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authorBjorn Helgaas <bhelgaas@google.com>2017-10-20 15:48:06 +0200
committerBjorn Helgaas <bhelgaas@google.com>2017-10-20 18:08:28 +0200
commit3321eafd2a79f15126ebaa82f1b5d7fce89c02cb (patch)
treee2072b7a5cc10eb2e61a086d53f7866175fee558
parentPCI/portdrv: Consolidate comments (diff)
downloadlinux-3321eafd2a79f15126ebaa82f1b5d7fce89c02cb.tar.xz
linux-3321eafd2a79f15126ebaa82f1b5d7fce89c02cb.zip
PCI/portdrv: Factor out Interrupt Message Number lookup
Factor out Interrupt Message Number lookup from the MSI/MSI-X interrupt setup. One side effect is that we only have to check once to see if we have enough vectors for all the services. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
-rw-r--r--drivers/pci/pcie/portdrv_core.c110
1 files changed, 62 insertions, 48 deletions
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index accd16082348..102f5c5fcfe0 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -43,6 +43,53 @@ static void release_pcie_device(struct device *dev)
kfree(to_pcie_device(dev));
}
+/*
+ * Fill in *pme, *aer, *dpc with the relevant Interrupt Message Numbers if
+ * services are enabled in "mask". Return the number of MSI/MSI-X vectors
+ * required to accommodate the largest Message Number.
+ */
+static int pcie_message_numbers(struct pci_dev *dev, int mask,
+ u32 *pme, u32 *aer, u32 *dpc)
+{
+ u32 nvec = 0, pos, reg32;
+ u16 reg16;
+
+ /*
+ * The Interrupt Message Number indicates which vector is used, i.e.,
+ * the MSI-X table entry or the MSI offset between the base Message
+ * Data and the generated interrupt message. See PCIe r3.1, sec
+ * 7.8.2, 7.10.10, 7.31.2.
+ */
+
+ if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
+ pcie_capability_read_word(dev, PCI_EXP_FLAGS, &reg16);
+ *pme = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
+ nvec = *pme + 1;
+ }
+
+ if (mask & PCIE_PORT_SERVICE_AER) {
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
+ if (pos) {
+ pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS,
+ &reg32);
+ *aer = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27;
+ nvec = max(nvec, *aer + 1);
+ }
+ }
+
+ if (mask & PCIE_PORT_SERVICE_DPC) {
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);
+ if (pos) {
+ pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP,
+ &reg16);
+ *dpc = reg16 & PCI_EXP_DPC_IRQ;
+ nvec = max(nvec, *dpc + 1);
+ }
+ }
+
+ return nvec;
+}
+
/**
* pcie_port_enable_irq_vec - try to set up MSI-X or MSI as interrupt mode
* for given port
@@ -54,7 +101,8 @@ static void release_pcie_device(struct device *dev)
*/
static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
{
- int nr_entries, entry, nvec = 0;
+ int nr_entries, nvec;
+ u32 pme = 0, aer = 0, dpc = 0;
/* Allocate the maximum possible number of MSI/MSI-X vectors */
nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES,
@@ -62,54 +110,24 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
if (nr_entries < 0)
return nr_entries;
- /*
- * The Interrupt Message Number indicates which vector is used, i.e.,
- * the MSI-X table entry or the MSI offset between the base Message
- * Data and the generated interrupt message. See PCIe r3.1, sec
- * 7.8.2, 7.10.10, 7.31.2.
- */
- if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
- u16 reg16;
-
- pcie_capability_read_word(dev, PCI_EXP_FLAGS, &reg16);
- entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
- if (entry >= nr_entries)
- goto out_free_irqs;
-
- /* PME and hotplug share an MSI/MSI-X vector */
- irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, entry);
- irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, entry);
-
- nvec = max(nvec, entry + 1);
+ /* See how many and which Interrupt Message Numbers we actually use */
+ nvec = pcie_message_numbers(dev, mask, &pme, &aer, &dpc);
+ if (nvec > nr_entries) {
+ pci_free_irq_vectors(dev);
+ return -EIO;
}
- if (mask & PCIE_PORT_SERVICE_AER) {
- u32 reg32, pos;
-
- pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
- pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
- entry = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27;
- if (entry >= nr_entries)
- goto out_free_irqs;
-
- irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, entry);
-
- nvec = max(nvec, entry + 1);
+ /* PME and hotplug share an MSI/MSI-X vector */
+ if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
+ irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, pme);
+ irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, pme);
}
- if (mask & PCIE_PORT_SERVICE_DPC) {
- u16 reg16, pos;
-
- pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);
- pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP, &reg16);
- entry = reg16 & PCI_EXP_DPC_IRQ;
- if (entry >= nr_entries)
- goto out_free_irqs;
-
- irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, entry);
+ if (mask & PCIE_PORT_SERVICE_AER)
+ irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, aer);
- nvec = max(nvec, entry + 1);
- }
+ if (mask & PCIE_PORT_SERVICE_DPC)
+ irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, dpc);
/* If we allocated more than we need, free them and allocate fewer */
if (nvec != nr_entries) {
@@ -122,10 +140,6 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
}
return 0;
-
-out_free_irqs:
- pci_free_irq_vectors(dev);
- return -EIO;
}
/**