From f2db633d301b4b50f5f93de0e8314cc81e9bc7de Mon Sep 17 00:00:00 2001 From: Michael Cree Date: Sun, 19 Aug 2012 14:40:58 +1200 Subject: alpha: Use new generic strncpy_from_user() and strnlen_user() Similar to x86/sparc/powerpc implementations except: 1) we implement an extremely efficient has_zero()/find_zero() sequence with both prep_zero_mask() and create_zero_mask() no-operations. 2) Our output from prep_zero_mask() differs in that only the lowest eight bits are used to represent the zero bytes nevertheless it can be safely ORed with other similar masks from prep_zero_mask() and forms input to create_zero_mask(), the two fundamental properties prep_zero_mask() must satisfy. Tests on EV67 and EV68 CPUs revealed that the generic code is essentially as fast (to within 0.5% of CPU cycles) of the old Alpha specific code for large quadword-aligned strings, despite the 30% extra CPU instructions executed. In contrast, the generic code for unaligned strings is substantially slower (by more than a factor of 3) than the old Alpha specific code. Signed-off-by: Michael Cree Acked-by: Matt Turner Signed-off-by: Linus Torvalds --- arch/alpha/kernel/alpha_ksyms.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/alpha/kernel') diff --git a/arch/alpha/kernel/alpha_ksyms.c b/arch/alpha/kernel/alpha_ksyms.c index d96e742d4dc2..a354277bbaa7 100644 --- a/arch/alpha/kernel/alpha_ksyms.c +++ b/arch/alpha/kernel/alpha_ksyms.c @@ -74,8 +74,6 @@ EXPORT_SYMBOL(alpha_fp_emul); */ EXPORT_SYMBOL(__copy_user); EXPORT_SYMBOL(__do_clear_user); -EXPORT_SYMBOL(__strncpy_from_user); -EXPORT_SYMBOL(__strnlen_user); /* * SMP-specific symbols. -- cgit v1.2.2