[igt-dev] [PATCH i-g-t v3 1/4] lib/i915/gem_mman: add mmap_offset support
Chris Wilson
chris at chris-wilson.co.uk
Wed Nov 20 19:41:45 UTC 2019
Quoting Zbigniew Kempczyński (2019-11-20 18:57:36)
> From: Lukasz Kalamarz <lukasz.kalamarz at intel.com>
>
> With introduction of LMEM concept new IOCTL call were implemented
> - gem_mmap_offset. This patch add support in IGT for it.
>
> Signed-off-by: Lukasz Kalamarz <lukasz.kalamarz at intel.com>
> Signed-off-by: Antonio Argenziano <antonio.argenziano at intel.com>
> Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Vanshidhar Konda <vanshidhar.r.konda at intel.com>
> ---
> lib/i915/gem_mman.c | 222 ++++++++++++++++++++++++++++++++++++--------
> lib/i915/gem_mman.h | 42 ++++++++-
> 2 files changed, 224 insertions(+), 40 deletions(-)
>
> diff --git a/lib/i915/gem_mman.c b/lib/i915/gem_mman.c
> index 6256627b..1467b883 100644
> --- a/lib/i915/gem_mman.c
> +++ b/lib/i915/gem_mman.c
> @@ -40,6 +40,39 @@
> #define VG(x) do {} while (0)
> #endif
>
> +#define LOCAL_I915_PARAM_MMAP_OFFSET_VERSION 54
> +
> +static bool gem_has_mmap_offset(int fd)
> +{
> + int has_mmap_offset = 0;
> + struct drm_i915_getparam gp;
> +
> + memset(&gp, 0, sizeof(gp));
> + gp.param = LOCAL_I915_PARAM_MMAP_OFFSET_VERSION;
> + gp.value = &has_mmap_offset;
> + ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
* Blinks.
Oh no it isn't.
It's just I915_PARAM_MMAP_GTT_VERSION >= 4
> +
> + return has_mmap_offset > 0;
> +}
> +
> +void gem_require_mmap_offset(int i915)
> +{
> + igt_require(gem_has_mmap_offset(i915));
> +}
> +
> +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 = >t_version;
> + ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
> +
> + return gtt_version;
> +}
> +
> /**
> * __gem_mmap__gtt:
> * @fd: open i915 drm file descriptor
> @@ -101,46 +134,63 @@ int gem_munmap(void *ptr, uint64_t size)
> return ret;
> }
>
> -bool gem_mmap__has_wc(int fd)
> +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 = >t_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);
> }
> + errno = 0;
Ok.
>
> return has_wc > 0;
> }
>
> +bool __gem_mmap_offset__has_wc(int fd)
> +{
> + int has_wc = 0;
> +
> + if (gem_has_mmap_offset(fd)) {
Don't need the double ioctl... Hmm, oh wait. That's what you get for not
checking arg.pad. Gah.
> + struct local_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.flags = LOCAL_I915_MMAP_OFFSET_WC;
> + has_wc = igt_ioctl(fd, LOCAL_IOCTL_I915_GEM_MMAP_OFFSET,
> + &arg) == 0;
> + gem_close(fd, arg.handle);
> + }
Ok.
> +
> + errno = 0;
> +
> + return has_wc > 0;
> +}
> +
> +bool gem_mmap__has_wc(int fd)
> +{
> + return __gem_mmap_offset__has_wc(fd) || __gem_mmap__has_wc(fd);
> +}
> +
> /**
> * __gem_mmap:
> * @fd: open i915 drm file descriptor
> @@ -157,8 +207,8 @@ 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)
> +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 +227,43 @@ 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.
> + */
> +void *__gem_mmap_offset(int fd, uint32_t handle, uint64_t offset, uint64_t size,
> + unsigned int prot, uint64_t flags)
> +{
> + struct local_i915_gem_mmap_offset arg;
> + void *ptr;
> +
> + memset(&arg, 0, sizeof(arg));
> + arg.handle = handle;
> + arg.offset = offset;
That's an interesting extension :-p
Yeah, being able to mmap a slice of the object is one of the extensions
I had in mind.
> + arg.flags = flags;
> +
> + if (igt_ioctl(fd, LOCAL_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
> @@ -194,7 +281,12 @@ 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);
> + void *ptr = __gem_mmap_offset(fd, handle, offset, size, prot,
> + LOCAL_I915_MMAP_OFFSET_WC);
> + if (!ptr)
> + ptr = __gem_mmap(fd, handle, offset, size, prot, I915_MMAP_WC);
Ok.
> +
> + return ptr;
> }
>
> /**
> @@ -205,14 +297,62 @@ 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.
It was better when it was __wc, at least then it matches the function
name ;)
> *
> * Returns: A pointer to the created memory mapping
> */
> 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);
> +
> + 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()
> + *
> + * Try to __gem_mmap_offset, then __gem_mmap__wc(), then __gem_mmap__gtt().
Don't repeat the code, we can read that! You need to explain the
semantics.
Returns a pointer to a block of linear device memory mapped into the
process with WC semantics.
That's a slight lie if we fallback to __gtt as it may end up being
tiled, so note the exception.
> + *
> + * Returns: A pointer to the created memory mapping or NULL.
> + */
> +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,
> + LOCAL_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.
> + *
> + * 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 = gem_mmap__device_coherent(fd, handle, offset, size, prot);
> igt_assert(ptr);
Might as well abide by kernel coding style, blank lines after variables.
And if we are writing a library function, lets be nice and include debug
info in the assert (handle, size, protection etc).
You never know, we might start a trend of being helpful.
> +
> return ptr;
> }
>
> @@ -248,7 +388,11 @@ 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 = __gem_mmap_offset(fd, handle, offset, size, prot,
> + LOCAL_I915_MMAP_OFFSET_WB);
> + if (!ptr)
> + ptr = __gem_mmap__cpu(fd, handle, offset, size, prot);
Ok.
> +
> igt_assert(ptr);
> return ptr;
> }
> diff --git a/lib/i915/gem_mman.h b/lib/i915/gem_mman.h
> index 096ff592..e774d5c8 100644
> --- a/lib/i915/gem_mman.h
> +++ b/lib/i915/gem_mman.h
> @@ -25,12 +25,46 @@
> #ifndef GEM_MMAN_H
> #define GEM_MMAN_H
>
> +#define LOCAL_I915_GEM_MMAP_OFFSET DRM_I915_GEM_MMAP_GTT
> +#define LOCAL_IOCTL_I915_GEM_MMAP_OFFSET DRM_IOWR(DRM_COMMAND_BASE + \
> + LOCAL_I915_GEM_MMAP_OFFSET, struct local_i915_gem_mmap_offset)
> +
> +struct local_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_I915_MMAP_OFFSET_WC (1 << 0)
> +#define LOCAL_I915_MMAP_OFFSET_WB (1 << 1)
> +#define LOCAL_I915_MMAP_OFFSET_UC (1 << 2)
> +#define LOCAL_I915_MMAP_OFFSET_FLAGS \
> + (LOCAL_I915_MMAP_OFFSET_WC | LOCAL_I915_MMAP_OFFSET_WB | LOCAL_I915_MMAP_OFFSET_UC)
> +};
I suggest just having a dummy commit to update i915_drm.h until the real
commit lands.
-Chris
More information about the igt-dev
mailing list