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net: mana: Allocate MSI-X vectors dynamically

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Currently, the MANA driver allocates MSI-X vectors statically based on
MANA_MAX_NUM_QUEUES and num_online_cpus() values and in some cases ends
up allocating more vectors than it needs. This is because, by this time
we do not have a HW channel and do not know how many IRQs should be
allocated.

To avoid this, we allocate 1 MSI-X vector during the creation of HWC and
after getting the value supported by hardware, dynamically add the
remaining MSI-X vectors.

Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
This commit is contained in:
Shradha Gupta 2025-06-11 07:11:13 -07:00
parent 845c62c543
commit 7553911210
2 changed files with 236 additions and 85 deletions
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291
drivers/net/ethernet/microsoft/mana/gdma_main.c
View file

@ -6,6 +6,8 @@
#include <linux/pci.h>
#include <linux/utsname.h>
#include <linux/version.h>
#include <linux/msi.h>
#include <linux/irqdomain.h>
#include <net/mana/mana.h>
@ -80,8 +82,15 @@ static int mana_gd_query_max_resources(struct pci_dev *pdev)
return err ? err : -EPROTO;
}
if (!pci_msix_can_alloc_dyn(pdev)) {
if (gc->num_msix_usable > resp.max_msix)
gc->num_msix_usable = resp.max_msix;
} else {
/* If dynamic allocation is enabled we have already allocated
* hwc msi
*/
gc->num_msix_usable = min(resp.max_msix, num_online_cpus() + 1);
}
if (gc->num_msix_usable <= 1)
return -ENOSPC;
@ -483,7 +492,9 @@ static int mana_gd_register_irq(struct gdma_queue *queue,
}
queue->eq.msix_index = msi_index;
gic = &gc->irq_contexts[msi_index];
gic = xa_load(&gc->irq_contexts, msi_index);
if (WARN_ON(!gic))
return -EINVAL;
spin_lock_irqsave(&gic->lock, flags);
list_add_rcu(&queue->entry, &gic->eq_list);
@ -508,7 +519,10 @@ 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 = xa_load(&gc->irq_contexts, msix_index);
if (WARN_ON(!gic))
return;
spin_lock_irqsave(&gic->lock, flags);
list_for_each_entry_rcu(eq, &gic->eq_list, entry) {
if (queue == eq) {
@ -1366,47 +1380,108 @@ done:
return 0;
}
static int mana_gd_setup_irqs(struct pci_dev *pdev)
static int mana_gd_setup_dyn_irqs(struct pci_dev *pdev, int nvec)
{
struct gdma_context *gc = pci_get_drvdata(pdev);
unsigned int max_queues_per_port;
struct gdma_irq_context *gic;
unsigned int max_irqs, cpu;
int start_irq_index = 1;
int nvec, *irqs, irq;
int err, i = 0, j;
bool skip_first_cpu = false;
int *irqs, irq, err, i;
irqs = kmalloc_array(nvec, sizeof(int), GFP_KERNEL);
if (!irqs)
return -ENOMEM;
/*
* While processing the next pci irq vector, we start with index 1,
* as IRQ vector at index 0 is already processed for HWC.
* However, the population of irqs array starts with index 0, to be
* further used in irq_setup()
*/
for (i = 1; i <= nvec; i++) {
gic = kzalloc(sizeof(*gic), GFP_KERNEL);
if (!gic) {
err = -ENOMEM;
goto free_irq;
}
gic->handler = mana_gd_process_eq_events;
INIT_LIST_HEAD(&gic->eq_list);
spin_lock_init(&gic->lock);
snprintf(gic->name, MANA_IRQ_NAME_SZ, "mana_q%d@pci:%s",
i - 1, pci_name(pdev));
/* one pci vector is already allocated for HWC */
irqs[i - 1] = pci_irq_vector(pdev, i);
if (irqs[i - 1] < 0) {
err = irqs[i - 1];
goto free_current_gic;
}
err = request_irq(irqs[i - 1], mana_gd_intr, 0, gic->name, gic);
if (err)
goto free_current_gic;
xa_store(&gc->irq_contexts, i, gic, GFP_KERNEL);
}
/*
* When calling irq_setup() for dynamically added IRQs, if number of
* CPUs is more than or equal to allocated MSI-X, we need to skip the
* first CPU sibling group since they are already affinitized to HWC IRQ
*/
cpus_read_lock();
max_queues_per_port = num_online_cpus();
if (max_queues_per_port > MANA_MAX_NUM_QUEUES)
max_queues_per_port = MANA_MAX_NUM_QUEUES;
if (gc->num_msix_usable <= num_online_cpus())
skip_first_cpu = true;
/* Need 1 interrupt for the Hardware communication Channel (HWC) */
max_irqs = max_queues_per_port + 1;
nvec = pci_alloc_irq_vectors(pdev, 2, max_irqs, PCI_IRQ_MSIX);
if (nvec < 0) {
err = irq_setup(irqs, nvec, gc->numa_node, skip_first_cpu);
if (err) {
cpus_read_unlock();
return nvec;
}
if (nvec <= num_online_cpus())
start_irq_index = 0;
irqs = kmalloc_array((nvec - start_irq_index), sizeof(int), GFP_KERNEL);
if (!irqs) {
err = -ENOMEM;
goto free_irq_vector;
goto free_irq;
}
gc->irq_contexts = kcalloc(nvec, sizeof(struct gdma_irq_context),
GFP_KERNEL);
if (!gc->irq_contexts) {
err = -ENOMEM;
goto free_irq_array;
cpus_read_unlock();
kfree(irqs);
return 0;
free_current_gic:
kfree(gic);
free_irq:
for (i -= 1; i > 0; i--) {
irq = pci_irq_vector(pdev, i);
gic = xa_load(&gc->irq_contexts, i);
if (WARN_ON(!gic))
continue;
irq_update_affinity_hint(irq, NULL);
free_irq(irq, gic);
xa_erase(&gc->irq_contexts, i);
kfree(gic);
}
kfree(irqs);
return err;
}
static int mana_gd_setup_irqs(struct pci_dev *pdev, int nvec)
{
struct gdma_context *gc = pci_get_drvdata(pdev);
struct gdma_irq_context *gic;
int *irqs, *start_irqs, irq;
unsigned int cpu;
int err, i;
irqs = kmalloc_array(nvec, sizeof(int), GFP_KERNEL);
if (!irqs)
return -ENOMEM;
start_irqs = irqs;
for (i = 0; i < nvec; i++) {
gic = &gc->irq_contexts[i];
gic = kzalloc(sizeof(*gic), GFP_KERNEL);
if (!gic) {
err = -ENOMEM;
goto free_irq;
}
gic->handler = mana_gd_process_eq_events;
INIT_LIST_HEAD(&gic->eq_list);
spin_lock_init(&gic->lock);
@ -1418,16 +1493,18 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
snprintf(gic->name, MANA_IRQ_NAME_SZ, "mana_q%d@pci:%s",
i - 1, pci_name(pdev));
irq = pci_irq_vector(pdev, i);
if (irq < 0) {
err = irq;
goto free_irq;
irqs[i] = pci_irq_vector(pdev, i);
if (irqs[i] < 0) {
err = irqs[i];
goto free_current_gic;
}
if (!i) {
err = request_irq(irq, mana_gd_intr, 0, gic->name, gic);
err = request_irq(irqs[i], mana_gd_intr, 0, gic->name, gic);
if (err)
goto free_irq;
goto free_current_gic;
xa_store(&gc->irq_contexts, i, gic, GFP_KERNEL);
}
/* If number of IRQ is one extra than number of online CPUs,
* then we need to assign IRQ0 (hwc irq) and IRQ1 to
@ -1437,48 +1514,105 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
* cpumask_first for the node, because the node can be
* mem only.
*/
if (start_irq_index) {
cpu = cpumask_local_spread(i, gc->numa_node);
irq_set_affinity_and_hint(irq, cpumask_of(cpu));
} else {
irqs[start_irq_index] = irq;
}
} else {
irqs[i - start_irq_index] = irq;
err = request_irq(irqs[i - start_irq_index], mana_gd_intr, 0,
gic->name, gic);
if (err)
goto free_irq;
}
cpus_read_lock();
if (nvec > num_online_cpus()) {
cpu = cpumask_local_spread(0, gc->numa_node);
irq_set_affinity_and_hint(irqs[0], cpumask_of(cpu));
irqs++;
nvec -= 1;
}
err = irq_setup(irqs, nvec - start_irq_index, gc->numa_node, false);
if (err)
goto free_irq;
gc->max_num_msix = nvec;
gc->num_msix_usable = nvec;
err = irq_setup(irqs, nvec, gc->numa_node, false);
if (err) {
cpus_read_unlock();
kfree(irqs);
goto free_irq;
}
cpus_read_unlock();
kfree(start_irqs);
return 0;
free_current_gic:
kfree(gic);
free_irq:
for (j = i - 1; j >= 0; j--) {
irq = pci_irq_vector(pdev, j);
gic = &gc->irq_contexts[j];
for (i -= 1; i >= 0; i--) {
irq = pci_irq_vector(pdev, i);
gic = xa_load(&gc->irq_contexts, i);
if (WARN_ON(!gic))
continue;
irq_update_affinity_hint(irq, NULL);
free_irq(irq, gic);
xa_erase(&gc->irq_contexts, i);
kfree(gic);
}
kfree(gc->irq_contexts);
gc->irq_contexts = NULL;
free_irq_array:
kfree(irqs);
free_irq_vector:
cpus_read_unlock();
kfree(start_irqs);
return err;
}
static int mana_gd_setup_hwc_irqs(struct pci_dev *pdev)
{
struct gdma_context *gc = pci_get_drvdata(pdev);
unsigned int max_irqs, min_irqs;
int nvec, err;
if (pci_msix_can_alloc_dyn(pdev)) {
max_irqs = 1;
min_irqs = 1;
} else {
/* Need 1 interrupt for HWC */
max_irqs = min(num_online_cpus(), MANA_MAX_NUM_QUEUES) + 1;
min_irqs = 2;
}
nvec = pci_alloc_irq_vectors(pdev, min_irqs, max_irqs, PCI_IRQ_MSIX);
if (nvec < 0)
return nvec;
err = mana_gd_setup_irqs(pdev, nvec);
if (err) {
pci_free_irq_vectors(pdev);
return err;
}
gc->num_msix_usable = nvec;
gc->max_num_msix = nvec;
return 0;
}
static int mana_gd_setup_remaining_irqs(struct pci_dev *pdev)
{
struct gdma_context *gc = pci_get_drvdata(pdev);
struct msi_map irq_map;
int max_irqs, i, err;
if (!pci_msix_can_alloc_dyn(pdev))
/* remain irqs are already allocated with HWC IRQ */
return 0;
/* allocate only remaining IRQs*/
max_irqs = gc->num_msix_usable - 1;
for (i = 1; i <= max_irqs; i++) {
irq_map = pci_msix_alloc_irq_at(pdev, i, NULL);
if (!irq_map.virq) {
err = irq_map.index;
/* caller will handle cleaning up all allocated
* irqs, after HWC is destroyed
*/
return err;
}
}
err = mana_gd_setup_dyn_irqs(pdev, max_irqs);
if (err)
return err;
gc->max_num_msix = gc->max_num_msix + max_irqs;
return 0;
}
static void mana_gd_remove_irqs(struct pci_dev *pdev)
@ -1495,19 +1629,21 @@ static void mana_gd_remove_irqs(struct pci_dev *pdev)
if (irq < 0)
continue;
gic = &gc->irq_contexts[i];
gic = xa_load(&gc->irq_contexts, i);
if (WARN_ON(!gic))
continue;
/* Need to clear the hint before free_irq */
irq_update_affinity_hint(irq, NULL);
free_irq(irq, gic);
xa_erase(&gc->irq_contexts, i);
kfree(gic);
}
pci_free_irq_vectors(pdev);
gc->max_num_msix = 0;
gc->num_msix_usable = 0;
kfree(gc->irq_contexts);
gc->irq_contexts = NULL;
}
static int mana_gd_setup(struct pci_dev *pdev)
@ -1522,9 +1658,10 @@ static int mana_gd_setup(struct pci_dev *pdev)
if (!gc->service_wq)
return -ENOMEM;
err = mana_gd_setup_irqs(pdev);
err = mana_gd_setup_hwc_irqs(pdev);
if (err) {
dev_err(gc->dev, "Failed to setup IRQs: %d\n", err);
dev_err(gc->dev, "Failed to setup IRQs for HWC creation: %d\n",
err);
goto free_workqueue;
}
@ -1540,6 +1677,12 @@ static int mana_gd_setup(struct pci_dev *pdev)
if (err)
goto destroy_hwc;
err = mana_gd_setup_remaining_irqs(pdev);
if (err) {
dev_err(gc->dev, "Failed to setup remaining IRQs: %d", err);
goto destroy_hwc;
}
err = mana_gd_detect_devices(pdev);
if (err)
goto destroy_hwc;
@ -1620,6 +1763,7 @@ static int mana_gd_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
gc->is_pf = mana_is_pf(pdev->device);
gc->bar0_va = bar0_va;
gc->dev = &pdev->dev;
xa_init(&gc->irq_contexts);
if (gc->is_pf)
gc->mana_pci_debugfs = debugfs_create_dir("0", mana_debugfs_root);
@ -1654,6 +1798,7 @@ unmap_bar:
*/
debugfs_remove_recursive(gc->mana_pci_debugfs);
gc->mana_pci_debugfs = NULL;
xa_destroy(&gc->irq_contexts);
pci_iounmap(pdev, bar0_va);
free_gc:
pci_set_drvdata(pdev, NULL);
@ -1679,6 +1824,8 @@ static void mana_gd_remove(struct pci_dev *pdev)
gc->mana_pci_debugfs = NULL;
xa_destroy(&gc->irq_contexts);
pci_iounmap(pdev, gc->bar0_va);
vfree(gc);

8
include/net/mana/gdma.h
View file

@ -388,7 +388,7 @@ struct gdma_context {
unsigned int max_num_queues;
unsigned int max_num_msix;
unsigned int num_msix_usable;
struct gdma_irq_context *irq_contexts;
struct xarray irq_contexts;
/* L2 MTU */
u16 adapter_mtu;
@ -578,12 +578,16 @@ enum {
/* Driver can handle holes (zeros) in the device list */
#define GDMA_DRV_CAP_FLAG_1_DEV_LIST_HOLES_SUP BIT(11)
/* Driver supports dynamic MSI-X vector allocation */
#define GDMA_DRV_CAP_FLAG_1_DYNAMIC_IRQ_ALLOC_SUPPORT BIT(13)
#define GDMA_DRV_CAP_FLAGS1 \
(GDMA_DRV_CAP_FLAG_1_EQ_SHARING_MULTI_VPORT | \
GDMA_DRV_CAP_FLAG_1_NAPI_WKDONE_FIX | \
GDMA_DRV_CAP_FLAG_1_HWC_TIMEOUT_RECONFIG | \
GDMA_DRV_CAP_FLAG_1_VARIABLE_INDIRECTION_TABLE_SUPPORT | \
GDMA_DRV_CAP_FLAG_1_DEV_LIST_HOLES_SUP)
GDMA_DRV_CAP_FLAG_1_DEV_LIST_HOLES_SUP | \
GDMA_DRV_CAP_FLAG_1_DYNAMIC_IRQ_ALLOC_SUPPORT)
#define GDMA_DRV_CAP_FLAGS2 0