.IX \f4dcache_inval\fP(D3DK)

NAME

dcache_inval − invalidate the data cache

SYNOPSIS

#include <sys/types.h>
#include <sys/buf.h>
#include <sys/iosystm.h>
void dcache_inval(paddr_t paddr int len);

ARGUMENTS

paddrthe physical address of the first location

lenthe number of bytes to be invalidated

DESCRIPTION

When the standard driver support routines that automatically invalidate the cache (for example, bp_iosetup) are not used, dcache_inval should be called to perform explicit cache invalidate operations if the target memory is not cache-inhibited. 

The data cache must be invalidated before a kernel read of device memory or before a read DMA transfer is initiated to ensure that memory accesses will return non-stale data.  Note that no other reads should occur until the DMA transfer is completed. 

On systems that implement bus snooping, dcache_inval has no effect. 

RETURN VALUE

None. 

LEVEL

Base, interrupt. 

SEE ALSO

dcache_sync(D3DK)

DDI/DKI