With the introduction of per-process GTT space, the hardware designers
thought it wise to also limit the ability to write to MMIO space to only
a "secure" batch buffer. The ability to rewrite registers is the only
way to program the hardware to perform certain operations like scanline
waits (required for tear-free windowed updates). So we either have a
choice of adding an interface to perform those synchronized updates
inside the kernel, or we permit certain processes the ability to write
to the "safe" registers from within its command stream. This patch
exposes the ability to submit a SECURE batch buffer to
DRM_ROOT_ONLY|DRM_MASTER processes.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_dma.c | 3 +++
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 21 ++++++++++++++++++---
drivers/gpu/drm/i915/i915_trace.h | 10 ++++++----
drivers/gpu/drm/i915/intel_ringbuffer.c | 23 +++++++++++++++--------
drivers/gpu/drm/i915/intel_ringbuffer.h | 4 +++-
include/drm/i915_drm.h | 6 ++++++
6 files changed, 51 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 5779e8f..f92c849 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1015,6 +1015,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
case I915_PARAM_HAS_PRIME_VMAP_FLUSH:
value = 1;
break;
+ case I915_PARAM_HAS_SECURE_BATCHES:
+ value = capable(CAP_SYS_ADMIN);
+ break;
default:
DRM_DEBUG_DRIVER("Unknown parameter %d\n",
param->param);
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index bcd5aa2..4bbd088 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -816,6 +816,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
u32 exec_start, exec_len;
u32 seqno;
u32 mask;
+ u32 flags;
int ret, mode, i;
if (!i915_gem_check_execbuffer(args)) {
@@ -827,6 +828,14 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
if (ret)
return ret;
+ flags = 0;
+ if (args->flags & I915_EXEC_SECURE) {
+ if (!file->is_master || !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ flags |= I915_DISPATCH_SECURE;
+ }
+
switch (args->flags & I915_EXEC_RING_MASK) {
case I915_EXEC_DEFAULT:
case I915_EXEC_RENDER:
@@ -999,6 +1008,9 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
}
batch_obj->base.pending_read_domains |= I915_GEM_DOMAIN_COMMAND;
+ if (flags & I915_DISPATCH_SECURE && !batch_obj->has_global_gtt_mapping)
+ i915_gem_gtt_bind_object(batch_obj, batch_obj->cache_level);
+
ret = i915_gem_execbuffer_move_to_gpu(ring, &objects);
if (ret)
goto err;
@@ -1044,7 +1056,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
goto err;
}
- trace_i915_gem_ring_dispatch(ring, seqno);
+ trace_i915_gem_ring_dispatch(ring, seqno, flags);
exec_start = batch_obj->gtt_offset + args->batch_start_offset;
exec_len = args->batch_len;
@@ -1056,12 +1068,15 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
goto err;
ret = ring->dispatch_execbuffer(ring,
- exec_start, exec_len);
+ exec_start, exec_len,
+ flags);
if (ret)
goto err;
}
} else {
- ret = ring->dispatch_execbuffer(ring, exec_start, exec_len);
+ ret = ring->dispatch_execbuffer(ring,
+ exec_start, exec_len,
+ flags);
if (ret)
goto err;
}
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index 8134421..3db4a68 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -229,24 +229,26 @@ TRACE_EVENT(i915_gem_evict_everything,
);
TRACE_EVENT(i915_gem_ring_dispatch,
- TP_PROTO(struct intel_ring_buffer *ring, u32 seqno),
- TP_ARGS(ring, seqno),
+ TP_PROTO(struct intel_ring_buffer *ring, u32 seqno, u32 flags),
+ TP_ARGS(ring, seqno, flags),
TP_STRUCT__entry(
__field(u32, dev)
__field(u32, ring)
__field(u32, seqno)
+ __field(u32, flags)
),
TP_fast_assign(
__entry->dev = ring->dev->primary->index;
__entry->ring = ring->id;
__entry->seqno = seqno;
+ __entry->flags = flags;
i915_trace_irq_get(ring, seqno);
),
- TP_printk("dev=%u, ring=%u, seqno=%u",
- __entry->dev, __entry->ring, __entry->seqno)
+ TP_printk("dev=%u, ring=%u, seqno=%u, flags=%x",
+ __entry->dev, __entry->ring, __entry->seqno, __entry->flags)
);
TRACE_EVENT(i915_gem_ring_flush,
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 133beb6..6a4b8fa 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -964,7 +964,9 @@ gen6_ring_put_irq(struct intel_ring_buffer *ring)
}
static int
-i965_dispatch_execbuffer(struct intel_ring_buffer *ring, u32 offset, u32 length)
+i965_dispatch_execbuffer(struct intel_ring_buffer *ring,
+ u32 offset, u32 length,
+ unsigned flags)
{
int ret;
@@ -975,7 +977,7 @@ i965_dispatch_execbuffer(struct intel_ring_buffer *ring, u32 offset, u32 length)
intel_ring_emit(ring,
MI_BATCH_BUFFER_START |
MI_BATCH_GTT |
- MI_BATCH_NON_SECURE_I965);
+ (flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE_I965));
intel_ring_emit(ring, offset);
intel_ring_advance(ring);
@@ -984,7 +986,8 @@ i965_dispatch_execbuffer(struct intel_ring_buffer *ring, u32 offset, u32 length)
static int
i830_dispatch_execbuffer(struct intel_ring_buffer *ring,
- u32 offset, u32 len)
+ u32 offset, u32 len,
+ unsigned flags)
{
int ret;
@@ -993,7 +996,7 @@ i830_dispatch_execbuffer(struct intel_ring_buffer *ring,
return ret;
intel_ring_emit(ring, MI_BATCH_BUFFER);
- intel_ring_emit(ring, offset | MI_BATCH_NON_SECURE);
+ intel_ring_emit(ring, offset | (flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE));
intel_ring_emit(ring, offset + len - 8);
intel_ring_emit(ring, 0);
intel_ring_advance(ring);
@@ -1003,7 +1006,8 @@ i830_dispatch_execbuffer(struct intel_ring_buffer *ring,
static int
i915_dispatch_execbuffer(struct intel_ring_buffer *ring,
- u32 offset, u32 len)
+ u32 offset, u32 len,
+ unsigned flags)
{
int ret;
@@ -1012,7 +1016,7 @@ i915_dispatch_execbuffer(struct intel_ring_buffer *ring,
return ret;
intel_ring_emit(ring, MI_BATCH_BUFFER_START | MI_BATCH_GTT);
- intel_ring_emit(ring, offset | MI_BATCH_NON_SECURE);
+ intel_ring_emit(ring, offset | (flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE));
intel_ring_advance(ring);
return 0;
@@ -1410,7 +1414,8 @@ static int gen6_ring_flush(struct intel_ring_buffer *ring,
static int
gen6_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
- u32 offset, u32 len)
+ u32 offset, u32 len,
+ unsigned flags)
{
int ret;
@@ -1418,7 +1423,9 @@ gen6_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
if (ret)
return ret;
- intel_ring_emit(ring, MI_BATCH_BUFFER_START | MI_BATCH_NON_SECURE_I965);
+ intel_ring_emit(ring,
+ MI_BATCH_BUFFER_START |
+ (flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE_I965));
/* bit0-7 is the length on GEN6+ */
intel_ring_emit(ring, offset);
intel_ring_advance(ring);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 40b252e..2667f33 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -81,7 +81,9 @@ struct intel_ring_buffer {
u32 (*get_seqno)(struct intel_ring_buffer *ring,
bool lazy_coherency);
int (*dispatch_execbuffer)(struct intel_ring_buffer *ring,
- u32 offset, u32 length);
+ u32 offset, u32 length,
+ unsigned flags);
+#define I915_DISPATCH_SECURE 0x1
void (*cleanup)(struct intel_ring_buffer *ring);
int (*sync_to)(struct intel_ring_buffer *ring,
struct intel_ring_buffer *to,
diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
index acfb377..4f41f8d 100644
--- a/include/drm/i915_drm.h
+++ b/include/drm/i915_drm.h
@@ -316,6 +316,7 @@ typedef struct drm_i915_irq_wait {
#define I915_PARAM_HAS_SEMAPHORES 20
#define I915_PARAM_HAS_PRIME_VMAP_FLUSH 21
#define I915_PARAM_RSVD_FOR_FUTURE_USE 22
+#define I915_PARAM_HAS_SECURE_BATCHES 23
typedef struct drm_i915_getparam {
int param;
@@ -694,6 +695,11 @@ struct drm_i915_gem_execbuffer2 {
/** Resets the SO write offset registers for transform feedback on gen7. */
#define I915_EXEC_GEN7_SOL_RESET (1<<8)
+/** Request a privileged ("secure") batch buffer. Note only available for
+ * DRM_ROOT_ONLY | DRM_MASTER processes.
+ */
+#define I915_EXEC_SECURE (1<<9)
+
#define I915_EXEC_CONTEXT_ID_MASK (0xffffffff)
#define i915_execbuffer2_set_context_id(eb2, context) \
(eb2).rsvd1 = context & I915_EXEC_CONTEXT_ID_MASK
--
1.7.10.4
