x86, irq: Reorganize IO_APIC_get_PCI_irq_vector() to prepare for irqdomain

Reorganize function IO_APIC_get_PCI_irq_vector() a bit to better support
coming irqdomain.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1402302011-23642-16-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 33 insertions, 28 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 446a931d5f44..09e5c7b4df5a 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -997,7 +997,7 @@ static int pin_2_irq(int idx, int apic, int pin)
 int IO_APIC_get_PCI_irq_vector(int bus, int slot, int pin,
                                 struct io_apic_irq_attr *irq_attr)
 {
-        int ioapic_idx, i, best_guess = -1;
+        int irq, i, best_guess = -1;
 
         apic_printk(APIC_DEBUG,
                     "querying PCI -> IRQ mapping bus:%d, slot:%d, pin:%d.\n",
@@ -1007,41 +1007,46 @@ int IO_APIC_get_PCI_irq_vector(int bus, int slot, int pin,
                             "PCI BIOS passed nonexistent PCI bus %d!\n", bus);
                 return -1;
         }
+
         for (i = 0; i < mp_irq_entries; i++) {
                 int lbus = mp_irqs[i].srcbus;
+                int ioapic_idx, found = 0;
+
+                if (bus != lbus || mp_irqs[i].irqtype != mp_INT ||
+                    slot != ((mp_irqs[i].srcbusirq >> 2) & 0x1f))
+                        continue;
 
                 for_each_ioapic(ioapic_idx)
                         if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic ||
-                            mp_irqs[i].dstapic == MP_APIC_ALL)
+                            mp_irqs[i].dstapic == MP_APIC_ALL) {
+                                found = 1;
                                 break;
+                        }
+                if (!found)
+                        continue;
 
-                if (!test_bit(lbus, mp_bus_not_pci) &&
-                    mp_irqs[i].irqtype == mp_INT &&
-                    (bus == lbus) &&
-                    (slot == ((mp_irqs[i].srcbusirq >> 2) & 0x1f))) {
-                        int irq = pin_2_irq(i, ioapic_idx, mp_irqs[i].dstirq);
-
-                        if (!(ioapic_idx || IO_APIC_IRQ(irq)))
-                                continue;
+                /* Skip ISA IRQs */
+                irq = pin_2_irq(i, ioapic_idx, mp_irqs[i].dstirq);
+                if (ioapic_idx == 0 && !IO_APIC_IRQ(irq))
+                        continue;
 
-                        if (pin == (mp_irqs[i].srcbusirq & 3)) {
-                                set_io_apic_irq_attr(irq_attr, ioapic_idx,
-                                                     mp_irqs[i].dstirq,
-                                                     irq_trigger(i),
-                                                     irq_polarity(i));
-                                return irq;
-                        }
-                        /*
-                         * Use the first all-but-pin matching entry as a
-                         * best-guess fuzzy result for broken mptables.
-                         */
-                        if (best_guess < 0) {
-                                set_io_apic_irq_attr(irq_attr, ioapic_idx,
-                                                     mp_irqs[i].dstirq,
-                                                     irq_trigger(i),
-                                                     irq_polarity(i));
-                                best_guess = irq;
-                        }
+                if (pin == (mp_irqs[i].srcbusirq & 3)) {
+                        set_io_apic_irq_attr(irq_attr, ioapic_idx,
+                                             mp_irqs[i].dstirq,
+                                             irq_trigger(i),
+                                             irq_polarity(i));
+                        return irq;
+                }
+                /*
+                 * Use the first all-but-pin matching entry as a
+                 * best-guess fuzzy result for broken mptables.
+                 */
+                if (best_guess < 0) {
+                        set_io_apic_irq_attr(irq_attr, ioapic_idx,
+                                             mp_irqs[i].dstirq,
+                                             irq_trigger(i),
+                                             irq_polarity(i));
+                        best_guess = irq;
                 }
         }
         return best_guess;