended behaviour.
+	 *
+	 * It is mandatory that either one of the _WC/_WB flags
+	 * should be passed here.
+	 */
+	__u64 flags;
+};
+
+#define LOCAL_DRM_I915_GEM_MMAP_OFFSET 0x24
+#define LOCAL_I915_MMAP_OFFSET_WC (1 << 0)
+#define LOCAL_I915_MMAP_OFFSET_WB (1 << 1)
+#define LOCAL_I915_MMAP_OFFSET_UC (1 << 2)
+
+#define LOCAL_DRM_IOCTL_I915_GEM_MMAP_OFFSET \
+		DRM_IOWR(DRM_COMMAND_BASE + LOCAL_DRM_I915_GEM_MMAP_OFFSET, struct local_drm_i915_gem_mmap_offset)
+
+bool gem_has_mmap_offset(int fd);
+
+void *__gem_mmap_offset(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned int prot, uint64_t flags);
+
+
 #endif /* GEM_MMAN_H */
 
-- 
2.21.0



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