Attachment 313758 Details for Bug 454981 – test patch

[patch] test patch

RHEL5-cpuid-update.patch (text/plain), 2.44 KB, created by Brian Maly on 2008-08-07 22:26:14 UTC

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Creator: Brian Maly

Created: 2008-08-07 22:26:14 UTC

Size: 2.44 KB

patch

obsolete

>--- linux-2.6.18.noarch/arch/i386/kernel/cpuid.c.orig	2008-08-07 14:28:11.000000000 -0400
>+++ linux-2.6.18.noarch/arch/i386/kernel/cpuid.c	2008-08-07 18:15:35.000000000 -0400
>@@ -19,6 +19,10 @@
>  * and then read in chunks of 16 bytes.  A larger size means multiple
>  * reads of consecutive levels.
>  *
>+ * The lower 32 bits of the file position is used as the incoming %eax,
>+ * and the upper 32 bits of the file position as the incoming %ecx,
>+ * the latter intended for "counting" eax levels like eax=4.
>+ *
>  * This driver uses /dev/cpu/%d/cpuid where %d is the minor number, and on
>  * an SMP box will direct the access to CPU %d.
>  */
>@@ -46,48 +50,18 @@
> 
> static struct class *cpuid_class;
> 
>-#ifdef CONFIG_SMP
>-
>-struct cpuid_command {
>-	int cpu;
>-	u32 reg;
>-	u32 *data;
>+struct cpuid_regs {
>+	u32 eax, ebx, ecx, edx;
> };
> 
> static void cpuid_smp_cpuid(void *cmd_block)
> {
>-	struct cpuid_command *cmd = (struct cpuid_command *)cmd_block;
>-
>-	if (cmd->cpu == smp_processor_id())
>-		cpuid(cmd->reg, &cmd->data[0], &cmd->data[1], &cmd->data[2],
>-		      &cmd->data[3]);
>-}
>-
>-static inline void do_cpuid(int cpu, u32 reg, u32 * data)
>-{
>-	struct cpuid_command cmd;
>+	struct cpuid_regs *cmd = (struct cpuid_regs *)cmd_block;
> 
>-	preempt_disable();
>-	if (cpu == smp_processor_id()) {
>-		cpuid(reg, &data[0], &data[1], &data[2], &data[3]);
>-	} else {
>-		cmd.cpu = cpu;
>-		cmd.reg = reg;
>-		cmd.data = data;
>-
>-		smp_call_function(cpuid_smp_cpuid, &cmd, 1, 1);
>-	}
>-	preempt_enable();
>-}
>-#else				/* ! CONFIG_SMP */
>-
>-static inline void do_cpuid(int cpu, u32 reg, u32 * data)
>-{
>-	cpuid(reg, &data[0], &data[1], &data[2], &data[3]);
>+	cpuid_count(cmd->eax, cmd->ecx,
>+		    &cmd->eax, &cmd->ebx, &cmd->ecx, &cmd->edx);
> }
> 
>-#endif				/* ! CONFIG_SMP */
>-
> static loff_t cpuid_seek(struct file *file, loff_t offset, int orig)
> {
> 	loff_t ret;
>@@ -115,19 +89,21 @@ static ssize_t cpuid_read(struct file *f
> 			  size_t count, loff_t * ppos)
> {
> 	char __user *tmp = buf;
>-	u32 data[4];
>-	u32 reg = *ppos;
>+	struct cpuid_regs cmd;
> 	int cpu = iminor(file->f_dentry->d_inode);
>+	u64 pos = *ppos;
> 
> 	if (count % 16)
> 		return -EINVAL;	/* Invalid chunk size */
> 
> 	for (; count; count -= 16) {
>-		do_cpuid(cpu, reg, data);
>-		if (copy_to_user(tmp, &data, 16))
>+		cmd.eax = pos;
>+		cmd.ecx = pos >> 32;
>+		smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1, 1);
>+		if (copy_to_user(tmp, &cmd, 16))
> 			return -EFAULT;
> 		tmp += 16;
>-		*ppos = reg++;
>+		*ppos = ++pos;
> 	}
> 
> 	return tmp - buf;

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