From 61b1e75f7d8004461f2e18f171c26c2f545eed32 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 21 Jan 2016 19:28:15 +0000 Subject: overhaul sh atomics for new atomics framework, add j-core cas.l backend sh needs runtime-selected atomic backends since there are a number of supported models that use non-forwards-compatible (non-smp-compatible) atomic mechanisms. previously, the code paths for this were highly inefficient since they involved C function calls with multiple branches in the callee and heavy spills in the caller. the new code performs calls the runtime-selected asm fragment from inline asm with extremely minimal clobbers, rather than using a function call. for the sh4a case where the atomic mechanism is known and there is no forward-compatibility issue, the movli.l and movco.l instructions are provided as a_ll and a_sc, allowing the new shared atomic.h to generate efficient inline versions of all the basic atomic operations without needing a cas loop. --- arch/sh/src/__set_thread_area.c | 34 ---------------------------------- 1 file changed, 34 deletions(-) delete mode 100644 arch/sh/src/__set_thread_area.c (limited to 'arch/sh/src/__set_thread_area.c') diff --git a/arch/sh/src/__set_thread_area.c b/arch/sh/src/__set_thread_area.c deleted file mode 100644 index 1d3e0225..00000000 --- a/arch/sh/src/__set_thread_area.c +++ /dev/null @@ -1,34 +0,0 @@ -#include "pthread_impl.h" -#include "libc.h" -#include "sh_atomic.h" -#include - -/* Also perform sh-specific init */ - -#define CPU_HAS_LLSC 0x0040 - -__attribute__((__visibility__("hidden"))) unsigned __sh_atomic_model, __sh_nommu; - -int __set_thread_area(void *p) -{ - size_t *aux; - __asm__ __volatile__ ( "ldc %0, gbr" : : "r"(p) : "memory" ); -#ifndef __SH4A__ - if (__hwcap & CPU_HAS_LLSC) { - __sh_atomic_model = SH_A_LLSC; - return 0; - } -#if !defined(__SH3__) && !defined(__SH4__) - for (aux=libc.auxv; *aux; aux+=2) { - if (*aux != AT_PLATFORM) continue; - const char *s = (void *)aux[1]; - if (s[0]!='s' || s[1]!='h' || s[2]!='2' || s[3]-'0'<10u) break; - __sh_atomic_model = SH_A_IMASK; - __sh_nommu = 1; - return 0; - } -#endif - /* __sh_atomic_model = SH_A_GUSA; */ /* 0, default */ -#endif - return 0; -} -- cgit v1.2.1