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Work around yet another ChibiOS DMA/Cache bug

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This commit is contained in:
inmarket 2017-10-02 13:25:54 +10:00
parent 8bf95a1128
commit cd4c389e48
2 changed files with 47 additions and 20 deletions
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31
src/gfile/gfile_fatfs_diskio_chibios.c
View File

@ -25,13 +25,26 @@ extern SDCDriver SDCD1;
/*-----------------------------------------------------------------------*/
/* Correspondence between physical drive number and physical drive. */
#define MMC 0
#define SDC 0
/*-----------------------------------------------------------------------*/
/* Initialize a Drive */
// WOW - Bugs galore!!! (in ChibiOS)
// Bugs:
// 1. ChibiOS DMA operations do not do the appropriate cache flushing or invalidating
// on cpu's that require it eg STM32F7 series.
// Instead they provide explicit dmaBufferInvalidate and dmaBufferFlush calls
// and rely on the user to explicitly flush the cache.
// Solution: We explicitly flush the cache after any possible DMA operation.
// 2. Unfortunately these explicit routines also have a bug. They assume that the
// specified data structure is aligned on a cache line boundary - not a good assumption.
// Solution: We increase the size provided to ChibiOS so that it does it properly.
// This assumes of course that we know the size of the cpu cache line.
#define CPU_CACHE_LINE_SIZE 32
#define CACHE_FLUSH(buf, sz) dmaBufferFlush((buf), (sz)+(CPU_CACHE_LINE_SIZE-1))
#define CACHE_INVALIDATE(buf, sz) dmaBufferInvalidate((buf), (sz)+(CPU_CACHE_LINE_SIZE-1))
/* Initialize a Drive */
DSTATUS disk_initialize (
BYTE drv /* Physical drive nmuber (0..) */
)
@ -116,7 +129,7 @@ DRESULT disk_read (
return RES_NOTRDY;
if (mmcStartSequentialRead(&MMCD1, sector))
return RES_ERROR;
dmaBufferFlush(buff, MMCSD_BLOCK_SIZE*count);
CACHE_FLUSH(buff, MMCSD_BLOCK_SIZE*count);
while (count > 0) {
if (mmcSequentialRead(&MMCD1, buff))
return RES_ERROR;
@ -125,16 +138,16 @@ DRESULT disk_read (
}
if (mmcStopSequentialRead(&MMCD1))
return RES_ERROR;
dmaBufferInvalidate(buff, MMCSD_BLOCK_SIZE*count);
CACHE_INVALIDATE(buff, MMCSD_BLOCK_SIZE*count);
return RES_OK;
#else
case SDC:
if (blkGetDriverState(&SDCD1) != BLK_READY)
return RES_NOTRDY;
dmaBufferFlush(buff, MMCSD_BLOCK_SIZE*count);
CACHE_FLUSH(buff, MMCSD_BLOCK_SIZE*count);
if (sdcRead(&SDCD1, sector, buff, count))
return RES_ERROR;
dmaBufferInvalidate(buff, MMCSD_BLOCK_SIZE*count);
CACHE_INVALIDATE(buff, MMCSD_BLOCK_SIZE*count);
return RES_OK;
#endif
}
@ -163,7 +176,7 @@ DRESULT disk_write (
return RES_WRPRT;
if (mmcStartSequentialWrite(&MMCD1, sector))
return RES_ERROR;
dmaBufferFlush(buff, MMCSD_BLOCK_SIZE*count);
CACHE_FLUSH(buff, MMCSD_BLOCK_SIZE*count);
while (count > 0) {
if (mmcSequentialWrite(&MMCD1, buff))
return RES_ERROR;
@ -177,7 +190,7 @@ DRESULT disk_write (
case SDC:
if (blkGetDriverState(&SDCD1) != BLK_READY)
return RES_NOTRDY;
dmaBufferFlush(buff, MMCSD_BLOCK_SIZE*count);
CACHE_FLUSH(buff, MMCSD_BLOCK_SIZE*count);
if (sdcWrite(&SDCD1, sector, buff, count))
return RES_ERROR;
return RES_OK;

18
src/gfile/gfile_petitfs_diskio_chibios.c
View File

@ -10,7 +10,6 @@
#if GFX_USE_GFILE && GFILE_NEED_PETITFS && GFX_USE_OS_CHIBIOS && !GFILE_PETITFS_EXTERNAL_LIB
#include "gfile_petitfs_wrapper.h"
#include <string.h>
#if HAL_USE_MMC_SPI && HAL_USE_SDC
@ -25,6 +24,21 @@ extern SDCDriver SDCD1;
#error "MMC_SPI or SDC driver must be specified"
#endif
// WOW - Bugs galore!!! (in ChibiOS)
// Bugs:
// 1. ChibiOS DMA operations do not do the appropriate cache flushing or invalidating
// on cpu's that require it eg STM32F7 series.
// Instead they provide explicit dmaBufferInvalidate and dmaBufferFlush calls
// and rely on the user to explicitly flush the cache.
// Solution: We explicitly flush the cache after any possible DMA operation.
// 2. Unfortunately these explicit routines also have a bug. They assume that the
// specified data structure is aligned on a cache line boundary - not a good assumption.
// Solution: We increase the size provided to ChibiOS so that it does it properly.
// This assumes of course that we know the size of the cpu cache line.
#define CPU_CACHE_LINE_SIZE 32
#define CACHE_FLUSH(buf, sz) dmaBufferFlush((buf), (sz)+(CPU_CACHE_LINE_SIZE-1))
#define CACHE_INVALIDATE(buf, sz) dmaBufferInvalidate((buf), (sz)+(CPU_CACHE_LINE_SIZE-1))
/*-----------------------------------------------------------------------*/
/* Initialize a Drive */
@ -72,7 +86,7 @@ DRESULT disk_readp (
return RES_ERROR;
#endif
sectpos = sector;
dmaBufferInvalidate(sectBuf, sizeof(sectBuf));
CACHE_INVALIDATE(sectBuf, sizeof(sectBuf));
}
memcpy(buff, sectBuf + offset, count);
return RES_OK;