Christophe Leroy <christophe.le...@csgroup.eu> writes: > Hi Michael, > > I see this patch is marked as "defered" in patchwork, but I can't see > any related discussion. Is it normal ?
Because it uses the "m<>" constraint which didn't work on GCC 4.6. https://github.com/linuxppc/issues/issues/297 So we should be able to pick it up for v5.9 hopefully. cheers > Le 16/04/2020 à 14:39, Christophe Leroy a écrit : >> At the time being, __put_user()/__get_user() and friends only use >> D-form addressing, with 0 offset. Ex: >> >> lwz reg1, 0(reg2) >> >> Give the compiler the opportunity to use other adressing modes >> whenever possible, to get more optimised code. >> >> Hereunder is a small exemple: >> >> struct test { >> u32 item1; >> u16 item2; >> u8 item3; >> u64 item4; >> }; >> >> int set_test_user(struct test __user *from, struct test __user *to) >> { >> int err; >> u32 item1; >> u16 item2; >> u8 item3; >> u64 item4; >> >> err = __get_user(item1, &from->item1); >> err |= __get_user(item2, &from->item2); >> err |= __get_user(item3, &from->item3); >> err |= __get_user(item4, &from->item4); >> >> err |= __put_user(item1, &to->item1); >> err |= __put_user(item2, &to->item2); >> err |= __put_user(item3, &to->item3); >> err |= __put_user(item4, &to->item4); >> >> return err; >> } >> >> Before the patch: >> >> 00000df0 <set_test_user>: >> df0: 94 21 ff f0 stwu r1,-16(r1) >> df4: 39 40 00 00 li r10,0 >> df8: 93 c1 00 08 stw r30,8(r1) >> dfc: 93 e1 00 0c stw r31,12(r1) >> e00: 7d 49 53 78 mr r9,r10 >> e04: 80 a3 00 00 lwz r5,0(r3) >> e08: 38 e3 00 04 addi r7,r3,4 >> e0c: 7d 46 53 78 mr r6,r10 >> e10: a0 e7 00 00 lhz r7,0(r7) >> e14: 7d 29 33 78 or r9,r9,r6 >> e18: 39 03 00 06 addi r8,r3,6 >> e1c: 7d 46 53 78 mr r6,r10 >> e20: 89 08 00 00 lbz r8,0(r8) >> e24: 7d 29 33 78 or r9,r9,r6 >> e28: 38 63 00 08 addi r3,r3,8 >> e2c: 7d 46 53 78 mr r6,r10 >> e30: 83 c3 00 00 lwz r30,0(r3) >> e34: 83 e3 00 04 lwz r31,4(r3) >> e38: 7d 29 33 78 or r9,r9,r6 >> e3c: 7d 43 53 78 mr r3,r10 >> e40: 90 a4 00 00 stw r5,0(r4) >> e44: 7d 29 1b 78 or r9,r9,r3 >> e48: 38 c4 00 04 addi r6,r4,4 >> e4c: 7d 43 53 78 mr r3,r10 >> e50: b0 e6 00 00 sth r7,0(r6) >> e54: 7d 29 1b 78 or r9,r9,r3 >> e58: 38 e4 00 06 addi r7,r4,6 >> e5c: 7d 43 53 78 mr r3,r10 >> e60: 99 07 00 00 stb r8,0(r7) >> e64: 7d 23 1b 78 or r3,r9,r3 >> e68: 38 84 00 08 addi r4,r4,8 >> e6c: 93 c4 00 00 stw r30,0(r4) >> e70: 93 e4 00 04 stw r31,4(r4) >> e74: 7c 63 53 78 or r3,r3,r10 >> e78: 83 c1 00 08 lwz r30,8(r1) >> e7c: 83 e1 00 0c lwz r31,12(r1) >> e80: 38 21 00 10 addi r1,r1,16 >> e84: 4e 80 00 20 blr >> >> After the patch: >> >> 00000dbc <set_test_user>: >> dbc: 39 40 00 00 li r10,0 >> dc0: 7d 49 53 78 mr r9,r10 >> dc4: 80 03 00 00 lwz r0,0(r3) >> dc8: 7d 48 53 78 mr r8,r10 >> dcc: a1 63 00 04 lhz r11,4(r3) >> dd0: 7d 29 43 78 or r9,r9,r8 >> dd4: 7d 48 53 78 mr r8,r10 >> dd8: 88 a3 00 06 lbz r5,6(r3) >> ddc: 7d 29 43 78 or r9,r9,r8 >> de0: 7d 48 53 78 mr r8,r10 >> de4: 80 c3 00 08 lwz r6,8(r3) >> de8: 80 e3 00 0c lwz r7,12(r3) >> dec: 7d 29 43 78 or r9,r9,r8 >> df0: 7d 43 53 78 mr r3,r10 >> df4: 90 04 00 00 stw r0,0(r4) >> df8: 7d 29 1b 78 or r9,r9,r3 >> dfc: 7d 43 53 78 mr r3,r10 >> e00: b1 64 00 04 sth r11,4(r4) >> e04: 7d 29 1b 78 or r9,r9,r3 >> e08: 7d 43 53 78 mr r3,r10 >> e0c: 98 a4 00 06 stb r5,6(r4) >> e10: 7d 23 1b 78 or r3,r9,r3 >> e14: 90 c4 00 08 stw r6,8(r4) >> e18: 90 e4 00 0c stw r7,12(r4) >> e1c: 7c 63 53 78 or r3,r3,r10 >> e20: 4e 80 00 20 blr >> >> Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr> >> Reviewed-by: Segher Boessenkool <seg...@kernel.crashing.org> >> --- >> v2: >> - Added <> modifier in __put_user_asm() and __get_user_asm() >> - Removed %U2 in __put_user_asm2() and __get_user_asm2() >> - Reworded the commit log >> --- >> arch/powerpc/include/asm/uaccess.h | 28 ++++++++++++++-------------- >> 1 file changed, 14 insertions(+), 14 deletions(-) >> >> diff --git a/arch/powerpc/include/asm/uaccess.h >> b/arch/powerpc/include/asm/uaccess.h >> index 7c811442b607..9365b59495a2 100644 >> --- a/arch/powerpc/include/asm/uaccess.h >> +++ b/arch/powerpc/include/asm/uaccess.h >> @@ -114,7 +114,7 @@ extern long __put_user_bad(void); >> */ >> #define __put_user_asm(x, addr, err, op) \ >> __asm__ __volatile__( \ >> - "1: " op " %1,0(%2) # put_user\n" \ >> + "1: " op "%U2%X2 %1,%2 # put_user\n" \ >> "2:\n" \ >> ".section .fixup,\"ax\"\n" \ >> "3: li %0,%3\n" \ >> @@ -122,7 +122,7 @@ extern long __put_user_bad(void); >> ".previous\n" \ >> EX_TABLE(1b, 3b) \ >> : "=r" (err) \ >> - : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) >> + : "r" (x), "m<>" (*addr), "i" (-EFAULT), "0" (err)) >> >> #ifdef __powerpc64__ >> #define __put_user_asm2(x, ptr, retval) \ >> @@ -130,8 +130,8 @@ extern long __put_user_bad(void); >> #else /* __powerpc64__ */ >> #define __put_user_asm2(x, addr, err) \ >> __asm__ __volatile__( \ >> - "1: stw %1,0(%2)\n" \ >> - "2: stw %1+1,4(%2)\n" \ >> + "1: stw%X2 %1,%2\n" \ >> + "2: stw%X2 %L1,%L2\n" \ >> "3:\n" \ >> ".section .fixup,\"ax\"\n" \ >> "4: li %0,%3\n" \ >> @@ -140,7 +140,7 @@ extern long __put_user_bad(void); >> EX_TABLE(1b, 4b) \ >> EX_TABLE(2b, 4b) \ >> : "=r" (err) \ >> - : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) >> + : "r" (x), "m" (*addr), "i" (-EFAULT), "0" (err)) >> #endif /* __powerpc64__ */ >> >> #define __put_user_size_allowed(x, ptr, size, retval) \ >> @@ -260,7 +260,7 @@ extern long __get_user_bad(void); >> >> #define __get_user_asm(x, addr, err, op) \ >> __asm__ __volatile__( \ >> - "1: "op" %1,0(%2) # get_user\n" \ >> + "1: "op"%U2%X2 %1, %2 # get_user\n" \ >> "2:\n" \ >> ".section .fixup,\"ax\"\n" \ >> "3: li %0,%3\n" \ >> @@ -269,7 +269,7 @@ extern long __get_user_bad(void); >> ".previous\n" \ >> EX_TABLE(1b, 3b) \ >> : "=r" (err), "=r" (x) \ >> - : "b" (addr), "i" (-EFAULT), "0" (err)) >> + : "m<>" (*addr), "i" (-EFAULT), "0" (err)) >> >> #ifdef __powerpc64__ >> #define __get_user_asm2(x, addr, err) \ >> @@ -277,8 +277,8 @@ extern long __get_user_bad(void); >> #else /* __powerpc64__ */ >> #define __get_user_asm2(x, addr, err) \ >> __asm__ __volatile__( \ >> - "1: lwz %1,0(%2)\n" \ >> - "2: lwz %1+1,4(%2)\n" \ >> + "1: lwz%X2 %1, %2\n" \ >> + "2: lwz%X2 %L1, %L2\n" \ >> "3:\n" \ >> ".section .fixup,\"ax\"\n" \ >> "4: li %0,%3\n" \ >> @@ -289,7 +289,7 @@ extern long __get_user_bad(void); >> EX_TABLE(1b, 4b) \ >> EX_TABLE(2b, 4b) \ >> : "=r" (err), "=&r" (x) \ >> - : "b" (addr), "i" (-EFAULT), "0" (err)) >> + : "m" (*addr), "i" (-EFAULT), "0" (err)) >> #endif /* __powerpc64__ */ >> >> #define __get_user_size_allowed(x, ptr, size, retval) \ >> @@ -299,10 +299,10 @@ do { >> \ >> if (size > sizeof(x)) \ >> (x) = __get_user_bad(); \ >> switch (size) { \ >> - case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ >> - case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ >> - case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ >> - case 8: __get_user_asm2(x, ptr, retval); break; \ >> + case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; >> \ >> + case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; >> \ >> + case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; >> \ >> + case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \ >> default: (x) = __get_user_bad(); \ >> } \ >> } while (0) >>
