From f1e39a4a616cd9981a9decfd5332fd07a01abb8b Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Thu, 17 Sep 2009 02:25:05 +0200 Subject: [PATCH] MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler This way it doesn't have to use CONFIG_CPU_HAS_LLSC anymore. Signed-off-by: Ralf Baechle --- arch/mips/include/asm/system.h | 3 + arch/mips/kernel/scall32-o32.S | 72 --------------------- arch/mips/kernel/scall64-64.S | 72 --------------------- arch/mips/kernel/syscall.c | 112 ++++++++++++++++++++++++++++++++- arch/mips/kernel/traps.c | 5 +- 5 files changed, 114 insertions(+), 150 deletions(-) diff --git a/arch/mips/include/asm/system.h b/arch/mips/include/asm/system.h index a2e9239b45aa..23f68b40d4bb 100644 --- a/arch/mips/include/asm/system.h +++ b/arch/mips/include/asm/system.h @@ -32,6 +32,9 @@ extern asmlinkage void *resume(void *last, void *next, void *next_ti); struct task_struct; +extern unsigned int ll_bit; +extern struct task_struct *ll_task; + #ifdef CONFIG_MIPS_MT_FPAFF /* diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S index b57082123536..7c2de4f091c4 100644 --- a/arch/mips/kernel/scall32-o32.S +++ b/arch/mips/kernel/scall32-o32.S @@ -187,78 +187,6 @@ illegal_syscall: j o32_syscall_exit END(handle_sys) - LEAF(mips_atomic_set) - andi v0, a1, 3 # must be word aligned - bnez v0, bad_alignment - - lw v1, TI_ADDR_LIMIT($28) # in legal address range? - addiu a0, a1, 4 - or a0, a0, a1 - and a0, a0, v1 - bltz a0, bad_address - -#ifdef CONFIG_CPU_HAS_LLSC - /* Ok, this is the ll/sc case. World is sane :-) */ -1: ll v0, (a1) - move a0, a2 -2: sc a0, (a1) -#if R10000_LLSC_WAR - beqzl a0, 1b -#else - beqz a0, 1b -#endif - - .section __ex_table,"a" - PTR 1b, bad_stack - PTR 2b, bad_stack - .previous -#else - sw a1, 16(sp) - sw a2, 20(sp) - - move a0, sp - move a2, a1 - li a1, 1 - jal do_page_fault - - lw a1, 16(sp) - lw a2, 20(sp) - - /* - * At this point the page should be readable and writable unless - * there was no more memory available. - */ -1: lw v0, (a1) -2: sw a2, (a1) - - .section __ex_table,"a" - PTR 1b, no_mem - PTR 2b, no_mem - .previous -#endif - - sw zero, PT_R7(sp) # success - sw v0, PT_R2(sp) # result - - j o32_syscall_exit # continue like a normal syscall - -no_mem: li v0, -ENOMEM - jr ra - -bad_address: - li v0, -EFAULT - jr ra - -bad_alignment: - li v0, -EINVAL - jr ra - END(mips_atomic_set) - - LEAF(sys_sysmips) - beq a0, MIPS_ATOMIC_SET, mips_atomic_set - j _sys_sysmips - END(sys_sysmips) - LEAF(sys_syscall) subu t0, a0, __NR_O32_Linux # check syscall number sltiu v0, t0, __NR_O32_Linux_syscalls + 1 diff --git a/arch/mips/kernel/scall64-64.S b/arch/mips/kernel/scall64-64.S index 3d866f24e064..b97b993846d6 100644 --- a/arch/mips/kernel/scall64-64.S +++ b/arch/mips/kernel/scall64-64.S @@ -124,78 +124,6 @@ illegal_syscall: j n64_syscall_exit END(handle_sys64) - LEAF(mips_atomic_set) - andi v0, a1, 3 # must be word aligned - bnez v0, bad_alignment - - LONG_L v1, TI_ADDR_LIMIT($28) # in legal address range? - LONG_ADDIU a0, a1, 4 - or a0, a0, a1 - and a0, a0, v1 - bltz a0, bad_address - -#ifdef CONFIG_CPU_HAS_LLSC - /* Ok, this is the ll/sc case. World is sane :-) */ -1: ll v0, (a1) - move a0, a2 -2: sc a0, (a1) -#if R10000_LLSC_WAR - beqzl a0, 1b -#else - beqz a0, 1b -#endif - - .section __ex_table,"a" - PTR 1b, bad_stack - PTR 2b, bad_stack - .previous -#else - sw a1, 16(sp) - sw a2, 20(sp) - - move a0, sp - move a2, a1 - li a1, 1 - jal do_page_fault - - lw a1, 16(sp) - lw a2, 20(sp) - - /* - * At this point the page should be readable and writable unless - * there was no more memory available. - */ -1: lw v0, (a1) -2: sw a2, (a1) - - .section __ex_table,"a" - PTR 1b, no_mem - PTR 2b, no_mem - .previous -#endif - - sd zero, PT_R7(sp) # success - sd v0, PT_R2(sp) # result - - j n64_syscall_exit # continue like a normal syscall - -no_mem: li v0, -ENOMEM - jr ra - -bad_address: - li v0, -EFAULT - jr ra - -bad_alignment: - li v0, -EINVAL - jr ra - END(mips_atomic_set) - - LEAF(sys_sysmips) - beq a0, MIPS_ATOMIC_SET, mips_atomic_set - j _sys_sysmips - END(sys_sysmips) - .align 3 sys_call_table: PTR sys_read /* 5000 */ diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c index 8cf384644040..3fe1fcfa2e73 100644 --- a/arch/mips/kernel/syscall.c +++ b/arch/mips/kernel/syscall.c @@ -28,7 +28,9 @@ #include #include #include +#include +#include #include #include #include @@ -290,12 +292,116 @@ SYSCALL_DEFINE1(set_thread_area, unsigned long, addr) return 0; } -asmlinkage int _sys_sysmips(long cmd, long arg1, long arg2, long arg3) +static inline int mips_atomic_set(struct pt_regs *regs, + unsigned long addr, unsigned long new) { + unsigned long old, tmp; + unsigned int err; + + if (unlikely(addr & 3)) + return -EINVAL; + + if (unlikely(!access_ok(VERIFY_WRITE, addr, 4))) + return -EINVAL; + + if (cpu_has_llsc && R10000_LLSC_WAR) { + __asm__ __volatile__ ( + " li %[err], 0 \n" + "1: ll %[old], (%[addr]) \n" + " move %[tmp], %[new] \n" + "2: sc %[tmp], (%[addr]) \n" + " beqzl %[tmp], 1b \n" + "3: \n" + " .section .fixup,\"ax\" \n" + "4: li %[err], %[efault] \n" + " j 3b \n" + " .previous \n" + " .section __ex_table,\"a\" \n" + " "STR(PTR)" 1b, 4b \n" + " "STR(PTR)" 2b, 4b \n" + " .previous \n" + : [old] "=&r" (old), + [err] "=&r" (err), + [tmp] "=&r" (tmp) + : [addr] "r" (addr), + [new] "r" (new), + [efault] "i" (-EFAULT) + : "memory"); + } else if (cpu_has_llsc) { + __asm__ __volatile__ ( + " li %[err], 0 \n" + "1: ll %[old], (%[addr]) \n" + " move %[tmp], %[new] \n" + "2: sc %[tmp], (%[addr]) \n" + " bnez %[tmp], 4f \n" + "3: \n" + " .subsection 2 \n" + "4: b 1b \n" + " .previous \n" + " \n" + " .section .fixup,\"ax\" \n" + "5: li %[err], %[efault] \n" + " j 3b \n" + " .previous \n" + " .section __ex_table,\"a\" \n" + " "STR(PTR)" 1b, 5b \n" + " "STR(PTR)" 2b, 5b \n" + " .previous \n" + : [old] "=&r" (old), + [err] "=&r" (err), + [tmp] "=&r" (tmp) + : [addr] "r" (addr), + [new] "r" (new), + [efault] "i" (-EFAULT) + : "memory"); + } else { + do { + preempt_disable(); + ll_bit = 1; + ll_task = current; + preempt_enable(); + + err = __get_user(old, (unsigned int *) addr); + err |= __put_user(new, (unsigned int *) addr); + if (err) + break; + rmb(); + } while (!ll_bit); + } + + if (unlikely(err)) + return err; + + regs->regs[2] = old; + regs->regs[7] = 0; /* No error */ + + /* + * Don't let your children do this ... + */ + __asm__ __volatile__( + " move $29, %0 \n" + " j syscall_exit \n" + : /* no outputs */ + : "r" (regs)); + + /* unreached. Honestly. */ + while (1); +} + +save_static_function(sys_sysmips); +static int __used noinline +_sys_sysmips(nabi_no_regargs struct pt_regs regs) +{ + long cmd, arg1, arg2, arg3; + + cmd = regs.regs[4]; + arg1 = regs.regs[5]; + arg2 = regs.regs[6]; + arg3 = regs.regs[7]; + switch (cmd) { case MIPS_ATOMIC_SET: - printk(KERN_CRIT "How did I get here?\n"); - return -EINVAL; + return mips_atomic_set(®s, arg1, arg2); case MIPS_FIXADE: if (arg1 & ~3) diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 08f1edf355e8..0a18b4c62afb 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -466,9 +466,8 @@ asmlinkage void do_be(struct pt_regs *regs) * The ll_bit is cleared by r*_switch.S */ -unsigned long ll_bit; - -static struct task_struct *ll_task = NULL; +unsigned int ll_bit; +struct task_struct *ll_task; static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode) { -- 2.34.1