x86, ioapic: Introduce helper utilities to walk ioapics and pins

Introduce helper utilities for_each_ioapic(), for_each_ioapic_reverse(),
for_each_pin() and for_each_ioapic_pin() to walk ioapics and pins.
They will be rewritten e will rewrite later to support IOAPIC hotplug.

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/1402302011-23642-14-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 62 insertions, 58 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 46d09eac1777..16b0247392a5 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -62,6 +62,16 @@
 
 #define __apicdebuginit(type) static type __init
 
+#define for_each_ioapic(idx)            \
+        for ((idx) = 0; (idx) < nr_ioapics; (idx)++)
+#define for_each_ioapic_reverse(idx)    \
+        for ((idx) = nr_ioapics - 1; (idx) >= 0; (idx)--)
+#define for_each_pin(idx, pin)          \
+        for ((pin) = 0; (pin) < ioapics[(idx)].nr_registers; (pin)++)
+#define for_each_ioapic_pin(idx, pin)   \
+        for_each_ioapic((idx))          \
+                for_each_pin((idx), (pin))
+
 #define for_each_irq_pin(entry, head) \
         for (entry = head; entry; entry = entry->next)
 
@@ -191,7 +201,7 @@ int __init arch_early_irq_init(void)
         if (!legacy_pic->nr_legacy_irqs)
                 io_apic_irqs = ~0UL;
 
-        for (i = 0; i < nr_ioapics; i++) {
+        for_each_ioapic(i) {
                 ioapics[i].saved_registers =
                         kzalloc(sizeof(struct IO_APIC_route_entry) *
                                 ioapics[i].nr_registers, GFP_KERNEL);
@@ -624,9 +634,8 @@ static void clear_IO_APIC (void)
 {
         int apic, pin;
 
-        for (apic = 0; apic < nr_ioapics; apic++)
-                for (pin = 0; pin < ioapics[apic].nr_registers; pin++)
-                        clear_IO_APIC_pin(apic, pin);
+        for_each_ioapic_pin(apic, pin)
+                clear_IO_APIC_pin(apic, pin);
 }
 
 #ifdef CONFIG_X86_32
@@ -675,13 +684,13 @@ int save_ioapic_entries(void)
         int apic, pin;
         int err = 0;
 
-        for (apic = 0; apic < nr_ioapics; apic++) {
+        for_each_ioapic(apic) {
                 if (!ioapics[apic].saved_registers) {
                         err = -ENOMEM;
                         continue;
                 }
 
-                for (pin = 0; pin < ioapics[apic].nr_registers; pin++)
+                for_each_pin(apic, pin)
                         ioapics[apic].saved_registers[pin] =
                                 ioapic_read_entry(apic, pin);
         }
@@ -696,11 +705,11 @@ void mask_ioapic_entries(void)
 {
         int apic, pin;
 
-        for (apic = 0; apic < nr_ioapics; apic++) {
+        for_each_ioapic(apic) {
                 if (!ioapics[apic].saved_registers)
                         continue;
 
-                for (pin = 0; pin < ioapics[apic].nr_registers; pin++) {
+                for_each_pin(apic, pin) {
                         struct IO_APIC_route_entry entry;
 
                         entry = ioapics[apic].saved_registers[pin];
@@ -719,11 +728,11 @@ int restore_ioapic_entries(void)
 {
         int apic, pin;
 
-        for (apic = 0; apic < nr_ioapics; apic++) {
+        for_each_ioapic(apic) {
                 if (!ioapics[apic].saved_registers)
                         continue;
 
-                for (pin = 0; pin < ioapics[apic].nr_registers; pin++)
+                for_each_pin(apic, pin)
                         ioapic_write_entry(apic, pin,
                                            ioapics[apic].saved_registers[pin]);
         }
@@ -782,7 +791,7 @@ static int __init find_isa_irq_apic(int irq, int type)
         if (i < mp_irq_entries) {
                 int ioapic_idx;
 
-                for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++)
+                for_each_ioapic(ioapic_idx)
                         if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic)
                                 return ioapic_idx;
         }
@@ -1001,7 +1010,7 @@ int IO_APIC_get_PCI_irq_vector(int bus, int slot, int pin,
         for (i = 0; i < mp_irq_entries; i++) {
                 int lbus = mp_irqs[i].srcbus;
 
-                for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++)
+                for_each_ioapic(ioapic_idx)
                         if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic ||
                             mp_irqs[i].dstapic == MP_APIC_ALL)
                                 break;
@@ -1224,12 +1233,10 @@ static inline int IO_APIC_irq_trigger(int irq)
 {
         int apic, idx, pin;
 
-        for (apic = 0; apic < nr_ioapics; apic++) {
-                for (pin = 0; pin < ioapics[apic].nr_registers; pin++) {
-                        idx = find_irq_entry(apic, pin, mp_INT);
-                        if ((idx != -1) && (irq == pin_2_irq(idx, apic, pin)))
-                                return irq_trigger(idx);
-                }
+        for_each_ioapic_pin(apic, pin) {
+                idx = find_irq_entry(apic, pin, mp_INT);
+                if ((idx != -1) && (irq == pin_2_irq(idx, apic, pin)))
+                        return irq_trigger(idx);
         }
         /*
          * nonexistent IRQs are edge default
@@ -1349,7 +1356,7 @@ static void __init __io_apic_setup_irqs(unsigned int ioapic_idx)
         struct io_apic_irq_attr attr;
         unsigned int pin, irq;
 
-        for (pin = 0; pin < ioapics[ioapic_idx].nr_registers; pin++) {
+        for_each_pin(ioapic_idx, pin) {
                 idx = find_irq_entry(ioapic_idx, pin, mp_INT);
                 if (io_apic_pin_not_connected(idx, ioapic_idx, pin))
                         continue;
@@ -1380,7 +1387,7 @@ static void __init setup_IO_APIC_irqs(void)
 
         apic_printk(APIC_VERBOSE, KERN_DEBUG "init IO_APIC IRQs\n");
 
-        for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++)
+        for_each_ioapic(ioapic_idx)
                 __io_apic_setup_irqs(ioapic_idx);
 }
 
@@ -1583,7 +1590,7 @@ __apicdebuginit(void) print_IO_APICs(void)
         struct irq_chip *chip;
 
         printk(KERN_DEBUG "number of MP IRQ sources: %d.\n", mp_irq_entries);
-        for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++)
+        for_each_ioapic(ioapic_idx)
                 printk(KERN_DEBUG "number of IO-APIC #%d registers: %d.\n",
                        mpc_ioapic_id(ioapic_idx),
                        ioapics[ioapic_idx].nr_registers);
@@ -1594,7 +1601,7 @@ __apicdebuginit(void) print_IO_APICs(void)
          */
         printk(KERN_INFO "testing the IO APIC.......................\n");
 
-        for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++)
+        for_each_ioapic(ioapic_idx)
                 print_IO_APIC(ioapic_idx);
 
         printk(KERN_DEBUG "IRQ to pin mappings:\n");
@@ -1825,26 +1832,22 @@ static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
 void __init enable_IO_APIC(void)
 {
         int i8259_apic, i8259_pin;
-        int apic;
+        int apic, pin;
 
         if (!legacy_pic->nr_legacy_irqs)
                 return;
 
-        for(apic = 0; apic < nr_ioapics; apic++) {
-                int pin;
+        for_each_ioapic_pin(apic, pin) {
                 /* See if any of the pins is in ExtINT mode */
-                for (pin = 0; pin < ioapics[apic].nr_registers; pin++) {
-                        struct IO_APIC_route_entry entry;
-                        entry = ioapic_read_entry(apic, pin);
+                struct IO_APIC_route_entry entry = ioapic_read_entry(apic, pin);
 
-                        /* If the interrupt line is enabled and in ExtInt mode
-                         * I have found the pin where the i8259 is connected.
-                         */
-                        if ((entry.mask == 0) && (entry.delivery_mode == dest_ExtINT)) {
-                                ioapic_i8259.apic = apic;
-                                ioapic_i8259.pin  = pin;
-                                goto found_i8259;
-                        }
+                /* If the interrupt line is enabled and in ExtInt mode
+                 * I have found the pin where the i8259 is connected.
+                 */
+                if ((entry.mask == 0) && (entry.delivery_mode == dest_ExtINT)) {
+                        ioapic_i8259.apic = apic;
+                        ioapic_i8259.pin  = pin;
+                        goto found_i8259;
                 }
         }
  found_i8259:
@@ -1947,7 +1950,7 @@ void __init setup_ioapic_ids_from_mpc_nocheck(void)
         /*
          * Set the IOAPIC ID to the value stored in the MPC table.
          */
-        for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++) {
+        for_each_ioapic(ioapic_idx) {
                 /* Read the register 0 value */
                 raw_spin_lock_irqsave(&ioapic_lock, flags);
                 reg_00.raw = io_apic_read(ioapic_idx, 0);
@@ -2863,7 +2866,7 @@ static void ioapic_resume(void)
 {
         int ioapic_idx;
 
-        for (ioapic_idx = nr_ioapics - 1; ioapic_idx >= 0; ioapic_idx--)
+        for_each_ioapic_reverse(ioapic_idx)
                 resume_ioapic_id(ioapic_idx);
 
         restore_ioapic_entries();
@@ -3457,9 +3460,8 @@ static u8 __init io_apic_unique_id(u8 id)
         DECLARE_BITMAP(used, 256);
 
         bitmap_zero(used, 256);
-        for (i = 0; i < nr_ioapics; i++) {
+        for_each_ioapic(i)
                 __set_bit(mpc_ioapic_id(i), used);
-        }
         if (!test_bit(id, used))
                 return id;
         return find_first_zero_bit(used, 256);
@@ -3517,8 +3519,7 @@ void __init setup_ioapic_dest(void)
         if (skip_ioapic_setup == 1)
                 return;
 
-        for (ioapic = 0; ioapic < nr_ioapics; ioapic++)
-        for (pin = 0; pin < ioapics[ioapic].nr_registers; pin++) {
+        for_each_ioapic_pin(ioapic, pin) {
                 irq_entry = find_irq_entry(ioapic, pin, mp_INT);
                 if (irq_entry == -1)
                         continue;
@@ -3547,29 +3548,33 @@ void __init setup_ioapic_dest(void)
 
 static struct resource *ioapic_resources;
 
-static struct resource * __init ioapic_setup_resources(int nr_ioapics)
+static struct resource * __init ioapic_setup_resources(void)
 {
         unsigned long n;
         struct resource *res;
         char *mem;
-        int i;
+        int i, num = 0;
 
-        if (nr_ioapics <= 0)
+        for_each_ioapic(i)
+                num++;
+        if (num == 0)
                 return NULL;
 
         n = IOAPIC_RESOURCE_NAME_SIZE + sizeof(struct resource);
-        n *= nr_ioapics;
+        n *= num;
 
         mem = alloc_bootmem(n);
         res = (void *)mem;
 
-        mem += sizeof(struct resource) * nr_ioapics;
+        mem += sizeof(struct resource) * num;
 
-        for (i = 0; i < nr_ioapics; i++) {
-                res[i].name = mem;
-                res[i].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+        num = 0;
+        for_each_ioapic(i) {
+                res[num].name = mem;
+                res[num].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
                 snprintf(mem, IOAPIC_RESOURCE_NAME_SIZE, "IOAPIC %u", i);
                 mem += IOAPIC_RESOURCE_NAME_SIZE;
+                num++;
         }
 
         ioapic_resources = res;
@@ -3583,8 +3588,8 @@ void __init native_io_apic_init_mappings(void)
         struct resource *ioapic_res;
         int i;
 
-        ioapic_res = ioapic_setup_resources(nr_ioapics);
-        for (i = 0; i < nr_ioapics; i++) {
+        ioapic_res = ioapic_setup_resources();
+        for_each_ioapic(i) {
                 if (smp_found_config) {
                         ioapic_phys = mpc_ioapic_addr(i);
 #ifdef CONFIG_X86_32
@@ -3629,7 +3634,7 @@ void __init ioapic_insert_resources(void)
                 return;
         }
 
-        for (i = 0; i < nr_ioapics; i++) {
+        for_each_ioapic(i) {
                 insert_resource(&iomem_resource, r);
                 r++;
         }
@@ -3637,16 +3642,15 @@ void __init ioapic_insert_resources(void)
 
 int mp_find_ioapic(u32 gsi)
 {
-        int i = 0;
+        int i;
 
         if (nr_ioapics == 0)
                 return -1;
 
         /* Find the IOAPIC that manages this GSI. */
-        for (i = 0; i < nr_ioapics; i++) {
+        for_each_ioapic(i) {
                 struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(i);
-                if ((gsi >= gsi_cfg->gsi_base)
-                    && (gsi <= gsi_cfg->gsi_end))
+                if (gsi >= gsi_cfg->gsi_base && gsi <= gsi_cfg->gsi_end)
                         return i;
         }
 
@@ -3658,7 +3662,7 @@ int mp_find_ioapic_pin(int ioapic, u32 gsi)
 {
         struct mp_ioapic_gsi *gsi_cfg;
 
-        if (WARN_ON(ioapic == -1))
+        if (WARN_ON(ioapic < 0))
                 return -1;
 
         gsi_cfg = mp_ioapic_gsi_routing(ioapic);