[Intel-gfx] [PATCH 2/5] drm/i915: Introduce DRM_I915_GEM_MMAP_OFFSET
Abdiel Janulgue
abdiel.janulgue at linux.intel.com
Mon Aug 26 12:20:59 UTC 2019
This is really just an alias of mmap_gtt. Add a new CPU mmap
implementation that allows multiple fault handlers that depends on
the object's backing pages.
Note that we multiplex mmap_gtt and mmap_offset through the same ioctl,
and use the zero extending behaviour of drm to differentiate between
them, when we inspect the flags.
Signed-off-by: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 34 ++++++++++++++++++-
.../gpu/drm/i915/gem/i915_gem_object_types.h | 3 ++
drivers/gpu/drm/i915/i915_drv.c | 2 +-
include/uapi/drm/i915_drm.h | 28 +++++++++++++++
4 files changed, 65 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index fb7e39f115d7..87690aa64814 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -143,6 +143,9 @@ static unsigned int tile_row_pages(const struct drm_i915_gem_object *obj)
* 3 - Remove implicit set-domain(GTT) and synchronisation on initial
* pagefault; swapin remains transparent.
*
+ * 4 - Support multiple fault handlers per object depending on object's
+ * backing storage (a.k.a. MMAP_OFFSET).
+ *
* Restrictions:
*
* * snoopable objects cannot be accessed via the GTT. It can cause machine
@@ -170,7 +173,7 @@ static unsigned int tile_row_pages(const struct drm_i915_gem_object *obj)
*/
int i915_gem_mmap_gtt_version(void)
{
- return 3;
+ return 4;
}
static inline struct i915_ggtt_view
@@ -524,6 +527,27 @@ __assign_gem_object_mmap_data(struct drm_file *file,
return ret;
}
+static int gem_mmap_offset(struct drm_device *dev, void *data,
+ struct drm_file *file)
+{
+ struct drm_i915_gem_mmap_offset *args = data;
+ enum i915_mmap_type type;
+
+ if ((args->flags & (I915_MMAP_OFFSET_WC | I915_MMAP_OFFSET_WB)) &&
+ !boot_cpu_has(X86_FEATURE_PAT))
+ return -ENODEV;
+
+ if (args->flags & I915_MMAP_OFFSET_WC)
+ type = I915_MMAP_TYPE_OFFSET_WC;
+ else if (args->flags & I915_MMAP_OFFSET_WB)
+ type = I915_MMAP_TYPE_OFFSET_WB;
+ else if (args->flags & I915_MMAP_OFFSET_UC)
+ type = I915_MMAP_TYPE_OFFSET_UC;
+
+ return __assign_gem_object_mmap_data(file, args->handle, type,
+ &args->offset);
+}
+
/**
* i915_gem_mmap_gtt_ioctl - prepare an object for GTT mmap'ing
* @dev: DRM device
@@ -544,6 +568,14 @@ i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_mmap_offset *args = data;
+ struct drm_i915_private *i915 = to_i915(dev);
+
+ if (args->flags & I915_MMAP_OFFSET_FLAGS)
+ return gem_mmap_offset(dev, data, file);
+
+ if (!HAS_MAPPABLE_APERTURE(i915))
+ /* No aperture, cannot mmap via legacy GTT */
+ return -ENODEV;
return __assign_gem_object_mmap_data(file, args->handle,
I915_MMAP_TYPE_GTT,
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index d74ddb479318..cf7712aea2d9 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -62,6 +62,9 @@ struct drm_i915_gem_object_ops {
enum i915_mmap_type {
I915_MMAP_TYPE_GTT = 0,
+ I915_MMAP_TYPE_OFFSET_WC,
+ I915_MMAP_TYPE_OFFSET_WB,
+ I915_MMAP_TYPE_OFFSET_UC,
};
struct i915_mmap_offset {
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index bdd597200984..68ed4499fa52 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -2774,7 +2774,7 @@ static const struct drm_ioctl_desc i915_ioctls[] = {
DRM_IOCTL_DEF_DRV(I915_GEM_PREAD, i915_gem_pread_ioctl, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(I915_GEM_PWRITE, i915_gem_pwrite_ioctl, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(I915_GEM_MMAP, i915_gem_mmap_ioctl, DRM_RENDER_ALLOW),
- DRM_IOCTL_DEF_DRV(I915_GEM_MMAP_GTT, i915_gem_mmap_gtt_ioctl, DRM_RENDER_ALLOW),
+ DRM_IOCTL_DEF_DRV(I915_GEM_MMAP_OFFSET, i915_gem_mmap_gtt_ioctl, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(I915_GEM_SET_DOMAIN, i915_gem_set_domain_ioctl, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(I915_GEM_SW_FINISH, i915_gem_sw_finish_ioctl, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(I915_GEM_SET_TILING, i915_gem_set_tiling_ioctl, DRM_RENDER_ALLOW),
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 469dc512cca3..75fc9277e9ab 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -359,6 +359,7 @@ typedef struct _drm_i915_sarea {
#define DRM_I915_QUERY 0x39
#define DRM_I915_GEM_VM_CREATE 0x3a
#define DRM_I915_GEM_VM_DESTROY 0x3b
+#define DRM_I915_GEM_MMAP_OFFSET DRM_I915_GEM_MMAP_GTT
/* Must be kept compact -- no holes */
#define DRM_IOCTL_I915_INIT DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t)
@@ -421,6 +422,7 @@ typedef struct _drm_i915_sarea {
#define DRM_IOCTL_I915_QUERY DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_QUERY, struct drm_i915_query)
#define DRM_IOCTL_I915_GEM_VM_CREATE DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_GEM_VM_CREATE, struct drm_i915_gem_vm_control)
#define DRM_IOCTL_I915_GEM_VM_DESTROY DRM_IOW (DRM_COMMAND_BASE + DRM_I915_GEM_VM_DESTROY, struct drm_i915_gem_vm_control)
+#define DRM_IOCTL_I915_GEM_MMAP_OFFSET DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_GEM_MMAP_OFFSET, struct drm_i915_gem_mmap_offset)
/* Allow drivers to submit batchbuffers directly to hardware, relying
* on the security mechanisms provided by hardware.
@@ -611,6 +613,7 @@ typedef struct drm_i915_irq_wait {
* See I915_EXEC_FENCE_OUT and I915_EXEC_FENCE_SUBMIT.
*/
#define I915_PARAM_HAS_EXEC_SUBMIT_FENCE 53
+
/* Must be kept compact -- no holes and well documented */
typedef struct drm_i915_getparam {
@@ -786,6 +789,31 @@ struct drm_i915_gem_mmap_gtt {
__u64 offset;
};
+struct 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 I915_MMAP_OFFSET_WC (1 << 0)
+#define I915_MMAP_OFFSET_WB (1 << 1)
+#define I915_MMAP_OFFSET_UC (1 << 2)
+#define I915_MMAP_OFFSET_FLAGS \
+ (I915_MMAP_OFFSET_WC | I915_MMAP_OFFSET_WB | I915_MMAP_OFFSET_UC)
+};
+
struct drm_i915_gem_set_domain {
/** Handle for the object */
__u32 handle;
--
2.23.0
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