redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

ahci: use pci_alloc_irq_vectors 

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@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
hifive-unleashed-5.1
Christoph Hellwig 2016-09-05 17:21:45 +02:00 committed by Tejun Heo
parent 2536524a91
commit 0b9e2988ab
3 changed files with 46 additions and 140 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

151
drivers/ata/ahci.c
View File

@ -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;
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;
}
rc = pci_enable_msi_exact(pdev, nvec);
if (rc == -ENOSPC)
goto single_msi;
if (rc < 0)
return rc;
/* 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;
/*
* -ENOSPC indicated we don't have enough vectors. Don't bother trying
* a single vectors for any other error:
*/
if (nvec < 0 && nvec != -ENOSPC)
return 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.
* If the host is not capable of supporting per-port vectors, fall
* back to single MSI before finally attempting single MSI-X.
*/
nvec = ahci_init_msix(pdev, n_ports, hpriv, AHCI_HFLAG_MULTI_MSIX);
if (nvec >= 0)
nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
if (nvec == 1)
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)
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;

24
drivers/ata/ahci.h
View File

@ -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;

11
drivers/ata/libahci.c
View File

@ -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 {