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[arch][arm-m] make number of priority levels hard coded

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-Turn off the dynamic priority calculation so we can much more efficiently
set different levels. All arm-ms support at least 3 bits of priority,
so default to that.
This commit is contained in:
Travis Geiselbrecht
2012-10-27 16:31:28 -07:00
parent 2ae76494e5
commit bb5e3d40d8
2 changed files with 43 additions and 4 deletions
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8
arch/arm/arm-m/arch.c
View File

@@ -34,8 +34,10 @@ extern void *vectab;
extern int _end_of_ram;
void *_heap_end = &_end_of_ram;
#if ARM_M_DYNAMIC_PRIORITY_SIZE
unsigned int cm3_num_irq_pri_bits;
unsigned int cm3_irq_pri_mask;
#endif
void arch_early_init(void)
{
@@ -56,6 +58,7 @@ void arch_early_init(void)
NVIC->IP[i*4+3] = 128; /* medium priority */
}
#if ARM_M_DYNAMIC_PRIORITY_SIZE
/* number of priorities */
for (i=0; i < 7; i++) {
__set_BASEPRI(1 << i);
@@ -64,6 +67,7 @@ void arch_early_init(void)
}
cm3_num_irq_pri_bits = 8 - i;
cm3_irq_pri_mask = ~((1 << i) - 1) & 0xff;
#endif
/* leave BASEPRI at 0 */
__set_BASEPRI(0);
@@ -99,7 +103,7 @@ void arch_idle(void)
{
}
void cm3_set_irqpri(uint32_t pri)
void _cm3_set_irqpri(uint32_t pri)
{
if (pri == 0) {
__disable_irq(); // cpsid i
@@ -114,7 +118,7 @@ void cm3_set_irqpri(uint32_t pri)
__set_BASEPRI(1 << (8 - cm3_num_irq_pri_bits));
else
__set_BASEPRI(_pri);
__enable_irq(); // cpsid i
__enable_irq(); // cpsie i
}
}

39
arch/arm/arm-m/include/arch/arm/cm3.h
View File

@@ -81,10 +81,45 @@ struct cm3_exception_frame_long {
uint32_t psr;
};
void cm3_set_irqpri(uint32_t pri);
#if ARM_M_DYNAMIC_PRIORITY_SIZE
extern unsigned int cm3_num_irq_pri_bits;
extern unsigned int cm3_irq_pri_mask;
#else
/* if we don't want to calculate the nubmer of priority bits, then assume
* the cpu implements 3 (8 priority levels), which is the minimum according to spec.
*/
#ifndef ARM_M_PRIORITY_BITS
#define ARM_M_PRIORITY_BITS 3
#endif
static const unsigned int cm3_num_irq_pri_bits = 8 - ARM_M_PRIORITY_BITS;
static const unsigned int cm3_irq_pri_mask = ~((1 << ARM_M_PRIORITY_BITS) - 1) & 0xff;
#endif
void _cm3_set_irqpri(uint32_t pri);
static __ALWAYS_INLINE void cm3_set_irqpri(uint32_t pri)
{
if (__ISCONSTANT(pri)) {
if (pri == 0) {
__disable_irq(); // cpsid i
__set_BASEPRI(0);
} else if (pri >= 256) {
__set_BASEPRI(0);
__enable_irq();
} else {
uint32_t _pri = pri & cm3_irq_pri_mask;
if (_pri == 0)
__set_BASEPRI(1 << (8 - cm3_num_irq_pri_bits));
else
__set_BASEPRI(_pri);
__enable_irq(); // cpsie i
}
} else {
_cm3_set_irqpri(pri);
}
}
static __ALWAYS_INLINE inline uint32_t cm3_highest_priority(void)
{