From: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx>
Future GuC will require CTB buffers sizes to be multiple of 4K.
Make these changes now as this shouldn't impact us too much.
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx>
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Reviewed-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Cc: John Harrison <john.c.harrison@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 60 ++++++++++++-----------
1 file changed, 32 insertions(+), 28 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
index 882ae1ed41b0..8d70f637640b 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
@@ -38,6 +38,32 @@ static inline struct drm_device *ct_to_drm(struct intel_guc_ct *ct)
#define CT_PROBE_ERROR(_ct, _fmt, ...) \
i915_probe_error(ct_to_i915(ct), "CT: " _fmt, ##__VA_ARGS__)
+/**
+ * DOC: CTB Blob
+ *
+ * We allocate single blob to hold both CTB descriptors and buffers:
+ *
+ * +--------+-----------------------------------------------+------+
+ * | offset | contents | size |
+ * +========+===============================================+======+
+ * | 0x0000 | H2G `CTB Descriptor`_ (send) | |
+ * +--------+-----------------------------------------------+ 4K |
+ * | 0x0800 | G2H `CTB Descriptor`_ (recv) | |
+ * +--------+-----------------------------------------------+------+
+ * | 0x1000 | H2G `CT Buffer`_ (send) | n*4K |
+ * | | | |
+ * +--------+-----------------------------------------------+------+
+ * | 0x1000 | G2H `CT Buffer`_ (recv) | m*4K |
+ * | + n*4K | | |
+ * +--------+-----------------------------------------------+------+
+ *
+ * Size of each `CT Buffer`_ must be multiple of 4K.
+ * As we don't expect too many messages, for now use minimum sizes.
+ */
+#define CTB_DESC_SIZE ALIGN(sizeof(struct guc_ct_buffer_desc), SZ_2K)
+#define CTB_H2G_BUFFER_SIZE (SZ_4K)
+#define CTB_G2H_BUFFER_SIZE (SZ_4K)
+
struct ct_request {
struct list_head link;
u32 fence;
@@ -175,29 +201,7 @@ int intel_guc_ct_init(struct intel_guc_ct *ct)
GEM_BUG_ON(ct->vma);
- /* We allocate 1 page to hold both descriptors and both buffers.
- * ___________.....................
- * |desc (SEND)| :
- * |___________| PAGE/4
- * :___________....................:
- * |desc (RECV)| :
- * |___________| PAGE/4
- * :_______________________________:
- * |cmds (SEND) |
- * | PAGE/4
- * |_______________________________|
- * |cmds (RECV) |
- * | PAGE/4
- * |_______________________________|
- *
- * Each message can use a maximum of 32 dwords and we don't expect to
- * have more than 1 in flight at any time, so we have enough space.
- * Some logic further ahead will rely on the fact that there is only 1
- * page and that it is always mapped, so if the size is changed the
- * other code will need updating as well.
- */
-
- blob_size = PAGE_SIZE;
+ blob_size = 2 * CTB_DESC_SIZE + CTB_H2G_BUFFER_SIZE + CTB_G2H_BUFFER_SIZE;
err = intel_guc_allocate_and_map_vma(guc, blob_size, &ct->vma, &blob);
if (unlikely(err)) {
CT_PROBE_ERROR(ct, "Failed to allocate %u for CTB data (%pe)\n",
@@ -209,17 +213,17 @@ int intel_guc_ct_init(struct intel_guc_ct *ct)
/* store pointers to desc and cmds for send ctb */
desc = blob;
- cmds = blob + PAGE_SIZE / 2;
- cmds_size = PAGE_SIZE / 4;
+ cmds = blob + 2 * CTB_DESC_SIZE;
+ cmds_size = CTB_H2G_BUFFER_SIZE;
CT_DEBUG(ct, "%s desc %#p cmds %#p size %u\n", "send",
ptrdiff(desc, blob), ptrdiff(cmds, blob), cmds_size);
guc_ct_buffer_init(&ct->ctbs.send, desc, cmds, cmds_size);
/* store pointers to desc and cmds for recv ctb */
- desc = blob + PAGE_SIZE / 4;
- cmds = blob + PAGE_SIZE / 4 + PAGE_SIZE / 2;
- cmds_size = PAGE_SIZE / 4;
+ desc = blob + CTB_DESC_SIZE;
+ cmds = blob + 2 * CTB_DESC_SIZE + CTB_H2G_BUFFER_SIZE;
+ cmds_size = CTB_G2H_BUFFER_SIZE;
CT_DEBUG(ct, "%s desc %#p cmds %#p size %u\n", "recv",
ptrdiff(desc, blob), ptrdiff(cmds, blob), cmds_size);
--
2.28.0
