From: Heiko Carstens Date: Tue, 26 May 2026 05:57:02 +0000 (+0200) Subject: s390/percpu: Provide arch_this_cpu_write() implementation X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=4a9d66c6704d43124dc064dc36fbc3f32953c5b4;p=thirdparty%2Fkernel%2Flinux.git s390/percpu: Provide arch_this_cpu_write() implementation Provide an s390 specific implementation of arch_this_cpu_write() instead of the generic variant. The generic variant uses a quite expensive raw_local_irq_save() / raw_local_irq_restore() pair. Get rid of this by providing an own variant which makes use of the new percpu code section infrastructure. With this the text size of the kernel image is reduced by ~1k (defconfig). Acked-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev --- diff --git a/arch/s390/include/asm/percpu.h b/arch/s390/include/asm/percpu.h index 83195a5dc409d..1d955dd0defa3 100644 --- a/arch/s390/include/asm/percpu.h +++ b/arch/s390/include/asm/percpu.h @@ -279,6 +279,36 @@ do { \ #define this_cpu_read_4(pcp) arch_this_cpu_read(pcp, "llgf") #define this_cpu_read_8(pcp) arch_this_cpu_read(pcp, "lg") +#define arch_this_cpu_write(pcp, val, op) \ +do { \ + unsigned long lc_pcpr, lc_pcpo; \ + typedef typeof(pcp) pcp_op_T__; \ + pcp_op_T__ *ptr__, val__ = (val); \ + \ + lc_pcpr = offsetof(struct lowcore, percpu_register); \ + lc_pcpo = offsetof(struct lowcore, percpu_offset); \ + ptr__ = PERCPU_PTR(&(pcp)); \ + asm_inline volatile( \ + MVIY_PERCPU("%[disppcpr]", "%[dispaltpcpr]", "%[ptr__]")\ + AG_ALT("%[disppcpo]", "%[dispaltpcpo]", "%[ptr__]") \ + op " %[val__],0(%[ptr__])\n" \ + MVIY_ALT("%[disppcpr]", "%[dispaltpcpr]") \ + : [ptr__] "+&a" (ptr__), "=m" (*ptr__), \ + "=m" (((struct lowcore *)0)->percpu_register) \ + : [val__] "d" (val__), \ + [disppcpr] "i" (lc_pcpr), \ + [disppcpo] "i" (lc_pcpo), \ + [dispaltpcpr] "i" (lc_pcpr + LOWCORE_ALT_ADDRESS), \ + [dispaltpcpo] "i" (lc_pcpo + LOWCORE_ALT_ADDRESS), \ + "m" (((struct lowcore *)0)->percpu_offset) \ + : "cc"); \ +} while (0) + +#define this_cpu_write_1(pcp, val) arch_this_cpu_write(pcp, val, "stc") +#define this_cpu_write_2(pcp, val) arch_this_cpu_write(pcp, val, "sth") +#define this_cpu_write_4(pcp, val) arch_this_cpu_write(pcp, val, "st") +#define this_cpu_write_8(pcp, val) arch_this_cpu_write(pcp, val, "stg") + #define arch_this_cpu_cmpxchg(pcp, oval, nval) \ ({ \ typedef typeof(pcp) pcp_op_T__; \