x86, irq: Count legacy IRQs by legacy_pic->nr_legacy_irqs instead of NR_IRQS_LEGACY

Some platforms, such as Intel MID and mshypv, do not support legacy
interrupt controllers. So count legacy IRQs by legacy_pic->nr_legacy_irqs
instead of hard-coded NR_IRQS_LEGACY.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.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: xen-devel@lists.xenproject.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>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Tony Lindgren <tony@atomide.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Link: http://lkml.kernel.org/r/1402302011-23642-20-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

6 files changed, 51 insertions, 36 deletions

diff --git a/arch/x86/include/asm/i8259.h b/arch/x86/include/asm/i8259.h
index a20365953bf8..ccffa53750a8 100644
--- a/arch/x86/include/asm/i8259.h
+++ b/arch/x86/include/asm/i8259.h
@@ -67,4 +67,9 @@ struct legacy_pic {
 extern struct legacy_pic *legacy_pic;
 extern struct legacy_pic null_legacy_pic;
 
+static inline int nr_legacy_irqs(void)
+{
+        return legacy_pic->nr_legacy_irqs;
+}
+
 #endif /* _ASM_X86_I8259_H */
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index f3bafcd32b98..b12976590a72 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -43,6 +43,7 @@
 #include <asm/io.h>
 #include <asm/mpspec.h>
 #include <asm/smp.h>
+#include <asm/i8259.h>
 
 #include "sleep.h" /* To include x86_acpi_suspend_lowlevel */
 static int __initdata acpi_force = 0;
@@ -101,10 +102,10 @@ static u32 isa_irq_to_gsi[NR_IRQS_LEGACY] __read_mostly = {
 
 static unsigned int gsi_to_irq(unsigned int gsi)
 {
-        unsigned int irq = gsi + NR_IRQS_LEGACY;
+        unsigned int irq = gsi + nr_legacy_irqs();
         unsigned int i;
 
-        for (i = 0; i < NR_IRQS_LEGACY; i++) {
+        for (i = 0; i < nr_legacy_irqs(); i++) {
                 if (isa_irq_to_gsi[i] == gsi) {
                         return i;
                 }
@@ -114,7 +115,7 @@ static unsigned int gsi_to_irq(unsigned int gsi)
          * except on truly weird platforms that have
          * non isa irqs in the first 16 gsis.
          */
-        if (gsi >= NR_IRQS_LEGACY)
+        if (gsi >= nr_legacy_irqs())
                 irq = gsi;
         else
                 irq = gsi_top + gsi;
@@ -371,7 +372,7 @@ static void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger,
          * otherwise there will be more than one entry with the same GSI
          * and acpi_isa_irq_to_gsi() may give wrong result.
          */
-        if (gsi < NR_IRQS_LEGACY && isa_irq_to_gsi[gsi] == gsi)
+        if (gsi < nr_legacy_irqs() && isa_irq_to_gsi[gsi] == gsi)
                 isa_irq_to_gsi[gsi] = ACPI_INVALID_GSI;
         isa_irq_to_gsi[bus_irq] = gsi;
 }
@@ -628,7 +629,7 @@ EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
 
 int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi)
 {
-        if (isa_irq < NR_IRQS_LEGACY &&
+        if (isa_irq < nr_legacy_irqs() &&
             isa_irq_to_gsi[isa_irq] != ACPI_INVALID_GSI) {
                 *gsi = isa_irq_to_gsi[isa_irq];
                 return 0;
@@ -1017,7 +1018,7 @@ static void __init mp_config_acpi_legacy_irqs(void)
          * Use the default configuration for the IRQs 0-15.  Unless
          * overridden by (MADT) interrupt source override entries.
          */
-        for (i = 0; i < NR_IRQS_LEGACY; i++) {
+        for (i = 0; i < nr_legacy_irqs(); i++) {
                 int ioapic, pin;
                 unsigned int dstapic;
                 int idx;
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 424f795a1c78..4208ea9edc10 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -129,10 +129,17 @@ u32 mp_pin_to_gsi(int ioapic, int pin)
         return mp_ioapic_gsi_routing(ioapic)->gsi_base + pin;
 }
 
-/* Initialize all legacy IRQs and all pins on the first IOAPIC at boot */
+/*
+ * Initialize all legacy IRQs and all pins on the first IOAPIC
+ * if we have legacy interrupt controller. Kernel boot option "pirq="
+ * may rely on non-legacy pins on the first IOAPIC.
+ */
 static inline int mp_init_irq_at_boot(int ioapic, int irq)
 {
-        return ioapic == 0 || (irq >= 0 && irq < NR_IRQS_LEGACY);
+        if (!nr_legacy_irqs())
+                return 0;
+
+        return ioapic == 0 || (irq >= 0 && irq < nr_legacy_irqs());
 }
 
 int nr_ioapics;
@@ -216,7 +223,7 @@ int __init arch_early_irq_init(void)
         struct irq_cfg *cfg;
         int count, node, i;
 
-        if (!legacy_pic->nr_legacy_irqs)
+        if (!nr_legacy_irqs())
                 io_apic_irqs = ~0UL;
 
         for_each_ioapic(i) {
@@ -239,7 +246,7 @@ int __init arch_early_irq_init(void)
                  * For legacy IRQ's, start with assigning irq0 to irq15 to
                  * IRQ0_VECTOR to IRQ15_VECTOR for all cpu's.
                  */
-                if (i < legacy_pic->nr_legacy_irqs) {
+                if (i < nr_legacy_irqs()) {
                         cfg[i].vector = IRQ0_VECTOR + i;
                         cpumask_setall(cfg[i].domain);
                 }
@@ -823,7 +830,7 @@ static int __init find_isa_irq_apic(int irq, int type)
  */
 static int EISA_ELCR(unsigned int irq)
 {
-        if (irq < legacy_pic->nr_legacy_irqs) {
+        if (irq < nr_legacy_irqs()) {
                 unsigned int port = 0x4d0 + (irq >> 3);
                 return (inb(port) >> (irq & 7)) & 1;
         }
@@ -980,7 +987,7 @@ static int pin_2_irq(int idx, int apic, int pin)
         } else {
                 u32 gsi = gsi_cfg->gsi_base + pin;
 
-                if (gsi >= NR_IRQS_LEGACY)
+                if (gsi >= nr_legacy_irqs())
                         irq = gsi;
                 else
                         irq = gsi_top + gsi;
@@ -1357,7 +1364,7 @@ static void setup_ioapic_irq(unsigned int irq, struct irq_cfg *cfg,
         }
 
         ioapic_register_intr(irq, cfg, attr->trigger);
-        if (irq < legacy_pic->nr_legacy_irqs)
+        if (irq < nr_legacy_irqs())
                 legacy_pic->mask(irq);
 
         ioapic_write_entry(attr->ioapic, attr->ioapic_pin, entry);
@@ -1782,7 +1789,7 @@ __apicdebuginit(void) print_PIC(void)
         unsigned int v;
         unsigned long flags;
 
-        if (!legacy_pic->nr_legacy_irqs)
+        if (!nr_legacy_irqs())
                 return;
 
         printk(KERN_DEBUG "\nprinting PIC contents\n");
@@ -1854,7 +1861,7 @@ void __init enable_IO_APIC(void)
         int i8259_apic, i8259_pin;
         int apic, pin;
 
-        if (!legacy_pic->nr_legacy_irqs)
+        if (!nr_legacy_irqs())
                 return;
 
         for_each_ioapic_pin(apic, pin) {
@@ -1939,7 +1946,7 @@ void disable_IO_APIC(void)
          */
         clear_IO_APIC();
 
-        if (!legacy_pic->nr_legacy_irqs)
+        if (!nr_legacy_irqs())
                 return;
 
         x86_io_apic_ops.disable();
@@ -2143,7 +2150,7 @@ static unsigned int startup_ioapic_irq(struct irq_data *data)
         unsigned long flags;
 
         raw_spin_lock_irqsave(&ioapic_lock, flags);
-        if (irq < legacy_pic->nr_legacy_irqs) {
+        if (irq < nr_legacy_irqs()) {
                 legacy_pic->mask(irq);
                 if (legacy_pic->irq_pending(irq))
                         was_pending = 1;
@@ -2542,7 +2549,7 @@ static inline void init_IO_APIC_traps(void)
                          * so default to an old-fashioned 8259
                          * interrupt if we can..
                          */
-                        if (irq < legacy_pic->nr_legacy_irqs)
+                        if (irq < nr_legacy_irqs())
                                 legacy_pic->make_irq(irq);
                         else
                                 /* Strange. Oh, well.. */
@@ -2839,7 +2846,7 @@ void __init setup_IO_APIC(void)
         /*
          * calling enable_IO_APIC() is moved to setup_local_APIC for BP
          */
-        io_apic_irqs = legacy_pic->nr_legacy_irqs ? ~PIC_IRQS : ~0UL;
+        io_apic_irqs = nr_legacy_irqs() ? ~PIC_IRQS : ~0UL;
 
         apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
         /*
@@ -2850,7 +2857,7 @@ void __init setup_IO_APIC(void)
         sync_Arb_IDs();
         setup_IO_APIC_irqs();
         init_IO_APIC_traps();
-        if (legacy_pic->nr_legacy_irqs)
+        if (nr_legacy_irqs())
                 check_timer();
 }
 
@@ -3348,7 +3355,7 @@ static int __init io_apic_get_redir_entries(int ioapic)
 
 unsigned int arch_dynirq_lower_bound(unsigned int from)
 {
-        unsigned int min = gsi_top + NR_IRQS_LEGACY;
+        unsigned int min = gsi_top + nr_legacy_irqs();
 
         return from < min ? min : from;
 }
@@ -3360,17 +3367,17 @@ int __init arch_probe_nr_irqs(void)
         if (nr_irqs > (NR_VECTORS * nr_cpu_ids))
                 nr_irqs = NR_VECTORS * nr_cpu_ids;
 
-        nr = (gsi_top + NR_IRQS_LEGACY) + 8 * nr_cpu_ids;
+        nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids;
 #if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ)
         /*
          * for MSI and HT dyn irq
          */
-        nr += (gsi_top + NR_IRQS_LEGACY) * 16;
+        nr += gsi_top * 16;
 #endif
         if (nr < nr_irqs)
                 nr_irqs = nr;
 
-        return NR_IRQS_LEGACY;
+        return nr_legacy_irqs();
 }
 
 int io_apic_set_pci_routing(struct device *dev, int irq,
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 7db54b5d5f86..b4680058db8b 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -21,6 +21,7 @@
 #include <asm/apic.h>
 #include <asm/pci_x86.h>
 #include <asm/setup.h>
+#include <asm/i8259.h>
 
 __initdata u64 initial_dtb;
 char __initdata cmd_line[COMMAND_LINE_SIZE];
@@ -314,7 +315,7 @@ static void dt_add_ioapic_domain(unsigned int ioapic_num,
         struct irq_domain *id;
         struct mp_ioapic_gsi *gsi_cfg;
         int ret;
-        int num;
+        int num, legacy_irqs = nr_legacy_irqs();
 
         gsi_cfg = mp_ioapic_gsi_routing(ioapic_num);
         num = gsi_cfg->gsi_end - gsi_cfg->gsi_base + 1;
@@ -324,17 +325,17 @@ static void dt_add_ioapic_domain(unsigned int ioapic_num,
         BUG_ON(!id);
         if (gsi_cfg->gsi_base == 0) {
                 /*
-                 * The first NR_IRQS_LEGACY irq descs are allocated in
+                 * The first nr_legacy_irqs() irq descs are allocated in
                  * early_irq_init() and need just a mapping. The
                  * remaining irqs need both. All of them are preallocated
                  * and assigned so we can keep the 1:1 mapping which the ioapic
                  * is having.
                  */
-                irq_domain_associate_many(id, 0, 0, NR_IRQS_LEGACY);
+                irq_domain_associate_many(id, 0, 0, legacy_irqs);
 
-                if (num > NR_IRQS_LEGACY) {
-                        ret = irq_create_strict_mappings(id, NR_IRQS_LEGACY,
-                                        NR_IRQS_LEGACY, num - NR_IRQS_LEGACY);
+                if (num > legacy_irqs) {
+                        ret = irq_create_strict_mappings(id, legacy_irqs,
+                                        legacy_irqs, num - legacy_irqs);
                         if (ret)
                                 pr_err("Error creating mapping for the "
                                                 "remaining IRQs: %d\n", ret);
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index 7f50156542fb..a0111e91eb4b 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -78,7 +78,7 @@ void __init init_ISA_irqs(void)
 #endif
         legacy_pic->init(0);
 
-        for (i = 0; i < legacy_pic->nr_legacy_irqs; i++)
+        for (i = 0; i < nr_legacy_irqs(); i++)
                 irq_set_chip_and_handler_name(i, chip, handle_level_irq, name);
 }
 
@@ -100,7 +100,7 @@ void __init init_IRQ(void)
          * then this vector space can be freed and re-used dynamically as the
          * irq's migrate etc.
          */
-        for (i = 0; i < legacy_pic->nr_legacy_irqs; i++)
+        for (i = 0; i < nr_legacy_irqs(); i++)
                 per_cpu(vector_irq, 0)[IRQ0_VECTOR + i] = i;
 
         x86_init.irqs.intr_init();
@@ -121,7 +121,7 @@ void setup_vector_irq(int cpu)
          * legacy PIC, for the new cpu that is coming online, setup the static
          * legacy vector to irq mapping:
          */
-        for (irq = 0; irq < legacy_pic->nr_legacy_irqs; irq++)
+        for (irq = 0; irq < nr_legacy_irqs(); irq++)
                 per_cpu(vector_irq, cpu)[IRQ0_VECTOR + irq] = irq;
 #endif
 
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 905956f16465..093f5f4272d3 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -23,6 +23,7 @@
 #include <xen/features.h>
 #include <xen/events.h>
 #include <asm/xen/pci.h>
+#include <asm/i8259.h>
 
 static int xen_pcifront_enable_irq(struct pci_dev *dev)
 {
@@ -40,7 +41,7 @@ static int xen_pcifront_enable_irq(struct pci_dev *dev)
         /* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/
         pirq = gsi;
 
-        if (gsi < NR_IRQS_LEGACY)
+        if (gsi < nr_legacy_irqs())
                 share = 0;
 
         rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
@@ -511,7 +512,7 @@ int __init pci_xen_initial_domain(void)
         xen_setup_acpi_sci();
         __acpi_register_gsi = acpi_register_gsi_xen;
         /* Pre-allocate legacy irqs */
-        for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
+        for (irq = 0; irq < nr_legacy_irqs(); irq++) {
                 int trigger, polarity;
 
                 if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
@@ -522,7 +523,7 @@ int __init pci_xen_initial_domain(void)
                         true /* Map GSI to PIRQ */);
         }
         if (0 == nr_ioapics) {
-                for (irq = 0; irq < NR_IRQS_LEGACY; irq++)
+                for (irq = 0; irq < nr_legacy_irqs(); irq++)
                         xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic");
         }
         return 0;