diff options
Diffstat (limited to 'arch/xtensa/kernel/entry.S')
| -rw-r--r-- | arch/xtensa/kernel/entry.S | 228 |
1 files changed, 150 insertions, 78 deletions
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index c0b56b17927f..9e271ba009bf 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -1004,13 +1004,10 @@ ENTRY(fast_syscall_kernel) rsr a0, DEPC # get syscall-nr _beqz a0, fast_syscall_spill_registers - - addi a0, a0, -__NR_sysxtensa - _beqz a0, fast_syscall_sysxtensa + _beqi a0, __NR_xtensa, fast_syscall_xtensa j kernel_exception - ENTRY(fast_syscall_user) /* Skip syscall. */ @@ -1024,9 +1021,7 @@ ENTRY(fast_syscall_user) rsr a0, DEPC # get syscall-nr _beqz a0, fast_syscall_spill_registers - - addi a0, a0, -__NR_sysxtensa - _beqz a0, fast_syscall_sysxtensa + _beqi a0, __NR_xtensa, fast_syscall_xtensa j user_exception @@ -1047,18 +1042,19 @@ ENTRY(fast_syscall_unrecoverable) /* * sysxtensa syscall handler * - * int sysxtensa (XTENSA_ATOMIC_SET, ptr, val, unused); - * int sysxtensa (XTENSA_ATOMIC_ADD, ptr, val, unused); - * int sysxtensa (XTENSA_ATOMIC_EXG_ADD, ptr, val, unused); - * int sysxtensa (XTENSA_ATOMIC_CMP_SWP, ptr, oldval, newval); - * a2 a6 a3 a4 a5 + * int sysxtensa (SYS_XTENSA_ATOMIC_SET, ptr, val, unused); + * int sysxtensa (SYS_XTENSA_ATOMIC_ADD, ptr, val, unused); + * int sysxtensa (SYS_XTENSA_ATOMIC_EXG_ADD, ptr, val, unused); + * int sysxtensa (SYS_XTENSA_ATOMIC_CMP_SWP, ptr, oldval, newval); + * a2 a6 a3 a4 a5 * * Entry condition: * - * a0: trashed, original value saved on stack (PT_AREG0) + * a0: a2 (syscall-nr), original value saved on stack (PT_AREG0) * a1: a1 - * a2: new stack pointer, original in DEPC - * a3: dispatch table + * a2: new stack pointer, original in a0 and DEPC + * a3: dispatch table, original in excsave_1 + * a4..a15: unchanged * depc: a2, original value saved on stack (PT_DEPC) * excsave_1: a3 * @@ -1091,59 +1087,62 @@ ENTRY(fast_syscall_unrecoverable) #define CATCH \ 67: -ENTRY(fast_syscall_sysxtensa) - - _beqz a6, 1f - _blti a6, SYSXTENSA_COUNT, 2f +ENTRY(fast_syscall_xtensa) -1: j user_exception - -2: xsr a3, EXCSAVE_1 # restore a3, excsave1 - s32i a7, a2, PT_AREG7 + xsr a3, EXCSAVE_1 # restore a3, excsave1 + s32i a7, a2, PT_AREG7 # we need an additional register movi a7, 4 # sizeof(unsigned int) - access_ok a0, a3, a7, a2, .Leac + access_ok a3, a7, a0, a2, .Leac # a0: scratch reg, a2: sp - _beqi a6, SYSXTENSA_ATOMIC_SET, .Lset - _beqi a6, SYSXTENSA_ATOMIC_EXG_ADD, .Lexg - _beqi a6, SYSXTENSA_ATOMIC_ADD, .Ladd + addi a6, a6, -1 # assuming SYS_XTENSA_ATOMIC_SET = 1 + _bgeui a6, SYS_XTENSA_COUNT - 1, .Lill + _bnei a6, SYS_XTENSA_ATOMIC_CMP_SWP - 1, .Lnswp - /* Fall through for SYSXTENSA_ATOMIC_CMP_SWP */ + /* Fall through for ATOMIC_CMP_SWP. */ .Lswp: /* Atomic compare and swap */ -TRY l32i a7, a3, 0 # read old value - bne a7, a4, 1f # same as old value? jump - s32i a5, a3, 0 # different, modify value - movi a7, 1 # and return 1 - j .Lret - -1: movi a7, 0 # same values: return 0 - j .Lret - -.Ladd: /* Atomic add */ -.Lexg: /* Atomic (exchange) add */ +TRY l32i a0, a3, 0 # read old value + bne a0, a4, 1f # same as old value? jump +TRY s32i a5, a3, 0 # different, modify value + l32i a7, a2, PT_AREG7 # restore a7 + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, 1 # and return 1 + addi a6, a6, 1 # restore a6 (really necessary?) + rfe -TRY l32i a7, a3, 0 - add a4, a4, a7 - s32i a4, a3, 0 - j .Lret +1: l32i a7, a2, PT_AREG7 # restore a7 + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, 0 # return 0 (note that we cannot set + addi a6, a6, 1 # restore a6 (really necessary?) + rfe -.Lset: /* Atomic set */ +.Lnswp: /* Atomic set, add, and exg_add. */ -TRY l32i a7, a3, 0 # read old value as return value - s32i a4, a3, 0 # write new value +TRY l32i a7, a3, 0 # orig + add a0, a4, a7 # + arg + moveqz a0, a4, a6 # set +TRY s32i a0, a3, 0 # write new value -.Lret: mov a0, a2 + mov a0, a2 mov a2, a7 - l32i a7, a0, PT_AREG7 - l32i a3, a0, PT_AREG3 - l32i a0, a0, PT_AREG0 + l32i a7, a0, PT_AREG7 # restore a7 + l32i a0, a0, PT_AREG0 # restore a0 + addi a6, a6, 1 # restore a6 (really necessary?) rfe CATCH -.Leac: movi a7, -EFAULT - j .Lret +.Leac: l32i a7, a2, PT_AREG7 # restore a7 + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, -EFAULT + rfe + +.Lill: l32i a7, a2, PT_AREG0 # restore a7 + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, -EINVAL + rfe + @@ -1907,6 +1906,103 @@ ENTRY(fast_coprocessor) #endif /* XCHAL_EXTRA_SA_SIZE */ /* + * System Calls. + * + * void system_call (struct pt_regs* regs, int exccause) + * a2 a3 + */ + +ENTRY(system_call) + entry a1, 32 + + /* regs->syscall = regs->areg[2] */ + + l32i a3, a2, PT_AREG2 + mov a6, a2 + movi a4, do_syscall_trace_enter + s32i a3, a2, PT_SYSCALL + callx4 a4 + + /* syscall = sys_call_table[syscall_nr] */ + + movi a4, sys_call_table; + movi a5, __NR_syscall_count + movi a6, -ENOSYS + bgeu a3, a5, 1f + + addx4 a4, a3, a4 + l32i a4, a4, 0 + movi a5, sys_ni_syscall; + beq a4, a5, 1f + + /* Load args: arg0 - arg5 are passed via regs. */ + + l32i a6, a2, PT_AREG6 + l32i a7, a2, PT_AREG3 + l32i a8, a2, PT_AREG4 + l32i a9, a2, PT_AREG5 + l32i a10, a2, PT_AREG8 + l32i a11, a2, PT_AREG9 + + /* Pass one additional argument to the syscall: pt_regs (on stack) */ + s32i a2, a1, 0 + + callx4 a4 + +1: /* regs->areg[2] = return_value */ + + s32i a6, a2, PT_AREG2 + movi a4, do_syscall_trace_leave + mov a6, a2 + callx4 a4 + retw + + +/* + * Create a kernel thread + * + * int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) + * a2 a2 a3 a4 + */ + +ENTRY(kernel_thread) + entry a1, 16 + + mov a5, a2 # preserve fn over syscall + mov a7, a3 # preserve args over syscall + + movi a3, _CLONE_VM | _CLONE_UNTRACED + movi a2, __NR_clone + or a6, a4, a3 # arg0: flags + mov a3, a1 # arg1: sp + syscall + + beq a3, a1, 1f # branch if parent + mov a6, a7 # args + callx4 a5 # fn(args) + + movi a2, __NR_exit + syscall # return value of fn(args) still in a6 + +1: retw + +/* + * Do a system call from kernel instead of calling sys_execve, so we end up + * with proper pt_regs. + * + * int kernel_execve(const char *fname, char *const argv[], charg *const envp[]) + * a2 a2 a3 a4 + */ + +ENTRY(kernel_execve) + entry a1, 16 + mov a6, a2 # arg0 is in a6 + movi a2, __NR_execve + syscall + + retw + +/* * Task switch. * * struct task* _switch_to (struct task* prev, struct task* next) @@ -1964,33 +2060,9 @@ ENTRY(ret_from_fork) movi a4, schedule_tail callx4 a4 - movi a4, do_syscall_trace + movi a4, do_syscall_trace_leave + mov a6, a1 callx4 a4 j common_exception_return - - -/* - * Table of syscalls - */ - -.data -.align 4 -.global sys_call_table -sys_call_table: - -#define SYSCALL(call, narg) .word call -#include "syscalls.h" - -/* - * Number of arguments of each syscall - */ - -.global sys_narg_table -sys_narg_table: - -#undef SYSCALL -#define SYSCALL(call, narg) .byte narg -#include "syscalls.h" - |