Hello Russell,
On Sun, Aug 05, 2012 at 04:02:38PM -0700, Anton Vorontsov wrote:
During KDB FIQ patches review you mentioned that I should not introduce another FIQ_START. It seems that in v3.6-rc the FIQ_START issue was somewhat band-aided, i.e. machines don't necessary need to define this stuff any longer, but I also read the background of the issue, and you once said that you don't want the FIQ subsystem to mess with genirq.
Just wonder if you had a chance to look into this patch set...
Plus, I also realized that maybe it's a good time to get rid of init_FIQ() altogether? Maybe there are some not so obvious reasons for its existence, but if not, does the following patch on top of this series makes sense?
(Also, I noticed that we save no_fiq_insn w/o bothering about !CONFIG_CPU_USE_DOMAINS case, but set_fiq_handler() has a special handling for this. I wonder, was that on purpose, e.g. it does not matter for init_FIQ(), or it was just overlooked? In latter case, the patch fixes the issue.)
- - - - [PATCH] ARM: FIQ: Get rid of init_FIQ()
The function only saves initial arch-specific "no FIQ" instruction, by placing the code into set_fiq_handler() we can:
- Have less code and logic in the platform-specific files; - Have the code that manages FIQ vector overwriting in one place, i.e. not spread the logic around (both code placement wise and execution time wise).
Signed-off-by: Anton Vorontsov anton.vorontsov@linaro.org --- arch/arm/include/asm/mach/irq.h | 2 -- arch/arm/kernel/fiq.c | 17 ++++++++--------- arch/arm/mach-rpc/irq.c | 2 -- arch/arm/plat-mxc/avic.c | 3 --- arch/arm/plat-mxc/tzic.c | 3 --- arch/arm/plat-s3c24xx/irq.c | 2 -- 6 files changed, 8 insertions(+), 21 deletions(-)
diff --git a/arch/arm/include/asm/mach/irq.h b/arch/arm/include/asm/mach/irq.h index 8be5ba9..6e70ae3 100644 --- a/arch/arm/include/asm/mach/irq.h +++ b/arch/arm/include/asm/mach/irq.h @@ -18,10 +18,8 @@ struct seq_file; * This is internal. Do not use it. */ #ifdef CONFIG_FIQ -extern void init_FIQ(void); extern void show_fiq_list(struct seq_file *, int); #else -static inline void init_FIQ(void) {} static inline void show_fiq_list(struct seq_file *p, int prec) {} #endif
diff --git a/arch/arm/kernel/fiq.c b/arch/arm/kernel/fiq.c index 9bf3a60..3602df6 100644 --- a/arch/arm/kernel/fiq.c +++ b/arch/arm/kernel/fiq.c @@ -49,6 +49,7 @@ #include <asm/mach/irq.h>
static unsigned long no_fiq_insn; +static int got_no_fiq_insn;
/* Default reacquire function * - we always relinquish FIQ control @@ -78,11 +79,14 @@ void show_fiq_list(struct seq_file *p, int prec)
void set_fiq_handler(void *start, unsigned int length) { -#if defined(CONFIG_CPU_USE_DOMAINS) - memcpy((void *)0xffff001c, start, length); -#else - memcpy(vectors_page + 0x1c, start, length); + unsigned long *addr = (void *)0xffff001c; + +#ifndef CONFIG_CPU_USE_DOMAINS + addr = vectors_page + 0x1c; #endif + if (!cmpxchg(&got_no_fiq_insn, 0, 1)) + no_fiq_insn = *addr; + memcpy(addr, start, length); flush_icache_range(0xffff001c, 0xffff001c + length); if (!vectors_high()) flush_icache_range(0x1c, 0x1c + length); @@ -126,8 +130,3 @@ EXPORT_SYMBOL(__set_fiq_regs); /* defined in fiqasm.S */ EXPORT_SYMBOL(__get_fiq_regs); /* defined in fiqasm.S */ EXPORT_SYMBOL(claim_fiq); EXPORT_SYMBOL(release_fiq); - -void __init init_FIQ(void) -{ - no_fiq_insn = *(unsigned long *)0xffff001c; -} diff --git a/arch/arm/mach-rpc/irq.c b/arch/arm/mach-rpc/irq.c index 07770c8..2d915ba 100644 --- a/arch/arm/mach-rpc/irq.c +++ b/arch/arm/mach-rpc/irq.c @@ -151,7 +151,5 @@ void __init rpc_init_irq(void) break; } } - - init_FIQ(); }
diff --git a/arch/arm/plat-mxc/avic.c b/arch/arm/plat-mxc/avic.c index 426980c..b173dc6 100644 --- a/arch/arm/plat-mxc/avic.c +++ b/arch/arm/plat-mxc/avic.c @@ -216,8 +216,5 @@ void __init mxc_init_irq(void __iomem *irqbase) for (i = 0; i < 8; i++) __raw_writel(0, avic_base + AVIC_NIPRIORITY(i));
- /* Initialize FIQ */ - init_FIQ(); - printk(KERN_INFO "MXC IRQ initialized\n"); } diff --git a/arch/arm/plat-mxc/tzic.c b/arch/arm/plat-mxc/tzic.c index 8a5a633..889267c 100644 --- a/arch/arm/plat-mxc/tzic.c +++ b/arch/arm/plat-mxc/tzic.c @@ -191,9 +191,6 @@ void __init tzic_init_irq(void __iomem *irqbase) for (i = 0; i < 4; i++, irq_base += 32) tzic_init_gc(i, irq_base);
- /* Initialize FIQ */ - init_FIQ(); - pr_info("TrustZone Interrupt Controller (TZIC) initialized\n"); }
diff --git a/arch/arm/plat-s3c24xx/irq.c b/arch/arm/plat-s3c24xx/irq.c index 531d6a4..66b8856 100644 --- a/arch/arm/plat-s3c24xx/irq.c +++ b/arch/arm/plat-s3c24xx/irq.c @@ -532,8 +532,6 @@ void __init s3c24xx_init_irq(void) int irqno; int i;
- init_FIQ(); - irqdbf("s3c2410_init_irq: clearing interrupt status flags\n");
/* first, clear all interrupts pending... */