scsi: mpi3mr: Support for Segmented Hardware Trace buffer

Allocate segmented trace buffer if firmware advertises the capability in
IOCfacts.

Upon driver load, read the trace buffer size from driver page 1, calculate
the required segments for trace buffer, and allocate segmented buffers.
Each segment is 4096 bytes in size.

While posting driver diagnostic buffer to firmware, advertise that trace
buffer is segmented.

Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Link: https://lore.kernel.org/r/20250129100850.25430-3-ranjan.kumar@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 95 insertions, 9 deletions

diff --git a/drivers/scsi/mpi3mr/mpi3mr_app.c b/drivers/scsi/mpi3mr/mpi3mr_app.c
index 1532436f0f3a..26582776749f 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_app.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_app.c
@@ -12,23 +12,98 @@
 #include <uapi/scsi/scsi_bsg_mpi3mr.h>
 
 /**
- * mpi3mr_alloc_trace_buffer:	Allocate trace buffer
+ * mpi3mr_alloc_trace_buffer: Allocate segmented trace buffer
  * @mrioc: Adapter instance reference
  * @trace_size: Trace buffer size
  *
- * Allocate trace buffer
+ * Allocate either segmented memory pools or contiguous buffer
+ * based on the controller capability for the host trace
+ * buffer.
+ *
  * Return: 0 on success, non-zero on failure.
  */
 static int mpi3mr_alloc_trace_buffer(struct mpi3mr_ioc *mrioc, u32 trace_size)
 {
 	struct diag_buffer_desc *diag_buffer = &mrioc->diag_buffers[0];
+	int i, sz;
+	u64 *diag_buffer_list = NULL;
+	dma_addr_t diag_buffer_list_dma;
+	u32 seg_count;
+
+	if (mrioc->seg_tb_support) {
+		seg_count = (trace_size) / MPI3MR_PAGE_SIZE_4K;
+		trace_size = seg_count * MPI3MR_PAGE_SIZE_4K;
+
+		diag_buffer_list = dma_alloc_coherent(&mrioc->pdev->dev,
+				sizeof(u64) * seg_count,
+				&diag_buffer_list_dma, GFP_KERNEL);
+		if (!diag_buffer_list)
+			return -1;
+
+		mrioc->num_tb_segs = seg_count;
+
+		sz = sizeof(struct segments) * seg_count;
+		mrioc->trace_buf = kzalloc(sz, GFP_KERNEL);
+		if (!mrioc->trace_buf)
+			goto trace_buf_failed;
+
+		mrioc->trace_buf_pool = dma_pool_create("trace_buf pool",
+		    &mrioc->pdev->dev, MPI3MR_PAGE_SIZE_4K, MPI3MR_PAGE_SIZE_4K,
+		    0);
+		if (!mrioc->trace_buf_pool) {
+			ioc_err(mrioc, "trace buf pool: dma_pool_create failed\n");
+			goto trace_buf_pool_failed;
+		}
 
-	diag_buffer->addr = dma_alloc_coherent(&mrioc->pdev->dev,
-	    trace_size, &diag_buffer->dma_addr, GFP_KERNEL);
-	if (diag_buffer->addr) {
-		dprint_init(mrioc, "trace diag buffer is allocated successfully\n");
+		for (i = 0; i < seg_count; i++) {
+			mrioc->trace_buf[i].segment =
+			    dma_pool_zalloc(mrioc->trace_buf_pool, GFP_KERNEL,
+			    &mrioc->trace_buf[i].segment_dma);
+			diag_buffer_list[i] =
+			    (u64) mrioc->trace_buf[i].segment_dma;
+			if (!diag_buffer_list[i])
+				goto tb_seg_alloc_failed;
+		}
+
+		diag_buffer->addr =  diag_buffer_list;
+		diag_buffer->dma_addr = diag_buffer_list_dma;
+		diag_buffer->is_segmented = true;
+
+		dprint_init(mrioc, "segmented trace diag buffer\n"
+				"is allocated successfully seg_count:%d\n", seg_count);
 		return 0;
+	} else {
+		diag_buffer->addr = dma_alloc_coherent(&mrioc->pdev->dev,
+		    trace_size, &diag_buffer->dma_addr, GFP_KERNEL);
+		if (diag_buffer->addr) {
+			dprint_init(mrioc, "trace diag buffer is allocated successfully\n");
+			return 0;
+		}
+		return -1;
 	}
+
+tb_seg_alloc_failed:
+	if (mrioc->trace_buf_pool) {
+		for (i = 0; i < mrioc->num_tb_segs; i++) {
+			if (mrioc->trace_buf[i].segment) {
+				dma_pool_free(mrioc->trace_buf_pool,
+				    mrioc->trace_buf[i].segment,
+				    mrioc->trace_buf[i].segment_dma);
+				mrioc->trace_buf[i].segment = NULL;
+			}
+			mrioc->trace_buf[i].segment = NULL;
+		}
+		dma_pool_destroy(mrioc->trace_buf_pool);
+		mrioc->trace_buf_pool = NULL;
+	}
+trace_buf_pool_failed:
+	kfree(mrioc->trace_buf);
+	mrioc->trace_buf = NULL;
+trace_buf_failed:
+	if (diag_buffer_list)
+		dma_free_coherent(&mrioc->pdev->dev,
+		    sizeof(u64) * mrioc->num_tb_segs,
+		    diag_buffer_list, diag_buffer_list_dma);
 	return -1;
 }
 
@@ -100,8 +175,9 @@ retry_trace:
 			dprint_init(mrioc,
 			    "trying to allocate trace diag buffer of size = %dKB\n",
 			    trace_size / 1024);
-		if (get_order(trace_size) > MAX_PAGE_ORDER ||
+		if ((!mrioc->seg_tb_support && (get_order(trace_size) > MAX_PAGE_ORDER)) ||
 		    mpi3mr_alloc_trace_buffer(mrioc, trace_size)) {
+
 			retry = true;
 			trace_size -= trace_dec_size;
 			dprint_init(mrioc, "trace diag buffer allocation failed\n"
@@ -161,6 +237,12 @@ int mpi3mr_issue_diag_buf_post(struct mpi3mr_ioc *mrioc,
 	u8 prev_status;
 	int retval = 0;
 
+	if (diag_buffer->disabled_after_reset) {
+		dprint_bsg_err(mrioc, "%s: skiping diag buffer posting\n"
+				"as it is disabled after reset\n", __func__);
+		return -1;
+	}
+
 	memset(&diag_buf_post_req, 0, sizeof(diag_buf_post_req));
 	mutex_lock(&mrioc->init_cmds.mutex);
 	if (mrioc->init_cmds.state & MPI3MR_CMD_PENDING) {
@@ -177,8 +259,12 @@ int mpi3mr_issue_diag_buf_post(struct mpi3mr_ioc *mrioc,
 	diag_buf_post_req.address = le64_to_cpu(diag_buffer->dma_addr);
 	diag_buf_post_req.length = le32_to_cpu(diag_buffer->size);
 
-	dprint_bsg_info(mrioc, "%s: posting diag buffer type %d\n", __func__,
-	    diag_buffer->type);
+	if (diag_buffer->is_segmented)
+		diag_buf_post_req.msg_flags |= MPI3_DIAG_BUFFER_POST_MSGFLAGS_SEGMENTED;
+
+	dprint_bsg_info(mrioc, "%s: posting diag buffer type %d segmented:%d\n", __func__,
+	    diag_buffer->type, diag_buffer->is_segmented);
+
 	prev_status = diag_buffer->status;
 	diag_buffer->status = MPI3MR_HDB_BUFSTATUS_POSTED_UNPAUSED;
 	init_completion(&mrioc->init_cmds.done);