[PATCH] mark struct file_operations const 9

[linux-2.6] / arch / i386 / kernel / apm.c

diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c
index b42f2d914af3bb15eada724c854bc92581f47169..db99a8948dae1abad5b16357841b54efe969c9d7 100644 (file)
--- 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);
@@ -767,7 +785,11 @@ static int apm_do_idle(void)
        polling = !!(current_thread_info()->status & TS_POLLING);
        if (polling) {
                current_thread_info()->status &= ~TS_POLLING;
-               smp_mb__after_clear_bit();
+               /*
+                * TS_POLLING-cleared state must be visible before we
+                * test NEED_RESCHED:
+                */
+               smp_mb();
        }
        if (!need_resched()) {
                idled = 1;
@@ -1586,7 +1608,7 @@ static int do_open(struct inode * inode, struct file * filp)
 {
        struct apm_user *       as;
 
-       as = (struct apm_user *)kmalloc(sizeof(*as), GFP_KERNEL);
+       as = kmalloc(sizeof(*as), GFP_KERNEL);
        if (as == NULL) {
                printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
                       sizeof(*as));
@@ -1872,7 +1894,7 @@ static int __init apm_setup(char *str)
 __setup("apm=", apm_setup);
 #endif
 
-static struct file_operations apm_bios_fops = {
+static const struct file_operations apm_bios_fops = {
        .owner          = THIS_MODULE,
        .read           = do_read,
        .poll           = do_poll,
@@ -2218,7 +2240,7 @@ 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;
        }