[PATCH] net: mana: add msix index sharing between EQs

From: Konstantin Taranov
Date: Fri Dec 08 2023 - 07:35:55 EST


From: Konstantin Taranov <kotaranov@xxxxxxxxxxxxx>

This patch allows to assign and poll more than 1 EQ on the same msix index.
It is achieved by introducing a list of attached EQs in each IRQ context.
This patch export symbols for creating EQs from other MANA kernel modules.

Signed-off-by: Konstantin Taranov <kotaranov@xxxxxxxxxxxxx>
---
.../net/ethernet/microsoft/mana/gdma_main.c | 55 ++++++++++++++-----
.../net/ethernet/microsoft/mana/hw_channel.c | 1 +
drivers/net/ethernet/microsoft/mana/mana_en.c | 1 +
include/net/mana/gdma.h | 4 +-
4 files changed, 45 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index 6367de0..82a4534 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -401,6 +401,9 @@ static void mana_gd_process_eq_events(void *arg)
u32 head, num_eqe;
int i;

+ if (eq->id == INVALID_QUEUE_ID)
+ return;
+
gc = eq->gdma_dev->gdma_context;

num_eqe = eq->queue_size / GDMA_EQE_SIZE;
@@ -414,8 +417,12 @@ static void mana_gd_process_eq_events(void *arg)

old_bits = (eq->head / num_eqe - 1) & GDMA_EQE_OWNER_MASK;
/* No more entries */
- if (owner_bits == old_bits)
+ if (owner_bits == old_bits) {
+ /* return here without ringing the doorbell */
+ if (i == 0)
+ return;
break;
+ }

new_bits = (eq->head / num_eqe) & GDMA_EQE_OWNER_MASK;
if (owner_bits != new_bits) {
@@ -457,12 +464,16 @@ static int mana_gd_register_irq(struct gdma_queue *queue,

spin_lock_irqsave(&r->lock, flags);

- msi_index = find_first_zero_bit(r->map, r->size);
+ if (queue->eq.msix_index == INVALID_PCI_MSIX_INDEX)
+ queue->eq.msix_index = find_first_zero_bit(r->map, r->size);
+
+ msi_index = queue->eq.msix_index;
+
if (msi_index >= r->size || msi_index >= gc->num_msix_usable) {
err = -ENOSPC;
+ queue->eq.msix_index = INVALID_PCI_MSIX_INDEX;
} else {
bitmap_set(r->map, msi_index, 1);
- queue->eq.msix_index = msi_index;
}

spin_unlock_irqrestore(&r->lock, flags);
@@ -476,9 +487,7 @@ static int mana_gd_register_irq(struct gdma_queue *queue,

gic = &gc->irq_contexts[msi_index];

- WARN_ON(gic->handler || gic->arg);
-
- gic->arg = queue;
+ list_add_rcu(&queue->entry, &gic->eq_list);

gic->handler = mana_gd_process_eq_events;

@@ -493,6 +502,7 @@ static void mana_gd_deregiser_irq(struct gdma_queue *queue)
struct gdma_resource *r;
unsigned int msix_index;
unsigned long flags;
+ struct gdma_queue *eq;

gc = gd->gdma_context;
r = &gc->msix_resource;
@@ -502,12 +512,19 @@ static void mana_gd_deregiser_irq(struct gdma_queue *queue)
if (WARN_ON(msix_index >= gc->num_msix_usable))
return;

- gic = &gc->irq_contexts[msix_index];
- gic->handler = NULL;
- gic->arg = NULL;
-
spin_lock_irqsave(&r->lock, flags);
- bitmap_clear(r->map, msix_index, 1);
+ gic = &gc->irq_contexts[msix_index];
+ list_for_each_entry_rcu(eq, &gic->eq_list, entry) {
+ if (queue == eq) {
+ list_del_rcu(&eq->entry);
+ synchronize_rcu();
+ break;
+ }
+ }
+ if (list_empty(&gic->eq_list)) {
+ gic->handler = NULL;
+ bitmap_clear(r->map, msix_index, 1);
+ }
spin_unlock_irqrestore(&r->lock, flags);

queue->eq.msix_index = INVALID_PCI_MSIX_INDEX;
@@ -587,7 +604,8 @@ static int mana_gd_create_eq(struct gdma_dev *gd,
u32 log2_num_entries;
int err;

- queue->eq.msix_index = INVALID_PCI_MSIX_INDEX;
+ queue->eq.msix_index = spec->eq.msix_index;
+ queue->id = INVALID_QUEUE_ID;

log2_num_entries = ilog2(queue->queue_size / GDMA_EQE_SIZE);

@@ -819,6 +837,7 @@ free_q:
kfree(queue);
return err;
}
+EXPORT_SYMBOL_NS(mana_gd_create_mana_eq, NET_MANA);

int mana_gd_create_mana_wq_cq(struct gdma_dev *gd,
const struct gdma_queue_spec *spec,
@@ -895,6 +914,7 @@ void mana_gd_destroy_queue(struct gdma_context *gc, struct gdma_queue *queue)
mana_gd_free_memory(gmi);
kfree(queue);
}
+EXPORT_SYMBOL_NS(mana_gd_destroy_queue, NET_MANA);

int mana_gd_verify_vf_version(struct pci_dev *pdev)
{
@@ -1217,9 +1237,14 @@ int mana_gd_poll_cq(struct gdma_queue *cq, struct gdma_comp *comp, int num_cqe)
static irqreturn_t mana_gd_intr(int irq, void *arg)
{
struct gdma_irq_context *gic = arg;
+ struct list_head *eq_list = &gic->eq_list;
+ struct gdma_queue *eq;

- if (gic->handler)
- gic->handler(gic->arg);
+ if (gic->handler) {
+ list_for_each_entry_rcu(eq, eq_list, entry) {
+ gic->handler(eq);
+ }
+ }

return IRQ_HANDLED;
}
@@ -1272,7 +1297,7 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
for (i = 0; i < nvec; i++) {
gic = &gc->irq_contexts[i];
gic->handler = NULL;
- gic->arg = NULL;
+ INIT_LIST_HEAD(&gic->eq_list);

if (!i)
snprintf(gic->name, MANA_IRQ_NAME_SZ, "mana_hwc@pci:%s",
diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c b/drivers/net/ethernet/microsoft/mana/hw_channel.c
index 9d1cd3b..0a5fc39 100644
--- a/drivers/net/ethernet/microsoft/mana/hw_channel.c
+++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c
@@ -300,6 +300,7 @@ static int mana_hwc_create_gdma_eq(struct hw_channel_context *hwc,
spec.eq.context = ctx;
spec.eq.callback = cb;
spec.eq.log2_throttle_limit = DEFAULT_LOG2_THROTTLING_FOR_ERROR_EQ;
+ spec.eq.msix_index = INVALID_PCI_MSIX_INDEX;

return mana_gd_create_hwc_queue(hwc->gdma_dev, &spec, queue);
}
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index fc3d290..8718c04 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1242,6 +1242,7 @@ static int mana_create_eq(struct mana_context *ac)
spec.eq.callback = NULL;
spec.eq.context = ac->eqs;
spec.eq.log2_throttle_limit = LOG2_EQ_THROTTLE;
+ spec.eq.msix_index = INVALID_PCI_MSIX_INDEX;

for (i = 0; i < gc->max_num_queues; i++) {
err = mana_gd_create_mana_eq(gd, &spec, &ac->eqs[i].eq);
diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
index 88b6ef7..8d6569d 100644
--- a/include/net/mana/gdma.h
+++ b/include/net/mana/gdma.h
@@ -293,6 +293,7 @@ struct gdma_queue {

u32 head;
u32 tail;
+ struct list_head entry;

/* Extra fields specific to EQ/CQ. */
union {
@@ -328,6 +329,7 @@ struct gdma_queue_spec {
void *context;

unsigned long log2_throttle_limit;
+ unsigned int msix_index;
} eq;

struct {
@@ -344,7 +346,7 @@ struct gdma_queue_spec {

struct gdma_irq_context {
void (*handler)(void *arg);
- void *arg;
+ struct list_head eq_list;
char name[MANA_IRQ_NAME_SZ];
};

--
2.43.0