Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760604AbZAMKnP (ORCPT ); Tue, 13 Jan 2009 05:43:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757237AbZAMKja (ORCPT ); Tue, 13 Jan 2009 05:39:30 -0500 Received: from hera.kernel.org ([140.211.167.34]:51185 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753250AbZAMKj2 (ORCPT ); Tue, 13 Jan 2009 05:39:28 -0500 From: Tejun Heo To: ebiederm@xmission.com, cl@linux-foundation.org, rusty@rustcorp.com.au, mingo@elte.hu, travis@sgi.com, linux-kernel@vger.kernel.org, hpa@zytor.com, akpm@linux-foundation.org, steiner@sgi.com, hugh@veritas.com Cc: Tejun Heo Subject: [PATCH 11/13] x86_64: convert pda ops to wrappers around x86 percpu accessors Date: Tue, 13 Jan 2009 19:38:15 +0900 Message-Id: <1231843097-18003-12-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.5.6 In-Reply-To: <1231843097-18003-1-git-send-email-tj@kernel.org> References: <1231843097-18003-1-git-send-email-tj@kernel.org> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Tue, 13 Jan 2009 10:38:38 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5538 Lines: 165 pda is now a percpu variable and there's no reason it can't use plain x86 percpu accessors. Add x86_test_and_clear_bit_percpu() and replace pda op implementations with wrappers around x86 percpu accessors. Signed-off-by: Tejun Heo --- arch/x86/include/asm/pda.h | 88 +++----------------------------------- arch/x86/include/asm/percpu.h | 10 ++++ arch/x86/kernel/vmlinux_64.lds.S | 1 - arch/x86/kernel/x8664_ksyms_64.c | 2 - 4 files changed, 16 insertions(+), 85 deletions(-) diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h index 66ae104..e3d3a08 100644 --- a/arch/x86/include/asm/pda.h +++ b/arch/x86/include/asm/pda.h @@ -45,91 +45,15 @@ extern void pda_init(int); #define cpu_pda(cpu) (&per_cpu(__pda, cpu)) -/* - * There is no fast way to get the base address of the PDA, all the accesses - * have to mention %fs/%gs. So it needs to be done this Torvaldian way. - */ -extern void __bad_pda_field(void) __attribute__((noreturn)); - -/* - * proxy_pda doesn't actually exist, but tell gcc it is accessed for - * all PDA accesses so it gets read/write dependencies right. - */ -extern struct x8664_pda _proxy_pda; - -#define pda_offset(field) offsetof(struct x8664_pda, field) - -#define pda_to_op(op, field, val) \ -do { \ - typedef typeof(_proxy_pda.field) T__; \ - if (0) { T__ tmp__; tmp__ = (val); } /* type checking */ \ - switch (sizeof(_proxy_pda.field)) { \ - case 2: \ - asm(op "w %1,%%gs:%c2" : \ - "+m" (_proxy_pda.field) : \ - "ri" ((T__)val), \ - "i"(pda_offset(field))); \ - break; \ - case 4: \ - asm(op "l %1,%%gs:%c2" : \ - "+m" (_proxy_pda.field) : \ - "ri" ((T__)val), \ - "i" (pda_offset(field))); \ - break; \ - case 8: \ - asm(op "q %1,%%gs:%c2": \ - "+m" (_proxy_pda.field) : \ - "r" ((T__)val), \ - "i"(pda_offset(field))); \ - break; \ - default: \ - __bad_pda_field(); \ - } \ -} while (0) - -#define pda_from_op(op, field) \ -({ \ - typeof(_proxy_pda.field) ret__; \ - switch (sizeof(_proxy_pda.field)) { \ - case 2: \ - asm(op "w %%gs:%c1,%0" : \ - "=r" (ret__) : \ - "i" (pda_offset(field)), \ - "m" (_proxy_pda.field)); \ - break; \ - case 4: \ - asm(op "l %%gs:%c1,%0": \ - "=r" (ret__): \ - "i" (pda_offset(field)), \ - "m" (_proxy_pda.field)); \ - break; \ - case 8: \ - asm(op "q %%gs:%c1,%0": \ - "=r" (ret__) : \ - "i" (pda_offset(field)), \ - "m" (_proxy_pda.field)); \ - break; \ - default: \ - __bad_pda_field(); \ - } \ - ret__; \ -}) - -#define read_pda(field) pda_from_op("mov", field) -#define write_pda(field, val) pda_to_op("mov", field, val) -#define add_pda(field, val) pda_to_op("add", field, val) -#define sub_pda(field, val) pda_to_op("sub", field, val) -#define or_pda(field, val) pda_to_op("or", field, val) +#define read_pda(field) x86_read_percpu(__pda.field) +#define write_pda(field, val) x86_write_percpu(__pda.field, val) +#define add_pda(field, val) x86_add_percpu(__pda.field, val) +#define sub_pda(field, val) x86_sub_percpu(__pda.field, val) +#define or_pda(field, val) x86_or_percpu(__pda.field, val) /* This is not atomic against other CPUs -- CPU preemption needs to be off */ #define test_and_clear_bit_pda(bit, field) \ -({ \ - int old__; \ - asm volatile("btr %2,%%gs:%c3\n\tsbbl %0,%0" \ - : "=r" (old__), "+m" (_proxy_pda.field) \ - : "dIr" (bit), "i" (pda_offset(field)) : "memory");\ - old__; \ -}) + x86_test_and_clear_bit_percpu(bit, __pda.field) #endif diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 556f84b..328b31a 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -121,6 +121,16 @@ do { \ #define x86_sub_percpu(var, val) percpu_to_op("sub", per_cpu__##var, val) #define x86_or_percpu(var, val) percpu_to_op("or", per_cpu__##var, val) +/* This is not atomic against other CPUs -- CPU preemption needs to be off */ +#define x86_test_and_clear_bit_percpu(bit, var) \ +({ \ + int old__; \ + asm volatile("btr %1,"__percpu_seg_str"%c2\n\tsbbl %0,%0" \ + : "=r" (old__) \ + : "dIr" (bit), "i" (&per_cpu__##var) : "memory"); \ + old__; \ +}) + #ifdef CONFIG_X86_64 extern void load_pda_offset(int cpu); #else diff --git a/arch/x86/kernel/vmlinux_64.lds.S b/arch/x86/kernel/vmlinux_64.lds.S index d2a0baa..a09abb8 100644 --- a/arch/x86/kernel/vmlinux_64.lds.S +++ b/arch/x86/kernel/vmlinux_64.lds.S @@ -14,7 +14,6 @@ OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64") OUTPUT_ARCH(i386:x86-64) ENTRY(phys_startup_64) jiffies_64 = jiffies; -_proxy_pda = 1; PHDRS { text PT_LOAD FLAGS(5); /* R_E */ data PT_LOAD FLAGS(7); /* RWE */ diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index 695e426..3909e3b 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -58,5 +58,3 @@ EXPORT_SYMBOL(__memcpy); EXPORT_SYMBOL(empty_zero_page); EXPORT_SYMBOL(init_level4_pgt); EXPORT_SYMBOL(load_gs_index); - -EXPORT_SYMBOL(_proxy_pda); -- 1.5.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/