[PATCH] i386: Factor out common io apic routing entry access

The IO APIC code had lots of duplicated code to read/write 64bit
routing entries into the IO-APIC. Factor this out int common read/write
functions

In a few cases the IO APIC lock is taken more often now, but this
isn't a problem because it's all initialization/shutdown only
slow path code.

Similar to earlier x86-64 patch.

Includes a fix by Jiri Slaby for a mistake that broke resume

Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 43 insertions, 57 deletions

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 4eacd52eeb74..b713f27d7e86 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -94,6 +94,34 @@ int vector_irq[NR_VECTORS] __read_mostly = { [0 ... NR_VECTORS - 1] = -1};
 #define vector_to_irq(vector)   (vector)
 #endif
 
+
+union entry_union {
+        struct { u32 w1, w2; };
+        struct IO_APIC_route_entry entry;
+};
+
+static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin)
+{
+        union entry_union eu;
+        unsigned long flags;
+        spin_lock_irqsave(&ioapic_lock, flags);
+        eu.w1 = io_apic_read(apic, 0x10 + 2 * pin);
+        eu.w2 = io_apic_read(apic, 0x11 + 2 * pin);
+        spin_unlock_irqrestore(&ioapic_lock, flags);
+        return eu.entry;
+}
+
+static void ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
+{
+        unsigned long flags;
+        union entry_union eu;
+        eu.entry = e;
+        spin_lock_irqsave(&ioapic_lock, flags);
+        io_apic_write(apic, 0x10 + 2*pin, eu.w1);
+        io_apic_write(apic, 0x11 + 2*pin, eu.w2);
+        spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
 /*
  * The common case is 1:1 IRQ<->pin mappings. Sometimes there are
  * shared ISA-space IRQs, so we have to support them. We are super
@@ -201,13 +229,9 @@ static void unmask_IO_APIC_irq (unsigned int irq)
 static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
 {
         struct IO_APIC_route_entry entry;
-        unsigned long flags;
         
         /* Check delivery_mode to be sure we're not clearing an SMI pin */
-        spin_lock_irqsave(&ioapic_lock, flags);
-        *(((int*)&entry) + 0) = io_apic_read(apic, 0x10 + 2 * pin);
-        *(((int*)&entry) + 1) = io_apic_read(apic, 0x11 + 2 * pin);
-        spin_unlock_irqrestore(&ioapic_lock, flags);
+        entry = ioapic_read_entry(apic, pin);
         if (entry.delivery_mode == dest_SMI)
                 return;
 
@@ -216,10 +240,7 @@ static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
          */
         memset(&entry, 0, sizeof(entry));
         entry.mask = 1;
-        spin_lock_irqsave(&ioapic_lock, flags);
-        io_apic_write(apic, 0x10 + 2 * pin, *(((int *)&entry) + 0));
-        io_apic_write(apic, 0x11 + 2 * pin, *(((int *)&entry) + 1));
-        spin_unlock_irqrestore(&ioapic_lock, flags);
+        ioapic_write_entry(apic, pin, entry);
 }
 
 static void clear_IO_APIC (void)
@@ -1284,9 +1305,8 @@ static void __init setup_IO_APIC_irqs(void)
                         if (!apic && (irq < 16))
                                 disable_8259A_irq(irq);
                 }
+                ioapic_write_entry(apic, pin, entry);
                 spin_lock_irqsave(&ioapic_lock, flags);
-                io_apic_write(apic, 0x11+2*pin, *(((int *)&entry)+1));
-                io_apic_write(apic, 0x10+2*pin, *(((int *)&entry)+0));
                 set_native_irq_info(irq, TARGET_CPUS);
                 spin_unlock_irqrestore(&ioapic_lock, flags);
         }
@@ -1302,7 +1322,6 @@ static void __init setup_IO_APIC_irqs(void)
 static void __init setup_ExtINT_IRQ0_pin(unsigned int apic, unsigned int pin, int vector)
 {
         struct IO_APIC_route_entry entry;
-        unsigned long flags;
 
         memset(&entry,0,sizeof(entry));
 
@@ -1332,10 +1351,7 @@ static void __init setup_ExtINT_IRQ0_pin(unsigned int apic, unsigned int pin, in
         /*
          * Add it to the IO-APIC irq-routing table:
          */
-        spin_lock_irqsave(&ioapic_lock, flags);
-        io_apic_write(apic, 0x11+2*pin, *(((int *)&entry)+1));
-        io_apic_write(apic, 0x10+2*pin, *(((int *)&entry)+0));
-        spin_unlock_irqrestore(&ioapic_lock, flags);
+        ioapic_write_entry(apic, pin, entry);
 
         enable_8259A_irq(0);
 }
@@ -1445,10 +1461,7 @@ void __init print_IO_APIC(void)
         for (i = 0; i <= reg_01.bits.entries; i++) {
                 struct IO_APIC_route_entry entry;
 
-                spin_lock_irqsave(&ioapic_lock, flags);
-                *(((int *)&entry)+0) = io_apic_read(apic, 0x10+i*2);
-                *(((int *)&entry)+1) = io_apic_read(apic, 0x11+i*2);
-                spin_unlock_irqrestore(&ioapic_lock, flags);
+                entry = ioapic_read_entry(apic, i);
 
                 printk(KERN_DEBUG " %02x %03X %02X  ",
                         i,
@@ -1667,10 +1680,7 @@ static void __init enable_IO_APIC(void)
                 /* See if any of the pins is in ExtINT mode */
                 for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
                         struct IO_APIC_route_entry entry;
-                        spin_lock_irqsave(&ioapic_lock, flags);
-                        *(((int *)&entry) + 0) = io_apic_read(apic, 0x10 + 2 * pin);
-                        *(((int *)&entry) + 1) = io_apic_read(apic, 0x11 + 2 * pin);
-                        spin_unlock_irqrestore(&ioapic_lock, flags);
+                        entry = ioapic_read_entry(apic, pin);
 
 
                         /* If the interrupt line is enabled and in ExtInt mode
@@ -1727,7 +1737,6 @@ void disable_IO_APIC(void)
          */
         if (ioapic_i8259.pin != -1) {
                 struct IO_APIC_route_entry entry;
-                unsigned long flags;
 
                 memset(&entry, 0, sizeof(entry));
                 entry.mask            = 0; /* Enabled */
@@ -1744,12 +1753,7 @@ void disable_IO_APIC(void)
                 /*
                  * Add it to the IO-APIC irq-routing table:
                  */
-                spin_lock_irqsave(&ioapic_lock, flags);
-                io_apic_write(ioapic_i8259.apic, 0x11+2*ioapic_i8259.pin,
-                        *(((int *)&entry)+1));
-                io_apic_write(ioapic_i8259.apic, 0x10+2*ioapic_i8259.pin,
-                        *(((int *)&entry)+0));
-                spin_unlock_irqrestore(&ioapic_lock, flags);
+                ioapic_write_entry(ioapic_i8259.apic, ioapic_i8259.pin, entry);
         }
         disconnect_bsp_APIC(ioapic_i8259.pin != -1);
 }
@@ -2214,17 +2218,13 @@ static inline void unlock_ExtINT_logic(void)
         int apic, pin, i;
         struct IO_APIC_route_entry entry0, entry1;
         unsigned char save_control, save_freq_select;
-        unsigned long flags;
 
         pin  = find_isa_irq_pin(8, mp_INT);
         apic = find_isa_irq_apic(8, mp_INT);
         if (pin == -1)
                 return;
 
-        spin_lock_irqsave(&ioapic_lock, flags);
-        *(((int *)&entry0) + 1) = io_apic_read(apic, 0x11 + 2 * pin);
-        *(((int *)&entry0) + 0) = io_apic_read(apic, 0x10 + 2 * pin);
-        spin_unlock_irqrestore(&ioapic_lock, flags);
+        entry0 = ioapic_read_entry(apic, pin);
         clear_IO_APIC_pin(apic, pin);
 
         memset(&entry1, 0, sizeof(entry1));
@@ -2237,10 +2237,7 @@ static inline void unlock_ExtINT_logic(void)
         entry1.trigger = 0;
         entry1.vector = 0;
 
-        spin_lock_irqsave(&ioapic_lock, flags);
-        io_apic_write(apic, 0x11 + 2 * pin, *(((int *)&entry1) + 1));
-        io_apic_write(apic, 0x10 + 2 * pin, *(((int *)&entry1) + 0));
-        spin_unlock_irqrestore(&ioapic_lock, flags);
+        ioapic_write_entry(apic, pin, entry1);
 
         save_control = CMOS_READ(RTC_CONTROL);
         save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
@@ -2259,10 +2256,7 @@ static inline void unlock_ExtINT_logic(void)
         CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
         clear_IO_APIC_pin(apic, pin);
 
-        spin_lock_irqsave(&ioapic_lock, flags);
-        io_apic_write(apic, 0x11 + 2 * pin, *(((int *)&entry0) + 1));
-        io_apic_write(apic, 0x10 + 2 * pin, *(((int *)&entry0) + 0));
-        spin_unlock_irqrestore(&ioapic_lock, flags);
+        ioapic_write_entry(apic, pin, entry0);
 }
 
 int timer_uses_ioapic_pin_0;
@@ -2462,17 +2456,12 @@ static int ioapic_suspend(struct sys_device *dev, pm_message_t state)
 {
         struct IO_APIC_route_entry *entry;
         struct sysfs_ioapic_data *data;
-        unsigned long flags;
         int i;
         
         data = container_of(dev, struct sysfs_ioapic_data, dev);
         entry = data->entry;
-        spin_lock_irqsave(&ioapic_lock, flags);
-        for (i = 0; i < nr_ioapic_registers[dev->id]; i ++, entry ++ ) {
-                *(((int *)entry) + 1) = io_apic_read(dev->id, 0x11 + 2 * i);
-                *(((int *)entry) + 0) = io_apic_read(dev->id, 0x10 + 2 * i);
-        }
-        spin_unlock_irqrestore(&ioapic_lock, flags);
+        for (i = 0; i < nr_ioapic_registers[dev->id]; i ++)
+                entry[i] = ioapic_read_entry(dev->id, i);
 
         return 0;
 }
@@ -2494,11 +2483,9 @@ static int ioapic_resume(struct sys_device *dev)
                 reg_00.bits.ID = mp_ioapics[dev->id].mpc_apicid;
                 io_apic_write(dev->id, 0, reg_00.raw);
         }
-        for (i = 0; i < nr_ioapic_registers[dev->id]; i ++, entry ++ ) {
-                io_apic_write(dev->id, 0x11+2*i, *(((int *)entry)+1));
-                io_apic_write(dev->id, 0x10+2*i, *(((int *)entry)+0));
-        }
         spin_unlock_irqrestore(&ioapic_lock, flags);
+        for (i = 0; i < nr_ioapic_registers[dev->id]; i ++)
+                ioapic_write_entry(dev->id, i, entry[i]);
 
         return 0;
 }
@@ -2695,9 +2682,8 @@ int io_apic_set_pci_routing (int ioapic, int pin, int irq, int edge_level, int a
         if (!ioapic && (irq < 16))
                 disable_8259A_irq(irq);
 
+        ioapic_write_entry(ioapic, pin, entry);
         spin_lock_irqsave(&ioapic_lock, flags);
-        io_apic_write(ioapic, 0x11+2*pin, *(((int *)&entry)+1));
-        io_apic_write(ioapic, 0x10+2*pin, *(((int *)&entry)+0));
         set_native_irq_info(use_pci_vector() ? entry.vector : irq, TARGET_CPUS);
         spin_unlock_irqrestore(&ioapic_lock, flags);