Messages in this thread | | | Subject | Re: [PATCH v2] powerpc/uaccess: Use flexible addressing with __put_user()/__get_user() | From | Christophe Leroy <> | Date | Mon, 29 Jun 2020 08:52:00 +0200 |
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Hi Michael,
I see this patch is marked as "defered" in patchwork, but I can't see any related discussion. Is it normal ?
Christophe
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.leroy@c-s.fr> > Reviewed-by: Segher Boessenkool <segher@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) >
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