diff options
Diffstat (limited to 'arch/parisc/kernel/syscall.S')
| -rw-r--r-- | arch/parisc/kernel/syscall.S | 66 |
1 files changed, 34 insertions, 32 deletions
diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index d03422e5f188..23de307c3052 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -100,14 +100,12 @@ set_thread_pointer: .endr /* This address must remain fixed at 0x100 for glibc's syscalls to work */ - .align 256 + .align LINUX_GATEWAY_ADDR linux_gateway_entry: gate .+8, %r0 /* become privileged */ mtsp %r0,%sr4 /* get kernel space into sr4 */ mtsp %r0,%sr5 /* get kernel space into sr5 */ mtsp %r0,%sr6 /* get kernel space into sr6 */ - mfsp %sr7,%r1 /* save user sr7 */ - mtsp %r1,%sr3 /* and store it in sr3 */ #ifdef CONFIG_64BIT /* for now we can *always* set the W bit on entry to the syscall @@ -133,6 +131,14 @@ linux_gateway_entry: depdi 0, 31, 32, %r21 1: #endif + + /* We use a rsm/ssm pair to prevent sr3 from being clobbered + * by external interrupts. + */ + mfsp %sr7,%r1 /* save user sr7 */ + rsm PSW_SM_I, %r0 /* disable interrupts */ + mtsp %r1,%sr3 /* and store it in sr3 */ + mfctl %cr30,%r1 xor %r1,%r30,%r30 /* ye olde xor trick */ xor %r1,%r30,%r1 @@ -147,6 +153,7 @@ linux_gateway_entry: */ mtsp %r0,%sr7 /* get kernel space into sr7 */ + ssm PSW_SM_I, %r0 /* enable interrupts */ STREGM %r1,FRAME_SIZE(%r30) /* save r1 (usp) here for now */ mfctl %cr30,%r1 /* get task ptr in %r1 */ LDREG TI_TASK(%r1),%r1 @@ -474,11 +481,6 @@ lws_start: comiclr,>> __NR_lws_entries, %r20, %r0 b,n lws_exit_nosys - /* WARNING: Trashing sr2 and sr3 */ - mfsp %sr7,%r1 /* get userspace into sr3 */ - mtsp %r1,%sr3 - mtsp %r0,%sr2 /* get kernel space into sr2 */ - /* Load table start */ ldil L%lws_table, %r1 ldo R%lws_table(%r1), %r28 /* Scratch use of r28 */ @@ -627,9 +629,9 @@ cas_action: stw %r1, 4(%sr2,%r20) #endif /* The load and store could fail */ -1: ldw,ma 0(%sr3,%r26), %r28 +1: ldw,ma 0(%r26), %r28 sub,<> %r28, %r25, %r0 -2: stw,ma %r24, 0(%sr3,%r26) +2: stw,ma %r24, 0(%r26) /* Free lock */ stw,ma %r20, 0(%sr2,%r20) #if ENABLE_LWS_DEBUG @@ -706,9 +708,9 @@ lws_compare_and_swap_2: nop /* 8bit load */ -4: ldb 0(%sr3,%r25), %r25 +4: ldb 0(%r25), %r25 b cas2_lock_start -5: ldb 0(%sr3,%r24), %r24 +5: ldb 0(%r24), %r24 nop nop nop @@ -716,9 +718,9 @@ lws_compare_and_swap_2: nop /* 16bit load */ -6: ldh 0(%sr3,%r25), %r25 +6: ldh 0(%r25), %r25 b cas2_lock_start -7: ldh 0(%sr3,%r24), %r24 +7: ldh 0(%r24), %r24 nop nop nop @@ -726,9 +728,9 @@ lws_compare_and_swap_2: nop /* 32bit load */ -8: ldw 0(%sr3,%r25), %r25 +8: ldw 0(%r25), %r25 b cas2_lock_start -9: ldw 0(%sr3,%r24), %r24 +9: ldw 0(%r24), %r24 nop nop nop @@ -737,14 +739,14 @@ lws_compare_and_swap_2: /* 64bit load */ #ifdef CONFIG_64BIT -10: ldd 0(%sr3,%r25), %r25 -11: ldd 0(%sr3,%r24), %r24 +10: ldd 0(%r25), %r25 +11: ldd 0(%r24), %r24 #else /* Load new value into r22/r23 - high/low */ -10: ldw 0(%sr3,%r25), %r22 -11: ldw 4(%sr3,%r25), %r23 +10: ldw 0(%r25), %r22 +11: ldw 4(%r25), %r23 /* Load new value into fr4 for atomic store later */ -12: flddx 0(%sr3,%r24), %fr4 +12: flddx 0(%r24), %fr4 #endif cas2_lock_start: @@ -794,30 +796,30 @@ cas2_action: ldo 1(%r0),%r28 /* 8bit CAS */ -13: ldb,ma 0(%sr3,%r26), %r29 +13: ldb,ma 0(%r26), %r29 sub,= %r29, %r25, %r0 b,n cas2_end -14: stb,ma %r24, 0(%sr3,%r26) +14: stb,ma %r24, 0(%r26) b cas2_end copy %r0, %r28 nop nop /* 16bit CAS */ -15: ldh,ma 0(%sr3,%r26), %r29 +15: ldh,ma 0(%r26), %r29 sub,= %r29, %r25, %r0 b,n cas2_end -16: sth,ma %r24, 0(%sr3,%r26) +16: sth,ma %r24, 0(%r26) b cas2_end copy %r0, %r28 nop nop /* 32bit CAS */ -17: ldw,ma 0(%sr3,%r26), %r29 +17: ldw,ma 0(%r26), %r29 sub,= %r29, %r25, %r0 b,n cas2_end -18: stw,ma %r24, 0(%sr3,%r26) +18: stw,ma %r24, 0(%r26) b cas2_end copy %r0, %r28 nop @@ -825,22 +827,22 @@ cas2_action: /* 64bit CAS */ #ifdef CONFIG_64BIT -19: ldd,ma 0(%sr3,%r26), %r29 +19: ldd,ma 0(%r26), %r29 sub,*= %r29, %r25, %r0 b,n cas2_end -20: std,ma %r24, 0(%sr3,%r26) +20: std,ma %r24, 0(%r26) copy %r0, %r28 #else /* Compare first word */ -19: ldw,ma 0(%sr3,%r26), %r29 +19: ldw,ma 0(%r26), %r29 sub,= %r29, %r22, %r0 b,n cas2_end /* Compare second word */ -20: ldw,ma 4(%sr3,%r26), %r29 +20: ldw,ma 4(%r26), %r29 sub,= %r29, %r23, %r0 b,n cas2_end /* Perform the store */ -21: fstdx %fr4, 0(%sr3,%r26) +21: fstdx %fr4, 0(%r26) copy %r0, %r28 #endif |