ANDROID: ARM: fiq_glue: Add custom fiq return handler api.
Change-Id: I5ff2764e85151ca0a88576542fda07c2d33dd065
Signed-off-by: Arve Hjønnevåg <arve@android.com>
diff --git a/arch/arm/common/fiq_glue.S b/arch/arm/common/fiq_glue.S
index 9e3455a..24b42ce 100644
--- a/arch/arm/common/fiq_glue.S
+++ b/arch/arm/common/fiq_glue.S
@@ -22,13 +22,14 @@
/* fiq stack: r0-r15,cpsr,spsr of interrupted mode */
ENTRY(fiq_glue)
- /* store pc, cpsr from previous mode */
+ /* store pc, cpsr from previous mode, reserve space for spsr */
mrs r12, spsr
- sub r11, lr, #4
+ sub lr, lr, #4
subs r10, #1
bne nested_fiq
- stmfd sp!, {r11-r12, lr}
+ str r12, [sp, #-8]!
+ str lr, [sp, #-4]!
/* store r8-r14 from previous mode */
sub sp, sp, #(7 * 4)
@@ -85,12 +86,15 @@
msr cpsr_c, #(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)
ldmfd sp!, {r0-r7}
- add sp, sp, #(7 * 4)
- ldmfd sp!, {r11-r12, lr}
+ ldr lr, [sp, #(4 * 7)]
+ ldr r12, [sp, #(4 * 8)]
+ add sp, sp, #(10 * 4)
exit_fiq:
msr spsr_cxsf, r12
add r10, #1
- movs pc, r11
+ cmp r11, #0
+ moveqs pc, lr
+ bx r11 /* jump to custom fiq return function */
nested_fiq:
orr r12, r12, #(PSR_F_BIT)
@@ -98,14 +102,17 @@
fiq_glue_end:
-ENTRY(fiq_glue_setup) /* func, data, sp */
- mrs r3, cpsr
+ENTRY(fiq_glue_setup) /* func, data, sp, smc call number */
+ stmfd sp!, {r4}
+ mrs r4, cpsr
msr cpsr_c, #(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)
movs r8, r0
mov r9, r1
mov sp, r2
+ mov r11, r3
moveq r10, #0
movne r10, #1
- msr cpsr_c, r3
+ msr cpsr_c, r4
+ ldmfd sp!, {r4}
bx lr
diff --git a/arch/arm/common/fiq_glue_setup.c b/arch/arm/common/fiq_glue_setup.c
index 4044c7d..8cb1b61 100644
--- a/arch/arm/common/fiq_glue_setup.c
+++ b/arch/arm/common/fiq_glue_setup.c
@@ -18,20 +18,23 @@
#include <asm/fiq_glue.h>
extern unsigned char fiq_glue, fiq_glue_end;
-extern void fiq_glue_setup(void *func, void *data, void *sp);
+extern void fiq_glue_setup(void *func, void *data, void *sp,
+ fiq_return_handler_t fiq_return_handler);
static struct fiq_handler fiq_debbuger_fiq_handler = {
.name = "fiq_glue",
};
DEFINE_PER_CPU(void *, fiq_stack);
static struct fiq_glue_handler *current_handler;
+static fiq_return_handler_t fiq_return_handler;
static DEFINE_MUTEX(fiq_glue_lock);
static void fiq_glue_setup_helper(void *info)
{
struct fiq_glue_handler *handler = info;
fiq_glue_setup(handler->fiq, handler,
- __get_cpu_var(fiq_stack) + THREAD_START_SP);
+ __get_cpu_var(fiq_stack) + THREAD_START_SP,
+ fiq_return_handler);
}
int fiq_glue_register_handler(struct fiq_glue_handler *handler)
@@ -80,6 +83,49 @@
return ret;
}
+static void fiq_glue_update_return_handler(void (*fiq_return)(void))
+{
+ fiq_return_handler = fiq_return;
+ if (current_handler)
+ on_each_cpu(fiq_glue_setup_helper, current_handler, true);
+}
+
+int fiq_glue_set_return_handler(void (*fiq_return)(void))
+{
+ int ret;
+
+ mutex_lock(&fiq_glue_lock);
+ if (fiq_return_handler) {
+ ret = -EBUSY;
+ goto err_busy;
+ }
+ fiq_glue_update_return_handler(fiq_return);
+ ret = 0;
+err_busy:
+ mutex_unlock(&fiq_glue_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(fiq_glue_set_return_handler);
+
+int fiq_glue_clear_return_handler(void (*fiq_return)(void))
+{
+ int ret;
+
+ mutex_lock(&fiq_glue_lock);
+ if (WARN_ON(fiq_return_handler != fiq_return)) {
+ ret = -EINVAL;
+ goto err_inval;
+ }
+ fiq_glue_update_return_handler(NULL);
+ ret = 0;
+err_inval:
+ mutex_unlock(&fiq_glue_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(fiq_glue_clear_return_handler);
+
/**
* fiq_glue_resume - Restore fiqs after suspend or low power idle states
*
@@ -93,7 +139,8 @@
if (!current_handler)
return;
fiq_glue_setup(current_handler->fiq, current_handler,
- __get_cpu_var(fiq_stack) + THREAD_START_SP);
+ __get_cpu_var(fiq_stack) + THREAD_START_SP,
+ fiq_return_handler);
if (current_handler->resume)
current_handler->resume(current_handler);
}
diff --git a/arch/arm/include/asm/fiq_glue.h b/arch/arm/include/asm/fiq_glue.h
index d54c29d..a9e244f9 100644
--- a/arch/arm/include/asm/fiq_glue.h
+++ b/arch/arm/include/asm/fiq_glue.h
@@ -18,8 +18,11 @@
void (*fiq)(struct fiq_glue_handler *h, void *regs, void *svc_sp);
void (*resume)(struct fiq_glue_handler *h);
};
+typedef void (*fiq_return_handler_t)(void);
int fiq_glue_register_handler(struct fiq_glue_handler *handler);
+int fiq_glue_set_return_handler(fiq_return_handler_t fiq_return);
+int fiq_glue_clear_return_handler(fiq_return_handler_t fiq_return);
#ifdef CONFIG_FIQ_GLUE
void fiq_glue_resume(void);