/* Must be kept compact -- no holes and well documented */
-typedef struct drm_i915_getparam {
+/**
+ * struct drm_i915_getparam - Driver parameter query structure.
+ */
+struct drm_i915_getparam {
+ /** @param: Driver parameter to query. */
__s32 param;
- /*
+
+ /**
+ * @value: Address of memory where queried value should be put.
+ *
* WARNING: Using pointers instead of fixed-size u64 means we need to write
* compat32 code. Don't repeat this mistake.
*/
int *value;
-} drm_i915_getparam_t;
+};
+
+/**
+ * typedef drm_i915_getparam_t - Driver parameter query structure.
+ * See struct drm_i915_getparam.
+ */
+typedef struct drm_i915_getparam drm_i915_getparam_t;
/* Ioctl to set kernel params:
*/
__u64 rsvd2;
};
+/**
+ * struct drm_i915_gem_exec_fence - An input or output fence for the execbuf
+ * ioctl.
+ *
+ * The request will wait for input fence to signal before submission.
+ *
+ * The returned output fence will be signaled after the completion of the
+ * request.
+ */
struct drm_i915_gem_exec_fence {
- /**
- * User's handle for a drm_syncobj to wait on or signal.
- */
+ /** @handle: User's handle for a drm_syncobj to wait on or signal. */
__u32 handle;
+ /**
+ * @flags: Supported flags are:
+ *
+ * I915_EXEC_FENCE_WAIT:
+ * Wait for the input fence before request submission.
+ *
+ * I915_EXEC_FENCE_SIGNAL:
+ * Return request completion fence as output
+ */
+ __u32 flags;
#define I915_EXEC_FENCE_WAIT (1<<0)
#define I915_EXEC_FENCE_SIGNAL (1<<1)
#define __I915_EXEC_FENCE_UNKNOWN_FLAGS (-(I915_EXEC_FENCE_SIGNAL << 1))
- __u32 flags;
};
-/*
- * See drm_i915_gem_execbuffer_ext_timeline_fences.
- */
-#define DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES 0
-
-/*
+/**
+ * struct drm_i915_gem_execbuffer_ext_timeline_fences - Timeline fences
+ * for execbuf ioctl.
+ *
* This structure describes an array of drm_syncobj and associated points for
* timeline variants of drm_syncobj. It is invalid to append this structure to
* the execbuf if I915_EXEC_FENCE_ARRAY is set.
*/
struct drm_i915_gem_execbuffer_ext_timeline_fences {
+#define DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES 0
+ /** @base: Extension link. See struct i915_user_extension. */
struct i915_user_extension base;
/**
- * Number of element in the handles_ptr & value_ptr arrays.
+ * @fence_count: Number of elements in the @handles_ptr & @value_ptr
+ * arrays.
*/
__u64 fence_count;
/**
- * Pointer to an array of struct drm_i915_gem_exec_fence of length
- * fence_count.
+ * @handles_ptr: Pointer to an array of struct drm_i915_gem_exec_fence
+ * of length @fence_count.
*/
__u64 handles_ptr;
/**
- * Pointer to an array of u64 values of length fence_count. Values
- * must be 0 for a binary drm_syncobj. A Value of 0 for a timeline
- * drm_syncobj is invalid as it turns a drm_syncobj into a binary one.
+ * @values_ptr: Pointer to an array of u64 values of length
+ * @fence_count.
+ * Values must be 0 for a binary drm_syncobj. A Value of 0 for a
+ * timeline drm_syncobj is invalid as it turns a drm_syncobj into a
+ * binary one.
*/
__u64 values_ptr;
};
+/**
+ * struct drm_i915_gem_execbuffer2 - Structure for DRM_I915_GEM_EXECBUFFER2
+ * ioctl.
+ */
struct drm_i915_gem_execbuffer2 {
- /**
- * List of gem_exec_object2 structs
- */
+ /** @buffers_ptr: Pointer to a list of gem_exec_object2 structs */
__u64 buffers_ptr;
+
+ /** @buffer_count: Number of elements in @buffers_ptr array */
__u32 buffer_count;
- /** Offset in the batchbuffer to start execution from. */
+ /**
+ * @batch_start_offset: Offset in the batchbuffer to start execution
+ * from.
+ */
__u32 batch_start_offset;
- /** Bytes used in batchbuffer from batch_start_offset */
+
+ /**
+ * @batch_len: Length in bytes of the batch buffer, starting from the
+ * @batch_start_offset. If 0, length is assumed to be the batch buffer
+ * object size.
+ */
__u32 batch_len;
+
+ /** @DR1: deprecated */
__u32 DR1;
+
+ /** @DR4: deprecated */
__u32 DR4;
+
+ /** @num_cliprects: See @cliprects_ptr */
__u32 num_cliprects;
+
/**
- * This is a struct drm_clip_rect *cliprects if I915_EXEC_FENCE_ARRAY
- * & I915_EXEC_USE_EXTENSIONS are not set.
+ * @cliprects_ptr: Kernel clipping was a DRI1 misfeature.
+ *
+ * It is invalid to use this field if I915_EXEC_FENCE_ARRAY or
+ * I915_EXEC_USE_EXTENSIONS flags are not set.
*
* If I915_EXEC_FENCE_ARRAY is set, then this is a pointer to an array
- * of struct drm_i915_gem_exec_fence and num_cliprects is the length
- * of the array.
+ * of &drm_i915_gem_exec_fence and @num_cliprects is the length of the
+ * array.
*
* If I915_EXEC_USE_EXTENSIONS is set, then this is a pointer to a
- * single struct i915_user_extension and num_cliprects is 0.
+ * single &i915_user_extension and num_cliprects is 0.
*/
__u64 cliprects_ptr;
+
+ /** @flags: Execbuf flags */
+ __u64 flags;
#define I915_EXEC_RING_MASK (0x3f)
#define I915_EXEC_DEFAULT (0<<0)
#define I915_EXEC_RENDER (1<<0)
#define I915_EXEC_CONSTANTS_REL_GENERAL (0<<6) /* default */
#define I915_EXEC_CONSTANTS_ABSOLUTE (1<<6)
#define I915_EXEC_CONSTANTS_REL_SURFACE (2<<6) /* gen4/5 only */
- __u64 flags;
- __u64 rsvd1; /* now used for context info */
- __u64 rsvd2;
-};
/** Resets the SO write offset registers for transform feedback on gen7. */
#define I915_EXEC_GEN7_SOL_RESET (1<<8)
* drm_i915_gem_execbuffer_ext enum.
*/
#define I915_EXEC_USE_EXTENSIONS (1 << 21)
-
#define __I915_EXEC_UNKNOWN_FLAGS (-(I915_EXEC_USE_EXTENSIONS << 1))
+ /** @rsvd1: Context id */
+ __u64 rsvd1;
+
+ /**
+ * @rsvd2: in and out sync_file file descriptors.
+ *
+ * When I915_EXEC_FENCE_IN or I915_EXEC_FENCE_SUBMIT flag is set, the
+ * lower 32 bits of this field will have the in sync_file fd (input).
+ *
+ * When I915_EXEC_FENCE_OUT flag is set, the upper 32 bits of this
+ * field will have the out sync_file fd (output).
+ */
+ __u64 rsvd2;
+};
+
#define I915_EXEC_CONTEXT_ID_MASK (0xffffffff)
#define i915_execbuffer2_set_context_id(eb2, context) \
(eb2).rsvd1 = context & I915_EXEC_CONTEXT_ID_MASK
__u32 pad;
};
+/**
+ * struct drm_i915_gem_context_create_ext - Structure for creating contexts.
+ */
struct drm_i915_gem_context_create_ext {
- __u32 ctx_id; /* output: id of new context*/
+ /** @ctx_id: Id of the created context (output) */
+ __u32 ctx_id;
+
+ /**
+ * @flags: Supported flags are:
+ *
+ * I915_CONTEXT_CREATE_FLAGS_USE_EXTENSIONS:
+ *
+ * Extensions may be appended to this structure and driver must check
+ * for those. See @extensions.
+ *
+ * I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE
+ *
+ * Created context will have single timeline.
+ */
__u32 flags;
#define I915_CONTEXT_CREATE_FLAGS_USE_EXTENSIONS (1u << 0)
#define I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE (1u << 1)
#define I915_CONTEXT_CREATE_FLAGS_UNKNOWN \
(-(I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE << 1))
+
+ /**
+ * @extensions: Zero-terminated chain of extensions.
+ *
+ * I915_CONTEXT_CREATE_EXT_SETPARAM:
+ * Context parameter to set or query during context creation.
+ * See struct drm_i915_gem_context_create_ext_setparam.
+ *
+ * I915_CONTEXT_CREATE_EXT_CLONE:
+ * This extension has been removed. On the off chance someone somewhere
+ * has attempted to use it, never re-use this extension number.
+ */
__u64 extensions;
+#define I915_CONTEXT_CREATE_EXT_SETPARAM 0
+#define I915_CONTEXT_CREATE_EXT_CLONE 1
};
+/**
+ * struct drm_i915_gem_context_param - Context parameter to set or query.
+ */
struct drm_i915_gem_context_param {
+ /** @ctx_id: Context id */
__u32 ctx_id;
+
+ /** @size: Size of the parameter @value */
__u32 size;
+
+ /** @param: Parameter to set or query */
__u64 param;
#define I915_CONTEXT_PARAM_BAN_PERIOD 0x1
/* I915_CONTEXT_PARAM_NO_ZEROMAP has been removed. On the off chance
#define I915_CONTEXT_PARAM_PROTECTED_CONTENT 0xd
/* Must be kept compact -- no holes and well documented */
+ /** @value: Context parameter value to be set or queried */
__u64 value;
};
struct i915_engine_class_instance engines[N__]; \
} __attribute__((packed)) name__
+/**
+ * struct drm_i915_gem_context_create_ext_setparam - Context parameter
+ * to set or query during context creation.
+ */
struct drm_i915_gem_context_create_ext_setparam {
-#define I915_CONTEXT_CREATE_EXT_SETPARAM 0
+ /** @base: Extension link. See struct i915_user_extension. */
struct i915_user_extension base;
+
+ /**
+ * @param: Context parameter to set or query.
+ * See struct drm_i915_gem_context_param.
+ */
struct drm_i915_gem_context_param param;
};
-/* This API has been removed. On the off chance someone somewhere has
- * attempted to use it, never re-use this extension number.
- */
-#define I915_CONTEXT_CREATE_EXT_CLONE 1
-
struct drm_i915_gem_context_destroy {
__u32 ctx_id;
__u32 pad;
};
-/*
+/**
+ * struct drm_i915_gem_vm_control - Structure to create or destroy VM.
+ *
* DRM_I915_GEM_VM_CREATE -
*
* Create a new virtual memory address space (ppGTT) for use within a context
* The id of new VM (bound to the fd) for use with I915_CONTEXT_PARAM_VM is
* returned in the outparam @id.
*
- * No flags are defined, with all bits reserved and must be zero.
- *
* An extension chain maybe provided, starting with @extensions, and terminated
* by the @next_extension being 0. Currently, no extensions are defined.
*
* DRM_I915_GEM_VM_DESTROY -
*
- * Destroys a previously created VM id, specified in @id.
+ * Destroys a previously created VM id, specified in @vm_id.
*
* No extensions or flags are allowed currently, and so must be zero.
*/
struct drm_i915_gem_vm_control {
+ /** @extensions: Zero-terminated chain of extensions. */
__u64 extensions;
+
+ /** @flags: reserved for future usage, currently MBZ */
__u32 flags;
+
+ /** @vm_id: Id of the VM created or to be destroyed */
__u32 vm_id;
};
* struct drm_i915_memory_region_info - Describes one region as known to the
* driver.
*
- * Note that we reserve some stuff here for potential future work. As an example
- * we might want expose the capabilities for a given region, which could include
- * things like if the region is CPU mappable/accessible, what are the supported
- * mapping types etc.
- *
- * Note that to extend struct drm_i915_memory_region_info and struct
- * drm_i915_query_memory_regions in the future the plan is to do the following:
- *
- * .. code-block:: C
- *
- * struct drm_i915_memory_region_info {
- * struct drm_i915_gem_memory_class_instance region;
- * union {
- * __u32 rsvd0;
- * __u32 new_thing1;
- * };
- * ...
- * union {
- * __u64 rsvd1[8];
- * struct {
- * __u64 new_thing2;
- * __u64 new_thing3;
- * ...
- * };
- * };
- * };
- *
- * With this things should remain source compatible between versions for
- * userspace, even as we add new fields.
- *
* Note this is using both struct drm_i915_query_item and struct drm_i915_query.
* For this new query we are adding the new query id DRM_I915_QUERY_MEMORY_REGIONS
* at &drm_i915_query_item.query_id.
/** @rsvd0: MBZ */
__u32 rsvd0;
- /** @probed_size: Memory probed by the driver (-1 = unknown) */
+ /**
+ * @probed_size: Memory probed by the driver
+ *
+ * Note that it should not be possible to ever encounter a zero value
+ * here, also note that no current region type will ever return -1 here.
+ * Although for future region types, this might be a possibility. The
+ * same applies to the other size fields.
+ */
__u64 probed_size;
- /** @unallocated_size: Estimate of memory remaining (-1 = unknown) */
+ /**
+ * @unallocated_size: Estimate of memory remaining
+ *
+ * Requires CAP_PERFMON or CAP_SYS_ADMIN to get reliable accounting.
+ * Without this (or if this is an older kernel) the value here will
+ * always equal the @probed_size. Note this is only currently tracked
+ * for I915_MEMORY_CLASS_DEVICE regions (for other types the value here
+ * will always equal the @probed_size).
+ */
__u64 unallocated_size;
- /** @rsvd1: MBZ */
- __u64 rsvd1[8];
+ union {
+ /** @rsvd1: MBZ */
+ __u64 rsvd1[8];
+ struct {
+ /**
+ * @probed_cpu_visible_size: Memory probed by the driver
+ * that is CPU accessible.
+ *
+ * This will be always be <= @probed_size, and the
+ * remainder (if there is any) will not be CPU
+ * accessible.
+ *
+ * On systems without small BAR, the @probed_size will
+ * always equal the @probed_cpu_visible_size, since all
+ * of it will be CPU accessible.
+ *
+ * Note this is only tracked for
+ * I915_MEMORY_CLASS_DEVICE regions (for other types the
+ * value here will always equal the @probed_size).
+ *
+ * Note that if the value returned here is zero, then
+ * this must be an old kernel which lacks the relevant
+ * small-bar uAPI support (including
+ * I915_GEM_CREATE_EXT_FLAG_NEEDS_CPU_ACCESS), but on
+ * such systems we should never actually end up with a
+ * small BAR configuration, assuming we are able to load
+ * the kernel module. Hence it should be safe to treat
+ * this the same as when @probed_cpu_visible_size ==
+ * @probed_size.
+ */
+ __u64 probed_cpu_visible_size;
+
+ /**
+ * @unallocated_cpu_visible_size: Estimate of CPU
+ * visible memory remaining.
+ *
+ * Note this is only tracked for
+ * I915_MEMORY_CLASS_DEVICE regions (for other types the
+ * value here will always equal the
+ * @probed_cpu_visible_size).
+ *
+ * Requires CAP_PERFMON or CAP_SYS_ADMIN to get reliable
+ * accounting. Without this the value here will always
+ * equal the @probed_cpu_visible_size. Note this is only
+ * currently tracked for I915_MEMORY_CLASS_DEVICE
+ * regions (for other types the value here will also
+ * always equal the @probed_cpu_visible_size).
+ *
+ * If this is an older kernel the value here will be
+ * zero, see also @probed_cpu_visible_size.
+ */
+ __u64 unallocated_cpu_visible_size;
+ };
+ };
};
/**
* struct drm_i915_gem_create_ext - Existing gem_create behaviour, with added
* extension support using struct i915_user_extension.
*
- * Note that in the future we want to have our buffer flags here, at least for
- * the stuff that is immutable. Previously we would have two ioctls, one to
- * create the object with gem_create, and another to apply various parameters,
- * however this creates some ambiguity for the params which are considered
- * immutable. Also in general we're phasing out the various SET/GET ioctls.
+ * Note that new buffer flags should be added here, at least for the stuff that
+ * is immutable. Previously we would have two ioctls, one to create the object
+ * with gem_create, and another to apply various parameters, however this
+ * creates some ambiguity for the params which are considered immutable. Also in
+ * general we're phasing out the various SET/GET ioctls.
*/
struct drm_i915_gem_create_ext {
/**
*
* The (page-aligned) allocated size for the object will be returned.
*
- *
* DG2 64K min page size implications:
*
* On discrete platforms, starting from DG2, we have to contend with GTT
*
* Note that the returned size here will always reflect any required
* rounding up done by the kernel, i.e 4K will now become 64K on devices
- * such as DG2.
+ * such as DG2. The kernel will always select the largest minimum
+ * page-size for the set of possible placements as the value to use when
+ * rounding up the @size.
*
* Special DG2 GTT address alignment requirement:
*
* is deemed to be a good compromise.
*/
__u64 size;
+
/**
* @handle: Returned handle for the object.
*
* Object handles are nonzero.
*/
__u32 handle;
- /** @flags: MBZ */
+
+ /**
+ * @flags: Optional flags.
+ *
+ * Supported values:
+ *
+ * I915_GEM_CREATE_EXT_FLAG_NEEDS_CPU_ACCESS - Signal to the kernel that
+ * the object will need to be accessed via the CPU.
+ *
+ * Only valid when placing objects in I915_MEMORY_CLASS_DEVICE, and only
+ * strictly required on configurations where some subset of the device
+ * memory is directly visible/mappable through the CPU (which we also
+ * call small BAR), like on some DG2+ systems. Note that this is quite
+ * undesirable, but due to various factors like the client CPU, BIOS etc
+ * it's something we can expect to see in the wild. See
+ * &drm_i915_memory_region_info.probed_cpu_visible_size for how to
+ * determine if this system applies.
+ *
+ * Note that one of the placements MUST be I915_MEMORY_CLASS_SYSTEM, to
+ * ensure the kernel can always spill the allocation to system memory,
+ * if the object can't be allocated in the mappable part of
+ * I915_MEMORY_CLASS_DEVICE.
+ *
+ * Also note that since the kernel only supports flat-CCS on objects
+ * that can *only* be placed in I915_MEMORY_CLASS_DEVICE, we therefore
+ * don't support I915_GEM_CREATE_EXT_FLAG_NEEDS_CPU_ACCESS together with
+ * flat-CCS.
+ *
+ * Without this hint, the kernel will assume that non-mappable
+ * I915_MEMORY_CLASS_DEVICE is preferred for this object. Note that the
+ * kernel can still migrate the object to the mappable part, as a last
+ * resort, if userspace ever CPU faults this object, but this might be
+ * expensive, and so ideally should be avoided.
+ *
+ * On older kernels which lack the relevant small-bar uAPI support (see
+ * also &drm_i915_memory_region_info.probed_cpu_visible_size),
+ * usage of the flag will result in an error, but it should NEVER be
+ * possible to end up with a small BAR configuration, assuming we can
+ * also successfully load the i915 kernel module. In such cases the
+ * entire I915_MEMORY_CLASS_DEVICE region will be CPU accessible, and as
+ * such there are zero restrictions on where the object can be placed.
+ */
+#define I915_GEM_CREATE_EXT_FLAG_NEEDS_CPU_ACCESS (1 << 0)
__u32 flags;
+
/**
* @extensions: The chain of extensions to apply to this object.
*
* At which point we get the object handle in &drm_i915_gem_create_ext.handle,
* along with the final object size in &drm_i915_gem_create_ext.size, which
* should account for any rounding up, if required.
+ *
+ * Note that userspace has no means of knowing the current backing region
+ * for objects where @num_regions is larger than one. The kernel will only
+ * ensure that the priority order of the @regions array is honoured, either
+ * when initially placing the object, or when moving memory around due to
+ * memory pressure
+ *
+ * On Flat-CCS capable HW, compression is supported for the objects residing
+ * in I915_MEMORY_CLASS_DEVICE. When such objects (compressed) have other
+ * memory class in @regions and migrated (by i915, due to memory
+ * constraints) to the non I915_MEMORY_CLASS_DEVICE region, then i915 needs to
+ * decompress the content. But i915 doesn't have the required information to
+ * decompress the userspace compressed objects.
+ *
+ * So i915 supports Flat-CCS, on the objects which can reside only on
+ * I915_MEMORY_CLASS_DEVICE regions.
*/
struct drm_i915_gem_create_ext_memory_regions {
/** @base: Extension link. See struct i915_user_extension. */