Patches contributed by Eötvös Lorand University
commit 28e7d82d6325734c7ecd1f223b892701f7a8c171
Merge: c99dbbe9f8f6 cef30b3a84e1
Author: Ingo Molnar <mingo@elte.hu>
Date: Mon Jan 19 17:12:20 2009 +0100
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/travis/linux-2.6-cpus4096-for-ingo into cpus4096
commit 7890ba8c87604ca4c2c73f7de846bf5305d743e4
Merge: 99937d6455ce b2b062b81633
Author: Ingo Molnar <mingo@elte.hu>
Date: Mon Jan 19 12:36:09 2009 +0100
Merge branch 'stackprotector' into core/percpu
commit 4092762aebfe55c1f8e31440b80a053c2dbe519b
Merge: 745b1626dd71 1de9e8e70f5a
Author: Ingo Molnar <mingo@elte.hu>
Date: Sun Jan 18 20:15:05 2009 +0100
Merge branch 'tracing/ftrace'; commit 'v2.6.29-rc2' into tracing/core
commit 5662a2f8e7313f78d6b17ab383f3e4f04971c335
Author: Ingo Molnar <mingo@elte.hu>
Date: Sun Jan 18 19:37:21 2009 +0100
x86, rdc321x: remove/move leftover files
Impact: cleanup
Move/remove leftover RDC321 files. Now that it's not a subarch anymore,
arch/x86/mach-rdc321x and arch/x86/include/asm/mach-rdc321x/ are not
needed.
One include file was still in use: rdc321x_defs.h, move that to the
generic x86 asm header directory.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/mach-rdc321x/gpio.h b/arch/x86/include/asm/mach-rdc321x/gpio.h
deleted file mode 100644
index c210ab5788b0..000000000000
--- a/arch/x86/include/asm/mach-rdc321x/gpio.h
+++ /dev/null
@@ -1,60 +0,0 @@
-#ifndef _ASM_X86_MACH_RDC321X_GPIO_H
-#define _ASM_X86_MACH_RDC321X_GPIO_H
-
-#include <linux/kernel.h>
-
-extern int rdc_gpio_get_value(unsigned gpio);
-extern void rdc_gpio_set_value(unsigned gpio, int value);
-extern int rdc_gpio_direction_input(unsigned gpio);
-extern int rdc_gpio_direction_output(unsigned gpio, int value);
-extern int rdc_gpio_request(unsigned gpio, const char *label);
-extern void rdc_gpio_free(unsigned gpio);
-extern void __init rdc321x_gpio_setup(void);
-
-/* Wrappers for the arch-neutral GPIO API */
-
-static inline int gpio_request(unsigned gpio, const char *label)
-{
- return rdc_gpio_request(gpio, label);
-}
-
-static inline void gpio_free(unsigned gpio)
-{
- might_sleep();
- rdc_gpio_free(gpio);
-}
-
-static inline int gpio_direction_input(unsigned gpio)
-{
- return rdc_gpio_direction_input(gpio);
-}
-
-static inline int gpio_direction_output(unsigned gpio, int value)
-{
- return rdc_gpio_direction_output(gpio, value);
-}
-
-static inline int gpio_get_value(unsigned gpio)
-{
- return rdc_gpio_get_value(gpio);
-}
-
-static inline void gpio_set_value(unsigned gpio, int value)
-{
- rdc_gpio_set_value(gpio, value);
-}
-
-static inline int gpio_to_irq(unsigned gpio)
-{
- return gpio;
-}
-
-static inline int irq_to_gpio(unsigned irq)
-{
- return irq;
-}
-
-/* For cansleep */
-#include <asm-generic/gpio.h>
-
-#endif /* _ASM_X86_MACH_RDC321X_GPIO_H */
diff --git a/arch/x86/include/asm/mach-rdc321x/rdc321x_defs.h b/arch/x86/include/asm/rdc321x_defs.h
similarity index 100%
rename from arch/x86/include/asm/mach-rdc321x/rdc321x_defs.h
rename to arch/x86/include/asm/rdc321x_defs.h
diff --git a/arch/x86/mach-rdc321x/Makefile b/arch/x86/mach-rdc321x/Makefile
deleted file mode 100644
index 8325b4ca431c..000000000000
--- a/arch/x86/mach-rdc321x/Makefile
+++ /dev/null
@@ -1,5 +0,0 @@
-#
-# Makefile for the RDC321x specific parts of the kernel
-#
-obj-$(CONFIG_X86_RDC321X) := gpio.o platform.o
-
diff --git a/arch/x86/mach-rdc321x/gpio.c b/arch/x86/mach-rdc321x/gpio.c
deleted file mode 100644
index 247f33d3a407..000000000000
--- a/arch/x86/mach-rdc321x/gpio.c
+++ /dev/null
@@ -1,194 +0,0 @@
-/*
- * GPIO support for RDC SoC R3210/R8610
- *
- * Copyright (C) 2007, Florian Fainelli <florian@openwrt.org>
- * Copyright (C) 2008, Volker Weiss <dev@tintuc.de>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- */
-
-
-#include <linux/spinlock.h>
-#include <linux/io.h>
-#include <linux/types.h>
-#include <linux/module.h>
-
-#include <asm/gpio.h>
-#include <asm/mach-rdc321x/rdc321x_defs.h>
-
-
-/* spin lock to protect our private copy of GPIO data register plus
- the access to PCI conf registers. */
-static DEFINE_SPINLOCK(gpio_lock);
-
-/* copy of GPIO data registers */
-static u32 gpio_data_reg1;
-static u32 gpio_data_reg2;
-
-static u32 gpio_request_data[2];
-
-
-static inline void rdc321x_conf_write(unsigned addr, u32 value)
-{
- outl((1 << 31) | (7 << 11) | addr, RDC3210_CFGREG_ADDR);
- outl(value, RDC3210_CFGREG_DATA);
-}
-
-static inline void rdc321x_conf_or(unsigned addr, u32 value)
-{
- outl((1 << 31) | (7 << 11) | addr, RDC3210_CFGREG_ADDR);
- value |= inl(RDC3210_CFGREG_DATA);
- outl(value, RDC3210_CFGREG_DATA);
-}
-
-static inline u32 rdc321x_conf_read(unsigned addr)
-{
- outl((1 << 31) | (7 << 11) | addr, RDC3210_CFGREG_ADDR);
-
- return inl(RDC3210_CFGREG_DATA);
-}
-
-/* configure pin as GPIO */
-static void rdc321x_configure_gpio(unsigned gpio)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&gpio_lock, flags);
- rdc321x_conf_or(gpio < 32
- ? RDC321X_GPIO_CTRL_REG1 : RDC321X_GPIO_CTRL_REG2,
- 1 << (gpio & 0x1f));
- spin_unlock_irqrestore(&gpio_lock, flags);
-}
-
-/* initially setup the 2 copies of the gpio data registers.
- This function must be called by the platform setup code. */
-void __init rdc321x_gpio_setup()
-{
- /* this might not be, what others (BIOS, bootloader, etc.)
- wrote to these registers before, but it's a good guess. Still
- better than just using 0xffffffff. */
-
- gpio_data_reg1 = rdc321x_conf_read(RDC321X_GPIO_DATA_REG1);
- gpio_data_reg2 = rdc321x_conf_read(RDC321X_GPIO_DATA_REG2);
-}
-
-/* determine, if gpio number is valid */
-static inline int rdc321x_is_gpio(unsigned gpio)
-{
- return gpio <= RDC321X_MAX_GPIO;
-}
-
-/* request GPIO */
-int rdc_gpio_request(unsigned gpio, const char *label)
-{
- unsigned long flags;
-
- if (!rdc321x_is_gpio(gpio))
- return -EINVAL;
-
- spin_lock_irqsave(&gpio_lock, flags);
- if (gpio_request_data[(gpio & 0x20) ? 1 : 0] & (1 << (gpio & 0x1f)))
- goto inuse;
- gpio_request_data[(gpio & 0x20) ? 1 : 0] |= (1 << (gpio & 0x1f));
- spin_unlock_irqrestore(&gpio_lock, flags);
-
- return 0;
-inuse:
- spin_unlock_irqrestore(&gpio_lock, flags);
- return -EINVAL;
-}
-EXPORT_SYMBOL(rdc_gpio_request);
-
-/* release previously-claimed GPIO */
-void rdc_gpio_free(unsigned gpio)
-{
- unsigned long flags;
-
- if (!rdc321x_is_gpio(gpio))
- return;
-
- spin_lock_irqsave(&gpio_lock, flags);
- gpio_request_data[(gpio & 0x20) ? 1 : 0] &= ~(1 << (gpio & 0x1f));
- spin_unlock_irqrestore(&gpio_lock, flags);
-}
-EXPORT_SYMBOL(rdc_gpio_free);
-
-/* read GPIO pin */
-int rdc_gpio_get_value(unsigned gpio)
-{
- u32 reg;
- unsigned long flags;
-
- spin_lock_irqsave(&gpio_lock, flags);
- reg = rdc321x_conf_read(gpio < 32
- ? RDC321X_GPIO_DATA_REG1 : RDC321X_GPIO_DATA_REG2);
- spin_unlock_irqrestore(&gpio_lock, flags);
-
- return (1 << (gpio & 0x1f)) & reg ? 1 : 0;
-}
-EXPORT_SYMBOL(rdc_gpio_get_value);
-
-/* set GPIO pin to value */
-void rdc_gpio_set_value(unsigned gpio, int value)
-{
- unsigned long flags;
- u32 reg;
-
- reg = 1 << (gpio & 0x1f);
- if (gpio < 32) {
- spin_lock_irqsave(&gpio_lock, flags);
- if (value)
- gpio_data_reg1 |= reg;
- else
- gpio_data_reg1 &= ~reg;
- rdc321x_conf_write(RDC321X_GPIO_DATA_REG1, gpio_data_reg1);
- spin_unlock_irqrestore(&gpio_lock, flags);
- } else {
- spin_lock_irqsave(&gpio_lock, flags);
- if (value)
- gpio_data_reg2 |= reg;
- else
- gpio_data_reg2 &= ~reg;
- rdc321x_conf_write(RDC321X_GPIO_DATA_REG2, gpio_data_reg2);
- spin_unlock_irqrestore(&gpio_lock, flags);
- }
-}
-EXPORT_SYMBOL(rdc_gpio_set_value);
-
-/* configure GPIO pin as input */
-int rdc_gpio_direction_input(unsigned gpio)
-{
- if (!rdc321x_is_gpio(gpio))
- return -EINVAL;
-
- rdc321x_configure_gpio(gpio);
-
- return 0;
-}
-EXPORT_SYMBOL(rdc_gpio_direction_input);
-
-/* configure GPIO pin as output and set value */
-int rdc_gpio_direction_output(unsigned gpio, int value)
-{
- if (!rdc321x_is_gpio(gpio))
- return -EINVAL;
-
- gpio_set_value(gpio, value);
- rdc321x_configure_gpio(gpio);
-
- return 0;
-}
-EXPORT_SYMBOL(rdc_gpio_direction_output);
diff --git a/arch/x86/mach-rdc321x/platform.c b/arch/x86/mach-rdc321x/platform.c
deleted file mode 100644
index 4f4e50c3ad3b..000000000000
--- a/arch/x86/mach-rdc321x/platform.c
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Generic RDC321x platform devices
- *
- * Copyright (C) 2007 Florian Fainelli <florian@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the
- * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- * Boston, MA 02110-1301, USA.
- *
- */
-
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/list.h>
-#include <linux/device.h>
-#include <linux/platform_device.h>
-#include <linux/leds.h>
-
-#include <asm/gpio.h>
-
-/* LEDS */
-static struct gpio_led default_leds[] = {
- { .name = "rdc:dmz", .gpio = 1, },
-};
-
-static struct gpio_led_platform_data rdc321x_led_data = {
- .num_leds = ARRAY_SIZE(default_leds),
- .leds = default_leds,
-};
-
-static struct platform_device rdc321x_leds = {
- .name = "leds-gpio",
- .id = -1,
- .dev = {
- .platform_data = &rdc321x_led_data,
- }
-};
-
-/* Watchdog */
-static struct platform_device rdc321x_wdt = {
- .name = "rdc321x-wdt",
- .id = -1,
- .num_resources = 0,
-};
-
-static struct platform_device *rdc321x_devs[] = {
- &rdc321x_leds,
- &rdc321x_wdt
-};
-
-static int __init rdc_board_setup(void)
-{
- rdc321x_gpio_setup();
-
- return platform_add_devices(rdc321x_devs, ARRAY_SIZE(rdc321x_devs));
-}
-
-arch_initcall(rdc_board_setup);
diff --git a/drivers/watchdog/rdc321x_wdt.c b/drivers/watchdog/rdc321x_wdt.c
index bf92802f2bbe..36e221beedcd 100644
--- a/drivers/watchdog/rdc321x_wdt.c
+++ b/drivers/watchdog/rdc321x_wdt.c
@@ -37,7 +37,7 @@
#include <linux/io.h>
#include <linux/uaccess.h>
-#include <asm/mach-rdc321x/rdc321x_defs.h>
+#include <asm/rdc321x_defs.h>
#define RDC_WDT_MASK 0x80000000 /* Mask */
#define RDC_WDT_EN 0x00800000 /* Enable bit */
commit b2b062b8163391c42b3219d466ca1ac9742b9c7b
Merge: a9de18eb761f 99937d6455ce
Author: Ingo Molnar <mingo@elte.hu>
Date: Sun Jan 18 18:37:14 2009 +0100
Merge branch 'core/percpu' into stackprotector
Conflicts:
arch/x86/include/asm/pda.h
arch/x86/include/asm/system.h
Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --cc arch/x86/include/asm/pda.h
index 3fea2fdb3302,c31ca048a901..5976cd803e9a
--- a/arch/x86/include/asm/pda.h
+++ b/arch/x86/include/asm/pda.h
@@@ -9,114 -11,30 +11,28 @@@
/* Per processor datastructure. %gs points to it while the kernel runs */
struct x8664_pda {
- struct task_struct *pcurrent; /* 0 Current process */
- unsigned long data_offset; /* 8 Per cpu data offset from linker
- address */
- unsigned long kernelstack; /* 16 top of kernel stack for current */
- unsigned long oldrsp; /* 24 user rsp for system call */
- int irqcount; /* 32 Irq nesting counter. Starts -1 */
- unsigned int cpunumber; /* 36 Logical CPU number */
+ unsigned long unused1;
+ unsigned long unused2;
+ unsigned long unused3;
+ unsigned long unused4;
+ int unused5;
+ unsigned int unused6; /* 36 was cpunumber */
-#ifdef CONFIG_CC_STACKPROTECTOR
unsigned long stack_canary; /* 40 stack canary value */
/* gcc-ABI: this canary MUST be at
offset 40!!! */
- char *irqstackptr;
- short nodenumber; /* number of current node (32k max) */
-#endif
short in_bootmem; /* pda lives in bootmem */
- unsigned int __softirq_pending;
- unsigned int __nmi_count; /* number of NMI on this CPUs */
- short mmu_state;
- short isidle;
- struct mm_struct *active_mm;
- unsigned apic_timer_irqs;
- unsigned irq0_irqs;
- unsigned irq_resched_count;
- unsigned irq_call_count;
- unsigned irq_tlb_count;
- unsigned irq_thermal_count;
- unsigned irq_threshold_count;
- unsigned irq_spurious_count;
} ____cacheline_aligned_in_smp;
- extern struct x8664_pda **_cpu_pda;
+ DECLARE_PER_CPU(struct x8664_pda, __pda);
extern void pda_init(int);
- #define cpu_pda(i) (_cpu_pda[i])
+ #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) : \
- "ri" ((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) percpu_read(__pda.field)
+ #define write_pda(field, val) percpu_write(__pda.field, val)
+ #define add_pda(field, val) percpu_add(__pda.field, val)
+ #define sub_pda(field, val) percpu_sub(__pda.field, val)
+ #define or_pda(field, val) percpu_or(__pda.field, val)
/* This is not atomic against other CPUs -- CPU preemption needs to be off */
#define test_and_clear_bit_pda(bit, field) \
@@@ -130,8 -42,4 +40,6 @@@
#endif
- #define PDA_STACKOFFSET (5*8)
-
+#define refresh_stack_canary() write_pda(stack_canary, current->stack_canary)
+
#endif /* _ASM_X86_PDA_H */
diff --cc arch/x86/include/asm/stackprotector.h
index 3baf7ad89be1,000000000000..c7f0d10bae7b
mode 100644,000000..100644
--- a/arch/x86/include/asm/stackprotector.h
+++ b/arch/x86/include/asm/stackprotector.h
@@@ -1,38 -1,0 +1,39 @@@
+#ifndef _ASM_STACKPROTECTOR_H
+#define _ASM_STACKPROTECTOR_H 1
+
+#include <asm/tsc.h>
++#include <asm/pda.h>
+
+/*
+ * Initialize the stackprotector canary value.
+ *
+ * NOTE: this must only be called from functions that never return,
+ * and it must always be inlined.
+ */
+static __always_inline void boot_init_stack_canary(void)
+{
+ u64 canary;
+ u64 tsc;
+
+ /*
+ * If we're the non-boot CPU, nothing set the PDA stack
+ * canary up for us - and if we are the boot CPU we have
+ * a 0 stack canary. This is a good place for updating
+ * it, as we wont ever return from this function (so the
+ * invalid canaries already on the stack wont ever
+ * trigger).
+ *
+ * We both use the random pool and the current TSC as a source
+ * of randomness. The TSC only matters for very early init,
+ * there it already has some randomness on most systems. Later
+ * on during the bootup the random pool has true entropy too.
+ */
+ get_random_bytes(&canary, sizeof(canary));
+ tsc = __native_read_tsc();
+ canary += tsc + (tsc << 32UL);
+
+ current->stack_canary = canary;
+ write_pda(stack_canary, canary);
+}
+
+#endif
diff --cc arch/x86/include/asm/system.h
index 2f6340a44291,d1dc27dba36d..8cadfe9b1194
--- a/arch/x86/include/asm/system.h
+++ b/arch/x86/include/asm/system.h
@@@ -94,9 -94,7 +94,9 @@@ do {
"call __switch_to\n\t" \
".globl thread_return\n" \
"thread_return:\n\t" \
- "movq %%gs:%P[pda_pcurrent],%%rsi\n\t" \
+ "movq "__percpu_arg([current_task])",%%rsi\n\t" \
+ "movq %P[task_canary](%%rsi),%%r8\n\t" \
+ "movq %%r8,%%gs:%P[pda_canary]\n\t" \
"movq %P[thread_info](%%rsi),%%r8\n\t" \
LOCK_PREFIX "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \
"movq %%rax,%%rdi\n\t" \
@@@ -108,9 -106,7 +108,9 @@@
[ti_flags] "i" (offsetof(struct thread_info, flags)), \
[tif_fork] "i" (TIF_FORK), \
[thread_info] "i" (offsetof(struct task_struct, stack)), \
- [current_task] "m" (per_cpu_var(current_task)) \
+ [task_canary] "i" (offsetof(struct task_struct, stack_canary)),\
- [pda_pcurrent] "i" (offsetof(struct x8664_pda, pcurrent)), \
++ [current_task] "m" (per_cpu_var(current_task)), \
+ [pda_canary] "i" (offsetof(struct x8664_pda, stack_canary))\
: "memory", "cc" __EXTRA_CLOBBER)
#endif
diff --cc arch/x86/kernel/process_64.c
index efb0396e19bf,4523ff88a69d..aa89eabf09e0
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@@ -625,14 -619,15 +631,14 @@@ __switch_to(struct task_struct *prev_p
/*
* Switch the PDA and FPU contexts.
*/
- prev->usersp = read_pda(oldrsp);
- write_pda(oldrsp, next->usersp);
- write_pda(pcurrent, next_p);
+ prev->usersp = percpu_read(old_rsp);
+ percpu_write(old_rsp, next->usersp);
+ percpu_write(current_task, next_p);
- write_pda(kernelstack,
+ percpu_write(kernel_stack,
(unsigned long)task_stack_page(next_p) +
- THREAD_SIZE - PDA_STACKOFFSET);
+ THREAD_SIZE - KERNEL_STACK_OFFSET);
#ifdef CONFIG_CC_STACKPROTECTOR
- write_pda(stack_canary, next_p->stack_canary);
/*
* Build time only check to make sure the stack_canary is at
* offset 40 in the pda; this is a gcc ABI requirement
diff --cc init/main.c
index 07da4dea50c3,844209453c02..bfe4fb0c9842
--- a/init/main.c
+++ b/init/main.c
@@@ -561,15 -537,8 +538,14 @@@ asmlinkage void __init start_kernel(voi
* Need to run as early as possible, to initialize the
* lockdep hash:
*/
- unwind_init();
lockdep_init();
debug_objects_early_init();
+
+ /*
+ * Set up the the initial canary ASAP:
+ */
+ boot_init_stack_canary();
+
cgroup_init_early();
local_irq_disable();
commit af37501c792107c2bde1524bdae38d9a247b841a
Merge: d859e29fe34c 99937d6455ce
Author: Ingo Molnar <mingo@elte.hu>
Date: Sun Jan 18 18:15:49 2009 +0100
Merge branch 'core/percpu' into perfcounters/core
Conflicts:
arch/x86/include/asm/pda.h
We merge tip/core/percpu into tip/perfcounters/core because of a
semantic and contextual conflict: the former eliminates the PDA,
while the latter extends it with apic_perf_irqs field.
Resolve the conflict by moving the new field to the irq_cpustat
structure on 64-bit too.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --cc arch/x86/include/asm/hardirq_64.h
index b5a6b5d56704,a65bab20f6ce..42930b279215
--- a/arch/x86/include/asm/hardirq_64.h
+++ b/arch/x86/include/asm/hardirq_64.h
@@@ -3,9 -3,23 +3,24 @@@
#include <linux/threads.h>
#include <linux/irq.h>
- #include <asm/pda.h>
#include <asm/apic.h>
+ typedef struct {
+ unsigned int __softirq_pending;
+ unsigned int __nmi_count; /* arch dependent */
+ unsigned int apic_timer_irqs; /* arch dependent */
++ unsigned int apic_perf_irqs; /* arch dependent */
+ unsigned int irq0_irqs;
+ unsigned int irq_resched_count;
+ unsigned int irq_call_count;
+ unsigned int irq_tlb_count;
+ unsigned int irq_thermal_count;
+ unsigned int irq_spurious_count;
+ unsigned int irq_threshold_count;
+ } ____cacheline_aligned irq_cpustat_t;
+
+ DECLARE_PER_CPU(irq_cpustat_t, irq_stat);
+
/* We can have at most NR_VECTORS irqs routed to a cpu at a time */
#define MAX_HARDIRQS_PER_CPU NR_VECTORS
commit 99937d6455cea95405ac681c86a857d0fcd530bd
Merge: 74e7904559a1 87b264065880
Author: Ingo Molnar <mingo@elte.hu>
Date: Sun Jan 18 17:41:32 2009 +0100
Merge branch 'tj-percpu' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into core/percpu
commit 74296a8ed6aa3c5bf672808ada690de7ba323ecc
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Jan 16 17:43:50 2009 +0100
irq: provide debug_poll_all_shared_irqs() method under CONFIG_DEBUG_SHIRQ
Provide a shared interrupt debug facility under CONFIG_DEBUG_SHIRQ:
it uses the existing irqpoll facilities to iterate through all
registered interrupt handlers and call those which can handle shared
IRQ lines.
This can be handy for suspend/resume debugging: if we call this function
early during resume we can trigger crashes in those drivers which have
incorrect assumptions about when exactly their ISRs will be called
during suspend/resume.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 9127f6b51a39..468e3a25a4a1 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -462,6 +462,12 @@ static inline void init_irq_proc(void)
}
#endif
+#if defined(CONFIG_GENERIC_HARDIRQS) && defined(CONFIG_DEBUG_SHIRQ)
+extern void debug_poll_all_shared_irqs(void);
+#else
+static inline void debug_poll_all_shared_irqs(void) { }
+#endif
+
int show_interrupts(struct seq_file *p, void *v);
struct irq_desc;
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index dd364c11e56e..4d568294de3e 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -104,7 +104,7 @@ static int misrouted_irq(int irq)
return ok;
}
-static void poll_spurious_irqs(unsigned long dummy)
+static void poll_all_shared_irqs(void)
{
struct irq_desc *desc;
int i;
@@ -123,11 +123,23 @@ static void poll_spurious_irqs(unsigned long dummy)
try_one_irq(i, desc);
}
+}
+
+static void poll_spurious_irqs(unsigned long dummy)
+{
+ poll_all_shared_irqs();
mod_timer(&poll_spurious_irq_timer,
jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
}
+#ifdef CONFIG_DEBUG_SHIRQ
+void debug_poll_all_shared_irqs(void)
+{
+ poll_all_shared_irqs();
+}
+#endif
+
/*
* If 99,900 of the previous 100,000 interrupts have not been handled
* then assume that the IRQ is stuck in some manner. Drop a diagnostic
commit 5a2dd72abdae75ea2960145e0549635ce4e0be96
Merge: efdc64f0c792 7cb36b6ccdca
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Jan 16 17:46:22 2009 +0100
Merge branch 'linus' into irq/genirq
commit 6dbde3530850d4d8bfc1b6bd4006d92786a2787f
Author: Ingo Molnar <mingo@elte.hu>
Date: Thu Jan 15 22:15:53 2009 +0900
percpu: add optimized generic percpu accessors
It is an optimization and a cleanup, and adds the following new
generic percpu methods:
percpu_read()
percpu_write()
percpu_add()
percpu_sub()
percpu_and()
percpu_or()
percpu_xor()
and implements support for them on x86. (other architectures will fall
back to a default implementation)
The advantage is that for example to read a local percpu variable,
instead of this sequence:
return __get_cpu_var(var);
ffffffff8102ca2b: 48 8b 14 fd 80 09 74 mov -0x7e8bf680(,%rdi,8),%rdx
ffffffff8102ca32: 81
ffffffff8102ca33: 48 c7 c0 d8 59 00 00 mov $0x59d8,%rax
ffffffff8102ca3a: 48 8b 04 10 mov (%rax,%rdx,1),%rax
We can get a single instruction by using the optimized variants:
return percpu_read(var);
ffffffff8102ca3f: 65 48 8b 05 91 8f fd mov %gs:0x7efd8f91(%rip),%rax
I also cleaned up the x86-specific APIs and made the x86 code use
these new generic percpu primitives.
tj: * fixed generic percpu_sub() definition as Roel Kluin pointed out
* added percpu_and() for completeness's sake
* made generic percpu ops atomic against preemption
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/arch/x86/include/asm/current.h b/arch/x86/include/asm/current.h
index 0930b4f8d672..0728480f5c56 100644
--- a/arch/x86/include/asm/current.h
+++ b/arch/x86/include/asm/current.h
@@ -10,7 +10,7 @@ struct task_struct;
DECLARE_PER_CPU(struct task_struct *, current_task);
static __always_inline struct task_struct *get_current(void)
{
- return x86_read_percpu(current_task);
+ return percpu_read(current_task);
}
#else /* X86_32 */
diff --git a/arch/x86/include/asm/irq_regs_32.h b/arch/x86/include/asm/irq_regs_32.h
index 86afd7473457..d7ed33ee94e9 100644
--- a/arch/x86/include/asm/irq_regs_32.h
+++ b/arch/x86/include/asm/irq_regs_32.h
@@ -15,7 +15,7 @@ DECLARE_PER_CPU(struct pt_regs *, irq_regs);
static inline struct pt_regs *get_irq_regs(void)
{
- return x86_read_percpu(irq_regs);
+ return percpu_read(irq_regs);
}
static inline struct pt_regs *set_irq_regs(struct pt_regs *new_regs)
@@ -23,7 +23,7 @@ static inline struct pt_regs *set_irq_regs(struct pt_regs *new_regs)
struct pt_regs *old_regs;
old_regs = get_irq_regs();
- x86_write_percpu(irq_regs, new_regs);
+ percpu_write(irq_regs, new_regs);
return old_regs;
}
diff --git a/arch/x86/include/asm/mmu_context_32.h b/arch/x86/include/asm/mmu_context_32.h
index 7e98ce1d2c0e..08b53454f831 100644
--- a/arch/x86/include/asm/mmu_context_32.h
+++ b/arch/x86/include/asm/mmu_context_32.h
@@ -4,8 +4,8 @@
static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
#ifdef CONFIG_SMP
- if (x86_read_percpu(cpu_tlbstate.state) == TLBSTATE_OK)
- x86_write_percpu(cpu_tlbstate.state, TLBSTATE_LAZY);
+ if (percpu_read(cpu_tlbstate.state) == TLBSTATE_OK)
+ percpu_write(cpu_tlbstate.state, TLBSTATE_LAZY);
#endif
}
@@ -19,8 +19,8 @@ static inline void switch_mm(struct mm_struct *prev,
/* stop flush ipis for the previous mm */
cpu_clear(cpu, prev->cpu_vm_mask);
#ifdef CONFIG_SMP
- x86_write_percpu(cpu_tlbstate.state, TLBSTATE_OK);
- x86_write_percpu(cpu_tlbstate.active_mm, next);
+ percpu_write(cpu_tlbstate.state, TLBSTATE_OK);
+ percpu_write(cpu_tlbstate.active_mm, next);
#endif
cpu_set(cpu, next->cpu_vm_mask);
@@ -35,8 +35,8 @@ static inline void switch_mm(struct mm_struct *prev,
}
#ifdef CONFIG_SMP
else {
- x86_write_percpu(cpu_tlbstate.state, TLBSTATE_OK);
- BUG_ON(x86_read_percpu(cpu_tlbstate.active_mm) != next);
+ percpu_write(cpu_tlbstate.state, TLBSTATE_OK);
+ BUG_ON(percpu_read(cpu_tlbstate.active_mm) != next);
if (!cpu_test_and_set(cpu, next->cpu_vm_mask)) {
/* We were in lazy tlb mode and leave_mm disabled
diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h
index e3d3a081d798..47f274fe6953 100644
--- a/arch/x86/include/asm/pda.h
+++ b/arch/x86/include/asm/pda.h
@@ -45,11 +45,11 @@ extern void pda_init(int);
#define cpu_pda(cpu) (&per_cpu(__pda, cpu))
-#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)
+#define read_pda(field) percpu_read(__pda.field)
+#define write_pda(field, val) percpu_write(__pda.field, val)
+#define add_pda(field, val) percpu_add(__pda.field, val)
+#define sub_pda(field, val) percpu_sub(__pda.field, val)
+#define or_pda(field, val) percpu_or(__pda.field, val)
/* This is not atomic against other CPUs -- CPU preemption needs to be off */
#define test_and_clear_bit_pda(bit, field) \
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 328b31a429d7..03aa4b00a1c3 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -40,16 +40,11 @@
#ifdef CONFIG_SMP
#define __percpu_seg_str "%%"__stringify(__percpu_seg)":"
-#define __my_cpu_offset x86_read_percpu(this_cpu_off)
+#define __my_cpu_offset percpu_read(this_cpu_off)
#else
#define __percpu_seg_str
#endif
-#include <asm-generic/percpu.h>
-
-/* We can use this directly for local CPU (faster). */
-DECLARE_PER_CPU(unsigned long, this_cpu_off);
-
/* For arch-specific code, we can use direct single-insn ops (they
* don't give an lvalue though). */
extern void __bad_percpu_size(void);
@@ -115,11 +110,13 @@ do { \
ret__; \
})
-#define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var)
-#define x86_write_percpu(var, val) percpu_to_op("mov", per_cpu__##var, val)
-#define x86_add_percpu(var, val) percpu_to_op("add", per_cpu__##var, val)
-#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)
+#define percpu_read(var) percpu_from_op("mov", per_cpu__##var)
+#define percpu_write(var, val) percpu_to_op("mov", per_cpu__##var, val)
+#define percpu_add(var, val) percpu_to_op("add", per_cpu__##var, val)
+#define percpu_sub(var, val) percpu_to_op("sub", per_cpu__##var, val)
+#define percpu_and(var, val) percpu_to_op("and", per_cpu__##var, val)
+#define percpu_or(var, val) percpu_to_op("or", per_cpu__##var, val)
+#define percpu_xor(var, val) percpu_to_op("xor", 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) \
@@ -131,6 +128,11 @@ do { \
old__; \
})
+#include <asm-generic/percpu.h>
+
+/* We can use this directly for local CPU (faster). */
+DECLARE_PER_CPU(unsigned long, this_cpu_off);
+
#ifdef CONFIG_X86_64
extern void load_pda_offset(int cpu);
#else
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 127415402ea1..c7bbbbe65d3f 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -160,7 +160,7 @@ extern unsigned disabled_cpus __cpuinitdata;
* from the initial startup. We map APIC_BASE very early in page_setup(),
* so this is correct in the x86 case.
*/
-#define raw_smp_processor_id() (x86_read_percpu(cpu_number))
+#define raw_smp_processor_id() (percpu_read(cpu_number))
extern int safe_smp_processor_id(void);
#elif defined(CONFIG_X86_64_SMP)
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index a546f55c77b4..77d546817d94 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -591,7 +591,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
if (prev->gs | next->gs)
loadsegment(gs, next->gs);
- x86_write_percpu(current_task, next_p);
+ percpu_write(current_task, next_p);
return prev_p;
}
diff --git a/arch/x86/kernel/tlb_32.c b/arch/x86/kernel/tlb_32.c
index ec53818f4e38..e65449d0f7d9 100644
--- a/arch/x86/kernel/tlb_32.c
+++ b/arch/x86/kernel/tlb_32.c
@@ -34,8 +34,8 @@ static DEFINE_SPINLOCK(tlbstate_lock);
*/
void leave_mm(int cpu)
{
- BUG_ON(x86_read_percpu(cpu_tlbstate.state) == TLBSTATE_OK);
- cpu_clear(cpu, x86_read_percpu(cpu_tlbstate.active_mm)->cpu_vm_mask);
+ BUG_ON(percpu_read(cpu_tlbstate.state) == TLBSTATE_OK);
+ cpu_clear(cpu, percpu_read(cpu_tlbstate.active_mm)->cpu_vm_mask);
load_cr3(swapper_pg_dir);
}
EXPORT_SYMBOL_GPL(leave_mm);
@@ -103,8 +103,8 @@ void smp_invalidate_interrupt(struct pt_regs *regs)
* BUG();
*/
- if (flush_mm == x86_read_percpu(cpu_tlbstate.active_mm)) {
- if (x86_read_percpu(cpu_tlbstate.state) == TLBSTATE_OK) {
+ if (flush_mm == percpu_read(cpu_tlbstate.active_mm)) {
+ if (percpu_read(cpu_tlbstate.state) == TLBSTATE_OK) {
if (flush_va == TLB_FLUSH_ALL)
local_flush_tlb();
else
@@ -222,7 +222,7 @@ static void do_flush_tlb_all(void *info)
unsigned long cpu = smp_processor_id();
__flush_tlb_all();
- if (x86_read_percpu(cpu_tlbstate.state) == TLBSTATE_LAZY)
+ if (percpu_read(cpu_tlbstate.state) == TLBSTATE_LAZY)
leave_mm(cpu);
}
diff --git a/arch/x86/mach-voyager/voyager_smp.c b/arch/x86/mach-voyager/voyager_smp.c
index 1a48368acb09..96f15b09a4c5 100644
--- a/arch/x86/mach-voyager/voyager_smp.c
+++ b/arch/x86/mach-voyager/voyager_smp.c
@@ -402,7 +402,7 @@ void __init find_smp_config(void)
VOYAGER_SUS_IN_CONTROL_PORT);
current_thread_info()->cpu = boot_cpu_id;
- x86_write_percpu(cpu_number, boot_cpu_id);
+ percpu_write(cpu_number, boot_cpu_id);
}
/*
@@ -1782,7 +1782,7 @@ static void __init voyager_smp_cpus_done(unsigned int max_cpus)
void __init smp_setup_processor_id(void)
{
current_thread_info()->cpu = hard_smp_processor_id();
- x86_write_percpu(cpu_number, hard_smp_processor_id());
+ percpu_write(cpu_number, hard_smp_processor_id());
}
static void voyager_send_call_func(cpumask_t callmask)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 312414ef9365..75b94139e1f2 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -695,17 +695,17 @@ static void xen_write_cr0(unsigned long cr0)
static void xen_write_cr2(unsigned long cr2)
{
- x86_read_percpu(xen_vcpu)->arch.cr2 = cr2;
+ percpu_read(xen_vcpu)->arch.cr2 = cr2;
}
static unsigned long xen_read_cr2(void)
{
- return x86_read_percpu(xen_vcpu)->arch.cr2;
+ return percpu_read(xen_vcpu)->arch.cr2;
}
static unsigned long xen_read_cr2_direct(void)
{
- return x86_read_percpu(xen_vcpu_info.arch.cr2);
+ return percpu_read(xen_vcpu_info.arch.cr2);
}
static void xen_write_cr4(unsigned long cr4)
@@ -718,12 +718,12 @@ static void xen_write_cr4(unsigned long cr4)
static unsigned long xen_read_cr3(void)
{
- return x86_read_percpu(xen_cr3);
+ return percpu_read(xen_cr3);
}
static void set_current_cr3(void *v)
{
- x86_write_percpu(xen_current_cr3, (unsigned long)v);
+ percpu_write(xen_current_cr3, (unsigned long)v);
}
static void __xen_write_cr3(bool kernel, unsigned long cr3)
@@ -748,7 +748,7 @@ static void __xen_write_cr3(bool kernel, unsigned long cr3)
MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
if (kernel) {
- x86_write_percpu(xen_cr3, cr3);
+ percpu_write(xen_cr3, cr3);
/* Update xen_current_cr3 once the batch has actually
been submitted. */
@@ -764,7 +764,7 @@ static void xen_write_cr3(unsigned long cr3)
/* Update while interrupts are disabled, so its atomic with
respect to ipis */
- x86_write_percpu(xen_cr3, cr3);
+ percpu_write(xen_cr3, cr3);
__xen_write_cr3(true, cr3);
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index bb042608c602..2e8271431e1a 100644
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -39,7 +39,7 @@ static unsigned long xen_save_fl(void)
struct vcpu_info *vcpu;
unsigned long flags;
- vcpu = x86_read_percpu(xen_vcpu);
+ vcpu = percpu_read(xen_vcpu);
/* flag has opposite sense of mask */
flags = !vcpu->evtchn_upcall_mask;
@@ -62,7 +62,7 @@ static void xen_restore_fl(unsigned long flags)
make sure we're don't switch CPUs between getting the vcpu
pointer and updating the mask. */
preempt_disable();
- vcpu = x86_read_percpu(xen_vcpu);
+ vcpu = percpu_read(xen_vcpu);
vcpu->evtchn_upcall_mask = flags;
preempt_enable_no_resched();
@@ -83,7 +83,7 @@ static void xen_irq_disable(void)
make sure we're don't switch CPUs between getting the vcpu
pointer and updating the mask. */
preempt_disable();
- x86_read_percpu(xen_vcpu)->evtchn_upcall_mask = 1;
+ percpu_read(xen_vcpu)->evtchn_upcall_mask = 1;
preempt_enable_no_resched();
}
@@ -96,7 +96,7 @@ static void xen_irq_enable(void)
the caller is confused and is trying to re-enable interrupts
on an indeterminate processor. */
- vcpu = x86_read_percpu(xen_vcpu);
+ vcpu = percpu_read(xen_vcpu);
vcpu->evtchn_upcall_mask = 0;
/* Doesn't matter if we get preempted here, because any
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 503c240e26c7..7bc7852cc5c4 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1074,7 +1074,7 @@ static void drop_other_mm_ref(void *info)
/* If this cpu still has a stale cr3 reference, then make sure
it has been flushed. */
- if (x86_read_percpu(xen_current_cr3) == __pa(mm->pgd)) {
+ if (percpu_read(xen_current_cr3) == __pa(mm->pgd)) {
load_cr3(swapper_pg_dir);
arch_flush_lazy_cpu_mode();
}
diff --git a/arch/x86/xen/multicalls.h b/arch/x86/xen/multicalls.h
index 858938241616..e786fa7f2615 100644
--- a/arch/x86/xen/multicalls.h
+++ b/arch/x86/xen/multicalls.h
@@ -39,7 +39,7 @@ static inline void xen_mc_issue(unsigned mode)
xen_mc_flush();
/* restore flags saved in xen_mc_batch */
- local_irq_restore(x86_read_percpu(xen_mc_irq_flags));
+ local_irq_restore(percpu_read(xen_mc_irq_flags));
}
/* Set up a callback to be called when the current batch is flushed */
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 83fa4236477d..3bfd6dd0b47c 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -78,7 +78,7 @@ static __cpuinit void cpu_bringup(void)
xen_setup_cpu_clockevents();
cpu_set(cpu, cpu_online_map);
- x86_write_percpu(cpu_state, CPU_ONLINE);
+ percpu_write(cpu_state, CPU_ONLINE);
wmb();
/* We can take interrupts now: we're officially "up". */
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index b0e63c672ebd..00f45ff081a6 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -80,4 +80,56 @@ extern void setup_per_cpu_areas(void);
#define DECLARE_PER_CPU(type, name) extern PER_CPU_ATTRIBUTES \
__typeof__(type) per_cpu_var(name)
+/*
+ * Optional methods for optimized non-lvalue per-cpu variable access.
+ *
+ * @var can be a percpu variable or a field of it and its size should
+ * equal char, int or long. percpu_read() evaluates to a lvalue and
+ * all others to void.
+ *
+ * These operations are guaranteed to be atomic w.r.t. preemption.
+ * The generic versions use plain get/put_cpu_var(). Archs are
+ * encouraged to implement single-instruction alternatives which don't
+ * require preemption protection.
+ */
+#ifndef percpu_read
+# define percpu_read(var) \
+ ({ \
+ typeof(per_cpu_var(var)) __tmp_var__; \
+ __tmp_var__ = get_cpu_var(var); \
+ put_cpu_var(var); \
+ __tmp_var__; \
+ })
+#endif
+
+#define __percpu_generic_to_op(var, val, op) \
+do { \
+ get_cpu_var(var) op val; \
+ put_cpu_var(var); \
+} while (0)
+
+#ifndef percpu_write
+# define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
+#endif
+
+#ifndef percpu_add
+# define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
+#endif
+
+#ifndef percpu_sub
+# define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
+#endif
+
+#ifndef percpu_and
+# define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
+#endif
+
+#ifndef percpu_or
+# define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
+#endif
+
+#ifndef percpu_xor
+# define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
+#endif
+
#endif /* _ASM_GENERIC_PERCPU_H_ */