[PATCH 6/6] scsi: hisi_sas: Expose multiple hw queues for v3 as experimental

From: John Garry
Date: Thu Oct 24 2019 - 10:25:04 EST

Since we're not ready to expose mutliple queues to the upper layer always
due to CPU hotplug issue, add a new interim experimental command line
option to support it.

We still need to keep supporting auto_affine_msi_experimental, since
people are now replying the performance it provides, even though it is
unsafe.

If auto_affine_msi_experimental and expose_mq_experimental are both set,
then auto_affine_msi_experimental takes preference.

Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
drivers/scsi/hisi_sas/hisi_sas.h | 2 +
drivers/scsi/hisi_sas/hisi_sas_main.c | 55 ++++++++++++++++----------
drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 51 +++++++++++++++++++++---
3 files changed, 83 insertions(+), 25 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index 4eb8f1c53f78..884f2426d753 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -8,6 +8,8 @@
#define _HISI_SAS_H_

#include <linux/acpi.h>
+#include <linux/blk-mq.h>
+#include <linux/blk-mq-pci.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/dmapool.h>
diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 53802c1cc1d0..c8c96a46acfd 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -389,9 +389,11 @@ static int hisi_sas_task_prep(struct sas_task *task,
struct hisi_sas_slot *slot;
struct hisi_sas_cmd_hdr *cmd_hdr_base;
struct asd_sas_port *sas_port = device->port;
+ struct Scsi_Host *shost = hisi_hba->shost;
struct device *dev = hisi_hba->dev;
int dlvry_queue_slot, dlvry_queue, rc, slot_idx;
int n_elem = 0, n_elem_dif = 0, n_elem_req = 0;
+ struct scsi_cmnd *scmd = NULL;
struct hisi_sas_dq *dq;
unsigned long flags;
int wr_q_index;
@@ -407,13 +409,38 @@ static int hisi_sas_task_prep(struct sas_task *task,
return -ECOMM;
}

- if (hisi_hba->reply_map) {
- int cpu = raw_smp_processor_id();
- unsigned int dq_index = hisi_hba->reply_map[cpu];
+ if (task->uldd_task) {
+ struct ata_queued_cmd *qc;

- *dq_pointer = dq = &hisi_hba->dq[dq_index];
- } else {
+ if (dev_is_sata(device)) {
+ qc = task->uldd_task;
+ scmd = qc->scsicmd;
+ } else {
+ scmd = task->uldd_task;
+ }
+ }
+
+ /* We have to move to just a single mode: expose multiple queues */
+ if (!hisi_hba->reply_map && !shost->nr_hw_queues) {
*dq_pointer = dq = sas_dev->dq;
+ } else {
+ if (hisi_hba->reply_map) {
+ int cpu = raw_smp_processor_id();
+ unsigned int dq_index = hisi_hba->reply_map[cpu];
+
+ *dq_pointer = dq = &hisi_hba->dq[dq_index];
+ } else {
+ if (scmd) {
+ unsigned int dq_index;
+ u32 blk_tag;
+
+ blk_tag = blk_mq_unique_tag(scmd->request);
+ dq_index = blk_mq_unique_tag_to_hwq(blk_tag);
+ *dq_pointer = dq = &hisi_hba->dq[dq_index];
+ } else {
+ *dq_pointer = dq = sas_dev->dq;
+ }
+ }
}

port = to_hisi_sas_port(sas_port);
@@ -438,22 +465,10 @@ static int hisi_sas_task_prep(struct sas_task *task,
}

if (hisi_hba->hw->slot_index_alloc)
- rc = hisi_hba->hw->slot_index_alloc(hisi_hba, device, NULL);
- else {
- struct scsi_cmnd *scsi_cmnd = NULL;
-
- if (task->uldd_task) {
- struct ata_queued_cmd *qc;
+ rc = hisi_hba->hw->slot_index_alloc(hisi_hba, device, scmd);
+ else
+ rc = hisi_sas_slot_index_alloc(hisi_hba, scmd);

- if (dev_is_sata(device)) {
- qc = task->uldd_task;
- scsi_cmnd = qc->scsicmd;
- } else {
- scsi_cmnd = task->uldd_task;
- }
- }
- rc = hisi_sas_slot_index_alloc(hisi_hba, scsi_cmnd);
- }
if (rc < 0)
goto err_out_dif_dma_unmap;

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 29119d0b27a7..03ba0416f910 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -512,6 +512,11 @@ module_param(auto_affine_msi_experimental, bool, 0444);
MODULE_PARM_DESC(auto_affine_msi_experimental, "Enable auto-affinity of MSI IRQs as experimental:\n"
"default is off");

+static bool expose_mq_experimental;
+module_param(expose_mq_experimental, bool, 0444);
+MODULE_PARM_DESC(expose_mq_experimental, "Expose multiple hw queues to upper layer as experimental:\n"
+ "default is off");
+
static u32 hisi_sas_read32(struct hisi_hba *hisi_hba, u32 off)
{
void __iomem *regs = hisi_hba->regs + off;
@@ -558,6 +563,11 @@ static u32 hisi_sas_phy_read32(struct hisi_hba *hisi_hba,

static int bitmaps_alloc_v3_hw(struct hisi_hba *hisi_hba)
{
+ if (expose_mq_experimental)
+ return sbitmap_init_node(&hisi_hba->slot_index_tags,
+ HISI_SAS_MAX_COMMANDS, -1,
+ GFP_KERNEL,
+ dev_to_node(hisi_hba->dev));
return sbitmap_init_node(&hisi_hba->slot_index_tags,
HISI_SAS_UNRESERVED_IPTT, -1,
GFP_KERNEL, dev_to_node(hisi_hba->dev));
@@ -570,6 +580,10 @@ static int slot_index_alloc_v3_hw(struct hisi_hba *hisi_hba,
struct sbitmap *slot_index_tags = &hisi_hba->slot_index_tags;
int index;

+ if (expose_mq_experimental)
+ return sbitmap_get(slot_index_tags,
+ hisi_hba->sbitmap_alloc_hint, false);
+
if (scmd)
return scmd->request->tag;

@@ -583,7 +597,10 @@ static void slot_index_free_v3_hw(struct hisi_hba *hisi_hba, int slot_idx)
{
struct sbitmap *slot_index_tags = &hisi_hba->slot_index_tags;

- if (slot_idx >= HISI_SAS_UNRESERVED_IPTT)
+ if (expose_mq_experimental) {
+ sbitmap_clear_bit(slot_index_tags, slot_idx);
+ hisi_hba->sbitmap_alloc_hint = slot_idx;
+ } else if (slot_idx >= HISI_SAS_UNRESERVED_IPTT)
sbitmap_clear_bit(slot_index_tags,
slot_idx - HISI_SAS_UNRESERVED_IPTT);
}
@@ -2414,8 +2431,9 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba)
struct device *dev = hisi_hba->dev;
int vectors;
int max_msi = HISI_SAS_MSI_COUNT_V3_HW, min_msi;
+ struct Scsi_Host *shost = hisi_hba->shost;

- if (auto_affine_msi_experimental) {
+ if (auto_affine_msi_experimental || expose_mq_experimental) {
struct irq_affinity desc = {
.pre_vectors = BASE_VECTORS_V3_HW,
};
@@ -2434,7 +2452,9 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba)
&desc);
if (vectors < 0)
return -ENOENT;
- setup_reply_map_v3_hw(hisi_hba, vectors - BASE_VECTORS_V3_HW);
+ if (auto_affine_msi_experimental)
+ setup_reply_map_v3_hw(hisi_hba,
+ vectors - BASE_VECTORS_V3_HW);
} else {
min_msi = max_msi;
vectors = pci_alloc_irq_vectors(hisi_hba->pci_dev, min_msi,
@@ -2444,6 +2464,9 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba)
}

hisi_hba->cq_nvecs = vectors - BASE_VECTORS_V3_HW;
+ if (expose_mq_experimental)
+ shost->nr_hw_queues = hisi_hba->cq_nvecs;
+
return 0;
}

@@ -3096,6 +3119,17 @@ static int debugfs_set_bist_v3_hw(struct hisi_hba *hisi_hba, bool enable)
return 0;
}

+static int hisi_sas_map_queues(struct Scsi_Host *shost)
+{
+ struct hisi_hba *hisi_hba = shost_priv(shost);
+ struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT];
+
+ if (expose_mq_experimental)
+ return blk_mq_pci_map_queues(qmap, hisi_hba->pci_dev,
+ BASE_VECTORS_V3_HW);
+ return blk_mq_map_queues(qmap);
+}
+
static struct scsi_host_template sht_v3_hw = {
.name = DRV_NAME,
.module = THIS_MODULE,
@@ -3104,6 +3138,7 @@ static struct scsi_host_template sht_v3_hw = {
.slave_configure = hisi_sas_slave_configure,
.scan_finished = hisi_sas_scan_finished,
.scan_start = hisi_sas_scan_start,
+ .map_queues = hisi_sas_map_queues,
.change_queue_depth = sas_change_queue_depth,
.bios_param = sas_bios_param,
.this_id = -1,
@@ -3265,8 +3300,14 @@ hisi_sas_v3_probe(struct pci_dev *pdev, const struct pci_device_id *id)
shost->max_lun = ~0;
shost->max_channel = 1;
shost->max_cmd_len = 16;
- shost->can_queue = HISI_SAS_UNRESERVED_IPTT;
- shost->cmd_per_lun = HISI_SAS_UNRESERVED_IPTT;
+
+ if (expose_mq_experimental) {
+ shost->can_queue = HISI_SAS_MAX_COMMANDS;
+ shost->cmd_per_lun = HISI_SAS_MAX_COMMANDS;
+ } else {
+ shost->can_queue = HISI_SAS_UNRESERVED_IPTT;
+ shost->cmd_per_lun = HISI_SAS_UNRESERVED_IPTT;
+ }

sha->sas_ha_name = DRV_NAME;
sha->dev = dev;
--
2.17.1