As result of introduction of pci_get_msi_cap() interface
pci_enable_msi_block_auto() function became superflous.
To enable maximum possible number of MSIs drivers will
first obtain that number from pci_get_msi_cap() function
and then call pci_enable_msi_block() interface.
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
---
Documentation/PCI/MSI-HOWTO.txt | 30 +-------------------
drivers/ata/ahci.c | 56 ++++++++++++++++++++++++--------------
drivers/pci/msi.c | 22 ---------------
include/linux/pci.h | 7 -----
4 files changed, 37 insertions(+), 78 deletions(-)
diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt
index e7e3b20..47118f3 100644
--- a/Documentation/PCI/MSI-HOWTO.txt
+++ b/Documentation/PCI/MSI-HOWTO.txt
@@ -127,33 +127,7 @@ on the number of vectors that can be allocated; pci_enable_msi_block()
returns as soon as it finds any constraint that doesn't allow the
call to succeed.
-4.2.3 pci_enable_msi_block_auto
-
-int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *count)
-
-This variation on pci_enable_msi() call allows a device driver to request
-the maximum possible number of MSIs. The MSI specification only allows
-interrupts to be allocated in powers of two, up to a maximum of 2^5 (32).
-
-If this function returns a positive number, it indicates that it has
-succeeded and the returned value is the number of allocated interrupts. In
-this case, the function enables MSI on this device and updates dev->irq to
-be the lowest of the new interrupts assigned to it. The other interrupts
-assigned to the device are in the range dev->irq to dev->irq + returned
-value - 1.
-
-If this function returns a negative number, it indicates an error and
-the driver should not attempt to request any more MSI interrupts for
-this device.
-
-If the device driver needs to know the number of interrupts the device
-supports it can pass the pointer count where that number is stored. The
-device driver must decide what action to take if pci_enable_msi_block_auto()
-succeeds, but returns a value less than the number of interrupts supported.
-If the device driver does not need to know the number of interrupts
-supported, it can set the pointer count to NULL.
-
-4.2.4 pci_disable_msi
+4.2.3 pci_disable_msi
void pci_disable_msi(struct pci_dev *dev)
@@ -169,7 +143,7 @@ on any interrupt for which it previously called request_irq().
Failure to do so results in a BUG_ON(), leaving the device with
MSI enabled and thus leaking its vector.
-4.2.5 pci_get_msi_cap
+4.2.4 pci_get_msi_cap
int pci_get_msi_cap(struct pci_dev *dev)
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 9d715ae..f1c8838 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1091,26 +1091,40 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host)
{}
#endif
-int ahci_init_interrupts(struct pci_dev *pdev, struct ahci_host_priv *hpriv)
+int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
+ struct ahci_host_priv *hpriv)
{
- int rc;
- unsigned int maxvec;
+ int rc, nvec;
- if (!(hpriv->flags & AHCI_HFLAG_NO_MSI)) {
- rc = pci_enable_msi_block_auto(pdev, &maxvec);
- if (rc > 0) {
- if ((rc == maxvec) || (rc == 1))
- return rc;
- /*
- * Assume that advantage of multipe MSIs is negated,
- * so fallback to single MSI mode to save resources
- */
- pci_disable_msi(pdev);
- if (!pci_enable_msi(pdev))
- return 1;
- }
- }
+ if (hpriv->flags & AHCI_HFLAG_NO_MSI)
+ goto intx;
+
+ rc = pci_get_msi_cap(pdev);
+ if (rc < 0)
+ goto intx;
+
+ /*
+ * 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 (rc < n_ports)
+ goto single_msi;
+
+ nvec = rc;
+ rc = pci_enable_msi_block(pdev, nvec);
+ if (rc)
+ goto intx;
+ return nvec;
+
+single_msi:
+ rc = pci_enable_msi(pdev);
+ if (rc)
+ goto intx;
+ return 1;
+
+intx:
pci_intx(pdev, 1);
return 0;
}
@@ -1277,10 +1291,6 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
hpriv->mmio = pcim_iomap_table(pdev)[ahci_pci_bar];
- n_msis = ahci_init_interrupts(pdev, hpriv);
- if (n_msis > 1)
- hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
-
/* save initial config */
ahci_pci_save_initial_config(pdev, hpriv);
@@ -1335,6 +1345,10 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
*/
n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
+ n_msis = ahci_init_interrupts(pdev, n_ports, hpriv);
+ if (n_msis > 1)
+ hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
+
host = ata_host_alloc_pinfo(&pdev->dev, ppi, n_ports);
if (!host)
return -ENOMEM;
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 14dc4d1..13bd901 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -851,28 +851,6 @@ int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
}
EXPORT_SYMBOL(pci_enable_msi_block);
-int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec)
-{
- int ret, nvec;
-
- ret = pci_get_msi_cap(dev);
- if (ret < 0)
- return ret;
-
- if (maxvec)
- *maxvec = ret;
-
- do {
- nvec = ret;
- ret = pci_enable_msi_block(dev, nvec);
- } while (ret > 0);
-
- if (ret < 0)
- return ret;
- return nvec;
-}
-EXPORT_SYMBOL(pci_enable_msi_block_auto);
-
void pci_msi_shutdown(struct pci_dev *dev)
{
struct msi_desc *desc;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index df72084..a04f5da 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1156,12 +1156,6 @@ static inline int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
return -ENOSYS;
}
-static inline int
-pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec)
-{
- return -ENOSYS;
-}
-
static inline void pci_msi_shutdown(struct pci_dev *dev)
{ }
static inline void pci_disable_msi(struct pci_dev *dev)
@@ -1194,7 +1188,6 @@ static inline int pci_msi_enabled(void)
#else
int pci_get_msi_cap(struct pci_dev *dev);
int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec);
-int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec);
void pci_msi_shutdown(struct pci_dev *dev);
void pci_disable_msi(struct pci_dev *dev);
int pci_msix_table_size(struct pci_dev *dev);
--
1.7.7.6
--
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