Use the new pci_alloc_irq_vectors API to allocate MSI-X and MSI vectors.
The big advantage over the old code is that we can use the same API for
MSI and MSI-X, and that we don't need to store the MSI-X vector mapping
in driver-private data structures.
This first conversion keeps the probe order as-is: MSI-X multi vector,
MSI multi vector, MSI single vector, MSI-X single vector and last a
single least legacy interrupt line. There is one small change of
behavior: we now check the "MSI Revert to Single Message" flag for
MSI-X in addition to MSI.
Because the API to find the Linux IRQ number for a MSI/MSI-X vector
is PCI specific, but libahaci is bus-agnostic I had to a
get_irq_vector function pointer to struct ahci_host_priv. The
alternative would be to move the multi-vector case of ahci_host_activate
to ahci.c and just call ata_host_activate directly from the others
users of ahci_host_activate.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/ata/ahci.c | 149 +++++++++++---------------------------------------
drivers/ata/ahci.h | 24 ++------
drivers/ata/libahci.c | 11 +++-
3 files changed, 45 insertions(+), 139 deletions(-)
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 90eabaf..ba5f11c 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1400,142 +1400,56 @@ static irqreturn_t ahci_thunderx_irq_handler(int irq, void *dev_instance)
}
#endif
-/*
- * ahci_init_msix() - optionally enable per-port MSI-X otherwise defer
- * to single msi.
- */
-static int ahci_init_msix(struct pci_dev *pdev, unsigned int n_ports,
- struct ahci_host_priv *hpriv, unsigned long flags)
+static int ahci_get_irq_vector(struct ata_host *host, int port)
{
- int nvec, i, rc;
-
- /* Do not init MSI-X if MSI is disabled for the device */
- if (hpriv->flags & AHCI_HFLAG_NO_MSI)
- return -ENODEV;
-
- nvec = pci_msix_vec_count(pdev);
- if (nvec < 0)
- return nvec;
-
- /*
- * Proper MSI-X implementations will have a vector per-port.
- * Barring that, we prefer single-MSI over single-MSIX. If this
- * check fails (not enough MSI-X vectors for all ports) we will
- * be called again with the flag clear iff ahci_init_msi()
- * fails.
- */
- if (flags & AHCI_HFLAG_MULTI_MSIX) {
- if (nvec < n_ports)
- return -ENODEV;
- nvec = n_ports;
- } else if (nvec) {
- nvec = 1;
- } else {
- /*
- * Emit dev_err() since this was the non-legacy irq
- * method of last resort.
- */
- rc = -ENODEV;
- goto fail;
- }
-
- for (i = 0; i < nvec; i++)
- hpriv->msix[i].entry = i;
- rc = pci_enable_msix_exact(pdev, hpriv->msix, nvec);
- if (rc < 0)
- goto fail;
-
- if (nvec > 1)
- hpriv->flags |= AHCI_HFLAG_MULTI_MSIX;
- hpriv->irq = hpriv->msix[0].vector; /* for single msi-x */
-
- return nvec;
-fail:
- dev_err(&pdev->dev,
- "failed to enable MSI-X with error %d, # of vectors: %d\n",
- rc, nvec);
-
- return rc;
+ return pci_irq_vector(to_pci_dev(host->dev), port);
}
static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
struct ahci_host_priv *hpriv)
{
- int rc, nvec;
+ int nvec;
if (hpriv->flags & AHCI_HFLAG_NO_MSI)
return -ENODEV;
- nvec = pci_msi_vec_count(pdev);
- if (nvec < 0)
- return nvec;
-
/*
* If number of MSIs is less than number of ports then Sharing Last
* Message mode could be enforced. In this case assume that advantage
* of multipe MSIs is negated and use single MSI mode instead.
*/
- if (nvec < n_ports)
- goto single_msi;
-
- rc = pci_enable_msi_exact(pdev, nvec);
- if (rc == -ENOSPC)
- goto single_msi;
- if (rc < 0)
- return rc;
+ nvec = pci_alloc_irq_vectors(pdev, n_ports, INT_MAX,
+ PCI_IRQ_MSIX | PCI_IRQ_MSI);
+ if (nvec > 0) {
+ if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) {
+ hpriv->get_irq_vector = ahci_get_irq_vector;
+ hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
+ return nvec;
+ }
- /* fallback to single MSI mode if the controller enforced MRSM mode */
- if (readl(hpriv->mmio + HOST_CTL) & HOST_MRSM) {
- pci_disable_msi(pdev);
+ /*
+ * Fallback to single MSI mode if the controller enforced MRSM
+ * mode.
+ */
printk(KERN_INFO "ahci: MRSM is on, fallback to single MSI\n");
- goto single_msi;
+ pci_free_irq_vectors(pdev);
}
- if (nvec > 1)
- hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
-
- goto out;
-
-single_msi:
- nvec = 1;
-
- rc = pci_enable_msi(pdev);
- if (rc < 0)
- return rc;
-out:
- hpriv->irq = pdev->irq;
-
- return nvec;
-}
-
-static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
- struct ahci_host_priv *hpriv)
-{
- int nvec;
-
/*
- * Try to enable per-port MSI-X. If the host is not capable
- * fall back to single MSI before finally attempting single
- * MSI-X.
+ * -ENOSPC indicated we don't have enough vectors. Don't bother trying
+ * a single vectors for any other error:
*/
- nvec = ahci_init_msix(pdev, n_ports, hpriv, AHCI_HFLAG_MULTI_MSIX);
- if (nvec >= 0)
+ if (nvec < 0 && nvec != -ENOSPC)
return nvec;
- nvec = ahci_init_msi(pdev, n_ports, hpriv);
- if (nvec >= 0)
- return nvec;
-
- /* try single-msix */
- nvec = ahci_init_msix(pdev, n_ports, hpriv, 0);
- if (nvec >= 0)
+ /*
+ * If the host is not capable of supporting per-port vectors, fall
+ * back to single MSI before finally attempting single MSI-X.
+ */
+ nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
+ if (nvec == 1)
return nvec;
-
- /* legacy intx interrupts */
- pci_intx(pdev, 1);
- hpriv->irq = pdev->irq;
-
- return 0;
+ return pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX);
}
static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
@@ -1698,11 +1612,12 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
if (!host)
return -ENOMEM;
host->private_data = hpriv;
- hpriv->msix = devm_kzalloc(&pdev->dev,
- sizeof(struct msix_entry) * n_ports, GFP_KERNEL);
- if (!hpriv->msix)
- return -ENOMEM;
- ahci_init_interrupts(pdev, n_ports, hpriv);
+
+ if (ahci_init_msi(pdev, n_ports, hpriv) < 0) {
+ /* legacy intx interrupts */
+ pci_intx(pdev, 1);
+ }
+ hpriv->irq = pdev->irq;
if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
host->flags |= ATA_HOST_PARALLEL_SCAN;
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 70b06bc..0cc08f8 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -242,12 +242,10 @@ enum {
AHCI_HFLAG_NO_FBS = (1 << 18), /* no FBS */
#ifdef CONFIG_PCI_MSI
- AHCI_HFLAG_MULTI_MSI = (1 << 20), /* multiple PCI MSIs */
- AHCI_HFLAG_MULTI_MSIX = (1 << 21), /* per-port MSI-X */
+ AHCI_HFLAG_MULTI_MSI = (1 << 20), /* per-port MSI(-X) */
#else
/* compile out MSI infrastructure */
AHCI_HFLAG_MULTI_MSI = 0,
- AHCI_HFLAG_MULTI_MSIX = 0,
#endif
AHCI_HFLAG_WAKE_BEFORE_STOP = (1 << 22), /* wake before DMA stop */
@@ -351,7 +349,6 @@ struct ahci_host_priv {
* the PHY position in this array.
*/
struct phy **phys;
- struct msix_entry *msix; /* Optional MSI-X support */
unsigned nports; /* Number of ports */
void *plat_data; /* Other platform data */
unsigned int irq; /* interrupt line */
@@ -362,22 +359,11 @@ struct ahci_host_priv {
*/
void (*start_engine)(struct ata_port *ap);
irqreturn_t (*irq_handler)(int irq, void *dev_instance);
-};
-#ifdef CONFIG_PCI_MSI
-static inline int ahci_irq_vector(struct ahci_host_priv *hpriv, int port)
-{
- if (hpriv->flags & AHCI_HFLAG_MULTI_MSIX)
- return hpriv->msix[port].vector;
- else
- return hpriv->irq + port;
-}
-#else
-static inline int ahci_irq_vector(struct ahci_host_priv *hpriv, int port)
-{
- return hpriv->irq;
-}
-#endif
+ /* only required for per-port MSI(-X) support */
+ int (*get_irq_vector)(struct ata_host *host,
+ int port);
+};
extern int ahci_ignore_sss;
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 5a1329e..0d028ea 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -2378,7 +2378,7 @@ static int ahci_port_start(struct ata_port *ap)
/*
* Switch to per-port locking in case each port has its own MSI vector.
*/
- if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX)) {
+ if (hpriv->flags & AHCI_HFLAG_MULTI_MSI) {
spin_lock_init(&pp->lock);
ap->lock = &pp->lock;
}
@@ -2520,7 +2520,7 @@ static int ahci_host_activate_multi_irqs(struct ata_host *host,
*/
for (i = 0; i < host->n_ports; i++) {
struct ahci_port_priv *pp = host->ports[i]->private_data;
- int irq = ahci_irq_vector(hpriv, i);
+ int irq = hpriv->get_irq_vector(host, i);
/* Do not receive interrupts sent by dummy ports */
if (!pp) {
@@ -2556,10 +2556,15 @@ int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht)
int irq = hpriv->irq;
int rc;
- if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX)) {
+ if (hpriv->flags & AHCI_HFLAG_MULTI_MSI) {
if (hpriv->irq_handler)
dev_warn(host->dev,
"both AHCI_HFLAG_MULTI_MSI flag set and custom irq handler implemented\n");
+ if (!hpriv->get_irq_vector) {
+ dev_err(host->dev,
+ "AHCI_HFLAG_MULTI_MSI requires ->get_irq_vector!\n");
+ return -EIO;
+ }
rc = ahci_host_activate_multi_irqs(host, sht);
} else {
--
2.1.4
--
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