From: Max Filippov Date: Wed, 21 Sep 2016 00:58:20 +0000 (-0700) Subject: xtensa: ISS: allow simdisk to use high memory buffers X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=549409b4b584604f8eb225ebbb19be74204fe789;p=openwrt%2Fstaging%2Fblogic.git xtensa: ISS: allow simdisk to use high memory buffers ISS kernel by default has only low memory. But it may be configured to support high memory and started in a simulator with more than 128M of RAM. Simdisk driver in such configuration can get IO request with a high memory page. There may be no TLB entry for that page, only page table entry. However simulators don't do pagewalking, so such IO request will fail. Touch IO buffer in the buffer read/write loop so that a TLB entry is likely there when read or write simcall is invoked. Signed-off-by: Max Filippov --- diff --git a/arch/xtensa/platforms/iss/simdisk.c b/arch/xtensa/platforms/iss/simdisk.c index f58a4e6472cb..ede04cca30dd 100644 --- a/arch/xtensa/platforms/iss/simdisk.c +++ b/arch/xtensa/platforms/iss/simdisk.c @@ -86,6 +86,7 @@ static void simdisk_transfer(struct simdisk *dev, unsigned long sector, unsigned long io; simc_lseek(dev->fd, offset, SEEK_SET); + READ_ONCE(*buffer); if (write) io = simc_write(dev->fd, buffer, nbytes); else