[GIT PULL] SCSI fixes for 5.3-rc4

From: James Bottomley
Date: Tue Aug 13 2019 - 06:18:00 EST


single lpfc fix, for a single cpu corner case.

The patch is available here:

git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes

The short changelog is:

James Smart (1):
scsi: lpfc: Fix crash when cpu count is 1 and null irq affinity mask

And the diffstat

drivers/scsi/lpfc/lpfc_init.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)

With full diff below.

James

---

diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index faf43b1d3dbe..a7549ae32542 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -10776,12 +10776,31 @@ lpfc_cpu_affinity_check(struct lpfc_hba *phba, int vectors)
/* This loop sets up all CPUs that are affinitized with a
* irq vector assigned to the driver. All affinitized CPUs
* will get a link to that vectors IRQ and EQ.
+ *
+ * NULL affinity mask handling:
+ * If irq count is greater than one, log an error message.
+ * If the null mask is received for the first irq, find the
+ * first present cpu, and assign the eq index to ensure at
+ * least one EQ is assigned.
*/
for (idx = 0; idx < phba->cfg_irq_chann; idx++) {
/* Get a CPU mask for all CPUs affinitized to this vector */
maskp = pci_irq_get_affinity(phba->pcidev, idx);
- if (!maskp)
- continue;
+ if (!maskp) {
+ if (phba->cfg_irq_chann > 1)
+ lpfc_printf_log(phba, KERN_ERR, LOG_INIT,
+ "3329 No affinity mask found "
+ "for vector %d (%d)\n",
+ idx, phba->cfg_irq_chann);
+ if (!idx) {
+ cpu = cpumask_first(cpu_present_mask);
+ cpup = &phba->sli4_hba.cpu_map[cpu];
+ cpup->eq = idx;
+ cpup->irq = pci_irq_vector(phba->pcidev, idx);
+ cpup->flag |= LPFC_CPU_FIRST_IRQ;
+ }
+ break;
+ }

i = 0;
/* Loop through all CPUs associated with vector idx */