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

Antonio Argenziano
2019-02-21T19:27:55Z

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