From: Alex Williamson Date: Thu, 4 Aug 2005 20:06:00 +0000 (-0700) Subject: [IA64, X86_64] fix swiotlb sizing X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=e8579e72ca240f3fbaa669f09a9d610436505366;p=linux-edison.git [IA64, X86_64] fix swiotlb sizing Fix swiotlb sizing to match what the comments and the kernel parameters documentation indicate. Given a default 16k page size kernel (ia64) and a 2k swiotlb page size, we're off by a multiple of 8 trying to size the swiotlb. When specified on the boot line, the swiotlb is made 8x bigger than requested. When left to the default value, it's 8x smaller than the comments indicate. For x86_64 the multiplier would be 2x. The patch below fixes this. Now, what's a good default swiotlb size? Apparently we don't really need 64MB. Signed-off-by: Alex Williamson Signed-off-by: Tony Luck --- diff --git a/arch/ia64/lib/swiotlb.c b/arch/ia64/lib/swiotlb.c index ab7b3ad99a7..dbc0b3e449c 100644 --- a/arch/ia64/lib/swiotlb.c +++ b/arch/ia64/lib/swiotlb.c @@ -93,8 +93,7 @@ static int __init setup_io_tlb_npages(char *str) { if (isdigit(*str)) { - io_tlb_nslabs = simple_strtoul(str, &str, 0) << - (PAGE_SHIFT - IO_TLB_SHIFT); + io_tlb_nslabs = simple_strtoul(str, &str, 0); /* avoid tail segment of size < IO_TLB_SEGSIZE */ io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); } @@ -117,7 +116,7 @@ swiotlb_init_with_default_size (size_t default_size) unsigned long i; if (!io_tlb_nslabs) { - io_tlb_nslabs = (default_size >> PAGE_SHIFT); + io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); }