* [RFC PATCH v2 1/1] scsi: mpi3mr: Introduce smp_affinity_enable module parameter
2025-06-01 1:40 [RFC PATCH v2 0/1] scsi: mpi3mr: Introduce smp_affinity_enable module parameter Aaron Tomlin
@ 2025-06-01 1:40 ` Aaron Tomlin
2025-06-16 20:51 ` Martin K. Petersen
2025-06-17 7:18 ` John Garry
0 siblings, 2 replies; 4+ messages in thread
From: Aaron Tomlin @ 2025-06-01 1:40 UTC (permalink / raw)
To: mpi3mr-linuxdrv.pdl
Cc: kashyap.desai, sumit.saxena, sreekanth.reddy, James.Bottomley,
martin.petersen, atomlin, linux-scsi, linux-kernel
This patch introduces a new module parameter namely
"smp_affinity_enable", to govern the application of system-wide IRQ
affinity (with kernel boot-time parameter "irqaffinity") for MSI-X
interrupts. By default, the default IRQ affinity mask will not be
respected. Set smp_affinity_enable to 0 disables this behaviour.
Consequently, preventing the auto-assignment of MSI-X IRQs.
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
---
drivers/scsi/mpi3mr/mpi3mr.h | 1 +
drivers/scsi/mpi3mr/mpi3mr_fw.c | 14 ++++++++++++--
drivers/scsi/mpi3mr/mpi3mr_os.c | 14 +++++++++++---
3 files changed, 24 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/mpi3mr/mpi3mr.h b/drivers/scsi/mpi3mr/mpi3mr.h
index 9bbc7cb98ca3..82a0c1dd2f59 100644
--- a/drivers/scsi/mpi3mr/mpi3mr.h
+++ b/drivers/scsi/mpi3mr/mpi3mr.h
@@ -1378,6 +1378,7 @@ struct mpi3mr_ioc {
u32 num_tb_segs;
struct dma_pool *trace_buf_pool;
struct segments *trace_buf;
+ bool smp_affinity_enable;
};
diff --git a/drivers/scsi/mpi3mr/mpi3mr_fw.c b/drivers/scsi/mpi3mr/mpi3mr_fw.c
index 1d7901a8f0e4..9cbe1744213d 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_fw.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_fw.c
@@ -22,6 +22,10 @@ static int poll_queues;
module_param(poll_queues, int, 0444);
MODULE_PARM_DESC(poll_queues, "Number of queues for io_uring poll mode. (Range 1 - 126)");
+static int smp_affinity_enable = 1;
+module_param(smp_affinity_enable, int, 0444);
+MODULE_PARM_DESC(smp_affinity_enable, "SMP affinity feature enable/disable Default: enable(1)");
+
#if defined(writeq) && defined(CONFIG_64BIT)
static inline void mpi3mr_writeq(__u64 b, volatile void __iomem *addr)
{
@@ -821,6 +825,7 @@ static int mpi3mr_setup_isr(struct mpi3mr_ioc *mrioc, u8 setup_one)
int retval;
int i;
struct irq_affinity desc = { .pre_vectors = 1, .post_vectors = 1 };
+ struct irq_affinity *descp = &desc;
if (mrioc->is_intr_info_set)
return 0;
@@ -852,10 +857,13 @@ static int mpi3mr_setup_isr(struct mpi3mr_ioc *mrioc, u8 setup_one)
desc.post_vectors = mrioc->requested_poll_qcount;
min_vec = desc.pre_vectors + desc.post_vectors;
- irq_flags |= PCI_IRQ_AFFINITY | PCI_IRQ_ALL_TYPES;
+ if (mrioc->smp_affinity_enable)
+ irq_flags |= PCI_IRQ_AFFINITY | PCI_IRQ_ALL_TYPES;
+ else
+ descp = NULL;
retval = pci_alloc_irq_vectors_affinity(mrioc->pdev,
- min_vec, max_vectors, irq_flags, &desc);
+ min_vec, max_vectors, irq_flags, descp);
if (retval < 0) {
ioc_err(mrioc, "cannot allocate irq vectors, ret %d\n",
@@ -4233,6 +4241,8 @@ int mpi3mr_init_ioc(struct mpi3mr_ioc *mrioc)
goto out_failed_noretry;
}
+ mrioc->smp_affinity_enable = smp_affinity_enable ? true : false;
+
retval = mpi3mr_setup_isr(mrioc, 1);
if (retval) {
ioc_err(mrioc, "Failed to setup ISR error %d\n",
diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
index ce444efd859e..6ea73cf7579b 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_os.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
@@ -4064,6 +4064,9 @@ static void mpi3mr_map_queues(struct Scsi_Host *shost)
int i, qoff, offset;
struct blk_mq_queue_map *map = NULL;
+ if (shost->nr_hw_queues == 1)
+ return;
+
offset = mrioc->op_reply_q_offset;
for (i = 0, qoff = 0; i < HCTX_MAX_TYPES; i++) {
@@ -5422,8 +5425,6 @@ mpi3mr_probe(struct pci_dev *pdev, const struct pci_device_id *id)
shost->max_channel = 0;
shost->max_id = 0xFFFFFFFF;
- shost->host_tagset = 1;
-
if (prot_mask >= 0)
scsi_host_set_prot(shost, prot_mask);
else {
@@ -5471,7 +5472,14 @@ mpi3mr_probe(struct pci_dev *pdev, const struct pci_device_id *id)
goto init_ioc_failed;
}
- shost->nr_hw_queues = mrioc->num_op_reply_q;
+ shost->host_tagset = 0;
+ shost->nr_hw_queues = 1;
+
+ if (mrioc->smp_affinity_enable) {
+ shost->nr_hw_queues = mrioc->num_op_reply_q;
+ shost->host_tagset = 1;
+ }
+
if (mrioc->active_poll_qcount)
shost->nr_maps = 3;
--
2.49.0
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