kernel-ark/arch/cris/arch-v32/kernel/cache.c
Jesper Nilsson 57c230a873 CRISv32: add cache flush operations
These are needed due to a cache bug, and can be used to make sure that the
DMA descriptors are flushed to memory and can be safely handled by DMA.

flush_dma_descr - Flush one DMA descriptor.
flush_dma_list - Flush a complete list of DMA descriptors.
cris_flush_cache - Flush the complete cache.
cris_flush_cache_range - Flush only the specified range

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-14 18:45:47 -08:00

34 lines
896 B
C

#include <linux/module.h>
#include <asm/io.h>
#include <asm/arch/cache.h>
#include <asm/arch/hwregs/dma.h>
/* This file is used to workaround a cache bug, Guinness TR 106. */
inline void flush_dma_descr(struct dma_descr_data *descr, int flush_buf)
{
/* Flush descriptor to make sure we get correct in_eop and after. */
asm volatile ("ftagd [%0]" :: "r" (descr));
/* Flush buffer pointed out by descriptor. */
if (flush_buf)
cris_flush_cache_range(phys_to_virt((unsigned)descr->buf),
(unsigned)(descr->after - descr->buf));
}
EXPORT_SYMBOL(flush_dma_descr);
void flush_dma_list(struct dma_descr_data *descr)
{
while (1) {
flush_dma_descr(descr, 1);
if (descr->eol)
break;
descr = phys_to_virt((unsigned)descr->next);
}
}
EXPORT_SYMBOL(flush_dma_list);
/* From cacheflush.S */
EXPORT_SYMBOL(cris_flush_cache);
/* From cacheflush.S */
EXPORT_SYMBOL(cris_flush_cache_range);