diff options
author | juhosg <juhosg@3c298f89-4303-0410-b956-a3cf2f4a3e73> | 2012-12-18 17:54:02 +0000 |
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committer | juhosg <juhosg@3c298f89-4303-0410-b956-a3cf2f4a3e73> | 2012-12-18 17:54:02 +0000 |
commit | 82661f4b0ebe2c4173d178e94d529505458f8e0e (patch) | |
tree | 29177c3a256af17d3c3263f478b96f59baca9b1c /target/linux/s3c24xx/patches-2.6.30/013-fiq_c_handler.patch | |
parent | 13e1228de3690c8c831b9cccbe5a34674e743362 (diff) |
s3c2442: R.I.P.
It is broken and it is not maintained by anyone since long time.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@34767 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'target/linux/s3c24xx/patches-2.6.30/013-fiq_c_handler.patch')
-rw-r--r-- | target/linux/s3c24xx/patches-2.6.30/013-fiq_c_handler.patch | 286 |
1 files changed, 0 insertions, 286 deletions
diff --git a/target/linux/s3c24xx/patches-2.6.30/013-fiq_c_handler.patch b/target/linux/s3c24xx/patches-2.6.30/013-fiq_c_handler.patch deleted file mode 100644 index de12e10cd..000000000 --- a/target/linux/s3c24xx/patches-2.6.30/013-fiq_c_handler.patch +++ /dev/null @@ -1,286 +0,0 @@ ---- a/arch/arm/kernel/fiq.c -+++ b/arch/arm/kernel/fiq.c -@@ -8,6 +8,8 @@ - * - * FIQ support re-written by Russell King to be more generic - * -+ * FIQ handler in C supoprt written by Andy Green <andy@openmoko.com> -+ * - * We now properly support a method by which the FIQ handlers can - * be stacked onto the vector. We still do not support sharing - * the FIQ vector itself. -@@ -124,6 +126,83 @@ void __naked get_fiq_regs(struct pt_regs - : "r" (®s->ARM_r8), "I" (PSR_I_BIT | PSR_F_BIT | FIQ_MODE)); - } - -+/* -------- FIQ handler in C --------- -+ * -+ * Major Caveats for using this -+ * --------------------------- -+ * * -+ * * 1) it CANNOT touch any vmalloc()'d memory, only memory -+ * that was kmalloc()'d. Static allocations in the monolithic kernel -+ * are kmalloc()'d so they are okay. You can touch memory-mapped IO, but -+ * the pointer for it has to have been stored in kmalloc'd memory. The -+ * reason for this is simple: every now and then Linux turns off interrupts -+ * and reorders the paging tables. If a FIQ happens during this time, the -+ * virtual memory space can be partly or entirely disordered or missing. -+ * -+ * 2) Because vmalloc() is used when a module is inserted, THIS FIQ -+ * ISR HAS TO BE IN THE MONOLITHIC KERNEL, not a module. But the way -+ * it is set up, you can all to enable and disable it from your module -+ * and intercommunicate with it through struct fiq_ipc -+ * fiq_ipc which you can define in -+ * asm/archfiq_ipc_type.h. The reason is the same as above, a -+ * FIQ could happen while even the ISR is not present in virtual memory -+ * space due to pagetables being changed at the time. -+ * -+ * 3) You can't call any Linux API code except simple macros -+ * - understand that FIQ can come in at any time, no matter what -+ * state of undress the kernel may privately be in, thinking it -+ * locked the door by turning off interrupts... FIQ is an -+ * unstoppable monster force (which is its value) -+ * - they are not vmalloc()'d memory safe -+ * - they might do crazy stuff like sleep: FIQ pisses fire and -+ * is not interested in 'sleep' that the weak seem to need -+ * - calling APIs from FIQ can re-enter un-renterable things -+ * - summary: you cannot interoperate with linux APIs directly in the FIQ ISR -+ * -+ * If you follow these rules, it is fantastic, an extremely powerful, solid, -+ * genuine hard realtime feature. -+ */ -+ -+static void (*current_fiq_c_isr)(void); -+#define FIQ_C_ISR_STACK_SIZE 256 -+ -+static void __attribute__((naked)) __jump_to_isr(void) -+{ -+ asm __volatile__ ("mov pc, r8"); -+} -+ -+ -+static void __attribute__((naked)) __actual_isr(void) -+{ -+ asm __volatile__ ( -+ "stmdb sp!, {r0-r12, lr};" -+ "mov fp, sp;" -+ ); -+ -+ current_fiq_c_isr(); -+ -+ asm __volatile__ ( -+ "ldmia sp!, {r0-r12, lr};" -+ "subs pc, lr, #4;" -+ ); -+} -+ -+void set_fiq_c_handler(void (*isr)(void)) -+{ -+ struct pt_regs regs; -+ -+ memset(®s, 0, sizeof(regs)); -+ regs.ARM_r8 = (unsigned long) __actual_isr; -+ regs.ARM_sp = 0xffff001c + FIQ_C_ISR_STACK_SIZE; -+ -+ set_fiq_handler(__jump_to_isr, 4); -+ -+ current_fiq_c_isr = isr; -+ -+ set_fiq_regs(®s); -+} -+/* -------- FIQ handler in C ---------*/ -+ - int claim_fiq(struct fiq_handler *f) - { - int ret = 0; ---- a/arch/arm/include/asm/fiq.h -+++ b/arch/arm/include/asm/fiq.h -@@ -29,8 +29,9 @@ struct fiq_handler { - extern int claim_fiq(struct fiq_handler *f); - extern void release_fiq(struct fiq_handler *f); - extern void set_fiq_handler(void *start, unsigned int length); --extern void set_fiq_regs(struct pt_regs *regs); --extern void get_fiq_regs(struct pt_regs *regs); -+extern void set_fiq_c_handler(void (*handler)(void)); -+extern void __attribute__((naked)) set_fiq_regs(struct pt_regs *regs); -+extern void __attribute__((naked)) get_fiq_regs(struct pt_regs *regs); - extern void enable_fiq(int fiq); - extern void disable_fiq(int fiq); - ---- a/arch/arm/plat-s3c24xx/include/plat/irq.h -+++ b/arch/arm/plat-s3c24xx/include/plat/irq.h -@@ -12,6 +12,7 @@ - - #include <linux/io.h> - -+#include <mach/irqs.h> - #include <mach/hardware.h> - #include <mach/regs-irq.h> - #include <mach/regs-gpio.h> -@@ -31,8 +32,15 @@ s3c_irqsub_mask(unsigned int irqno, unsi - { - unsigned long mask; - unsigned long submask; -+#ifdef CONFIG_S3C2440_C_FIQ -+ unsigned long flags; -+#endif - - submask = __raw_readl(S3C2410_INTSUBMSK); -+#ifdef CONFIG_S3C2440_C_FIQ -+ local_save_flags(flags); -+ local_fiq_disable(); -+#endif - mask = __raw_readl(S3C2410_INTMSK); - - submask |= (1UL << (irqno - IRQ_S3CUART_RX0)); -@@ -45,6 +53,9 @@ s3c_irqsub_mask(unsigned int irqno, unsi - - /* write back masks */ - __raw_writel(submask, S3C2410_INTSUBMSK); -+#ifdef CONFIG_S3C2440_C_FIQ -+ local_irq_restore(flags); -+#endif - - } - -@@ -53,8 +64,15 @@ s3c_irqsub_unmask(unsigned int irqno, un - { - unsigned long mask; - unsigned long submask; -+#ifdef CONFIG_S3C2440_C_FIQ -+ unsigned long flags; -+#endif - - submask = __raw_readl(S3C2410_INTSUBMSK); -+#ifdef CONFIG_S3C2440_C_FIQ -+ local_save_flags(flags); -+ local_fiq_disable(); -+#endif - mask = __raw_readl(S3C2410_INTMSK); - - submask &= ~(1UL << (irqno - IRQ_S3CUART_RX0)); -@@ -63,6 +81,9 @@ s3c_irqsub_unmask(unsigned int irqno, un - /* write back masks */ - __raw_writel(submask, S3C2410_INTSUBMSK); - __raw_writel(mask, S3C2410_INTMSK); -+#ifdef CONFIG_S3C2440_C_FIQ -+ local_irq_restore(flags); -+#endif - } - - ---- a/arch/arm/plat-s3c24xx/irq.c -+++ b/arch/arm/plat-s3c24xx/irq.c -@@ -28,6 +28,8 @@ - #include <asm/mach/irq.h> - - #include <plat/regs-irqtype.h> -+#include <mach/regs-irq.h> -+#include <mach/regs-gpio.h> - - #include <plat/cpu.h> - #include <plat/pm.h> -@@ -37,12 +39,20 @@ static void - s3c_irq_mask(unsigned int irqno) - { - unsigned long mask; -- -+#ifdef CONFIG_S3C2440_C_FIQ -+ unsigned long flags; -+#endif - irqno -= IRQ_EINT0; -- -+#ifdef CONFIG_S3C2440_C_FIQ -+ local_save_flags(flags); -+ local_fiq_disable(); -+#endif - mask = __raw_readl(S3C2410_INTMSK); - mask |= 1UL << irqno; - __raw_writel(mask, S3C2410_INTMSK); -+#ifdef CONFIG_S3C2440_C_FIQ -+ local_irq_restore(flags); -+#endif - } - - static inline void -@@ -59,9 +69,19 @@ s3c_irq_maskack(unsigned int irqno) - { - unsigned long bitval = 1UL << (irqno - IRQ_EINT0); - unsigned long mask; -- -+#ifdef CONFIG_S3C2440_C_FIQ -+ unsigned long flags; -+#endif -+ -+#ifdef CONFIG_S3C2440_C_FIQ -+ local_save_flags(flags); -+ local_fiq_disable(); -+#endif - mask = __raw_readl(S3C2410_INTMSK); - __raw_writel(mask|bitval, S3C2410_INTMSK); -+#ifdef CONFIG_S3C2440_C_FIQ -+ local_irq_restore(flags); -+#endif - - __raw_writel(bitval, S3C2410_SRCPND); - __raw_writel(bitval, S3C2410_INTPND); -@@ -72,15 +92,25 @@ static void - s3c_irq_unmask(unsigned int irqno) - { - unsigned long mask; -+#ifdef CONFIG_S3C2440_C_FIQ -+ unsigned long flags; -+#endif - - if (irqno != IRQ_TIMER4 && irqno != IRQ_EINT8t23) - irqdbf2("s3c_irq_unmask %d\n", irqno); - - irqno -= IRQ_EINT0; - -+#ifdef CONFIG_S3C2440_C_FIQ -+ local_save_flags(flags); -+ local_fiq_disable(); -+#endif - mask = __raw_readl(S3C2410_INTMSK); - mask &= ~(1UL << irqno); - __raw_writel(mask, S3C2410_INTMSK); -+#ifdef CONFIG_S3C2440_C_FIQ -+ local_irq_restore(flags); -+#endif - } - - struct irq_chip s3c_irq_level_chip = { -@@ -523,26 +553,26 @@ void __init s3c24xx_init_irq(void) - - last = 0; - for (i = 0; i < 4; i++) { -- pend = __raw_readl(S3C2410_INTPND); -+ pend = __raw_readl(S3C2410_SUBSRCPND); - - if (pend == 0 || pend == last) - break; - -- __raw_writel(pend, S3C2410_SRCPND); -- __raw_writel(pend, S3C2410_INTPND); -- printk("irq: clearing pending status %08x\n", (int)pend); -+ printk("irq: clearing subpending status %08x\n", (int)pend); -+ __raw_writel(pend, S3C2410_SUBSRCPND); - last = pend; - } - - last = 0; - for (i = 0; i < 4; i++) { -- pend = __raw_readl(S3C2410_SUBSRCPND); -+ pend = __raw_readl(S3C2410_INTPND); - - if (pend == 0 || pend == last) - break; - -- printk("irq: clearing subpending status %08x\n", (int)pend); -- __raw_writel(pend, S3C2410_SUBSRCPND); -+ __raw_writel(pend, S3C2410_SRCPND); -+ __raw_writel(pend, S3C2410_INTPND); -+ printk("irq: clearing pending status %08x\n", (int)pend); - last = pend; - } - |