diff options
Diffstat (limited to 'arch/i386/kernel/apm.c')
| -rw-r--r-- | arch/i386/kernel/apm.c | 42 |
1 files changed, 30 insertions, 12 deletions
diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c index b42f2d914af3..a97847da9ed5 100644 --- a/arch/i386/kernel/apm.c +++ b/arch/i386/kernel/apm.c @@ -198,7 +198,7 @@ * (APM) BIOS Interface Specification, Revision 1.2, February 1996. * * [This document is available from Microsoft at: - * http://www.microsoft.com/hwdev/busbios/amp_12.htm] + * http://www.microsoft.com/whdc/archive/amp_12.mspx] */ #include <linux/module.h> @@ -231,6 +231,7 @@ #include <asm/uaccess.h> #include <asm/desc.h> #include <asm/i8253.h> +#include <asm/paravirt.h> #include "io_ports.h" @@ -540,11 +541,30 @@ static inline void apm_restore_cpus(cpumask_t mask) * Also, we KNOW that for the non error case of apm_bios_call, there * is no useful data returned in the low order 8 bits of eax. */ -#define APM_DO_CLI \ - if (apm_info.allow_ints) \ - local_irq_enable(); \ - else \ + +static inline unsigned long __apm_irq_save(void) +{ + unsigned long flags; + local_save_flags(flags); + if (apm_info.allow_ints) { + if (irqs_disabled_flags(flags)) + local_irq_enable(); + } else + local_irq_disable(); + + return flags; +} + +#define apm_irq_save(flags) \ + do { flags = __apm_irq_save(); } while (0) + +static inline void apm_irq_restore(unsigned long flags) +{ + if (irqs_disabled_flags(flags)) local_irq_disable(); + else if (irqs_disabled()) + local_irq_enable(); +} #ifdef APM_ZERO_SEGS # define APM_DECL_SEGS \ @@ -596,12 +616,11 @@ static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in, save_desc_40 = gdt[0x40 / 8]; gdt[0x40 / 8] = bad_bios_desc; - local_save_flags(flags); - APM_DO_CLI; + apm_irq_save(flags); APM_DO_SAVE_SEGS; apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi); APM_DO_RESTORE_SEGS; - local_irq_restore(flags); + apm_irq_restore(flags); gdt[0x40 / 8] = save_desc_40; put_cpu(); apm_restore_cpus(cpus); @@ -640,12 +659,11 @@ static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax) save_desc_40 = gdt[0x40 / 8]; gdt[0x40 / 8] = bad_bios_desc; - local_save_flags(flags); - APM_DO_CLI; + apm_irq_save(flags); APM_DO_SAVE_SEGS; error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax); APM_DO_RESTORE_SEGS; - local_irq_restore(flags); + apm_irq_restore(flags); gdt[0x40 / 8] = save_desc_40; put_cpu(); apm_restore_cpus(cpus); @@ -2218,7 +2236,7 @@ static int __init apm_init(void) dmi_check_system(apm_dmi_table); - if (apm_info.bios.version == 0) { + if (apm_info.bios.version == 0 || paravirt_enabled()) { printk(KERN_INFO "apm: BIOS not found.\n"); return -ENODEV; } |