diff options
| -rw-r--r-- | drivers/ata/ahci.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index a3c66c3bb76e..77a34fc04138 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -42,6 +42,7 @@ #include <linux/device.h> #include <linux/dmi.h> #include <linux/gfp.h> +#include <linux/msi.h> #include <scsi/scsi_host.h> #include <scsi/scsi_cmnd.h> #include <linux/libata.h> @@ -1201,6 +1202,68 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host) {} #endif +static struct msi_desc *msix_get_desc(struct pci_dev *dev, u16 entry) +{ + struct msi_desc *desc; + + list_for_each_entry(desc, &dev->msi_list, list) { + if (desc->msi_attrib.entry_nr == entry) + return desc; + } + + return NULL; +} + +/* + * ahci_init_msix() only implements single MSI-X support, not multiple + * MSI-X per-port interrupts. This is needed for host controllers that only + * have MSI-X support implemented, but no MSI or intx. + */ +static int ahci_init_msix(struct pci_dev *pdev, unsigned int n_ports, + struct ahci_host_priv *hpriv) +{ + struct msi_desc *desc; + int rc, nvec; + struct msix_entry entry = {}; + + /* 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; + + if (!nvec) { + rc = -ENODEV; + goto fail; + } + + /* + * There can be more than one vector (e.g. for error detection or + * hdd hotplug). Only the first vector (entry.entry = 0) is used. + */ + rc = pci_enable_msix_exact(pdev, &entry, 1); + if (rc < 0) + goto fail; + + desc = msix_get_desc(pdev, 0); /* first entry */ + if (!desc) { + rc = -EINVAL; + goto fail; + } + + hpriv->irq = desc->irq; + + return 1; +fail: + dev_err(&pdev->dev, + "failed to enable MSI-X with error %d, # of vectors: %d\n", + rc, nvec); + + return rc; +} + static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports, struct ahci_host_priv *hpriv) { @@ -1260,6 +1323,15 @@ static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports, if (nvec >= 0) return nvec; + /* + * Currently, MSI-X support only implements single IRQ mode and + * exists for controllers which can't do other types of IRQ. Only + * set it up if MSI fails. + */ + nvec = ahci_init_msix(pdev, n_ports, hpriv); + if (nvec >= 0) + return nvec; + /* lagacy intx interrupts */ pci_intx(pdev, 1); hpriv->irq = pdev->irq; |