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Diffstat (limited to 'arch/xtensa/kernel/entry.S')
-rw-r--r--arch/xtensa/kernel/entry.S256
1 files changed, 164 insertions, 92 deletions
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 89e409e9e0d..9e271ba009b 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -24,7 +24,7 @@
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/signal.h>
-#include <xtensa/coreasm.h>
+#include <asm/tlbflush.h>
/* Unimplemented features. */
@@ -364,7 +364,7 @@ common_exception:
movi a2, 1
extui a3, a3, 0, 1 # a3 = PS.INTLEVEL[0]
moveqz a3, a2, a0 # a3 = 1 iff interrupt exception
- movi a2, PS_WOE_MASK
+ movi a2, 1 << PS_WOE_BIT
or a3, a3, a2
rsr a0, EXCCAUSE
xsr a3, PS
@@ -399,7 +399,7 @@ common_exception_return:
/* Jump if we are returning from kernel exceptions. */
1: l32i a3, a1, PT_PS
- _bbsi.l a3, PS_UM_SHIFT, 2f
+ _bbsi.l a3, PS_UM_BIT, 2f
j kernel_exception_exit
/* Specific to a user exception exit:
@@ -422,7 +422,7 @@ common_exception_return:
* (Hint: There is only one user exception frame on stack)
*/
- movi a3, PS_WOE_MASK
+ movi a3, 1 << PS_WOE_BIT
_bbsi.l a4, TIF_NEED_RESCHED, 3f
_bbci.l a4, TIF_SIGPENDING, 4f
@@ -694,7 +694,7 @@ common_exception_exit:
ENTRY(debug_exception)
rsr a0, EPS + XCHAL_DEBUGLEVEL
- bbsi.l a0, PS_EXCM_SHIFT, 1f # exception mode
+ bbsi.l a0, PS_EXCM_BIT, 1f # exception mode
/* Set EPC_1 and EXCCAUSE */
@@ -707,7 +707,7 @@ ENTRY(debug_exception)
/* Restore PS to the value before the debug exc but with PS.EXCM set.*/
- movi a2, 1 << PS_EXCM_SHIFT
+ movi a2, 1 << PS_EXCM_BIT
or a2, a0, a2
movi a0, debug_exception # restore a3, debug jump vector
wsr a2, PS
@@ -715,7 +715,7 @@ ENTRY(debug_exception)
/* Switch to kernel/user stack, restore jump vector, and save a0 */
- bbsi.l a2, PS_UM_SHIFT, 2f # jump if user mode
+ bbsi.l a2, PS_UM_BIT, 2f # jump if user mode
addi a2, a1, -16-PT_SIZE # assume kernel stack
s32i a0, a2, PT_AREG0
@@ -778,7 +778,7 @@ ENTRY(unrecoverable_exception)
wsr a1, WINDOWBASE
rsync
- movi a1, PS_WOE_MASK | 1
+ movi a1, (1 << PS_WOE_BIT) | 1
wsr a1, PS
rsync
@@ -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
+
@@ -1491,7 +1490,7 @@ ENTRY(_spill_registers)
*/
rsr a0, PS
- _bbci.l a0, PS_UM_SHIFT, 1f
+ _bbci.l a0, PS_UM_BIT, 1f
/* User space: Setup a dummy frame and kill application.
* Note: We assume EXC_TABLE_KSTK contains a valid stack pointer.
@@ -1510,7 +1509,7 @@ ENTRY(_spill_registers)
l32i a1, a3, EXC_TABLE_KSTK
wsr a3, EXCSAVE_1
- movi a4, PS_WOE_MASK | 1
+ movi a4, (1 << PS_WOE_BIT) | 1
wsr a4, PS
rsync
@@ -1612,7 +1611,7 @@ ENTRY(fast_second_level_miss)
rsr a1, PTEVADDR
srli a1, a1, PAGE_SHIFT
slli a1, a1, PAGE_SHIFT # ptevaddr & PAGE_MASK
- addi a1, a1, DTLB_WAY_PGTABLE # ... + way_number
+ addi a1, a1, DTLB_WAY_PGD # ... + way_number
wdtlb a0, a1
dsync
@@ -1654,7 +1653,7 @@ ENTRY(fast_second_level_miss)
mov a1, a2
rsr a2, PS
- bbsi.l a2, PS_UM_SHIFT, 1f
+ bbsi.l a2, PS_UM_BIT, 1f
j _kernel_exception
1: j _user_exception
@@ -1753,7 +1752,7 @@ ENTRY(fast_store_prohibited)
mov a1, a2
rsr a2, PS
- bbsi.l a2, PS_UM_SHIFT, 1f
+ bbsi.l a2, PS_UM_BIT, 1f
j _kernel_exception
1: j _user_exception
@@ -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)
@@ -1924,7 +2020,7 @@ ENTRY(_switch_to)
/* Disable ints while we manipulate the stack pointer; spill regs. */
- movi a5, PS_EXCM_MASK | LOCKLEVEL
+ movi a5, (1 << PS_EXCM_BIT) | LOCKLEVEL
xsr a5, PS
rsr a3, EXCSAVE_1
rsync
@@ -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"
-
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-27 06:19:42 +0000