From 89bd55d1855f8e9a4e9add8e93f3144d049c469e Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 11 Mar 2009 16:31:29 +1030 Subject: x86: cpumask: update 32-bit APM not to mug current->cpus_allowed Impact: cleanup, avoid cpumask games The APM code wants to run on CPU 0: we create an "on_cpu0" wrapper which uses work_on_cpu() if we're not already on cpu 0. This introduces a new failure mode: -ENOMEM, so we add an explicit err arg and handle Linux-style errnos in apm_err(). Signed-off-by: Rusty Russell Cc: Andrew Morton Cc: Stephen Rothwell LKML-Reference: <200903111631.29787.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar --- arch/x86/kernel/apm_32.c | 248 +++++++++++++++++++++++++++-------------------- 1 file changed, 145 insertions(+), 103 deletions(-) (limited to 'arch/x86/kernel/apm_32.c') diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c index 10033fe718e0..c1941be9fb17 100644 --- a/arch/x86/kernel/apm_32.c +++ b/arch/x86/kernel/apm_32.c @@ -466,7 +466,7 @@ static const lookup_t error_table[] = { * @err: APM BIOS return code * * Write a meaningful log entry to the kernel log in the event of - * an APM error. + * an APM error. Note that this also handles (negative) kernel errors. */ static void apm_error(char *str, int err) @@ -478,42 +478,13 @@ static void apm_error(char *str, int err) break; if (i < ERROR_COUNT) printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg); + else if (err < 0) + printk(KERN_NOTICE "apm: %s: linux error code %i\n", str, err); else printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n", str, err); } -/* - * Lock APM functionality to physical CPU 0 - */ - -#ifdef CONFIG_SMP - -static cpumask_t apm_save_cpus(void) -{ - cpumask_t x = current->cpus_allowed; - /* Some bioses don't like being called from CPU != 0 */ - set_cpus_allowed(current, cpumask_of_cpu(0)); - BUG_ON(smp_processor_id() != 0); - return x; -} - -static inline void apm_restore_cpus(cpumask_t mask) -{ - set_cpus_allowed(current, mask); -} - -#else - -/* - * No CPU lockdown needed on a uniprocessor - */ - -#define apm_save_cpus() (current->cpus_allowed) -#define apm_restore_cpus(x) (void)(x) - -#endif - /* * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and * apm_info.allow_ints, we are being really paranoid here! Not only @@ -568,16 +539,23 @@ static inline void apm_irq_restore(unsigned long flags) # define APM_DO_RESTORE_SEGS #endif +struct apm_bios_call { + u32 func; + /* In and out */ + u32 ebx; + u32 ecx; + /* Out only */ + u32 eax; + u32 edx; + u32 esi; + + /* Error: -ENOMEM, or bits 8-15 of eax */ + int err; +}; + /** - * apm_bios_call - Make an APM BIOS 32bit call - * @func: APM function to execute - * @ebx_in: EBX register for call entry - * @ecx_in: ECX register for call entry - * @eax: EAX register return - * @ebx: EBX register return - * @ecx: ECX register return - * @edx: EDX register return - * @esi: ESI register return + * __apm_bios_call - Make an APM BIOS 32bit call + * @_call: pointer to struct apm_bios_call. * * Make an APM call using the 32bit protected mode interface. The * caller is responsible for knowing if APM BIOS is configured and @@ -586,79 +564,141 @@ static inline void apm_irq_restore(unsigned long flags) * flag is loaded into AL. If there is an error, then the error * code is returned in AH (bits 8-15 of eax) and this function * returns non-zero. + * + * Note: this makes the call on the current CPU. */ - -static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in, - u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi) +static long __apm_bios_call(void *_call) { APM_DECL_SEGS unsigned long flags; - cpumask_t cpus; int cpu; struct desc_struct save_desc_40; struct desc_struct *gdt; - - cpus = apm_save_cpus(); + struct apm_bios_call *call = _call; cpu = get_cpu(); + BUG_ON(cpu != 0); gdt = get_cpu_gdt_table(cpu); save_desc_40 = gdt[0x40 / 8]; gdt[0x40 / 8] = bad_bios_desc; apm_irq_save(flags); APM_DO_SAVE_SEGS; - apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi); + apm_bios_call_asm(call->func, call->ebx, call->ecx, + &call->eax, &call->ebx, &call->ecx, &call->edx, + &call->esi); APM_DO_RESTORE_SEGS; apm_irq_restore(flags); gdt[0x40 / 8] = save_desc_40; put_cpu(); - apm_restore_cpus(cpus); - return *eax & 0xff; + return call->eax & 0xff; +} + +/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */ +static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call) +{ + int ret; + + /* Don't bother with work_on_cpu in the common case, so we don't + * have to worry about OOM or overhead. */ + if (get_cpu() == 0) { + ret = fn(call); + put_cpu(); + } else { + put_cpu(); + ret = work_on_cpu(0, fn, call); + } + + /* work_on_cpu can fail with -ENOMEM */ + if (ret < 0) + call->err = ret; + else + call->err = (call->eax >> 8) & 0xff; + + return ret; } /** - * apm_bios_call_simple - make a simple APM BIOS 32bit call - * @func: APM function to invoke - * @ebx_in: EBX register value for BIOS call - * @ecx_in: ECX register value for BIOS call - * @eax: EAX register on return from the BIOS call + * apm_bios_call - Make an APM BIOS 32bit call (on CPU 0) + * @call: the apm_bios_call registers. + * + * If there is an error, it is returned in @call.err. + */ +static int apm_bios_call(struct apm_bios_call *call) +{ + return on_cpu0(__apm_bios_call, call); +} + +/** + * __apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0) + * @_call: pointer to struct apm_bios_call. * * Make a BIOS call that returns one value only, or just status. * If there is an error, then the error code is returned in AH - * (bits 8-15 of eax) and this function returns non-zero. This is - * used for simpler BIOS operations. This call may hold interrupts - * off for a long time on some laptops. + * (bits 8-15 of eax) and this function returns non-zero (it can + * also return -ENOMEM). This is used for simpler BIOS operations. + * This call may hold interrupts off for a long time on some laptops. + * + * Note: this makes the call on the current CPU. */ - -static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax) +static long __apm_bios_call_simple(void *_call) { u8 error; APM_DECL_SEGS unsigned long flags; - cpumask_t cpus; int cpu; struct desc_struct save_desc_40; struct desc_struct *gdt; - - cpus = apm_save_cpus(); + struct apm_bios_call *call = _call; cpu = get_cpu(); + BUG_ON(cpu != 0); gdt = get_cpu_gdt_table(cpu); save_desc_40 = gdt[0x40 / 8]; gdt[0x40 / 8] = bad_bios_desc; apm_irq_save(flags); APM_DO_SAVE_SEGS; - error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax); + error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx, + &call->eax); APM_DO_RESTORE_SEGS; apm_irq_restore(flags); gdt[0x40 / 8] = save_desc_40; put_cpu(); - apm_restore_cpus(cpus); return error; } +/** + * apm_bios_call_simple - make a simple APM BIOS 32bit call + * @func: APM function to invoke + * @ebx_in: EBX register value for BIOS call + * @ecx_in: ECX register value for BIOS call + * @eax: EAX register on return from the BIOS call + * @err: bits + * + * Make a BIOS call that returns one value only, or just status. + * If there is an error, then the error code is returned in @err + * and this function returns non-zero. This is used for simpler + * BIOS operations. This call may hold interrupts off for a long + * time on some laptops. + */ +static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax, + int *err) +{ + struct apm_bios_call call; + int ret; + + call.func = func; + call.ebx = ebx_in; + call.ecx = ecx_in; + + ret = on_cpu0(__apm_bios_call_simple, &call); + *eax = call.eax; + *err = call.err; + return ret; +} + /** * apm_driver_version - APM driver version * @val: loaded with the APM version on return @@ -678,9 +718,10 @@ static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax) static int apm_driver_version(u_short *val) { u32 eax; + int err; - if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax)) - return (eax >> 8) & 0xff; + if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err)) + return err; *val = eax; return APM_SUCCESS; } @@ -701,22 +742,21 @@ static int apm_driver_version(u_short *val) * that APM 1.2 is in use. If no messges are pending the value 0x80 * is returned (No power management events pending). */ - static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info) { - u32 eax; - u32 ebx; - u32 ecx; - u32 dummy; + struct apm_bios_call call; - if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx, - &dummy, &dummy)) - return (eax >> 8) & 0xff; - *event = ebx; + call.func = APM_FUNC_GET_EVENT; + call.ebx = call.ecx = 0; + + if (apm_bios_call(&call)) + return call.err; + + *event = call.ebx; if (apm_info.connection_version < 0x0102) *info = ~0; /* indicate info not valid */ else - *info = ecx; + *info = call.ecx; return APM_SUCCESS; } @@ -737,9 +777,10 @@ static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info) static int set_power_state(u_short what, u_short state) { u32 eax; + int err; - if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax)) - return (eax >> 8) & 0xff; + if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err)) + return err; return APM_SUCCESS; } @@ -770,6 +811,7 @@ static int apm_do_idle(void) u8 ret = 0; int idled = 0; int polling; + int err; polling = !!(current_thread_info()->status & TS_POLLING); if (polling) { @@ -782,7 +824,7 @@ static int apm_do_idle(void) } if (!need_resched()) { idled = 1; - ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax); + ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err); } if (polling) current_thread_info()->status |= TS_POLLING; @@ -797,8 +839,7 @@ static int apm_do_idle(void) * Only report the failure the first 5 times. */ if (++t < 5) { - printk(KERN_DEBUG "apm_do_idle failed (%d)\n", - (eax >> 8) & 0xff); + printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err); t = jiffies; } return -1; @@ -816,9 +857,10 @@ static int apm_do_idle(void) static void apm_do_busy(void) { u32 dummy; + int err; if (clock_slowed || ALWAYS_CALL_BUSY) { - (void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy); + (void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err); clock_slowed = 0; } } @@ -937,7 +979,7 @@ static void apm_power_off(void) /* Some bioses don't like being called from CPU != 0 */ if (apm_info.realmode_power_off) { - (void)apm_save_cpus(); + set_cpus_allowed_ptr(current, cpumask_of(0)); machine_real_restart(po_bios_call, sizeof(po_bios_call)); } else { (void)set_system_power_state(APM_STATE_OFF); @@ -956,12 +998,13 @@ static void apm_power_off(void) static int apm_enable_power_management(int enable) { u32 eax; + int err; if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED)) return APM_NOT_ENGAGED; if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL, - enable, &eax)) - return (eax >> 8) & 0xff; + enable, &eax, &err)) + return err; if (enable) apm_info.bios.flags &= ~APM_BIOS_DISABLED; else @@ -986,24 +1029,23 @@ static int apm_enable_power_management(int enable) static int apm_get_power_status(u_short *status, u_short *bat, u_short *life) { - u32 eax; - u32 ebx; - u32 ecx; - u32 edx; - u32 dummy; + struct apm_bios_call call; + + call.func = APM_FUNC_GET_STATUS; + call.ebx = APM_DEVICE_ALL; + call.ecx = 0; if (apm_info.get_power_status_broken) return APM_32_UNSUPPORTED; - if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0, - &eax, &ebx, &ecx, &edx, &dummy)) - return (eax >> 8) & 0xff; - *status = ebx; - *bat = ecx; + if (apm_bios_call(&call)) + return call.err; + *status = call.ebx; + *bat = call.ecx; if (apm_info.get_power_status_swabinminutes) { - *life = swab16((u16)edx); + *life = swab16((u16)call.edx); *life |= 0x8000; } else - *life = edx; + *life = call.edx; return APM_SUCCESS; } @@ -1048,12 +1090,14 @@ static int apm_get_battery_status(u_short which, u_short *status, static int apm_engage_power_management(u_short device, int enable) { u32 eax; + int err; if ((enable == 0) && (device == APM_DEVICE_ALL) && (apm_info.bios.flags & APM_BIOS_DISABLED)) return APM_DISABLED; - if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax)) - return (eax >> 8) & 0xff; + if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, + &eax, &err)) + return err; if (device == APM_DEVICE_ALL) { if (enable) apm_info.bios.flags &= ~APM_BIOS_DISENGAGED; @@ -1682,16 +1726,14 @@ static int apm(void *unused) char *power_stat; char *bat_stat; -#ifdef CONFIG_SMP /* 2002/08/01 - WT * This is to avoid random crashes at boot time during initialization * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D. * Some bioses don't like being called from CPU != 0. * Method suggested by Ingo Molnar. */ - set_cpus_allowed(current, cpumask_of_cpu(0)); + set_cpus_allowed_ptr(current, cpumask_of(0)); BUG_ON(smp_processor_id() != 0); -#endif if (apm_info.connection_version == 0) { apm_info.connection_version = apm_info.bios.version; -- cgit v1.2.2