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Subject[PATCH] PCI/MSI: Remove pci_enable_msix()
Date
There are no users of pci_enable_msix() function left. Obsolete
it in favor of pci_enable_msix_range() and pci_enable_msix_exact()
functions.

Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Cc: linux-pci@vger.kernel.org
---
Documentation/PCI/PCIEBUS-HOWTO.txt | 15 +++---
Documentation/PCI/pci.txt | 14 +++---
drivers/pci/msi.c | 91 +++++++++++++++----------------------
include/linux/pci.h | 4 --
4 files changed, 51 insertions(+), 73 deletions(-)

diff --git a/Documentation/PCI/PCIEBUS-HOWTO.txt b/Documentation/PCI/PCIEBUS-HOWTO.txt
index 6bd5f37..873a84a 100644
--- a/Documentation/PCI/PCIEBUS-HOWTO.txt
+++ b/Documentation/PCI/PCIEBUS-HOWTO.txt
@@ -190,13 +190,14 @@ in the field interrupt_mode of struct pcie_device.
6.2 MSI-X Vector Resources

Similar to the MSI a device driver for an MSI-X capable device can
-call pci_enable_msix to request MSI-X interrupts. All service drivers
-are not permitted to switch interrupt mode on its device. The PCI
-Express Port Bus driver is responsible for determining the interrupt
-mode and this should be transparent to service drivers. Any attempt
-by service driver to call pci_enable_msix/pci_disable_msix may
-result unpredictable behavior. Service drivers should use
-(struct pcie_device*)dev->irq and call request_irq/free_irq.
+call pci_enable_msix_range to request MSI-X interrupts. All service
+drivers are not permitted to switch interrupt mode on its device.
+The PCI Express Port Bus driver is responsible for determining the
+interrupt mode and this should be transparent to service drivers.
+Any attempt by service driver to call pci_enable_msix_range or
+pci_disable_msix may result unpredictable behavior. Service drivers
+should use (struct pcie_device*)dev->irq and call request_irq or
+free_irq.

6.3 PCI Memory/IO Mapped Regions

diff --git a/Documentation/PCI/pci.txt b/Documentation/PCI/pci.txt
index 9518006..eb57f0a 100644
--- a/Documentation/PCI/pci.txt
+++ b/Documentation/PCI/pci.txt
@@ -383,18 +383,18 @@ The fundamental difference between MSI and MSI-X is how multiple
"vectors" get allocated. MSI requires contiguous blocks of vectors
while MSI-X can allocate several individual ones.

-MSI capability can be enabled by calling pci_enable_msi() or
-pci_enable_msix() before calling request_irq(). This causes
+MSI capability can be enabled by calling pci_enable_msi_range() or
+pci_enable_msix_range() before calling request_irq(). This causes
the PCI support to program CPU vector data into the PCI device
capability registers.

If your PCI device supports both, try to enable MSI-X first.
Only one can be enabled at a time. Many architectures, chip-sets,
-or BIOSes do NOT support MSI or MSI-X and the call to pci_enable_msi/msix
-will fail. This is important to note since many drivers have
-two (or more) interrupt handlers: one for MSI/MSI-X and another for IRQs.
-They choose which handler to register with request_irq() based on the
-return value from pci_enable_msi/msix().
+or BIOSes do NOT support MSI or MSI-X and the call to pci_enable_msi_range()
+or pci_enable_msix_range() will fail. This is important to note since many
+drivers have two (or more) interrupt handlers: one for MSI/MSI-X and another
+for IRQs. They choose which handler to register with request_irq() based on
+the return value from pci_enable_msi_range() or pci_enable_msix_range().

There are (at least) two really good reasons for using MSI:
1) MSI is an exclusive interrupt vector by definition.
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 2f7c92c..0df0ce1 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -903,58 +903,6 @@ 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
- * @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)
-{
- int nr_entries;
- int i, j;
-
- if (!pci_msi_supported(dev, nvec))
- return -EINVAL;
-
- if (!entries)
- return -EINVAL;
-
- nr_entries = pci_msix_vec_count(dev);
- if (nr_entries < 0)
- return nr_entries;
- if (nvec > nr_entries)
- return nr_entries;
-
- /* Check for any invalid entries */
- for (i = 0; i < nvec; i++) {
- if (entries[i].entry >= nr_entries)
- return -EINVAL; /* invalid entry */
- for (j = i + 1; j < nvec; j++) {
- if (entries[i].entry == entries[j].entry)
- return -EINVAL; /* duplicate entry */
- }
- }
- WARN_ON(!!dev->msix_enabled);
-
- /* Check whether driver already requested for MSI irq */
- if (dev->msi_enabled) {
- dev_info(&dev->dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
- return -EINVAL;
- }
- return msix_capability_init(dev, entries, nvec);
-}
-EXPORT_SYMBOL(pci_enable_msix);
-
void pci_msix_shutdown(struct pci_dev *dev)
{
struct msi_desc *entry;
@@ -1088,16 +1036,49 @@ EXPORT_SYMBOL(pci_enable_msi_range);
* with new allocated MSI-X interrupts.
**/
int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
- int minvec, int maxvec)
+ int minvec, int maxvec)
{
- int nvec = maxvec;
+ int i, j;
+ int nvec;
int rc;

+ if (!pci_msi_supported(dev, minvec))
+ return -EINVAL;
+
+ WARN_ON(!!dev->msix_enabled);
+
+ /* Check whether driver already requested MSI irqs */
+ if (dev->msi_enabled) {
+ dev_info(&dev->dev,
+ "can't enable MSI-X (MSI already enabled)\n");
+ return -EINVAL;
+ }
+
if (maxvec < minvec)
return -ERANGE;
+ else if (!entries)
+ return -EINVAL;
+
+ nvec = pci_msix_vec_count(dev);
+ if (nvec < 0)
+ return nvec;
+ else if (nvec < minvec)
+ return -EINVAL;
+ else if (nvec > maxvec)
+ nvec = maxvec;
+
+ /* Check for any invalid entries */
+ for (i = 0; i < nvec; i++) {
+ if (entries[i].entry >= nvec)
+ return -EINVAL; /* invalid entry */
+ for (j = i + 1; j < nvec; j++) {
+ if (entries[i].entry == entries[j].entry)
+ return -EINVAL; /* duplicate entry */
+ }
+ }

do {
- rc = pci_enable_msix(dev, entries, nvec);
+ rc = msix_capability_init(dev, entries, nvec);
if (rc < 0) {
return rc;
} else if (rc > 0) {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 5be8db4..ad9b5d4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1197,7 +1197,6 @@ int pci_msi_vec_count(struct pci_dev *dev);
void pci_msi_shutdown(struct pci_dev *dev);
void pci_disable_msi(struct pci_dev *dev);
int pci_msix_vec_count(struct pci_dev *dev);
-int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec);
void pci_msix_shutdown(struct pci_dev *dev);
void pci_disable_msix(struct pci_dev *dev);
void pci_restore_msi_state(struct pci_dev *dev);
@@ -1225,9 +1224,6 @@ static inline int pci_msi_vec_count(struct pci_dev *dev) { return -ENOSYS; }
static inline void pci_msi_shutdown(struct pci_dev *dev) { }
static inline void pci_disable_msi(struct pci_dev *dev) { }
static inline int pci_msix_vec_count(struct pci_dev *dev) { return -ENOSYS; }
-static inline int pci_enable_msix(struct pci_dev *dev,
- struct msix_entry *entries, int nvec)
-{ return -ENOSYS; }
static inline void pci_msix_shutdown(struct pci_dev *dev) { }
static inline void pci_disable_msix(struct pci_dev *dev) { }
static inline void pci_restore_msi_state(struct pci_dev *dev) { }
--
1.8.3.1


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