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[NET]: Fix NAPI completion handling in some drivers.

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In order for the list handling in net_rx_action() to be
correct, drivers must follow certain rules as stated by
this comment in net_rx_action():

		/* Drivers must not modify the NAPI state if they
		 * consume the entire weight.  In such cases this code
		 * still "owns" the NAPI instance and therefore can
		 * move the instance around on the list at-will.
		 */

A few drivers do not do this because they mix the budget checks
with reading hardware state, resulting in crashes like the one
reported by takano@axe-inc.co.jp.

BNX2 and TG3 are taken care of here, SKY2 fix is from Stephen
Hemminger.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
2007-10-11 18:08:29 -07:00
parent b08d6cb22c
commit 6f53576316
3 changed files with 82 additions and 42 deletions
Download Patch File Download Diff File Expand all files Collapse all files

52
drivers/net/bnx2.c
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@@ -2633,15 +2633,11 @@ bnx2_has_work(struct bnx2 *bp)
return 0;
}
static int
bnx2_poll(struct napi_struct *napi, int budget)
static int bnx2_poll_work(struct bnx2 *bp, int work_done, int budget)
{
struct bnx2 *bp = container_of(napi, struct bnx2, napi);
struct net_device *dev = bp->dev;
struct status_block *sblk = bp->status_blk;
u32 status_attn_bits = sblk->status_attn_bits;
u32 status_attn_bits_ack = sblk->status_attn_bits_ack;
int work_done = 0;
if ((status_attn_bits & STATUS_ATTN_EVENTS) !=
(status_attn_bits_ack & STATUS_ATTN_EVENTS)) {
@@ -2660,27 +2656,43 @@ bnx2_poll(struct napi_struct *napi, int budget)
bnx2_tx_int(bp);
if (bp->status_blk->status_rx_quick_consumer_index0 != bp->hw_rx_cons)
work_done = bnx2_rx_int(bp, budget);
work_done += bnx2_rx_int(bp, budget - work_done);
bp->last_status_idx = bp->status_blk->status_idx;
rmb();
return work_done;
}
static int bnx2_poll(struct napi_struct *napi, int budget)
{
struct bnx2 *bp = container_of(napi, struct bnx2, napi);
int work_done = 0;
while (1) {
work_done = bnx2_poll_work(bp, work_done, budget);
if (unlikely(work_done >= budget))
break;
if (likely(!bnx2_has_work(bp))) {
bp->last_status_idx = bp->status_blk->status_idx;
rmb();
netif_rx_complete(bp->dev, napi);
if (likely(bp->flags & USING_MSI_FLAG)) {
REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD,
BNX2_PCICFG_INT_ACK_CMD_INDEX_VALID |
bp->last_status_idx);
return 0;
}
REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD,
BNX2_PCICFG_INT_ACK_CMD_INDEX_VALID |
BNX2_PCICFG_INT_ACK_CMD_MASK_INT |
bp->last_status_idx);
if (!bnx2_has_work(bp)) {
netif_rx_complete(dev, napi);
if (likely(bp->flags & USING_MSI_FLAG)) {
REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD,
BNX2_PCICFG_INT_ACK_CMD_INDEX_VALID |
bp->last_status_idx);
return 0;
break;
}
REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD,
BNX2_PCICFG_INT_ACK_CMD_INDEX_VALID |
BNX2_PCICFG_INT_ACK_CMD_MASK_INT |
bp->last_status_idx);
REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD,
BNX2_PCICFG_INT_ACK_CMD_INDEX_VALID |
bp->last_status_idx);
}
return work_done;