On 6/7/2021 11:03 AM, Matthew Brost wrote:
From: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx> Definition of the CTB descriptor has changed, leaving only minimal shared fields like HEAD/TAIL/STATUS. Both HEAD and TAIL are now in dwords. Add some ABI documentation and implement required changes. Signed-off-by: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx> Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx> --- .../gt/uc/abi/guc_communication_ctb_abi.h | 70 ++++++++++++++----- drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 70 +++++++++---------- drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h | 2 +- 3 files changed, 85 insertions(+), 57 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h index d38935f47ecf..c2a069a78e01 100644 --- a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h +++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h @@ -7,6 +7,58 @@ #define _ABI_GUC_COMMUNICATION_CTB_ABI_H#include <linux/types.h>+#include <linux/build_bug.h> + +#include "guc_messages_abi.h" + +/** + * DOC: CT Buffer + * + * TBD
What's the plan with this TBD here?
+ */ + +/** + * DOC: CTB Descriptor + * + * +---+-------+--------------------------------------------------------------+ + * | | Bits | Description | + * +===+=======+==============================================================+ + * | 0 | 31:0 | **HEAD** - offset (in dwords) to the last dword that was | + * | | | read from the `CT Buffer`_. | + * | | | It can only be updated by the receiver. | + * +---+-------+--------------------------------------------------------------+ + * | 1 | 31:0 | **TAIL** - offset (in dwords) to the last dword that was | + * | | | written to the `CT Buffer`_. | + * | | | It can only be updated by the sender. | + * +---+-------+--------------------------------------------------------------+ + * | 2 | 31:0 | **STATUS** - status of the CTB | + * | | | | + * | | | - _`GUC_CTB_STATUS_NO_ERROR` = 0 (normal operation) | + * | | | - _`GUC_CTB_STATUS_OVERFLOW` = 1 (head/tail too large) | + * | | | - _`GUC_CTB_STATUS_UNDERFLOW` = 2 (truncated message) | + * | | | - _`GUC_CTB_STATUS_MISMATCH` = 4 (head/tail modified) | + * | | | - _`GUC_CTB_STATUS_NO_BACKCHANNEL` = 8 | + * | | | - _`GUC_CTB_STATUS_MALFORMED_MSG` = 16 |
I don't see the last 2 error (8 & 16) in the 62.0.0 specs. Where is the reference for them?
+ * +---+-------+--------------------------------------------------------------+
+ * |...| | RESERVED = MBZ |
+ * +---+-------+--------------------------------------------------------------+
+ * | 15| 31:0 | RESERVED = MBZ |
+ * +---+-------+--------------------------------------------------------------+
+ */
+
+struct guc_ct_buffer_desc {
+ u32 head;
+ u32 tail;
+ u32 status;
+#define GUC_CTB_STATUS_NO_ERROR 0
+#define GUC_CTB_STATUS_OVERFLOW (1 << 0)
+#define GUC_CTB_STATUS_UNDERFLOW (1 << 1)
+#define GUC_CTB_STATUS_MISMATCH (1 << 2)
+#define GUC_CTB_STATUS_NO_BACKCHANNEL (1 << 3)
+#define GUC_CTB_STATUS_MALFORMED_MSG (1 << 4)
use BIT() ?
+ u32 reserved[13]; +} __packed; +static_assert(sizeof(struct guc_ct_buffer_desc) == 64);/*** DOC: CTB based communication @@ -60,24 +112,6 @@ * - **flags**, holds various bits to control message handling */-/*- * Describes single command transport buffer. - * Used by both guc-master and clients. - */ -struct guc_ct_buffer_desc { - u32 addr; /* gfx address */ - u64 host_private; /* host private data */ - u32 size; /* size in bytes */ - u32 head; /* offset updated by GuC*/ - u32 tail; /* offset updated by owner */ - u32 is_in_error; /* error indicator */ - u32 reserved1; - u32 reserved2; - u32 owner; /* id of the channel owner */ - u32 owner_sub_id; /* owner-defined field for extra tracking */ - u32 reserved[5]; -} __packed; - /* Type of command transport buffer */ #define INTEL_GUC_CT_BUFFER_TYPE_SEND 0x0u #define INTEL_GUC_CT_BUFFER_TYPE_RECV 0x1u 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 63056ea0631e..3241a477196f 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c @@ -112,32 +112,28 @@ static inline const char *guc_ct_buffer_type_to_str(u32 type) } }-static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc,- u32 cmds_addr, u32 size) +static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc)
this function is called from only 1 place and only does a memset now, so IMO we can just drop it and inline the memset.
The logic below matches the specs. Daniele
{ memset(desc, 0, sizeof(*desc)); - desc->addr = cmds_addr; - desc->size = size; - desc->owner = CTB_OWNER_HOST; }-static void guc_ct_buffer_reset(struct intel_guc_ct_buffer *ctb, u32 cmds_addr)+static void guc_ct_buffer_reset(struct intel_guc_ct_buffer *ctb) { ctb->broken = false; - guc_ct_buffer_desc_init(ctb->desc, cmds_addr, ctb->size); + guc_ct_buffer_desc_init(ctb->desc); }static void guc_ct_buffer_init(struct intel_guc_ct_buffer *ctb,struct guc_ct_buffer_desc *desc, - u32 *cmds, u32 size) + u32 *cmds, u32 size_in_bytes) { - GEM_BUG_ON(size % 4); + GEM_BUG_ON(size_in_bytes % 4);ctb->desc = desc;ctb->cmds = cmds; - ctb->size = size; + ctb->size = size_in_bytes / 4;- guc_ct_buffer_reset(ctb, 0);+ guc_ct_buffer_reset(ctb); }static int guc_action_register_ct_buffer(struct intel_guc *guc,@@ -279,10 +275,10 @@ int intel_guc_ct_enable(struct intel_guc_ct *ct)/* (re)initialize descriptors */cmds = base + ptrdiff(ct->ctbs.send.cmds, blob); - guc_ct_buffer_reset(&ct->ctbs.send, cmds); + guc_ct_buffer_reset(&ct->ctbs.send);cmds = base + ptrdiff(ct->ctbs.recv.cmds, blob);- guc_ct_buffer_reset(&ct->ctbs.recv, cmds); + guc_ct_buffer_reset(&ct->ctbs.recv);/** Register both CT buffers starting with RECV buffer. @@ -391,17 +387,15 @@ static int ct_write(struct intel_guc_ct *ct, if (unlikely(ctb->broken)) return -EPIPE;- if (unlikely(desc->is_in_error))+ if (unlikely(desc->status)) goto corrupted;- if (unlikely(!IS_ALIGNED(head | tail, 4) ||- (tail | head) >= size)) + if (unlikely((tail | head) >= size)) { + CT_ERROR(ct, "Invalid offsets head=%u tail=%u (size=%u)\n", + head, tail, size); + desc->status |= GUC_CTB_STATUS_OVERFLOW; goto corrupted; - - /* later calculations will be done in dwords */ - head /= 4; - tail /= 4; - size /= 4; + }/** tail == head condition indicates empty. GuC FW does not support @@ -447,14 +441,14 @@ static int ct_write(struct intel_guc_ct *ct, */ write_barrier(ct);- /* now update desc tail (back in bytes) */- desc->tail = tail * 4; + /* now update descriptor */ + WRITE_ONCE(desc->tail, tail); + return 0;corrupted:- CT_ERROR(ct, "Corrupted descriptor addr=%#x head=%u tail=%u size=%u\n", - desc->addr, desc->head, desc->tail, desc->size); - desc->is_in_error = 1; + CT_ERROR(ct, "Corrupted descriptor head=%u tail=%u status=%#x\n", + desc->head, desc->tail, desc->status); ctb->broken = true; return -EPIPE; } @@ -640,17 +634,15 @@ static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg) if (unlikely(ctb->broken)) return -EPIPE;- if (unlikely(desc->is_in_error))+ if (unlikely(desc->status)) goto corrupted;- if (unlikely(!IS_ALIGNED(head | tail, 4) ||- (tail | head) >= size)) + if (unlikely((tail | head) >= size)) { + CT_ERROR(ct, "Invalid offsets head=%u tail=%u (size=%u)\n", + head, tail, size); + desc->status |= GUC_CTB_STATUS_OVERFLOW; goto corrupted; - - /* later calculations will be done in dwords */ - head /= 4; - tail /= 4; - size /= 4; + }/* tail == head condition indicates empty */available = tail - head; @@ -677,6 +669,7 @@ static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg) size - head : available - 1), &cmds[head], 4 * (head + available - 1 > size ? available - 1 - size + head : 0), &cmds[0]); + desc->status |= GUC_CTB_STATUS_UNDERFLOW; goto corrupted; }@@ -699,13 +692,14 @@ static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg)} CT_DEBUG(ct, "received %*ph\n", 4 * len, (*msg)->msg);- desc->head = head * 4;+ /* now update descriptor */ + WRITE_ONCE(desc->head, head); + return available - len;corrupted:- CT_ERROR(ct, "Corrupted descriptor addr=%#x head=%u tail=%u size=%u\n", - desc->addr, desc->head, desc->tail, desc->size); - desc->is_in_error = 1; + CT_ERROR(ct, "Corrupted descriptor head=%u tail=%u status=%#x\n", + desc->head, desc->tail, desc->status); ctb->broken = true; return -EPIPE; } diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h index 7d3cd375d6a7..905202caaad3 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h @@ -31,7 +31,7 @@ struct intel_guc; * @lock: protects access to the commands buffer and buffer descriptor * @desc: pointer to the buffer descriptor * @cmds: pointer to the commands buffer - * @size: size of the commands buffer + * @size: size of the commands buffer in dwords * @broken: flag to indicate if descriptor data is broken */ struct intel_guc_ct_buffer {
