PCI/MSI: Remove pci_enable_msi_block()

There are no users of pci_enable_msi_block() function left.  Obsolete it in
favor of pci_enable_msi_range() and pci_enable_msi_exact() functions.

Previously, we called arch_setup_msi_irqs() once, requesting the same
vector count we passed to arch_msi_check_device().  Now we may call it
several times: if it returns failure, we may retry and request fewer
vectors.

We don't keep track of the vector count we initially passed to
arch_msi_check_device().  We only keep track of the number of vectors
successfully set up by arch_setup_msi_irqs(), and this is what we use to
clean things up when disabling MSI.  Therefore, we assume that
arch_msi_check_device() does nothing that will have to be cleaned up later.

[bhelgaas: changelog]
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

2 files changed, 34 insertions, 50 deletions

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 04130c3f9cf6..36dd0caa1759 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -879,50 +879,6 @@ int pci_msi_vec_count(struct pci_dev *dev)
 }
 EXPORT_SYMBOL(pci_msi_vec_count);
 
-/**
- * pci_enable_msi_block - configure device's MSI capability structure
- * @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.
- */
-int pci_enable_msi_block(struct pci_dev *dev, int nvec)
-{
-        int status, maxvec;
-
-        if (dev->current_state != PCI_D0)
-                return -EINVAL;
-
-        maxvec = pci_msi_vec_count(dev);
-        if (maxvec < 0)
-                return maxvec;
-        if (nvec > maxvec)
-                return maxvec;
-
-        status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI);
-        if (status)
-                return status;
-
-        WARN_ON(!!dev->msi_enabled);
-
-        /* Check whether driver already requested MSI-X irqs */
-        if (dev->msix_enabled) {
-                dev_info(&dev->dev, "can't enable MSI "
-                         "(MSI-X already enabled)\n");
-                return -EINVAL;
-        }
-
-        status = msi_capability_init(dev, nvec);
-        return status;
-}
-EXPORT_SYMBOL(pci_enable_msi_block);
-
 void pci_msi_shutdown(struct pci_dev *dev)
 {
         struct msi_desc *desc;
@@ -1128,14 +1084,45 @@ void pci_msi_init_pci_dev(struct pci_dev *dev)
  **/
 int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec)
 {
-        int nvec = maxvec;
+        int nvec;
         int rc;
 
+        if (dev->current_state != PCI_D0)
+                return -EINVAL;
+
+        WARN_ON(!!dev->msi_enabled);
+
+        /* Check whether driver already requested MSI-X irqs */
+        if (dev->msix_enabled) {
+                dev_info(&dev->dev,
+                         "can't enable MSI (MSI-X already enabled)\n");
+                return -EINVAL;
+        }
+
         if (maxvec < minvec)
                 return -ERANGE;
 
+        nvec = pci_msi_vec_count(dev);
+        if (nvec < 0)
+                return nvec;
+        else if (nvec < minvec)
+                return -EINVAL;
+        else if (nvec > maxvec)
+                nvec = maxvec;
+
+        do {
+                rc = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI);
+                if (rc < 0) {
+                        return rc;
+                } else if (rc > 0) {
+                        if (rc < minvec)
+                                return -ENOSPC;
+                        nvec = rc;
+                }
+        } while (rc);
+
         do {
-                rc = pci_enable_msi_block(dev, nvec);
+                rc = msi_capability_init(dev, nvec);
                 if (rc < 0) {
                         return rc;
                 } else if (rc > 0) {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index aab57b4abe7f..499755e6dab5 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1158,7 +1158,6 @@ struct msix_entry {
 
 #ifdef CONFIG_PCI_MSI
 int pci_msi_vec_count(struct pci_dev *dev);
-int pci_enable_msi_block(struct pci_dev *dev, int nvec);
 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);
@@ -1188,8 +1187,6 @@ static inline int pci_enable_msix_exact(struct pci_dev *dev,
 }
 #else
 static inline int pci_msi_vec_count(struct pci_dev *dev) { return -ENOSYS; }
-static inline int pci_enable_msi_block(struct pci_dev *dev, int nvec)
-{ 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; }
@@ -1244,7 +1241,7 @@ static inline void pcie_set_ecrc_checking(struct pci_dev *dev) { }
 static inline void pcie_ecrc_get_policy(char *str) { }
 #endif
 
-#define pci_enable_msi(pdev)    pci_enable_msi_block(pdev, 1)
+#define pci_enable_msi(pdev)    pci_enable_msi_exact(pdev, 1)
 
 #ifdef CONFIG_HT_IRQ
 /* The functions a driver should call */