ARM: gic: allow GIC to support non-banked setups

The GIC support code is heavily using the fact that hardware
implementations are exposing banked registers. Unfortunately, it
looks like at least one GIC implementation (EXYNOS) offers both
the distributor and the CPU interfaces at different addresses,
depending on the CPU.

This problem is solved by allowing the distributor and CPU interface
addresses to be per-cpu variables for the platforms that require it.
The EXYNOS code is updated not to mess with the GIC internals while
handling interrupts, and struct gic_chip_data is back to being private.
The DT binding for the gic is updated to allow an optional "cpu-offset"
value, which is used to compute the various base addresses.

Finally, a new config option (GIC_NON_BANKED) is used to control this
feature, so the overhead is only present on kernels compiled with
support for EXYNOS.

Tested on Origen (EXYNOS4) and Panda (OMAP4).

Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

2 files changed, 2 insertions, 42 deletions

diff --git a/arch/arm/mach-exynos/cpu.c b/arch/arm/mach-exynos/cpu.c
index 90ec247f3b37..e92e464bdbba 100644
--- a/arch/arm/mach-exynos/cpu.c
+++ b/arch/arm/mach-exynos/cpu.c
@@ -207,27 +207,13 @@ void __init exynos4_init_clocks(int xtal)
 	exynos4_setup_clocks();
 }
 
-static void exynos4_gic_irq_fix_base(struct irq_data *d)
-{
-	struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
-
-	gic_data->cpu_base = S5P_VA_GIC_CPU +
-			    (gic_bank_offset * smp_processor_id());
-
-	gic_data->dist_base = S5P_VA_GIC_DIST +
-			    (gic_bank_offset * smp_processor_id());
-}
-
 void __init exynos4_init_irq(void)
 {
 	int irq;
 
 	gic_bank_offset = soc_is_exynos4412() ? 0x4000 : 0x8000;
 
-	gic_init(0, IRQ_PPI(0), S5P_VA_GIC_DIST, S5P_VA_GIC_CPU);
-	gic_arch_extn.irq_eoi = exynos4_gic_irq_fix_base;
-	gic_arch_extn.irq_unmask = exynos4_gic_irq_fix_base;
-	gic_arch_extn.irq_mask = exynos4_gic_irq_fix_base;
+	gic_init_bases(0, IRQ_PPI(0), S5P_VA_GIC_DIST, S5P_VA_GIC_CPU, gic_bank_offset);
 
 	for (irq = 0; irq < MAX_COMBINER_NR; irq++) {
 
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index 69ffb2fb3875..60bc45e3e709 100644
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -32,7 +32,6 @@
 
 #include <plat/cpu.h>
 
-extern unsigned int gic_bank_offset;
 extern void exynos4_secondary_startup(void);
 
 #define CPU1_BOOT_REG		(samsung_rev() == EXYNOS4210_REV_1_1 ? \
@@ -65,31 +64,6 @@ static void __iomem *scu_base_addr(void)
 
 static DEFINE_SPINLOCK(boot_lock);
 
-static void __cpuinit exynos4_gic_secondary_init(void)
-{
-	void __iomem *dist_base = S5P_VA_GIC_DIST +
-				(gic_bank_offset * smp_processor_id());
-	void __iomem *cpu_base = S5P_VA_GIC_CPU +
-				(gic_bank_offset * smp_processor_id());
-	int i;
-
-	/*
-	 * Deal with the banked PPI and SGI interrupts - disable all
-	 * PPI interrupts, ensure all SGI interrupts are enabled.
-	 */
-	__raw_writel(0xffff0000, dist_base + GIC_DIST_ENABLE_CLEAR);
-	__raw_writel(0x0000ffff, dist_base + GIC_DIST_ENABLE_SET);
-
-	/*
-	 * Set priority on PPI and SGI interrupts
-	 */
-	for (i = 0; i < 32; i += 4)
-		__raw_writel(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4 / 4);
-
-	__raw_writel(0xf0, cpu_base + GIC_CPU_PRIMASK);
-	__raw_writel(1, cpu_base + GIC_CPU_CTRL);
-}
-
 void __cpuinit platform_secondary_init(unsigned int cpu)
 {
 	/*
@@ -97,7 +71,7 @@ void __cpuinit platform_secondary_init(unsigned int cpu)
 	 * core (e.g. timer irq), then they will not have been enabled
 	 * for us: do so
 	 */
-	exynos4_gic_secondary_init();
+	gic_secondary_init(0);
 
 	/*
 	 * let the primary processor know we're out of the