stm32/pendsv: Clean up pendsv IRQ handler and eliminate duplicate code.

This commit is contained in:
Damien George 2019-02-08 01:03:51 +11:00
parent 1bcf4afb10
commit b178958c07
3 changed files with 24 additions and 45 deletions

View File

@ -61,11 +61,16 @@ void pendsv_kbd_intr(void) {
}
}
void pendsv_isr_handler(void) {
// re-jig the stack so that when we return from this interrupt handler
__attribute__((naked)) void PendSV_Handler(void) {
// Handle a PendSV interrupt
//
// For the case of an asynchronous exception, re-jig the
// stack so that when we return from this interrupt handler
// it returns instead to nlr_jump with argument pendsv_object
// note that stack has a different layout if DEBUG is enabled
//
// For the case of a thread switch, swap stacks.
//
// on entry to this (naked) function, stack has the following layout:
//
// stack layout with DEBUG disabled:
@ -88,20 +93,30 @@ void pendsv_isr_handler(void) {
// sp[1]: 0xfffffff9
// sp[0]: ?
#if MICROPY_PY_THREAD
__asm volatile (
// Check if there is an active object to throw via nlr_jump
"ldr r1, pendsv_object_ptr\n"
"ldr r0, [r1]\n"
"cmp r0, 0\n"
"beq .no_obj\n"
#if defined(PENDSV_DEBUG)
"str r0, [sp, #8]\n" // store to r0 on stack
#else
"str r0, [sp, #0]\n" // store to r0 on stack
#endif
"mov r0, #0\n"
"str r0, [r1]\n" // clear pendsv_object
"ldr r0, nlr_jump_ptr\n"
#if defined(PENDSV_DEBUG)
"str r0, [sp, #32]\n" // store to pc on stack
#else
"str r0, [sp, #24]\n" // store to pc on stack
#endif
"bx lr\n" // return from interrupt; will return to nlr_jump
".no_obj:\n" // pendsv_object==NULL
#if MICROPY_PY_THREAD
// Do a thread context switch
"push {r4-r11, lr}\n"
"vpush {s16-s31}\n"
"mrs r5, primask\n" // save PRIMASK in r5
@ -115,37 +130,14 @@ void pendsv_isr_handler(void) {
"vpop {s16-s31}\n"
"pop {r4-r11, lr}\n"
"bx lr\n" // return from interrupt; will return to new thread
".align 2\n"
"pendsv_object_ptr: .word pendsv_object\n"
"nlr_jump_ptr: .word nlr_jump\n"
);
#else
__asm volatile (
"ldr r0, pendsv_object_ptr\n"
"ldr r0, [r0]\n"
#if defined(PENDSV_DEBUG)
"str r0, [sp, #8]\n"
#else
"str r0, [sp, #0]\n"
#endif
"ldr r0, nlr_jump_ptr\n"
#if defined(PENDSV_DEBUG)
"str r0, [sp, #32]\n"
#else
"str r0, [sp, #24]\n"
#endif
#else
// Spurious pendsv, just return
"bx lr\n"
#endif
// Data
".align 2\n"
"pendsv_object_ptr: .word pendsv_object\n"
"nlr_jump_ptr: .word nlr_jump\n"
);
#endif
/*
uint32_t x[2] = {0x424242, 0xdeaddead};
printf("PendSV: %p\n", x);
for (uint32_t *p = (uint32_t*)(((uint32_t)x - 15) & 0xfffffff0), i = 64; i > 0; p += 4, i -= 4) {
printf(" %p: %08x %08x %08x %08x\n", p, (uint)p[0], (uint)p[1], (uint)p[2], (uint)p[3]);
}
*/
}

View File

@ -29,8 +29,4 @@
void pendsv_init(void);
void pendsv_kbd_intr(void);
// since we play tricks with the stack, the compiler must not generate a
// prelude for this function
void pendsv_isr_handler(void) __attribute__((naked));
#endif // MICROPY_INCLUDED_STM32_PENDSV_H

View File

@ -290,15 +290,6 @@ void SVC_Handler(void) {
void DebugMon_Handler(void) {
}
/**
* @brief This function handles PendSVC exception.
* @param None
* @retval None
*/
void PendSV_Handler(void) {
pendsv_isr_handler();
}
/******************************************************************************/
/* STM32F4xx Peripherals Interrupt Handlers */
/* Add here the Interrupt Handler for the used peripheral(s) (PPP), for the */