linux-i386: cleanup head.S, sync default_ldt and {new,boot}_cpu_data with native.

Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>

linux-2.6-xen-sparse/arch/i386/kernel/head-xen.S

@@ -25,11 +25,6 @@
 
 ENTRY(startup_32)
 	movl %esi,xen_start_info
-
-#if 0
-ENTRY(startup_32_smp)
-#endif /* CONFIG_SMP */
-
 	cld
 
 	/* Set up the stack pointer */
@@ -57,29 +52,42 @@ checkCPUtype:
 	movb %cl,X86_MASK
 	movl %edx,X86_CAPABILITY
 
+	movb $1,X86_HARD_MATH
+
 	xorl %eax,%eax			# Clear FS/GS and LDT
 	movl %eax,%fs
 	movl %eax,%gs
 	cld			# gcc2 wants the direction flag cleared at all times
 
-#if 0
-	movb ready, %cl
-	movb $1, ready
-	cmpb $0,%cl
-	je 1f			# the first CPU calls start_kernel
-				# all other CPUs call initialize_secondary
-	call initialize_secondary
-	jmp L6
-1:
-#endif /* CONFIG_SMP */
 	call start_kernel
 L6:
 	jmp L6			# main should never return here, but
 				# just in case, we know what happens.
 
-	ALIGN
+#define HYPERCALL_PAGE_OFFSET 0x1000
+.org HYPERCALL_PAGE_OFFSET
+ENTRY(hypercall_page)
+.skip 0x1000
 
-# boot GDT descriptor (later on used by CPU#0):
+/*
+ * Real beginning of normal "text" segment
+ */
+ENTRY(stext)
+ENTRY(_stext)
+
+/*
+ * BSS section
+ */
+.section ".bss.page_aligned","w"
+ENTRY(empty_zero_page)
+	.fill 4096,1,0
+
+/*
+ * This starts the data section.
+ */
+.data
+
+	ALIGN
 	.word 0				# 32 bit align gdt_desc.address
 	.globl cpu_gdt_descr
 cpu_gdt_descr:
@@ -88,10 +96,10 @@ cpu_gdt_descr:
 
 	.fill NR_CPUS-1,8,0		# space for the other GDT descriptors
 
-.org 0x1000
-ENTRY(empty_zero_page)
-
-.org 0x2000
+/*
+ * The Global Descriptor Table contains 28 quadwords, per-CPU.
+ */
+	.align PAGE_SIZE_asm
 ENTRY(cpu_gdt_table)
 	.quad 0x0000000000000000	/* NULL descriptor */
 	.quad 0x0000000000000000	/* 0x0b reserved */
@@ -106,10 +114,10 @@ ENTRY(cpu_gdt_table)
 	.quad 0x0000000000000000	/* 0x53 reserved */
 	.quad 0x0000000000000000	/* 0x5b reserved */
 
-	.quad 0x00cf9b000000ffff	/* 0x60 kernel 4GB code at 0x00000000 */
-	.quad 0x00cf93000000ffff	/* 0x68 kernel 4GB data at 0x00000000 */
-	.quad 0x00cffb000000ffff	/* 0x73 user 4GB code at 0x00000000 */
-	.quad 0x00cff3000000ffff	/* 0x7b user 4GB data at 0x00000000 */
+	.quad 0x00cf9a000000ffff	/* 0x60 kernel 4GB code at 0x00000000 */
+	.quad 0x00cf92000000ffff	/* 0x68 kernel 4GB data at 0x00000000 */
+	.quad 0x00cffa000000ffff	/* 0x73 user 4GB code at 0x00000000 */
+	.quad 0x00cff2000000ffff	/* 0x7b user 4GB data at 0x00000000 */
 
 	.quad 0x0000000000000000	/* 0x80 TSS descriptor */
 	.quad 0x0000000000000000	/* 0x88 LDT descriptor */
@@ -143,20 +151,6 @@ ENTRY(cpu_gdt_table)
 	/* Be sure this is zeroed to avoid false validations in Xen */
 	.fill PAGE_SIZE_asm / 8 - GDT_ENTRIES,8,0
 
-.org 0x3000
-ENTRY(default_ldt)
-
-#define HYPERCALL_PAGE_OFFSET 0x4000
-.org HYPERCALL_PAGE_OFFSET
-ENTRY(hypercall_page)
-.skip 0x1000
-
-/*
- * Real beginning of normal "text" segment
- */
-ENTRY(stext)
-ENTRY(_stext)
-
 
 /*
  * __xen_guest information

linux-2.6-xen-sparse/arch/i386/kernel/setup-xen.c

@@ -94,9 +94,9 @@ EXPORT_SYMBOL(efi_enabled);
 #endif
 
 /* cpu data as detected by the assembly code in head.S */
-struct cpuinfo_x86 new_cpu_data __initdata = { 0, 0, 0, 0, -1, 0, 1, 0, -1 };
+struct cpuinfo_x86 new_cpu_data __initdata = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };
 /* common cpu data for all cpus */
-struct cpuinfo_x86 boot_cpu_data __read_mostly = { 0, 0, 0, 0, -1, 0, 1, 0, -1 };
+struct cpuinfo_x86 boot_cpu_data __read_mostly = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };
 EXPORT_SYMBOL(boot_cpu_data);
 
 unsigned long mmu_cr4_features;

linux-2.6-xen-sparse/arch/i386/kernel/traps-xen.c

@@ -58,6 +58,9 @@
 
 asmlinkage int system_call(void);
 
+struct desc_struct default_ldt[] = { { 0, 0 }, { 0, 0 }, { 0, 0 },
+		{ 0, 0 }, { 0, 0 } };
+
 /* Do we ignore FPU interrupts ? */
 char ignore_fpu_irq = 0;
 
@@ -498,20 +501,6 @@ DO_ERROR_INFO(32, SIGSEGV, "iret exception", iret_error, ILL_BADSTK, 0)
 fastcall void __kprobes do_general_protection(struct pt_regs * regs,
 					      long error_code)
 {
-	/*
-	 * If we trapped on an LDT access then ensure that the default_ldt is
-	 * loaded, if nothing else. We load default_ldt lazily because LDT
-	 * switching costs time and many applications don't need it.
-	 */
-	if (unlikely((error_code & 6) == 4)) {
-		unsigned long ldt;
-		__asm__ __volatile__ ("sldt %0" : "=r" (ldt));
-		if (ldt == 0) {
-			xen_set_ldt((unsigned long)&default_ldt[0], 5);
-			return;
-		}
-	}
-
 	current->thread.error_code = error_code;
 	current->thread.trap_no = 13;
 
@@ -1080,13 +1069,6 @@ void __init trap_init(void)
 		printk("done.\n");
 	}
 
-	/*
-	 * default LDT is a single-entry callgate to lcall7 for iBCS
-	 * and a callgate to lcall27 for Solaris/x86 binaries
-	 */
-	make_lowmem_page_readonly(
-		&default_ldt[0], XENFEAT_writable_descriptor_tables);
-
 	/*
 	 * Should be a barrier for any external CPU state.
 	 */

linux-2.6-xen-sparse/include/asm-i386/mach-xen/setup_arch_post.h

@@ -25,6 +25,7 @@ void __init machine_specific_modify_cpu_capabilities(struct cpuinfo_x86 *c)
 	clear_bit(X86_FEATURE_SEP, c->x86_capability);
 	if (!(xen_start_info->flags & SIF_PRIVILEGED))
 		clear_bit(X86_FEATURE_MTRR, c->x86_capability);
+	c->hlt_works_ok = 0;
 }
 
 extern void hypervisor_callback(void);