[igt-dev] [PATCH i-g-t] lib/i915/gem_mman: Add support for GEM_MMAP_OFFSET ioctl

* [igt-dev] [PATCH i-g-t] lib/i915/gem_mman: Add support for GEM_MMAP_OFFSET ioctl
@ 2019-12-05 12:31 Zbigniew Kempczyński
  2019-12-05 12:40 ` Chris Wilson
                   ` (3 more replies)
  0 siblings, 4 replies; 11+ messages in thread
From: Zbigniew Kempczyński @ 2019-12-05 12:31 UTC (permalink / raw)
  To: igt-dev

With introduction of new kernel ioctl we need to cover this in
the IGT's. Patch adds mmap functions appropriate for this.

Signed-off-by: Lukasz Kalamarz <lukasz.kalamarz@intel.com>
Signed-off-by: Antonio Argenziano <antonio.argenziano@intel.com>
Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
 lib/i915/gem_mman.c | 291 ++++++++++++++++++++++++++++++++++++++------
 lib/i915/gem_mman.h |  38 +++++-
 2 files changed, 291 insertions(+), 38 deletions(-)

diff --git a/lib/i915/gem_mman.c b/lib/i915/gem_mman.c
index 6256627b..c98f02ae 100644
--- a/lib/i915/gem_mman.c
+++ b/lib/i915/gem_mman.c
@@ -40,6 +40,26 @@
 #define VG(x) do {} while (0)
 #endif
 
+static int gem_mmap_gtt_version(int fd)
+{
+	struct drm_i915_getparam gp;
+	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);
+
+	return gtt_version;
+}
+
+bool gem_has_mmap_offset(int fd)
+{
+	int gtt_version = gem_mmap_gtt_version(fd);
+
+	return gtt_version >= 4;
+}
+
 /**
  * __gem_mmap__gtt:
  * @fd: open i915 drm file descriptor
@@ -103,40 +123,55 @@ int gem_munmap(void *ptr, uint64_t size)
 
 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;
-
-			/* 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;
+	int has_wc = 0;
+
+	struct drm_i915_getparam gp;
+	int mmap_version = -1;
+
+	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 && gem_mmap_gtt_version(fd) >= 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);
+
+		if (has_wc && from_user_pointer(arg.addr_ptr))
+			munmap(from_user_pointer(arg.addr_ptr), arg.size);
 	}
+	errno = 0;
+
+	return has_wc > 0;
+}
+
+bool gem_mmap_offset__has_wc(int fd)
+{
+	int has_wc = 0;
+	struct drm_i915_gem_mmap_offset arg;
+
+	if (!gem_has_mmap_offset(fd))
+		return false;
+
+	/* Does this device support wc-mmaps ? */
+	memset(&arg, 0, sizeof(arg));
+	arg.handle = gem_create(fd, 4096);
+	arg.offset = 0;
+	arg.flags = I915_MMAP_OFFSET_WC;
+	has_wc = igt_ioctl(fd, DRM_IOCTL_I915_GEM_MMAP_OFFSET,
+			   &arg) == 0;
+	gem_close(fd, arg.handle);
+
+	errno = 0;
 
 	return has_wc > 0;
 }
@@ -157,8 +192,8 @@ bool gem_mmap__has_wc(int fd)
  *
  * 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)
+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;
 
@@ -177,6 +212,50 @@ 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
+ *
+ * Mmap the gem buffer memory on offset returned in GEM_MMAP_OFFSET ioctl.
+ * 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, 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 drm_i915_gem_mmap_offset arg;
+	void *ptr;
+
+	if (!gem_has_mmap_offset(fd))
+		return NULL;
+
+	igt_assert(offset == 0);
+
+	memset(&arg, 0, sizeof(arg));
+	arg.handle = handle;
+	arg.flags = flags;
+
+	if (igt_ioctl(fd, DRM_IOCTL_I915_GEM_MMAP_OFFSET, &arg))
+		return NULL;
+
+	ptr = mmap64(0, size, prot, MAP_SHARED, fd, arg.offset + offset);
+
+	if (ptr == MAP_FAILED)
+		ptr = NULL;
+	else
+		errno = 0;
+
+	return ptr;
+}
+
 /**
  * __gem_mmap__wc:
  * @fd: open i915 drm file descriptor
@@ -185,7 +264,7 @@ static void
  * @size: size of the mmap arena
  * @prot: memory protection bits as used by mmap()
  *
- * This functions wraps up procedure to establish a memory mapping through
+ * This function wraps up procedure to establish a memory mapping through
  * direct cpu access, bypassing the gpu and cpu caches completely and also
  * bypassing the GTT system agent (i.e. there is no automatic tiling of
  * the mmapping through the fence registers).
@@ -205,7 +284,7 @@ void *__gem_mmap__wc(int fd, uint32_t handle, uint64_t offset, uint64_t size, un
  * @size: size of the mmap arena
  * @prot: memory protection bits as used by mmap()
  *
- * Like __gem_mmap__wc() except we assert on failure.
+ * Try to __gem_mmap__wc(). Assert on failure.
  *
  * Returns: A pointer to the created memory mapping
  */
@@ -216,6 +295,102 @@ void *gem_mmap__wc(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsi
 	return ptr;
 }
 
+/**
+ * __gem_mmap_offset__wc:
+ * @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, bypassing the gpu and cpu caches completely and also
+ * bypassing the 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.
+ */
+void *__gem_mmap_offset__wc(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_WC);
+}
+
+/**
+ * gem_mmap_offset__wc:
+ * @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()
+ *
+ * Try to __gem_mmap_offset__wc(). Assert on failure.
+ *
+ * Returns: A pointer to the created memory mapping
+ */
+void *gem_mmap_offset__wc(int fd, uint32_t handle, uint64_t offset,
+			  uint64_t size, unsigned prot)
+{
+	void *ptr = __gem_mmap_offset__wc(fd, handle, offset, size, prot);
+
+	igt_assert(ptr);
+	return ptr;
+}
+
+/**
+ * __gem_mmap__device_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()
+ *
+ * Returns: A pointer to a block of linear device memory mapped into the
+ * process with WC semantics. When no WC is available try to mmap using GGTT.
+ */
+void *__gem_mmap__device_coherent(int fd, uint32_t handle, uint64_t offset,
+				  uint64_t size, unsigned prot)
+{
+	void *ptr = __gem_mmap_offset(fd, handle, offset, size, prot,
+				      I915_MMAP_OFFSET_WC);
+	if (!ptr)
+		ptr = __gem_mmap__wc(fd, handle, offset, size, prot);
+
+	if (!ptr)
+		ptr = __gem_mmap__gtt(fd, handle, size, prot);
+
+	return ptr;
+}
+
+/**
+ * gem_mmap__device_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__device__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__device_coherent(int fd, uint32_t handle, uint64_t offset,
+				uint64_t size, unsigned prot)
+{
+	void *ptr;
+
+	igt_assert(offset == 0);
+
+	ptr = __gem_mmap__device_coherent(fd, handle, offset, size, prot);
+	igt_assert(ptr);
+
+	return ptr;
+}
+
 /**
  * __gem_mmap__cpu:
  * @fd: open i915 drm file descriptor
@@ -253,6 +428,48 @@ void *gem_mmap__cpu(int fd, uint32_t handle, uint64_t offset, uint64_t size, uns
 	return ptr;
 }
 
+/**
+ * __gem_mmap_offset__cpu:
+ * @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.
+ *
+ * Returns: A pointer to the created memory mapping, NULL on failure.
+ */
+void *__gem_mmap_offset__cpu(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_WB);
+}
+
+/**
+ * gem_mmap_offset__cpu:
+ * @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__cpu() except we assert on failure.
+ *
+ * Returns: A pointer to the created memory mapping
+ */
+void *gem_mmap_offset__cpu(int fd, uint32_t handle, uint64_t offset,
+			   uint64_t size, unsigned prot)
+{
+	void *ptr = __gem_mmap_offset(fd, handle, offset, size, prot,
+				      I915_MMAP_OFFSET_WB);
+
+	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 096ff592..7b4d6f90 100644
--- a/lib/i915/gem_mman.h
+++ b/lib/i915/gem_mman.h
@@ -25,25 +25,51 @@
 #ifndef GEM_MMAN_H
 #define GEM_MMAN_H
 
+#include <stdint.h>
+
 void *gem_mmap__gtt(int fd, uint32_t handle, uint64_t size, unsigned prot);
 void *gem_mmap__cpu(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned prot);
+void *gem_mmap_offset__cpu(int fd, uint32_t handle, uint64_t offset,
+			   uint64_t size, unsigned prot);
 
 bool gem_mmap__has_wc(int fd);
+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__device_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
 
 bool gem_has_mappable_ggtt(int i915);
 void gem_require_mappable_ggtt(int i915);
+bool gem_has_mmap_offset(int fd);
 
 void *__gem_mmap__gtt(int fd, uint32_t handle, uint64_t size, unsigned prot);
 void *__gem_mmap__cpu(int fd, uint32_t handle, uint64_t offset, uint64_t size, unsigned prot);
+void *__gem_mmap_offset__cpu(int fd, uint32_t handle, uint64_t offset,
+			     uint64_t size, unsigned prot);
 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__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);
 
 int gem_munmap(void *ptr, uint64_t size);
 
+/**
+ * gem_require_mmap_offset:
+ * @fd: open i915 drm file descriptor
+ *
+ * Feature test macro to query whether is possible to map memory using mmap
+ * offset interface. Automatically skips through igt_require() if not.
+ */
+#define gem_require_mmap_offset(fd) igt_require(gem_has_mmap_offset(fd))
+
 /**
  * gem_require_mmap_wc:
  * @fd: open i915 drm file descriptor
@@ -54,5 +80,15 @@ int gem_munmap(void *ptr, uint64_t size);
  */
 #define gem_require_mmap_wc(fd) igt_require(gem_mmap__has_wc(fd))
 
+/**
+ * gem_require_mmap_offset_wc:
+ * @fd: open i915 drm file descriptor
+ *
+ * Feature test macro to query whether direct (i.e. cpu access path, bypassing
+ * the gtt) write-combine memory mappings are available. Automatically skips
+ * through igt_require() if not.
+ */
+#define gem_require_mmap_offset_wc(fd) igt_require(gem_mmap_offset__has_wc(fd))
+
 #endif /* GEM_MMAN_H */
 
-- 
2.23.0

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