[patch] espfix code cleanup more

[Stas Sergeev <stsp@aknet.ru>]

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Hi Andrew.

Attached is a micro-optimization on top of the
previous cleanup patch. It removes the redundant
arguments from the C functions. No functionality changes.

Signed-off-by: <stsp@aknet.ru>


[-- Attachment #2: espfcln_a.diff --]
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--- linux-2.6.18-rc2-mm1/arch/i386/kernel/traps.c	2006-07-29 15:32:14.000000000 +0400
+++ linux-2.6.18-rc2-mm1/arch/i386/kernel/traps.c	2006-07-30 02:19:59.000000000 +0400
@@ -1018,13 +1018,13 @@
 #endif
 }
 
-fastcall unsigned long patch_espfix_gdt(struct pt_regs *regs,
+fastcall unsigned long patch_espfix_base(unsigned long uesp,
 					  unsigned long kesp)
 {
 	int cpu = smp_processor_id();
 	struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu);
 	struct desc_struct *gdt = (struct desc_struct *)cpu_gdt_descr->address;
-	unsigned long base = (kesp - regs->esp) & -THREAD_SIZE;
+	unsigned long base = (kesp - uesp) & -THREAD_SIZE;
 	__u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS];
 	/* Set up base for espfix segment */
  	desc &= 0x00ffff000000ffffULL;
@@ -1034,14 +1034,13 @@
 	return kesp - base;
 }
 
-fastcall unsigned long get_orig_kesp(unsigned long kesp, unsigned long cpu)
+fastcall unsigned long get_espfix_base(unsigned long cpu)
 {
 	/* Since we are on a wrong stack, the smp_processor_id() cannot
 	 * be used. So the cpu number is passed from an assembly. */
 	struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu);
 	struct desc_struct *gdt = (struct desc_struct *)cpu_gdt_descr->address;
-	unsigned long base = get_desc_base(&gdt[GDT_ENTRY_ESPFIX_SS].a);
-	return base + kesp;
+	return get_desc_base(&gdt[GDT_ENTRY_ESPFIX_SS].a);
 }
 
 /*
--- linux-2.6.18-rc2-mm1/arch/i386/kernel/entry.S	2006-07-29 15:29:00.000000000 +0400
+++ linux-2.6.18-rc2-mm1/arch/i386/kernel/entry.S	2006-07-30 02:19:47.000000000 +0400
@@ -401,9 +401,9 @@
 	 * This is an "official" bug of all the x86-compatible
 	 * CPUs, which we can try to work around to make
 	 * dosemu and wine happy. */
-	movl %esp, %eax		# pt_regs pointer
+	movl OLDESP(%esp), %eax
 	movl %esp, %edx
-	call patch_espfix_gdt
+	call patch_espfix_base
 	pushl $__ESPFIX_SS
 	CFI_ADJUST_CFA_OFFSET 4
 	pushl %eax
@@ -502,10 +502,10 @@
 	CFI_ENDPROC
 
 #define FIXUP_ESPFIX_STACK \
-	movl %esp, %eax; \
 	GET_THREAD_INFO(%ebp); \
-	movl TI_cpu(%ebp), %edx; \
-	call get_orig_kesp; \
+	movl TI_cpu(%ebp), %eax; \
+	call get_espfix_base; \
+	addl %esp, %eax; \
 	pushl $__KERNEL_DS; \
 	pushl %eax; \
 	lss (%esp), %esp;