From patchwork Mon May 5 16:45:47 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Christoph Lameter (Ampere)" X-Patchwork-Id: 4116071 Return-Path: X-Original-To: patchwork-linux-sh@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 1C1EF9F23C for ; Mon, 5 May 2014 16:51:58 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0638C2021A for ; Mon, 5 May 2014 16:51:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD2FF20225 for ; Mon, 5 May 2014 16:51:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753968AbaEEQvz (ORCPT ); Mon, 5 May 2014 12:51:55 -0400 Received: from qmta03.emeryville.ca.mail.comcast.net ([76.96.30.32]:42373 "EHLO qmta03.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754342AbaEEQvy (ORCPT ); Mon, 5 May 2014 12:51:54 -0400 X-Greylist: delayed 365 seconds by postgrey-1.27 at vger.kernel.org; Mon, 05 May 2014 12:51:54 EDT Received: from omta20.emeryville.ca.mail.comcast.net ([76.96.30.87]) by qmta03.emeryville.ca.mail.comcast.net with comcast id yDc51n0041smiN4A3GlpiR; Mon, 05 May 2014 16:45:49 +0000 Received: from gentwo.org ([98.213.233.247]) by omta20.emeryville.ca.mail.comcast.net with comcast id yGln1n00g5Lw0ES8gGloQl; Mon, 05 May 2014 16:45:49 +0000 Received: by gentwo.org (Postfix, from userid 1001) id 3CECD3F9D; Mon, 5 May 2014 11:45:47 -0500 (CDT) Received: from localhost (localhost [127.0.0.1]) by gentwo.org (Postfix) with ESMTP id 38AA067A; Mon, 5 May 2014 11:45:47 -0500 (CDT) Date: Mon, 5 May 2014 11:45:47 -0500 (CDT) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: lethal@linux-sh.org cc: linux-sh@vger.kernel.org Subject: sh: Replace __get_cpu_var uses Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20140121; t=1399308349; bh=ccaA2yZ/zTp9fmAeU24Dk0tZc/SJUYhBW64Tx5ZXP88=; h=Received:Received:Received:Received:Date:From:To:Subject: Message-ID:Content-Type; b=BlZhcY/AOmdWtUgV7Z6bBqIc1OhkoLLdBvkfZWuOiN0pJFNHXEnB3ECIkSfc8fJtD f3u/lEND6KcEWyo+PAkd+6TBfPtYO1PK2zbdCRhk0suyZNers5pBI/5/TvRfJ2RVU6 2V0svq+zU6BYpfvD1zzioDYmZjgEpGnoWyZLUXQpDsmiGsr8IS3TnGEG//VWUc5JZ9 JEkK0scfoq39A3BBkuJ4EqZk4a1jvQzP7J2NbRMXBKJHrVvFe7mQZQQb8Awgyo/AB/ tvkFt2POTwW49CNzvFuYppR7M0kxNXZ3hJ3NSi++c8ihWHAHIUSYmuJKzMrDmU2YuG nPEbPRVdtBx6g== Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Could you see if this compiles and works? No sh build environment here. __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : #define __get_cpu_var(var) (*this_cpu_ptr(&(var))) __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Signed-off-by: Christoph Lameter --- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: linux/arch/sh/kernel/hw_breakpoint.c =================================================================== --- linux.orig/arch/sh/kernel/hw_breakpoint.c 2014-02-25 13:26:10.850735155 -0600 +++ linux/arch/sh/kernel/hw_breakpoint.c 2014-02-25 13:26:10.850735155 -0600 @@ -52,7 +52,7 @@ int i; for (i = 0; i < sh_ubc->num_events; i++) { - struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]); + struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]); if (!*slot) { *slot = bp; @@ -84,7 +84,7 @@ int i; for (i = 0; i < sh_ubc->num_events; i++) { - struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]); + struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]); if (*slot == bp) { *slot = NULL; Index: linux/arch/sh/kernel/kprobes.c =================================================================== --- linux.orig/arch/sh/kernel/kprobes.c 2014-02-25 13:26:10.850735155 -0600 +++ linux/arch/sh/kernel/kprobes.c 2014-02-25 13:26:10.850735155 -0600 @@ -102,7 +102,7 @@ void __kprobes arch_remove_kprobe(struct kprobe *p) { - struct kprobe *saved = &__get_cpu_var(saved_next_opcode); + struct kprobe *saved = this_cpu_ptr(&saved_next_opcode); if (saved->addr) { arch_disarm_kprobe(p); @@ -111,7 +111,7 @@ saved->addr = NULL; saved->opcode = 0; - saved = &__get_cpu_var(saved_next_opcode2); + saved = this_cpu_ptr(&saved_next_opcode2); if (saved->addr) { arch_disarm_kprobe(saved); @@ -129,14 +129,14 @@ static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) { - __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; + __this_cpu_write(current_kprobe, kcb->prev_kprobe.kp); kcb->kprobe_status = kcb->prev_kprobe.status; } static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { - __get_cpu_var(current_kprobe) = p; + __this_cpu_write(current_kprobe, p); } /* @@ -146,15 +146,15 @@ */ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) { - __get_cpu_var(saved_current_opcode).addr = (kprobe_opcode_t *)regs->pc; + __this_cpu_write(saved_current_opcode.addr, (kprobe_opcode_t *)regs->pc); if (p != NULL) { struct kprobe *op1, *op2; arch_disarm_kprobe(p); - op1 = &__get_cpu_var(saved_next_opcode); - op2 = &__get_cpu_var(saved_next_opcode2); + op1 = this_cpu_ptr(&saved_next_opcode); + op2 = this_cpu_ptr(&saved_next_opcode2); if (OPCODE_JSR(p->opcode) || OPCODE_JMP(p->opcode)) { unsigned int reg_nr = ((p->opcode >> 8) & 0x000F); @@ -249,7 +249,7 @@ kcb->kprobe_status = KPROBE_REENTER; return 1; } else { - p = __get_cpu_var(current_kprobe); + p = __this_cpu_read(current_kprobe); if (p->break_handler && p->break_handler(p, regs)) { goto ss_probe; } @@ -336,9 +336,9 @@ continue; if (ri->rp && ri->rp->handler) { - __get_cpu_var(current_kprobe) = &ri->rp->kp; + __this_cpu_write(current_kprobe, &ri->rp->kp); ri->rp->handler(ri, regs); - __get_cpu_var(current_kprobe) = NULL; + __this_cpu_write(current_kprobe, NULL); } orig_ret_address = (unsigned long)ri->ret_addr; @@ -383,19 +383,19 @@ cur->post_handler(cur, regs, 0); } - p = &__get_cpu_var(saved_next_opcode); + p = this_cpu_ptr(&saved_next_opcode); if (p->addr) { arch_disarm_kprobe(p); p->addr = NULL; p->opcode = 0; - addr = __get_cpu_var(saved_current_opcode).addr; - __get_cpu_var(saved_current_opcode).addr = NULL; + addr = __this_cpu_read(saved_current_opcode.addr); + __this_cpu_write(saved_current_opcode.addr, NULL); p = get_kprobe(addr); arch_arm_kprobe(p); - p = &__get_cpu_var(saved_next_opcode2); + p = this_cpu_ptr(&saved_next_opcode2); if (p->addr) { arch_disarm_kprobe(p); p->addr = NULL; @@ -511,7 +511,7 @@ if (kprobe_handler(args->regs)) { ret = NOTIFY_STOP; } else { - p = __get_cpu_var(current_kprobe); + p = __this_cpu_read(current_kprobe); if (p->break_handler && p->break_handler(p, args->regs)) ret = NOTIFY_STOP; Index: linux/arch/sh/kernel/localtimer.c =================================================================== --- linux.orig/arch/sh/kernel/localtimer.c 2014-02-25 13:26:10.850735155 -0600 +++ linux/arch/sh/kernel/localtimer.c 2014-02-25 13:26:10.850735155 -0600 @@ -32,7 +32,7 @@ */ void local_timer_interrupt(void) { - struct clock_event_device *clk = &__get_cpu_var(local_clockevent); + struct clock_event_device *clk = this_cpu_ptr(&local_clockevent); irq_enter(); clk->event_handler(clk); Index: linux/arch/sh/kernel/perf_event.c =================================================================== --- linux.orig/arch/sh/kernel/perf_event.c 2014-02-25 13:26:10.850735155 -0600 +++ linux/arch/sh/kernel/perf_event.c 2014-02-25 13:26:10.850735155 -0600 @@ -227,7 +227,7 @@ static void sh_pmu_stop(struct perf_event *event, int flags) { - struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); struct hw_perf_event *hwc = &event->hw; int idx = hwc->idx; @@ -245,7 +245,7 @@ static void sh_pmu_start(struct perf_event *event, int flags) { - struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); struct hw_perf_event *hwc = &event->hw; int idx = hwc->idx; @@ -262,7 +262,7 @@ static void sh_pmu_del(struct perf_event *event, int flags) { - struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); sh_pmu_stop(event, PERF_EF_UPDATE); __clear_bit(event->hw.idx, cpuc->used_mask); @@ -272,7 +272,7 @@ static int sh_pmu_add(struct perf_event *event, int flags) { - struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); struct hw_perf_event *hwc = &event->hw; int idx = hwc->idx; int ret = -EAGAIN; Index: linux/arch/sh/kernel/smp.c =================================================================== --- linux.orig/arch/sh/kernel/smp.c 2014-02-25 13:26:10.850735155 -0600 +++ linux/arch/sh/kernel/smp.c 2014-02-25 13:26:10.850735155 -0600 @@ -111,7 +111,7 @@ irq_ctx_exit(raw_smp_processor_id()); mb(); - __get_cpu_var(cpu_state) = CPU_DEAD; + __this_cpu_write(cpu_state, CPU_DEAD); local_irq_disable(); }