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 <shradhagu...@linux.microsoft.com>
Reviewed-by: Haiyang Zhang <haiya...@microsoft.com>
---
 Changes in v4:
 * added BUG_ON at appropriate places
 * moved xa_destroy to mana_gd_remove()
 * rearragned the cleanup logic in mana_gd_setup_dyn_irqs()
 * simplified processing around start_irq_index in mana_gd_setup_irqs()
 * return 0 instead of return err as appropriate
---
 Changes in v3:
 * implemented irq_contexts as xarrays rather than list
 * split the patch to create a perparation patch around irq_setup()
 * add log when IRQ allocation/setup for remaining IRQs fails
---
 Changes in v2:
 * Use string 'MSI-X vectors' instead of 'pci vectors'
 * make skip-cpu a bool instead of int
 * rearrange the comment arout skip_cpu variable appropriately
 * update the capability bit for driver indicating dynamic IRQ allocation
 * enforced max line length to 80
 * enforced RCT convention
 * initialized gic to NULL, for when there is a possibility of gic
   not being populated correctly
---
 .../net/ethernet/microsoft/mana/gdma_main.c   | 306 +++++++++++++-----
 include/net/mana/gdma.h                       |   8 +-
 2 files changed, 235 insertions(+), 79 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c 
b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index 763a548c4a2b..98ebecbec9a7 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -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 (gc->num_msix_usable > resp.max_msix)
-               gc->num_msix_usable = resp.max_msix;
+       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;
@@ -482,7 +491,9 @@ 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);
@@ -507,7 +518,10 @@ 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 +1380,113 @@ static int irq_setup(unsigned int *irqs, unsigned int 
len, int node,
        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;
 
        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;
 
-       /* 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) {
-               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);
+       irqs = kmalloc_array(nvec, sizeof(int), GFP_KERNEL);
        if (!irqs) {
                err = -ENOMEM;
                goto free_irq_vector;
        }
 
-       gc->irq_contexts = kcalloc(nvec, sizeof(struct gdma_irq_context),
-                                  GFP_KERNEL);
-       if (!gc->irq_contexts) {
+       /*
+        * 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
+        */
+       if (gc->num_msix_usable <= num_online_cpus())
+               skip_first_cpu = true;
+
+       err = irq_setup(irqs, nvec, gc->numa_node, skip_first_cpu);
+       if (err)
+               goto free_irq;
+
+       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);
+free_irq_vector:
+       cpus_read_unlock();
+       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;
+
+       cpus_read_lock();
+
+       irqs = kmalloc_array(nvec, sizeof(int), GFP_KERNEL);
+       if (!irqs) {
                err = -ENOMEM;
-               goto free_irq_array;
+               goto free_irq_vector;
        }
 
        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);
@@ -1418,69 +1498,128 @@ 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);
-                       if (err)
-                               goto free_irq;
-
-                       /* If number of IRQ is one extra than number of online 
CPUs,
-                        * then we need to assign IRQ0 (hwc irq) and IRQ1 to
-                        * same CPU.
-                        * Else we will use different CPUs for IRQ0 and IRQ1.
-                        * Also we are using cpumask_local_spread instead of
-                        * 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;
-               }
+               err = request_irq(irqs[i], mana_gd_intr, 0, gic->name, gic);
+               if (err)
+                       goto free_current_gic;
+
+               xa_store(&gc->irq_contexts, i, gic, GFP_KERNEL);
        }
 
-       err = irq_setup(irqs, nvec - start_irq_index, gc->numa_node, false);
+       /* If number of IRQ is one extra than number of online CPUs,
+        * then we need to assign IRQ0 (hwc irq) and IRQ1 to
+        * same CPU.
+        * Else we will use different CPUs for IRQ0 and IRQ1.
+        * Also we are using cpumask_local_spread instead of
+        * cpumask_first for the node, because the node can be
+        * mem only.
+        */
+       start_irqs = irqs;
+       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, gc->numa_node, false);
        if (err)
                goto free_irq;
 
-       gc->max_num_msix = nvec;
-       gc->num_msix_usable = nvec;
        cpus_read_unlock();
-       kfree(irqs);
+       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);
+       kfree(start_irqs);
 free_irq_vector:
        cpus_read_unlock();
-       pci_free_irq_vectors(pdev);
        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)
 {
        struct gdma_context *gc = pci_get_drvdata(pdev);
@@ -1495,19 +1634,21 @@ 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)
@@ -1518,9 +1659,10 @@ static int mana_gd_setup(struct pci_dev *pdev)
        mana_gd_init_registers(pdev);
        mana_smc_init(&gc->shm_channel, gc->dev, gc->shm_base);
 
-       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);
                return err;
        }
 
@@ -1536,6 +1678,12 @@ 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;
@@ -1612,6 +1760,7 @@ 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);
@@ -1640,6 +1789,7 @@ static int mana_gd_probe(struct pci_dev *pdev, const 
struct pci_device_id *ent)
         */
        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);
@@ -1664,6 +1814,8 @@ 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);
diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
index 228603bf03f2..f20d1d1ea5e8 100644
--- a/include/net/mana/gdma.h
+++ b/include/net/mana/gdma.h
@@ -373,7 +373,7 @@ 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;
@@ -558,12 +558,16 @@ 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
 
-- 
2.34.1


Reply via email to