staging: qlge: Update buffer queue prod index despite oom

Currently, if we repeatedly fail to allocate all of the buffers from the
desired batching budget, we will never update the prod_idx register.
Restructure code to always update prod_idx if new buffers could be
allocated. This eliminates the current two stage process (clean_idx ->
prod_idx) and some associated bookkeeping variables.

Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Link: https://lore.kernel.org/r/20190927101210.23856-16-bpoirier@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/qlge/qlge.h b/drivers/staging/qlge/qlge.h
index 5e773af..7c48e33 100644 (file)
--- a/drivers/staging/qlge/qlge.h
+++ b/drivers/staging/qlge/qlge.h
@@ -1424,10 +1424,10 @@ struct qlge_bq {
        dma_addr_t base_indirect_dma;
        struct qlge_bq_desc *queue;
        void __iomem *prod_idx_db_reg;
-       u32 prod_idx;                   /* current sw prod idx */
-       u32 curr_idx;                   /* next entry we expect */
-       u32 clean_idx;                  /* beginning of new descs */
-       u32 free_cnt;                   /* free buffer desc cnt */
+       /* next index where sw should refill a buffer for hw */
+       u16 next_to_use;
+       /* next index where sw expects to find a buffer filled by hw */
+       u16 next_to_clean;
        enum {
                QLGE_SB,                /* small buffer */
                QLGE_LB,                /* large buffer */

diff --git a/drivers/staging/qlge/qlge_dbg.c b/drivers/staging/qlge/qlge_dbg.c
index c6bf785..7e16066 100644 (file)
--- a/drivers/staging/qlge/qlge_dbg.c
+++ b/drivers/staging/qlge/qlge_dbg.c
@@ -1776,8 +1776,8 @@ void ql_dump_rx_ring(struct rx_ring *rx_ring)
        pr_err("rx_ring->lbq = %p\n", rx_ring->lbq.queue);
        pr_err("rx_ring->lbq.prod_idx_db_reg = %p\n",
               rx_ring->lbq.prod_idx_db_reg);
-       pr_err("rx_ring->lbq.prod_idx = %d\n", rx_ring->lbq.prod_idx);
-       pr_err("rx_ring->lbq.curr_idx = %d\n", rx_ring->lbq.curr_idx);
+       pr_err("rx_ring->lbq.next_to_use = %d\n", rx_ring->lbq.next_to_use);
+       pr_err("rx_ring->lbq.next_to_clean = %d\n", rx_ring->lbq.next_to_clean);
        pr_err("rx_ring->lbq_clean_idx = %d\n", rx_ring->lbq_clean_idx);
        pr_err("rx_ring->lbq_free_cnt = %d\n", rx_ring->lbq_free_cnt);
 
@@ -1791,10 +1791,8 @@ void ql_dump_rx_ring(struct rx_ring *rx_ring)
        pr_err("rx_ring->sbq = %p\n", rx_ring->sbq.queue);
        pr_err("rx_ring->sbq.prod_idx_db_reg addr = %p\n",
               rx_ring->sbq.prod_idx_db_reg);
-       pr_err("rx_ring->sbq.prod_idx = %d\n", rx_ring->sbq.prod_idx);
-       pr_err("rx_ring->sbq.curr_idx = %d\n", rx_ring->sbq.curr_idx);
-       pr_err("rx_ring->sbq.clean_idx = %d\n", rx_ring->sbq.clean_idx);
-       pr_err("rx_ring->sbq.free_cnt = %d\n", rx_ring->sbq.free_cnt);
+       pr_err("rx_ring->sbq.next_to_use = %d\n", rx_ring->sbq.next_to_use);
+       pr_err("rx_ring->sbq.next_to_clean = %d\n", rx_ring->sbq.next_to_clean);
        pr_err("rx_ring->cq_id = %d\n", rx_ring->cq_id);
        pr_err("rx_ring->irq = %d\n", rx_ring->irq);
        pr_err("rx_ring->cpu = %d\n", rx_ring->cpu);

diff --git a/drivers/staging/qlge/qlge_main.c b/drivers/staging/qlge/qlge_main.c
index 009934b..83e7500 100644 (file)
--- a/drivers/staging/qlge/qlge_main.c
+++ b/drivers/staging/qlge/qlge_main.c
@@ -982,9 +982,8 @@ static struct qlge_bq_desc *qlge_get_curr_buf(struct qlge_bq *bq)
 {
        struct qlge_bq_desc *bq_desc;
 
-       bq_desc = &bq->queue[bq->curr_idx];
-       bq->curr_idx = QLGE_BQ_WRAP(bq->curr_idx + 1);
-       bq->free_cnt++;
+       bq_desc = &bq->queue[bq->next_to_clean];
+       bq->next_to_clean = QLGE_BQ_WRAP(bq->next_to_clean + 1);
 
        return bq_desc;
 }
@@ -1114,9 +1113,9 @@ static void qlge_refill_bq(struct qlge_bq *bq)
 {
        struct rx_ring *rx_ring = QLGE_BQ_CONTAINER(bq);
        struct ql_adapter *qdev = rx_ring->qdev;
-       u32 clean_idx = bq->clean_idx;
+       struct qlge_bq_desc *bq_desc;
+       int free_count, refill_count;
        unsigned int reserved_count;
-       u32 start_idx = clean_idx;
        int i;
 
        if (bq->type == QLGE_SB)
@@ -1124,44 +1123,52 @@ static void qlge_refill_bq(struct qlge_bq *bq)
        else
                reserved_count = 32;
 
-       while (bq->free_cnt > reserved_count) {
-               for (i = (bq->clean_idx % 16); i < 16; i++) {
-                       struct qlge_bq_desc *bq_desc = &bq->queue[clean_idx];
-                       int retval;
+       free_count = bq->next_to_clean - bq->next_to_use;
+       if (free_count <= 0)
+               free_count += QLGE_BQ_LEN;
 
-                       netif_printk(qdev, rx_status, KERN_DEBUG, qdev->ndev,
-                                    "ring %u %s: try cleaning clean_idx = %d.\n",
-                                    rx_ring->cq_id, bq_type_name[bq->type],
-                                    clean_idx);
-
-                       if (bq->type == QLGE_SB)
-                               retval = qlge_refill_sb(rx_ring, bq_desc);
-                       else
-                               retval = qlge_refill_lb(rx_ring, bq_desc);
-                       if (retval < 0) {
-                               bq->clean_idx = clean_idx;
-                               netif_err(qdev, ifup, qdev->ndev,
-                                         "ring %u %s: Could not get a page chunk, i=%d, clean_idx =%d .\n",
-                                         rx_ring->cq_id,
-                                         bq_type_name[bq->type], i,
-                                         clean_idx);
-                               return;
-                       }
+       refill_count = free_count - reserved_count;
+       /* refill batch size */
+       if (refill_count < 16)
+               return;
+
+       i = bq->next_to_use;
+       bq_desc = &bq->queue[i];
+       i -= QLGE_BQ_LEN;
+       do {
+               int retval;
+
+               netif_printk(qdev, rx_status, KERN_DEBUG, qdev->ndev,
+                            "ring %u %s: try cleaning idx %d\n",
+                            rx_ring->cq_id, bq_type_name[bq->type], i);
 
-                       clean_idx = QLGE_BQ_WRAP(clean_idx + 1);
+               if (bq->type == QLGE_SB)
+                       retval = qlge_refill_sb(rx_ring, bq_desc);
+               else
+                       retval = qlge_refill_lb(rx_ring, bq_desc);
+               if (retval < 0) {
+                       netif_err(qdev, ifup, qdev->ndev,
+                                 "ring %u %s: Could not get a page chunk, idx %d\n",
+                                 rx_ring->cq_id, bq_type_name[bq->type], i);
+                       break;
                }
 
-               bq->clean_idx = clean_idx;
-               bq->prod_idx = QLGE_BQ_WRAP(bq->prod_idx + 16);
-               bq->free_cnt -= 16;
-       }
+               bq_desc++;
+               i++;
+               if (unlikely(!i)) {
+                       bq_desc = &bq->queue[0];
+                       i -= QLGE_BQ_LEN;
+               }
+               refill_count--;
+       } while (refill_count);
+       i += QLGE_BQ_LEN;
 
-       if (start_idx != clean_idx) {
+       if (bq->next_to_use != i) {
                netif_printk(qdev, rx_status, KERN_DEBUG, qdev->ndev,
                             "ring %u %s: updating prod idx = %d.\n",
-                            rx_ring->cq_id, bq_type_name[bq->type],
-                            bq->prod_idx);
-               ql_write_db_reg(bq->prod_idx, bq->prod_idx_db_reg);
+                            rx_ring->cq_id, bq_type_name[bq->type], i);
+               bq->next_to_use = i;
+               ql_write_db_reg(bq->next_to_use, bq->prod_idx_db_reg);
        }
 }
 
@@ -2709,25 +2716,21 @@ pci_alloc_err:
 
 static void ql_free_lbq_buffers(struct ql_adapter *qdev, struct rx_ring *rx_ring)
 {
+       struct qlge_bq *lbq = &rx_ring->lbq;
        unsigned int last_offset;
 
-       uint32_t  curr_idx, clean_idx;
-
        last_offset = ql_lbq_block_size(qdev) - qdev->lbq_buf_size;
-       curr_idx = rx_ring->lbq.curr_idx;
-       clean_idx = rx_ring->lbq.clean_idx;
-       while (curr_idx != clean_idx) {
-               struct qlge_bq_desc *lbq_desc = &rx_ring->lbq.queue[curr_idx];
+       while (lbq->next_to_clean != lbq->next_to_use) {
+               struct qlge_bq_desc *lbq_desc =
+                       &lbq->queue[lbq->next_to_clean];
 
                if (lbq_desc->p.pg_chunk.offset == last_offset)
                        pci_unmap_page(qdev->pdev, lbq_desc->dma_addr,
                                       ql_lbq_block_size(qdev),
                                       PCI_DMA_FROMDEVICE);
-
                put_page(lbq_desc->p.pg_chunk.page);
-               lbq_desc->p.pg_chunk.page = NULL;
 
-               curr_idx = QLGE_BQ_WRAP(curr_idx + 1);
+               lbq->next_to_clean = QLGE_BQ_WRAP(lbq->next_to_clean + 1);
        }
 
        if (rx_ring->master_chunk.page) {
@@ -3024,10 +3027,8 @@ static int ql_start_rx_ring(struct ql_adapter *qdev, struct rx_ring *rx_ring)
                cqicb->lbq_buf_size =
                        cpu_to_le16(QLGE_FIT16(qdev->lbq_buf_size));
                cqicb->lbq_len = cpu_to_le16(QLGE_FIT16(QLGE_BQ_LEN));
-               rx_ring->lbq.prod_idx = 0;
-               rx_ring->lbq.curr_idx = 0;
-               rx_ring->lbq.clean_idx = 0;
-               rx_ring->lbq.free_cnt = QLGE_BQ_LEN;
+               rx_ring->lbq.next_to_use = 0;
+               rx_ring->lbq.next_to_clean = 0;
 
                cqicb->flags |= FLAGS_LS;       /* Load sbq values */
                tmp = (u64)rx_ring->sbq.base_dma;
@@ -3043,10 +3044,8 @@ static int ql_start_rx_ring(struct ql_adapter *qdev, struct rx_ring *rx_ring)
                    cpu_to_le64(rx_ring->sbq.base_indirect_dma);
                cqicb->sbq_buf_size = cpu_to_le16(SMALL_BUFFER_SIZE);
                cqicb->sbq_len = cpu_to_le16(QLGE_FIT16(QLGE_BQ_LEN));
-               rx_ring->sbq.prod_idx = 0;
-               rx_ring->sbq.curr_idx = 0;
-               rx_ring->sbq.clean_idx = 0;
-               rx_ring->sbq.free_cnt = QLGE_BQ_LEN;
+               rx_ring->sbq.next_to_use = 0;
+               rx_ring->sbq.next_to_clean = 0;
        }
        if (rx_ring->cq_id < qdev->rss_ring_count) {
                /* Inbound completion handling rx_rings run in