From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Hellstrom Date: Thu, 13 Mar 2008 10:38:50 +0100 Subject: [U-Boot-Users] [PATCH 2/8] SPARC: SPARC cfi-flash support for 64-bit reads Message-ID: <47D8F62A.2000108@gaisler.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de For current SPARC architectures (LEON2 and LEON3) each read from the FLASH must lead to a cache miss. This is because FLASH can not be set non-cacheable since program code resides there, and alternatively disabling cache is poor from performance view, or doing a cache flush between each read is even poorer. Forcing a cache miss on a SPARC is done by a special instruction "lda" - load alternative space, the alternative space number (ASI) is processor implementation spcific and can be found by including . SPARC has implemented __raw_readq, it reads 64-bit from any 32-bit address. Best Regards, Daniel Hellstrom drivers/mtd/cfi_flash.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c index 439c950..6fc6bc4 100644 --- a/drivers/mtd/cfi_flash.c +++ b/drivers/mtd/cfi_flash.c @@ -241,8 +241,12 @@ static u32 flash_read32(void *addr) static u64 flash_read64(void *addr) { +#ifdef CONFIG_SPARC + return __raw_readq(addr); +#else /* No architectures currently implement __raw_readq() */ return *(volatile u64 *)addr; +#endif } /*-----------------------------------------------------------------------