From 322fdd37d307a12c913be78cebcc348a77731dd3 Mon Sep 17 00:00:00 2001 From: Waldemar Brodkorb Date: Thu, 12 Feb 2015 14:06:43 -0600 Subject: unbreak support for ARM no MMU case As suggested on the uCLibc mailing list: http://lists.uclibc.org/pipermail/uclibc/2014-November/048702.html http://lists.uclibc.org/pipermail/uclibc/2014-November/048703.html http://lists.uclibc.org/pipermail/uclibc/2014-November/048704.html --- extra/Configs/Config.arm | 8 ++++ extra/Configs/Config.in | 1 - libc/sysdeps/linux/arm/clone.S | 14 +++--- .../linuxthreads.old/sysdeps/arm/pt-machine.h | 56 +++++++++++++++++++--- 4 files changed, 65 insertions(+), 14 deletions(-) diff --git a/extra/Configs/Config.arm b/extra/Configs/Config.arm index a16c9197a..00cf98281 100644 --- a/extra/Configs/Config.arm +++ b/extra/Configs/Config.arm @@ -28,6 +28,7 @@ config CONFIG_ARM_EABI config COMPILE_IN_THUMB_MODE bool "Build using Thumb mode" select USE_BX + select USE_LDREXSTREX help Say 'y' here to force building uClibc in thumb mode. Say 'n' to use your compiler's default mode. @@ -38,3 +39,10 @@ config USE_BX Say 'y' to use BX to return from functions on your thumb-aware processor. Say 'y' if you need to use interworking. Say 'n' if not. It is safe to say 'y' even if you're not doing interworking. + +config USE_LDREXSTREX + bool "Use load-store exclusive ASM ops (not supported in SmartFusion)" + depends on COMPILE_IN_THUMB_MODE + default n + help + Say 'y' to use LDREX/STREX ASM ops. diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in index c7a3b2dd2..31944bea1 100644 --- a/extra/Configs/Config.in +++ b/extra/Configs/Config.in @@ -524,7 +524,6 @@ config LINUXTHREADS_OLD # linuxthreads and linuxthreads.old need nanosleep() select UCLIBC_HAS_REALTIME depends on !TARGET_arc && \ - !TARGET_arm && \ !TARGET_i386 && \ !TARGET_metag && \ !TARGET_mips && \ diff --git a/libc/sysdeps/linux/arm/clone.S b/libc/sysdeps/linux/arm/clone.S index 29045ef7b..d1c9239da 100644 --- a/libc/sysdeps/linux/arm/clone.S +++ b/libc/sysdeps/linux/arm/clone.S @@ -26,7 +26,10 @@ #include #include #include + +#if defined __UCLIBC_HAS_THREADS__ && !defined __LINUXTHREADS_OLD__ #include +#endif #define CLONE_VM 0x00000100 #define CLONE_THREAD 0x00010000 @@ -57,23 +60,22 @@ __clone: @ get flags mov r0, r2 @ new sp is already in r1 - @ load remaining arguments off the stack - stmfd sp!, {r4} - ldr r2, [sp, #4] - ldr r3, [sp, #8] - ldr r4, [sp, #12] DO_CALL (clone) movs a1, a1 blt __error - ldmnefd sp!, {r4} beq 1f bx lr 1: @ pick the function arg and call address off the stack and execute ldr r0, [sp, #4] +#if defined(__USE_BX__) ldr r1, [sp] bl 2f @ blx r1 +#else + mov lr, pc + ldr pc, [sp] +#endif @ and we are done, passing the return value through r0 bl HIDDEN_JUMPTARGET(_exit) diff --git a/libpthread/linuxthreads.old/sysdeps/arm/pt-machine.h b/libpthread/linuxthreads.old/sysdeps/arm/pt-machine.h index 438c12ab9..2b877f980 100644 --- a/libpthread/linuxthreads.old/sysdeps/arm/pt-machine.h +++ b/libpthread/linuxthreads.old/sysdeps/arm/pt-machine.h @@ -21,12 +21,50 @@ #ifndef _PT_MACHINE_H #define _PT_MACHINE_H 1 -#include +#include +#include #ifndef PT_EI # define PT_EI __extern_always_inline #endif +#if defined(__thumb__) +#if defined(__USE_LDREXSTREX__) +PT_EI long int ldrex(int *spinlock) +{ + long int ret; + __asm__ __volatile__( + "ldrex %0, [%1]\n" + : "=r"(ret) + : "r"(spinlock) : "memory"); + return ret; +} + +PT_EI long int strex(int val, int *spinlock) +{ + long int ret; + __asm__ __volatile__( + "strex %0, %1, [%2]\n" + : "=r"(ret) + : "r" (val), "r"(spinlock) : "memory"); + return ret; +} + +/* Spinlock implementation; required. */ +PT_EI long int +testandset (int *spinlock) +{ + register unsigned int ret; + + do { + ret = ldrex(spinlock); + } while (strex(1, spinlock)); + + return ret; +} + +#else /* __USE_LDREXSTREX__ */ + /* This will not work on ARM1 or ARM2 because SWP is lacking on those machines. Unfortunately we have no way to detect this at compile time; let's hope nobody tries to use one. */ @@ -36,8 +74,6 @@ PT_EI long int testandset (int *spinlock); PT_EI long int testandset (int *spinlock) { register unsigned int ret; - -#if defined(__thumb__) void *pc; __asm__ __volatile__( ".align 0\n" @@ -50,15 +86,21 @@ PT_EI long int testandset (int *spinlock) "\t.force_thumb" : "=r"(ret), "=r"(pc) : "0"(1), "r"(spinlock)); -#else + return ret; +} +#endif +#else /* __thumb__ */ + +PT_EI long int testandset (int *spinlock); +PT_EI long int testandset (int *spinlock) +{ + register unsigned int ret; __asm__ __volatile__("swp %0, %1, [%2]" : "=r"(ret) : "0"(1), "r"(spinlock)); -#endif - return ret; } - +#endif /* Get some notion of the current stack. Need not be exactly the top of the stack, just something somewhere in the current frame. */ -- cgit v1.2.3