nvme: Allocate all MSI resources up front so that we can fall back to

INTx if necessary.

Sponsored by:	Intel
MFC after:	3 days
This commit is contained in:
Jim Harris 2014-03-18 18:10:35 +00:00
parent 496a27520d
commit f42ca756b9
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=263311
3 changed files with 44 additions and 7 deletions

View File

@ -1075,8 +1075,8 @@ nvme_ctrlr_construct(struct nvme_controller *ctrlr, device_t dev)
{
union cap_lo_register cap_lo;
union cap_hi_register cap_hi;
int num_vectors, per_cpu_io_queues, status = 0;
int timeout_period;
int i, num_vectors, per_cpu_io_queues, rid;
int status, timeout_period;
ctrlr->dev = dev;
@ -1149,8 +1149,45 @@ nvme_ctrlr_construct(struct nvme_controller *ctrlr, device_t dev)
goto intx;
}
if (pci_alloc_msix(dev, &num_vectors) != 0)
if (pci_alloc_msix(dev, &num_vectors) != 0) {
ctrlr->msix_enabled = 0;
goto intx;
}
/*
* On earlier FreeBSD releases, there are reports that
* pci_alloc_msix() can return successfully with all vectors
* requested, but a subsequent bus_alloc_resource_any()
* for one of those vectors fails. This issue occurs more
* readily with multiple devices using per-CPU vectors.
* To workaround this issue, try to allocate the resources now,
* and fall back to INTx if we cannot allocate all of them.
* This issue cannot be reproduced on more recent versions of
* FreeBSD which have increased the maximum number of MSI-X
* vectors, but adding the workaround makes it easier for
* vendors wishing to import this driver into kernels based on
* older versions of FreeBSD.
*/
for (i = 0; i < num_vectors; i++) {
rid = i + 1;
ctrlr->msi_res[i] = bus_alloc_resource_any(ctrlr->dev,
SYS_RES_IRQ, &rid, RF_ACTIVE);
if (ctrlr->msi_res[i] == NULL) {
ctrlr->msix_enabled = 0;
while (i > 0) {
i--;
bus_release_resource(ctrlr->dev,
SYS_RES_IRQ,
rman_get_rid(ctrlr->msi_res[i]),
ctrlr->msi_res[i]);
}
pci_release_msi(dev);
nvme_printf(ctrlr, "could not obtain all MSI-X "
"resources, reverting to intx\n");
break;
}
}
intx:

View File

@ -289,6 +289,8 @@ struct nvme_controller {
struct task fail_req_task;
struct taskqueue *taskqueue;
struct resource *msi_res[MAXCPU + 1];
/* For shared legacy interrupt. */
int rid;
struct resource *res;

View File

@ -1,5 +1,5 @@
/*-
* Copyright (C) 2012-2013 Intel Corporation
* Copyright (C) 2012-2014 Intel Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -487,9 +487,7 @@ nvme_qpair_construct(struct nvme_qpair *qpair, uint32_t id,
* the queue's vector to get the corresponding rid to use.
*/
qpair->rid = vector + 1;
qpair->res = bus_alloc_resource_any(ctrlr->dev, SYS_RES_IRQ,
&qpair->rid, RF_ACTIVE);
qpair->res = ctrlr->msi_res[vector];
bus_setup_intr(ctrlr->dev, qpair->res,
INTR_TYPE_MISC | INTR_MPSAFE, NULL,