[RFC Patch 3/3] x86, irq: count legacy IRQs by legacy_pic->nr_legacy_irqs instead of NR_IRQS_LEGACY

From: Jiang Liu
Date: Thu Jun 05 2014 - 03:03:09 EST

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@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/i8259.h | 2 ++
arch/x86/kernel/acpi/boot.c | 13 ++++++------
arch/x86/kernel/apic/io_apic.c | 43 +++++++++++++++++++++++-----------------
arch/x86/kernel/devicetree.c | 12 +++++------
arch/x86/kernel/irqinit.c | 6 +++---
arch/x86/pci/xen.c | 6 +++---
6 files changed, 46 insertions(+), 36 deletions(-)

diff --git a/arch/x86/include/asm/i8259.h b/arch/x86/include/asm/i8259.h
index a20365953bf8..fdac75b8782a 100644
--- a/arch/x86/include/asm/i8259.h
+++ b/arch/x86/include/asm/i8259.h
@@ -67,4 +67,6 @@ struct legacy_pic {
extern struct legacy_pic *legacy_pic;
extern struct legacy_pic null_legacy_pic;

+#define nr_legacy_irqs() (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 d6493863bd4b..8b09249bb253 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 02faa7104aa5..72cbb92ca401 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();
}

@@ -3344,7 +3351,7 @@ 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;
}
@@ -3356,17 +3363,17 @@ 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 d35078ea1446..68f8805401be 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -316,7 +316,7 @@ 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;
@@ -326,17 +326,17 @@ 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..8debddd2c6d1 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -40,7 +40,7 @@ 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 +511,7 @@ 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 +522,7 @@ 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;
--
1.7.10.4

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