Merge branch 'pci/host-designware' into next

* pci/host-designware:
  PCI: designware: Use typical "for" loop idiom
  PCI: designware: Remove redundant call to pci_write_config_word()
  PCI: designware: Fix crash in dw_msi_teardown_irq()

1 files changed, 40 insertions, 19 deletions

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index e33b68be0391..1c92833a4ed3 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -209,6 +209,23 @@ static int find_valid_pos0(struct pcie_port *pp, int msgvec, int pos, int *pos0)
         return 0;
 }
 
+static void clear_irq_range(struct pcie_port *pp, unsigned int irq_base,
+                            unsigned int nvec, unsigned int pos)
+{
+        unsigned int i, res, bit, val;
+
+        for (i = 0; i < nvec; i++) {
+                irq_set_msi_desc_off(irq_base, i, NULL);
+                clear_bit(pos + i, pp->msi_irq_in_use);
+                /* Disable corresponding interrupt on MSI interrupt controller */
+                res = ((pos + i) / 32) * 12;
+                bit = (pos + i) % 32;
+                dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
+                val &= ~(1 << bit);
+                dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val);
+        }
+}
+
 static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos)
 {
         int res, bit, irq, pos0, pos1, i;
@@ -242,18 +259,25 @@ static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos)
         if (!irq)
                 goto no_valid_irq;
 
-        i = 0;
-        while (i < no_irqs) {
+        /*
+         * irq_create_mapping (called from dw_pcie_host_init) pre-allocates
+         * descs so there is no need to allocate descs here. We can therefore
+         * assume that if irq_find_mapping above returns non-zero, then the
+         * descs are also successfully allocated.
+         */
+
+        for (i = 0; i < no_irqs; i++) {
+                if (irq_set_msi_desc_off(irq, i, desc) != 0) {
+                        clear_irq_range(pp, irq, i, pos0);
+                        goto no_valid_irq;
+                }
                 set_bit(pos0 + i, pp->msi_irq_in_use);
-                irq_alloc_descs((irq + i), (irq + i), 1, 0);
-                irq_set_msi_desc(irq + i, desc);
                 /*Enable corresponding interrupt in MSI interrupt controller */
                 res = ((pos0 + i) / 32) * 12;
                 bit = (pos0 + i) % 32;
                 dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
                 val |= 1 << bit;
                 dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val);
-                i++;
         }
 
         *pos = pos0;
@@ -266,7 +290,7 @@ no_valid_irq:
 
 static void clear_irq(unsigned int irq)
 {
-        int res, bit, val, pos;
+        unsigned int pos, nvec;
         struct irq_desc *desc;
         struct msi_desc *msi;
         struct pcie_port *pp;
@@ -281,18 +305,15 @@ static void clear_irq(unsigned int irq)
                 return;
         }
 
+        /* undo what was done in assign_irq */
         pos = data->hwirq;
+        nvec = 1 << msi->msi_attrib.multiple;
 
-        irq_free_desc(irq);
+        clear_irq_range(pp, irq, nvec, pos);
 
-        clear_bit(pos, pp->msi_irq_in_use);
-
-        /* Disable corresponding interrupt on MSI interrupt controller */
-        res = (pos / 32) * 12;
-        bit = pos % 32;
-        dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
-        val &= ~(1 << bit);
-        dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val);
+        /* all irqs cleared; reset attributes */
+        msi->irq = 0;
+        msi->msi_attrib.multiple = 0;
 }
 
 static int dw_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev,
@@ -320,10 +341,10 @@ static int dw_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev,
         if (irq < 0)
                 return irq;
 
-        msg_ctr &= ~PCI_MSI_FLAGS_QSIZE;
-        msg_ctr |= msgvec << 4;
-        pci_write_config_word(pdev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
-                                msg_ctr);
+        /*
+         * write_msi_msg() will update PCI_MSI_FLAGS so there is
+         * no need to explicitly call pci_write_config_word().
+         */
         desc->msi_attrib.multiple = msgvec;
 
         msg.address_lo = virt_to_phys((void *)pp->msi_data);