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qlge: Allow running MSIx with fewer vectors.

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Currently we downshift to MSI/Legacy if we don't get enough vectors for
cpu_count RSS rings plus cpu_count TX completion rings.  This patch
allows running MSIX with the vector count that the platform provides.

Signed-off-by: Ron Mercer <ron.mercer@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ron Mercer 2009-08-27 11:02:10 +00:00 committed by David S. Miller
parent b2014ff8ac
commit a4ab613717
1 changed files with 37 additions and 46 deletions
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83
drivers/net/qlge/qlge_main.c
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@ -2815,17 +2815,20 @@ static void ql_disable_msix(struct ql_adapter *qdev)
}
}
/* We start by trying to get the number of vectors
* stored in qdev->intr_count. If we don't get that
* many then we reduce the count and try again.
*/
static void ql_enable_msix(struct ql_adapter *qdev)
{
int i;
int i, err;
qdev->intr_count = 1;
/* Get the MSIX vectors. */
if (irq_type == MSIX_IRQ) {
/* Try to alloc space for the msix struct,
* if it fails then go to MSI/legacy.
*/
qdev->msi_x_entry = kcalloc(qdev->rx_ring_count,
qdev->msi_x_entry = kcalloc(qdev->intr_count,
sizeof(struct msix_entry),
GFP_KERNEL);
if (!qdev->msi_x_entry) {
@ -2833,26 +2836,36 @@ static void ql_enable_msix(struct ql_adapter *qdev)
goto msi;
}
for (i = 0; i < qdev->rx_ring_count; i++)
for (i = 0; i < qdev->intr_count; i++)
qdev->msi_x_entry[i].entry = i;
if (!pci_enable_msix
(qdev->pdev, qdev->msi_x_entry, qdev->rx_ring_count)) {
set_bit(QL_MSIX_ENABLED, &qdev->flags);
qdev->intr_count = qdev->rx_ring_count;
QPRINTK(qdev, IFUP, DEBUG,
"MSI-X Enabled, got %d vectors.\n",
qdev->intr_count);
return;
} else {
/* Loop to get our vectors. We start with
* what we want and settle for what we get.
*/
do {
err = pci_enable_msix(qdev->pdev,
qdev->msi_x_entry, qdev->intr_count);
if (err > 0)
qdev->intr_count = err;
} while (err > 0);
if (err < 0) {
kfree(qdev->msi_x_entry);
qdev->msi_x_entry = NULL;
QPRINTK(qdev, IFUP, WARNING,
"MSI-X Enable failed, trying MSI.\n");
qdev->intr_count = 1;
irq_type = MSI_IRQ;
} else if (err == 0) {
set_bit(QL_MSIX_ENABLED, &qdev->flags);
QPRINTK(qdev, IFUP, INFO,
"MSI-X Enabled, got %d vectors.\n",
qdev->intr_count);
return;
}
}
msi:
qdev->intr_count = 1;
if (irq_type == MSI_IRQ) {
if (!pci_enable_msi(qdev->pdev)) {
set_bit(QL_MSI_ENABLED, &qdev->flags);
@ -2876,8 +2889,6 @@ static void ql_resolve_queues_to_irqs(struct ql_adapter *qdev)
int i = 0;
struct intr_context *intr_context = &qdev->intr_context[0];
ql_enable_msix(qdev);
if (likely(test_bit(QL_MSIX_ENABLED, &qdev->flags))) {
/* Each rx_ring has it's
* own intr_context since we have separate
@ -3438,40 +3449,20 @@ static int ql_configure_rings(struct ql_adapter *qdev)
int i;
struct rx_ring *rx_ring;
struct tx_ring *tx_ring;
int cpu_cnt = num_online_cpus();
int cpu_cnt = min(MAX_CPUS, (int)num_online_cpus());
/*
* For each processor present we allocate one
* rx_ring for outbound completions, and one
* rx_ring for inbound completions. Plus there is
* always the one default queue. For the CPU
* counts we end up with the following rx_rings:
* rx_ring count =
* one default queue +
* (CPU count * outbound completion rx_ring) +
* (CPU count * inbound (RSS) completion rx_ring)
* To keep it simple we limit the total number of
* queues to < 32, so we truncate CPU to 8.
* This limitation can be removed when requested.
/* In a perfect world we have one RSS ring for each CPU
* and each has it's own vector. To do that we ask for
* cpu_cnt vectors. ql_enable_msix() will adjust the
* vector count to what we actually get. We then
* allocate an RSS ring for each.
* Essentially, we are doing min(cpu_count, msix_vector_count).
*/
if (cpu_cnt > MAX_CPUS)
cpu_cnt = MAX_CPUS;
/*
* rx_ring[0] is always the default queue.
*/
/* Allocate outbound completion ring for each CPU. */
qdev->intr_count = cpu_cnt;
ql_enable_msix(qdev);
/* Adjust the RSS ring count to the actual vector count. */
qdev->rss_ring_count = qdev->intr_count;
qdev->tx_ring_count = cpu_cnt;
/* Allocate inbound completion (RSS) ring for each CPU. */
qdev->rss_ring_count = cpu_cnt;
/*
* qdev->rx_ring_count:
* Total number of rx_rings. This includes the one
* default queue, a number of outbound completion
* handler rx_rings, and the number of inbound
* completion handler rx_rings.
*/
qdev->rx_ring_count = qdev->tx_ring_count + qdev->rss_ring_count;
for (i = 0; i < qdev->tx_ring_count; i++) {