[igt-dev] [RFC 2/5] lib/ioctl_wrappers: add mmap_offset support

[Antonio Argenziano <antonio.argenziano@intel.com>]

From: "Kalamarz, Lukasz" <lukasz.kalamarz@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.

Signed-off-by: Lukasz Kalamarz <lukasz.kalamarz@intel.com>
Cc: Janulgue Abdiel <abdiel.janulgue@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Antonio Argenziano <antonio.argenziano@intel.com>
Cc: Daniele Spurio Ceraolo <daniele.ceraolospurio@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
---
 lib/ioctl_wrappers.c | 150 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 129 insertions(+), 21 deletions(-)

diff --git a/lib/ioctl_wrappers.c b/lib/ioctl_wrappers.c
index 404c2fbf..d9b46088 100644
--- a/lib/ioctl_wrappers.c
+++ b/lib/ioctl_wrappers.c
@@ -641,6 +641,24 @@ void gem_execbuf_wr(int fd, struct drm_i915_gem_execbuffer2 *execbuf)
 	igt_assert_eq(__gem_execbuf_wr(fd, execbuf), 0);
 }
 
+static bool 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 = 0x24; /* I915_PARAM_MMAP_OFFSET_VERSION */
+		gp.value = &has_mmap_offset;
+		ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
+	}
+
+	return has_mmap_offset > 0;
+}
+
 /**
  * __gem_mmap__gtt:
  * @fd: open i915 drm file descriptor
@@ -702,40 +720,83 @@ int gem_munmap(void *ptr, uint64_t size)
 	return ret;
 }
 
+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_mmap__has_wc(int fd)
 {
 	static int has_wc = -1;
 
 	if (has_wc == -1) {
-		struct drm_i915_getparam gp;
-		int mmap_version = -1;
-		int gtt_version = -1;
 
 		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 (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;
 	}
 
@@ -778,6 +839,43 @@ static void
 	return from_user_pointer(arg.addr_ptr);
 }
 
+/**
+ * __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.
+ */
+static 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 (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;
+}
+
 /**
  * __gem_mmap__wc:
  * @fd: open i915 drm file descriptor
@@ -795,7 +893,10 @@ static void
  */
 void *__gem_mmap__wc(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned prot)
 {
-	return __gem_mmap(fd, handle, offset, size, prot, I915_MMAP_WC);
+	if (has_mmap_offset(fd))
+		return __gem_mmap_offset(fd, handle, offset, size, prot, LOCAL_I915_MMAP_OFFSET_WC);
+	else
+		return __gem_mmap(fd, handle, offset, size, prot, I915_MMAP_WC);
 }
 
 /**
@@ -832,7 +933,14 @@ void *gem_mmap__wc(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsi
  */
 void *__gem_mmap__cpu(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned prot)
 {
-	return __gem_mmap(fd, handle, offset, size, prot, 0);
+	void *ptr;
+
+	if (has_mmap_offset(fd))
+		ptr = __gem_mmap_offset(fd, handle, offset, size, prot, LOCAL_I915_MMAP_OFFSET_WB);
+	else
+		ptr = __gem_mmap(fd, handle, offset, size, prot, 0);
+
+	return ptr;
 }
 
 /**
-- 
2.20.1

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