From 012a224e1fa31fc256aab921f691598e03db6018 Mon Sep 17 00:00:00 2001 From: Nico Boehr Date: Tue, 11 Jan 2022 11:00:03 +0100 Subject: s390/uaccess: introduce bit field for OAC specifier Previously, we've used magic values to specify the OAC (operand-access control) for mvcos. Instead we introduce a bit field for it. When using a bit field, we cannot use an immediate value with K constraint anymore, since GCC older than 10 doesn't recognize the bit field union as a compile time constant. To make things work with older compilers, load the OAC value through a register. Bloat-o-meter reports a slight increase in kernel size with this change: Total: Before=15692135, After=15693015, chg +0.01% Signed-off-by: Nico Boehr Co-developed-by: Janis Schoetterl-Glausch Signed-off-by: Janis Schoetterl-Glausch Link: https://lore.kernel.org/r/20220111100003.743116-1-scgl@linux.ibm.com Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Vasily Gorbik Cc: Sven Schnelle Signed-off-by: Heiko Carstens --- arch/s390/lib/uaccess.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'arch/s390/lib') diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c index a596e69d3c47..8a5d21461889 100644 --- a/arch/s390/lib/uaccess.c +++ b/arch/s390/lib/uaccess.c @@ -62,10 +62,14 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr unsigned long size) { unsigned long tmp1, tmp2; + union oac spec = { + .oac2.as = PSW_BITS_AS_SECONDARY, + .oac2.a = 1, + }; tmp1 = -4096UL; asm volatile( - " lghi 0,%[spec]\n" + " lr 0,%[spec]\n" "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n" "6: jz 4f\n" "1: algr %0,%3\n" @@ -84,7 +88,7 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr "5:\n" EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) - : [spec] "K" (0x81UL) + : [spec] "d" (spec.val) : "cc", "memory", "0"); return size; } @@ -135,10 +139,14 @@ static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, unsigned long size) { unsigned long tmp1, tmp2; + union oac spec = { + .oac1.as = PSW_BITS_AS_SECONDARY, + .oac1.a = 1, + }; tmp1 = -4096UL; asm volatile( - " llilh 0,%[spec]\n" + " lr 0,%[spec]\n" "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n" "6: jz 4f\n" "1: algr %0,%3\n" @@ -157,7 +165,7 @@ static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, "5:\n" EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) - : [spec] "K" (0x81UL) + : [spec] "d" (spec.val) : "cc", "memory", "0"); return size; } @@ -207,10 +215,14 @@ EXPORT_SYMBOL(raw_copy_to_user); static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size) { unsigned long tmp1, tmp2; + union oac spec = { + .oac1.as = PSW_BITS_AS_SECONDARY, + .oac1.a = 1, + }; tmp1 = -4096UL; asm volatile( - " llilh 0,%[spec]\n" + " lr 0,%[spec]\n" "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n" " jz 4f\n" "1: algr %0,%2\n" @@ -228,7 +240,7 @@ static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size "5:\n" EX_TABLE(0b,2b) EX_TABLE(3b,5b) : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2) - : "a" (empty_zero_page), [spec] "K" (0x81UL) + : "a" (empty_zero_page), [spec] "d" (spec.val) : "cc", "memory", "0"); return size; } -- cgit v1.2.3