micropython/ports/stm32/irq.h
Damien George 0941a467e7 stm32: Change flash IRQ priority from 2 to 6 to prevent preemption.
The flash-IRQ handler is used to flush the storage cache, ie write
outstanding block data from RAM to flash.  This is triggered by a timeout,
or by a direct call to flush all storage caches.

Prior to this commit, a timeout could trigger the cache flushing to occur
during the execution of a read/write to external SPI flash storage.  In
such a case the storage subsystem would break down.

SPI storage transfers are already protected against USB IRQs, so by
changing the priority of the flash IRQ to that of the USB IRQ (what is
done in this commit) the SPI transfers can be protected against any
timeouts triggering a cache flush (the cache flush would be postponed until
after the transfer finished, but note that in the case of SPI writes the
timeout is rescheduled after the transfer finishes).

The handling of internal flash sync'ing needs to be changed to directly
call flash_bdev_irq_handler() sync may be called with the IRQ priority
already raised (eg when called from a USB MSC IRQ handler).
2018-09-12 15:46:04 +10:00

160 lines
6.4 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef MICROPY_INCLUDED_STM32_IRQ_H
#define MICROPY_INCLUDED_STM32_IRQ_H
// Use this macro together with NVIC_SetPriority to indicate that an IRQn is non-negative,
// which helps the compiler optimise the resulting inline function.
#define IRQn_NONNEG(pri) ((pri) & 0x7f)
// these states correspond to values from query_irq, enable_irq and disable_irq
#define IRQ_STATE_DISABLED (0x00000001)
#define IRQ_STATE_ENABLED (0x00000000)
// Enable this to get a count for the number of times each irq handler is called,
// accessible via pyb.irq_stats().
#define IRQ_ENABLE_STATS (0)
#if IRQ_ENABLE_STATS
extern uint32_t irq_stats[FPU_IRQn + 1];
#define IRQ_ENTER(irq) ++irq_stats[irq]
#define IRQ_EXIT(irq)
#else
#define IRQ_ENTER(irq)
#define IRQ_EXIT(irq)
#endif
static inline mp_uint_t query_irq(void) {
return __get_PRIMASK();
}
// enable_irq and disable_irq are defined inline in mpconfigport.h
#if __CORTEX_M >= 0x03
// irqs with a priority value greater or equal to "pri" will be disabled
// "pri" should be between 1 and 15 inclusive
static inline uint32_t raise_irq_pri(uint32_t pri) {
uint32_t basepri = __get_BASEPRI();
// If non-zero, the processor does not process any exception with a
// priority value greater than or equal to BASEPRI.
// When writing to BASEPRI_MAX the write goes to BASEPRI only if either:
// - Rn is non-zero and the current BASEPRI value is 0
// - Rn is non-zero and less than the current BASEPRI value
pri <<= (8 - __NVIC_PRIO_BITS);
__ASM volatile ("msr basepri_max, %0" : : "r" (pri) : "memory");
return basepri;
}
// "basepri" should be the value returned from raise_irq_pri
static inline void restore_irq_pri(uint32_t basepri) {
__set_BASEPRI(basepri);
}
#endif
MP_DECLARE_CONST_FUN_OBJ_0(pyb_wfi_obj);
MP_DECLARE_CONST_FUN_OBJ_0(pyb_disable_irq_obj);
MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_enable_irq_obj);
MP_DECLARE_CONST_FUN_OBJ_0(pyb_irq_stats_obj);
// IRQ priority definitions.
//
// Lower number implies higher interrupt priority.
//
// The default priority grouping is set to NVIC_PRIORITYGROUP_4 in the
// HAL_Init function. This corresponds to 4 bits for the priority field
// and 0 bits for the sub-priority field (which means that for all intensive
// purposes that the sub-priorities below are ignored).
//
// While a given interrupt is being processed, only higher priority (lower number)
// interrupts will preempt a given interrupt. If sub-priorities are active
// then the sub-priority determines the order that pending interrupts of
// a given priority are executed. This is only meaningful if 2 or more
// interrupts of the same priority are pending at the same time.
//
// The priority of the SysTick timer is determined from the TICK_INT_PRIORITY
// value which is normally set to 0 in the stm32f4xx_hal_conf.h file.
//
// The following interrupts are arranged from highest priority to lowest
// priority to make it a bit easier to figure out.
#if __CORTEX_M == 0
//#def IRQ_PRI_SYSTICK 0
#define IRQ_PRI_UART 1
#define IRQ_PRI_SDIO 1
#define IRQ_PRI_DMA 1
#define IRQ_PRI_FLASH 2
#define IRQ_PRI_OTG_FS 2
#define IRQ_PRI_OTG_HS 2
#define IRQ_PRI_TIM5 2
#define IRQ_PRI_CAN 2
#define IRQ_PRI_TIMX 2
#define IRQ_PRI_EXTINT 2
#define IRQ_PRI_PENDSV 3
#define IRQ_PRI_RTC_WKUP 3
#else
//#def IRQ_PRI_SYSTICK NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 0, 0)
// The UARTs have no FIFOs, so if they don't get serviced quickly then characters
// get dropped. The handling for each character only consumes about 0.5 usec
#define IRQ_PRI_UART NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 1, 0)
// SDIO must be higher priority than DMA for SDIO DMA transfers to work.
#define IRQ_PRI_SDIO NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 4, 0)
// DMA should be higher priority than USB, since USB Mass Storage calls
// into the sdcard driver which waits for the DMA to complete.
#define IRQ_PRI_DMA NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 5, 0)
// Flash IRQ (used for flushing storage cache) must be at the same priority as
// the USB IRQs, so that the IRQ priority can be raised to this level to disable
// both the USB and cache flushing, when storage transfers are in progress.
#define IRQ_PRI_FLASH NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 6, 0)
#define IRQ_PRI_OTG_FS NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 6, 0)
#define IRQ_PRI_OTG_HS NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 6, 0)
#define IRQ_PRI_TIM5 NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 6, 0)
#define IRQ_PRI_CAN NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 7, 0)
// Interrupt priority for non-special timers.
#define IRQ_PRI_TIMX NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 13, 0)
#define IRQ_PRI_EXTINT NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 14, 0)
// PENDSV should be at the lowst priority so that other interrupts complete
// before exception is raised.
#define IRQ_PRI_PENDSV NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 15, 0)
#define IRQ_PRI_RTC_WKUP NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 15, 0)
#endif
#endif // MICROPY_INCLUDED_STM32_IRQ_H