[PATCH 03/13] genirq/msi: Switch to new irq spreading infrastructure
From: Christoph Hellwig
Date: Wed Sep 14 2016 - 10:19:25 EST
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Switch MSI over to the new spreading code. If a pci device contains a valid
pointer to a cpumask, then this mask is used for spreading otherwise the
online cpu mask is used. This allows a driver to restrict the spread to a
subset of CPUs, e.g. cpus on a particular node.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
drivers/pci/msi.c | 128 +++++++++++++++++++++++++++++----------------------
kernel/irq/irqdesc.c | 31 ++++++-------
2 files changed, 87 insertions(+), 72 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 0db72ba..06100dd 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -549,15 +549,23 @@ error_attrs:
return ret;
}
-static struct msi_desc *msi_setup_entry(struct pci_dev *dev, int nvec)
+static struct msi_desc *
+msi_setup_entry(struct pci_dev *dev, int nvec, bool affinity)
{
- u16 control;
+ struct cpumask *masks = NULL;
struct msi_desc *entry;
+ u16 control;
+
+ if (affinity) {
+ masks = irq_create_affinity_masks(dev->irq_affinity, nvec);
+ if (!masks)
+ pr_err("Unable to allocate affinity masks, ignoring\n");
+ }
/* MSI Entry Initialization */
- entry = alloc_msi_entry(&dev->dev, nvec, NULL);
+ entry = alloc_msi_entry(&dev->dev, nvec, masks);
if (!entry)
- return NULL;
+ goto out;
pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
@@ -568,7 +576,6 @@ static struct msi_desc *msi_setup_entry(struct pci_dev *dev, int nvec)
entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */
entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
- entry->affinity = dev->irq_affinity;
if (control & PCI_MSI_FLAGS_64BIT)
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
@@ -579,6 +586,8 @@ static struct msi_desc *msi_setup_entry(struct pci_dev *dev, int nvec)
if (entry->msi_attrib.maskbit)
pci_read_config_dword(dev, entry->mask_pos, &entry->masked);
+out:
+ kfree(masks);
return entry;
}
@@ -607,7 +616,7 @@ static int msi_verify_entries(struct pci_dev *dev)
* an error, and a positive return value indicates the number of interrupts
* which could have been allocated.
*/
-static int msi_capability_init(struct pci_dev *dev, int nvec)
+static int msi_capability_init(struct pci_dev *dev, int nvec, bool affinity)
{
struct msi_desc *entry;
int ret;
@@ -615,7 +624,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
pci_msi_set_enable(dev, 0); /* Disable MSI during set up */
- entry = msi_setup_entry(dev, nvec);
+ entry = msi_setup_entry(dev, nvec, affinity);
if (!entry)
return -ENOMEM;
@@ -678,28 +687,29 @@ static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
}
static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
- struct msix_entry *entries, int nvec)
+ struct msix_entry *entries, int nvec,
+ bool affinity)
{
- const struct cpumask *mask = NULL;
+ struct cpumask *curmsk, *masks = NULL;
struct msi_desc *entry;
- int cpu = -1, i;
-
- for (i = 0; i < nvec; i++) {
- if (dev->irq_affinity) {
- cpu = cpumask_next(cpu, dev->irq_affinity);
- if (cpu >= nr_cpu_ids)
- cpu = cpumask_first(dev->irq_affinity);
- mask = cpumask_of(cpu);
- }
+ int ret, i;
- entry = alloc_msi_entry(&dev->dev, 1, NULL);
+ if (affinity) {
+ masks = irq_create_affinity_masks(dev->irq_affinity, nvec);
+ if (!masks)
+ pr_err("Unable to allocate affinity masks, ignoring\n");
+ }
+
+ for (i = 0, curmsk = masks; i < nvec; i++) {
+ entry = alloc_msi_entry(&dev->dev, 1, curmsk);
if (!entry) {
if (!i)
iounmap(base);
else
free_msi_irqs(dev);
/* No enough memory. Don't try again */
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto out;
}
entry->msi_attrib.is_msix = 1;
@@ -710,11 +720,14 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
entry->msi_attrib.entry_nr = i;
entry->msi_attrib.default_irq = dev->irq;
entry->mask_base = base;
- entry->affinity = mask;
list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
+ if (masks)
+ curmsk++;
}
-
+ ret = 0;
+out:
+ kfree(masks);
return 0;
}
@@ -743,8 +756,8 @@ static void msix_program_entries(struct pci_dev *dev,
* single MSI-X irq. A return of zero indicates the successful setup of
* requested MSI-X entries with allocated irqs or non-zero for otherwise.
**/
-static int msix_capability_init(struct pci_dev *dev,
- struct msix_entry *entries, int nvec)
+static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
+ int nvec, bool affinity)
{
int ret;
u16 control;
@@ -759,7 +772,7 @@ static int msix_capability_init(struct pci_dev *dev,
if (!base)
return -ENOMEM;
- ret = msix_setup_entries(dev, base, entries, nvec);
+ ret = msix_setup_entries(dev, base, entries, nvec, affinity);
if (ret)
return ret;
@@ -939,22 +952,8 @@ int pci_msix_vec_count(struct pci_dev *dev)
}
EXPORT_SYMBOL(pci_msix_vec_count);
-/**
- * pci_enable_msix - configure device's MSI-X capability structure
- * @dev: pointer to the pci_dev data structure of MSI-X device function
- * @entries: pointer to an array of MSI-X entries (optional)
- * @nvec: number of MSI-X irqs requested for allocation by device driver
- *
- * Setup the MSI-X capability structure of device function with the number
- * of requested irqs upon its software driver call to request for
- * MSI-X mode enabled on its hardware device function. A return of zero
- * indicates the successful configuration of MSI-X capability structure
- * with new allocated MSI-X irqs. A return of < 0 indicates a failure.
- * Or a return of > 0 indicates that driver request is exceeding the number
- * of irqs or MSI-X vectors available. Driver should use the returned value to
- * re-send its request.
- **/
-int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
+static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
+ int nvec, bool affinity)
{
int nr_entries;
int i, j;
@@ -986,7 +985,27 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
dev_info(&dev->dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
return -EINVAL;
}
- return msix_capability_init(dev, entries, nvec);
+ return msix_capability_init(dev, entries, nvec, affinity);
+}
+
+/**
+ * pci_enable_msix - configure device's MSI-X capability structure
+ * @dev: pointer to the pci_dev data structure of MSI-X device function
+ * @entries: pointer to an array of MSI-X entries (optional)
+ * @nvec: number of MSI-X irqs requested for allocation by device driver
+ *
+ * Setup the MSI-X capability structure of device function with the number
+ * of requested irqs upon its software driver call to request for
+ * MSI-X mode enabled on its hardware device function. A return of zero
+ * indicates the successful configuration of MSI-X capability structure
+ * with new allocated MSI-X irqs. A return of < 0 indicates a failure.
+ * Or a return of > 0 indicates that driver request is exceeding the number
+ * of irqs or MSI-X vectors available. Driver should use the returned value to
+ * re-send its request.
+ **/
+int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
+{
+ return __pci_enable_msix(dev, entries, nvec, false);
}
EXPORT_SYMBOL(pci_enable_msix);
@@ -1039,6 +1058,7 @@ EXPORT_SYMBOL(pci_msi_enabled);
static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
unsigned int flags)
{
+ bool affinity = flags & PCI_IRQ_AFFINITY;
int nvec;
int rc;
@@ -1067,19 +1087,17 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
nvec = maxvec;
for (;;) {
- if (flags & PCI_IRQ_AFFINITY) {
- dev->irq_affinity = irq_create_affinity_mask(&nvec);
+ if (affinity) {
+ nvec = irq_calc_affinity_vectors(dev->irq_affinity,
+ nvec);
if (nvec < minvec)
return -ENOSPC;
}
- rc = msi_capability_init(dev, nvec);
+ rc = msi_capability_init(dev, nvec, affinity);
if (rc == 0)
return nvec;
- kfree(dev->irq_affinity);
- dev->irq_affinity = NULL;
-
if (rc < 0)
return rc;
if (rc < minvec)
@@ -1111,26 +1129,24 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
struct msix_entry *entries, int minvec, int maxvec,
unsigned int flags)
{
- int nvec = maxvec;
- int rc;
+ bool affinity = flags & PCI_IRQ_AFFINITY;
+ int rc, nvec = maxvec;
if (maxvec < minvec)
return -ERANGE;
for (;;) {
- if (flags & PCI_IRQ_AFFINITY) {
- dev->irq_affinity = irq_create_affinity_mask(&nvec);
+ if (affinity) {
+ nvec = irq_calc_affinity_vectors(dev->irq_affinity,
+ nvec);
if (nvec < minvec)
return -ENOSPC;
}
- rc = pci_enable_msix(dev, entries, nvec);
+ rc = __pci_enable_msix(dev, entries, nvec, affinity);
if (rc == 0)
return nvec;
- kfree(dev->irq_affinity);
- dev->irq_affinity = NULL;
-
if (rc < 0)
return rc;
if (rc < minvec)
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index a623b44..5a5a685 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -236,25 +236,24 @@ static int alloc_descs(unsigned int start, unsigned int cnt, int node,
const struct cpumask *mask = NULL;
struct irq_desc *desc;
unsigned int flags;
- int i, cpu = -1;
+ int i;
- if (affinity && cpumask_empty(affinity))
- return -EINVAL;
+ /* Validate affinity mask(s) */
+ if (affinity) {
+ for (i = 0, mask = affinity; i < cnt; i++, mask++) {
+ if (cpumask_empty(mask))
+ return -EINVAL;
+ }
+ }
flags = affinity ? IRQD_AFFINITY_MANAGED : 0;
+ mask = NULL;
for (i = 0; i < cnt; i++) {
if (affinity) {
- cpu = cpumask_next(cpu, affinity);
- if (cpu >= nr_cpu_ids)
- cpu = cpumask_first(affinity);
- node = cpu_to_node(cpu);
-
- /*
- * For single allocations we use the caller provided
- * mask otherwise we use the mask of the target cpu
- */
- mask = cnt == 1 ? affinity : cpumask_of(cpu);
+ node = cpu_to_node(cpumask_first(affinity));
+ mask = affinity;
+ affinity++;
}
desc = alloc_desc(start + i, node, flags, mask, owner);
if (!desc)
@@ -481,9 +480,9 @@ EXPORT_SYMBOL_GPL(irq_free_descs);
* @cnt: Number of consecutive irqs to allocate.
* @node: Preferred node on which the irq descriptor should be allocated
* @owner: Owning module (can be NULL)
- * @affinity: Optional pointer to an affinity mask which hints where the
- * irq descriptors should be allocated and which default
- * affinities to use
+ * @affinity: Optional pointer to an affinity mask array of size @cnt which
+ * hints where the irq descriptors should be allocated and which
+ * default affinities to use
*
* Returns the first irq number or error code
*/
--
2.1.4