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Subject[PATCH 9/9] PCI/MSI: Make return values only 0/-errno when MSIs allocated
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
---
drivers/pci/msi.c | 87 +++++++++++++++++++----------------------------------
1 files changed, 31 insertions(+), 56 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 21e6471..f5fcb74 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -702,7 +702,7 @@ static int msix_capability_init(struct pci_dev *dev,

ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
if (ret)
- goto out_avail;
+ goto error;

/*
* Some devices require MSI-X to be enabled before we can touch the
@@ -716,7 +716,7 @@ static int msix_capability_init(struct pci_dev *dev,

ret = populate_msi_sysfs(dev);
if (ret)
- goto out_free;
+ goto error;

/* Set MSI-X enabled bits and unmask the function */
pci_intx_for_msi(dev, 0);
@@ -727,24 +727,7 @@ static int msix_capability_init(struct pci_dev *dev,

return 0;

-out_avail:
- if (ret < 0) {
- /*
- * If we had some success, report the number of irqs
- * we succeeded in setting up.
- */
- struct msi_desc *entry;
- int avail = 0;
-
- list_for_each_entry(entry, &dev->msi_list, list) {
- if (entry->irq != 0)
- avail++;
- }
- if (avail != 0)
- ret = avail;
- }
-
-out_free:
+error:
free_msi_irqs(dev);

return ret;
@@ -800,17 +783,15 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
* @dev: device to configure
* @nvec: number of interrupts to configure
*
- * Allocate IRQs for a device with the MSI capability.
- * This function returns a negative errno if an error occurs. If it
- * is unable to allocate the number of interrupts requested, it returns
- * the number of interrupts it might be able to allocate. If it successfully
- * allocates at least the number of interrupts requested, it returns 0 and
- * updates the @dev's irq member to the lowest new interrupt number; the
- * other interrupt numbers allocated to this device are consecutive.
+ * Allocate IRQs for a device with the MSI capability. This function returns
+ * a negative errno if an error occurs. If it successfully allocates at least
+ * the number of interrupts requested, it returns 0 and updates the @dev's
+ * irq member to the lowest new interrupt number; the other interrupt numbers
+ * allocated to this device are consecutive.
*/
int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
{
- int status, maxvec;
+ int ret, maxvec;
u16 msgctl;

if (!dev->msi_cap)
@@ -819,11 +800,11 @@ int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
maxvec = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
if (nvec > maxvec)
- return maxvec;
+ return -EINVAL;

- status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI);
- if (status)
- return status;
+ ret = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI);
+ if (ret)
+ return ret;

WARN_ON(!!dev->msi_enabled);

@@ -834,33 +815,30 @@ int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
return -EINVAL;
}

- status = msi_capability_init(dev, nvec);
- return status;
+ ret = msi_capability_init(dev, nvec);
+ return ret;
}
EXPORT_SYMBOL(pci_enable_msi_block);

-int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec)
+int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec_ptr)
{
- int ret, nvec;
+ int ret, maxvec;
u16 msgctl;

if (!dev->msi_cap)
return -EINVAL;

pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
- ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
-
- if (maxvec)
- *maxvec = ret;
+ maxvec = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);

- do {
- nvec = ret;
- ret = pci_enable_msi_block(dev, nvec);
- } while (ret > 0);
+ if (maxvec_ptr)
+ *maxvec_ptr = maxvec;

- if (ret < 0)
+ ret = pci_enable_msi_block(dev, maxvec);
+ if (ret)
return ret;
- return nvec;
+
+ return maxvec;
}
EXPORT_SYMBOL(pci_enable_msi_block_auto);

@@ -928,25 +906,22 @@ int pci_msix_table_size(struct pci_dev *dev)
* 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 status, nr_entries;
+ int ret, nr_entries;
int i, j;

if (!entries || !dev->msix_cap)
return -EINVAL;

- status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);
- if (status)
- return status;
+ ret = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);
+ if (ret)
+ return ret;

nr_entries = pci_msix_table_size(dev);
if (nvec > nr_entries)
- return nr_entries;
+ return -EINVAL;

/* Check for any invalid entries */
for (i = 0; i < nvec; i++) {
@@ -965,8 +940,8 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
"(MSI IRQ already assigned)\n");
return -EINVAL;
}
- status = msix_capability_init(dev, entries, nvec);
- return status;
+ ret = msix_capability_init(dev, entries, nvec);
+ return ret;
}
EXPORT_SYMBOL(pci_enable_msix);

--
1.7.7.6
--
Regards,
Alexander Gordeev
agordeev@redhat.com


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