Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, mm: Initialize initial_page_table before paravirt jumps

Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, mm: Initialize initial_page_table before paravirt jumps
Linus Torvalds
2 parents 47935a731b d50d8fe192
Showing 2 changed files Side-by-side Diff
arch/x86/kernel/head_32.S
arch/x86/lguest/i386_head.S
@@ -139,39 +139,6 @@
 	movl %eax, pa(olpc_ofw_pgd)
 #endif
  
-#ifdef CONFIG_PARAVIRT
-	/* This is can only trip for a broken bootloader... */
-	cmpw $0x207, pa(boot_params + BP_version)
-	jb default_entry
-
-	/* Paravirt-compatible boot parameters.  Look to see what architecture
-		we're booting under. */
-	movl pa(boot_params + BP_hardware_subarch), %eax
-	cmpl $num_subarch_entries, %eax
-	jae bad_subarch
-
-	movl pa(subarch_entries)(,%eax,4), %eax
-	subl $__PAGE_OFFSET, %eax
-	jmp *%eax
-
-bad_subarch:
-WEAK(lguest_entry)
-WEAK(xen_entry)
-	/* Unknown implementation; there's really
-	   nothing we can do at this point. */
-	ud2a
-
-	__INITDATA
-
-subarch_entries:
-	.long default_entry		/* normal x86/PC */
-	.long lguest_entry		/* lguest hypervisor */
-	.long xen_entry			/* Xen hypervisor */
-	.long default_entry		/* Moorestown MID */
-num_subarch_entries = (. - subarch_entries) / 4
-.previous
-#endif /* CONFIG_PARAVIRT */
-
 /*
  * Initialize page tables.  This creates a PDE and a set of page
  * tables, which are located immediately beyond __brk_base.  The variable
@@ -181,7 +148,6 @@
  *
  * Note that the stack is not yet set up!
  */
-default_entry:
 #ifdef CONFIG_X86_PAE
  
 	/*
@@ -261,7 +227,42 @@
 	movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax
 	movl %eax,pa(initial_page_table+0xffc)
 #endif
-	jmp 3f
+
+#ifdef CONFIG_PARAVIRT
+	/* This is can only trip for a broken bootloader... */
+	cmpw $0x207, pa(boot_params + BP_version)
+	jb default_entry
+
+	/* Paravirt-compatible boot parameters.  Look to see what architecture
+		we're booting under. */
+	movl pa(boot_params + BP_hardware_subarch), %eax
+	cmpl $num_subarch_entries, %eax
+	jae bad_subarch
+
+	movl pa(subarch_entries)(,%eax,4), %eax
+	subl $__PAGE_OFFSET, %eax
+	jmp *%eax
+
+bad_subarch:
+WEAK(lguest_entry)
+WEAK(xen_entry)
+	/* Unknown implementation; there's really
+	   nothing we can do at this point. */
+	ud2a
+
+	__INITDATA
+
+subarch_entries:
+	.long default_entry		/* normal x86/PC */
+	.long lguest_entry		/* lguest hypervisor */
+	.long xen_entry			/* Xen hypervisor */
+	.long default_entry		/* Moorestown MID */
+num_subarch_entries = (. - subarch_entries) / 4
+.previous
+#else
+	jmp default_entry
+#endif /* CONFIG_PARAVIRT */
+
 /*
  * Non-boot CPU entry point; entered from trampoline.S
  * We can't lgdt here, because lgdt itself uses a data segment, but
@@ -282,7 +283,7 @@
 	movl %eax,%fs
 	movl %eax,%gs
 #endif /* CONFIG_SMP */
-3:
+default_entry:
  
 /*
  *	New page tables may be in 4Mbyte page mode and may
  
@@ -628,13 +629,13 @@
 __PAGE_ALIGNED_BSS
 	.align PAGE_SIZE_asm
 #ifdef CONFIG_X86_PAE
-ENTRY(initial_pg_pmd)
+initial_pg_pmd:
 	.fill 1024*KPMDS,4,0
 #else
 ENTRY(initial_page_table)
 	.fill 1024,4,0
 #endif
-ENTRY(initial_pg_fixmap)
+initial_pg_fixmap:
 	.fill 1024,4,0
 ENTRY(empty_zero_page)
 	.fill 4096,1,0
@@ -4,7 +4,6 @@
 #include <asm/asm-offsets.h>
 #include <asm/thread_info.h>
 #include <asm/processor-flags.h>
-#include <asm/pgtable.h>
  
 /*G:020
  * Our story starts with the kernel booting into startup_32 in
  
@@ -38,112 +37,8 @@
 	/* Set up the initial stack so we can run C code. */
 	movl $(init_thread_union+THREAD_SIZE),%esp
  
-	call init_pagetables
-
 	/* Jumps are relative: we're running __PAGE_OFFSET too low. */
 	jmp lguest_init+__PAGE_OFFSET
-
-/*
- * Initialize page tables.  This creates a PDE and a set of page
- * tables, which are located immediately beyond __brk_base.  The variable
- * _brk_end is set up to point to the first "safe" location.
- * Mappings are created both at virtual address 0 (identity mapping)
- * and PAGE_OFFSET for up to _end.
- *
- * FIXME: This code is taken verbatim from arch/x86/kernel/head_32.S: they
- * don't have a stack at this point, so we can't just use call and ret.
- */
-init_pagetables:
-#if PTRS_PER_PMD > 1
-#define PAGE_TABLE_SIZE(pages) (((pages) / PTRS_PER_PMD) + PTRS_PER_PGD)
-#else
-#define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
-#endif
-#define pa(X) ((X) - __PAGE_OFFSET)
-
-/* Enough space to fit pagetables for the low memory linear map */
-MAPPING_BEYOND_END = \
-	PAGE_TABLE_SIZE(((1<<32) - __PAGE_OFFSET) >> PAGE_SHIFT) << PAGE_SHIFT
-#ifdef CONFIG_X86_PAE
-
-	/*
-	 * In PAE mode initial_page_table is statically defined to contain
-	 * enough entries to cover the VMSPLIT option (that is the top 1, 2 or 3
-	 * entries). The identity mapping is handled by pointing two PGD entries
-	 * to the first kernel PMD.
-	 *
-	 * Note the upper half of each PMD or PTE are always zero at this stage.
-	 */
-
-#define KPMDS (((-__PAGE_OFFSET) >> 30) & 3) /* Number of kernel PMDs */
-
-	xorl %ebx,%ebx				/* %ebx is kept at zero */
-
-	movl $pa(__brk_base), %edi
-	movl $pa(initial_pg_pmd), %edx
-	movl $PTE_IDENT_ATTR, %eax
-10:
-	leal PDE_IDENT_ATTR(%edi),%ecx		/* Create PMD entry */
-	movl %ecx,(%edx)			/* Store PMD entry */
-						/* Upper half already zero */
-	addl $8,%edx
-	movl $512,%ecx
-11:
-	stosl
-	xchgl %eax,%ebx
-	stosl
-	xchgl %eax,%ebx
-	addl $0x1000,%eax
-	loop 11b
-
-	/*
-	 * End condition: we must map up to the end + MAPPING_BEYOND_END.
-	 */
-	movl $pa(_end) + MAPPING_BEYOND_END + PTE_IDENT_ATTR, %ebp
-	cmpl %ebp,%eax
-	jb 10b
-1:
-	addl $__PAGE_OFFSET, %edi
-	movl %edi, pa(_brk_end)
-	shrl $12, %eax
-	movl %eax, pa(max_pfn_mapped)
-
-	/* Do early initialization of the fixmap area */
-	movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax
-	movl %eax,pa(initial_pg_pmd+0x1000*KPMDS-8)
-#else	/* Not PAE */
-
-page_pde_offset = (__PAGE_OFFSET >> 20);
-
-	movl $pa(__brk_base), %edi
-	movl $pa(initial_page_table), %edx
-	movl $PTE_IDENT_ATTR, %eax
-10:
-	leal PDE_IDENT_ATTR(%edi),%ecx		/* Create PDE entry */
-	movl %ecx,(%edx)			/* Store identity PDE entry */
-	movl %ecx,page_pde_offset(%edx)		/* Store kernel PDE entry */
-	addl $4,%edx
-	movl $1024, %ecx
-11:
-	stosl
-	addl $0x1000,%eax
-	loop 11b
-	/*
-	 * End condition: we must map up to the end + MAPPING_BEYOND_END.
-	 */
-	movl $pa(_end) + MAPPING_BEYOND_END + PTE_IDENT_ATTR, %ebp
-	cmpl %ebp,%eax
-	jb 10b
-	addl $__PAGE_OFFSET, %edi
-	movl %edi, pa(_brk_end)
-	shrl $12, %eax
-	movl %eax, pa(max_pfn_mapped)
-
-	/* Do early initialization of the fixmap area */
-	movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax
-	movl %eax,pa(initial_page_table+0xffc)
-#endif
-	ret
  
 /*G:055
  * We create a macro which puts the assembler code between lgstart_ and lgend_
...	...	@@ -139,39 +139,6 @@
139	139	movl %eax, pa(olpc_ofw_pgd)
140	140	#endif
141	141
142		-#ifdef CONFIG_PARAVIRT
143		- /* This is can only trip for a broken bootloader... */
144		- cmpw $0x207, pa(boot_params + BP_version)
145		- jb default_entry
146		-
147		- /* Paravirt-compatible boot parameters. Look to see what architecture
148		- we're booting under. */
149		- movl pa(boot_params + BP_hardware_subarch), %eax
150		- cmpl $num_subarch_entries, %eax
151		- jae bad_subarch
152		-
153		- movl pa(subarch_entries)(,%eax,4), %eax
154		- subl $__PAGE_OFFSET, %eax
155		- jmp *%eax
156		-
157		-bad_subarch:
158		-WEAK(lguest_entry)
159		-WEAK(xen_entry)
160		- /* Unknown implementation; there's really
161		- nothing we can do at this point. */
162		- ud2a
163		-
164		- __INITDATA
165		-
166		-subarch_entries:
167		- .long default_entry /* normal x86/PC */
168		- .long lguest_entry /* lguest hypervisor */
169		- .long xen_entry /* Xen hypervisor */
170		- .long default_entry /* Moorestown MID */
171		-num_subarch_entries = (. - subarch_entries) / 4
172		-.previous
173		-#endif /* CONFIG_PARAVIRT */
174		-
175	142	/*
176	143	* Initialize page tables. This creates a PDE and a set of page
177	144	* tables, which are located immediately beyond __brk_base. The variable
...	...	@@ -181,7 +148,6 @@
181	148	*
182	149	* Note that the stack is not yet set up!
183	150	*/
184		-default_entry:
185	151	#ifdef CONFIG_X86_PAE
186	152
187	153	/*
...	...	@@ -261,7 +227,42 @@
261	227	movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax
262	228	movl %eax,pa(initial_page_table+0xffc)
263	229	#endif
264		- jmp 3f
	230	+
	231	+#ifdef CONFIG_PARAVIRT
	232	+ /* This is can only trip for a broken bootloader... */
	233	+ cmpw $0x207, pa(boot_params + BP_version)
	234	+ jb default_entry
	235	+
	236	+ /* Paravirt-compatible boot parameters. Look to see what architecture
	237	+ we're booting under. */
	238	+ movl pa(boot_params + BP_hardware_subarch), %eax
	239	+ cmpl $num_subarch_entries, %eax
	240	+ jae bad_subarch
	241	+
	242	+ movl pa(subarch_entries)(,%eax,4), %eax
	243	+ subl $__PAGE_OFFSET, %eax
	244	+ jmp *%eax
	245	+
	246	+bad_subarch:
	247	+WEAK(lguest_entry)
	248	+WEAK(xen_entry)
	249	+ /* Unknown implementation; there's really
	250	+ nothing we can do at this point. */
	251	+ ud2a
	252	+
	253	+ __INITDATA
	254	+
	255	+subarch_entries:
	256	+ .long default_entry /* normal x86/PC */
	257	+ .long lguest_entry /* lguest hypervisor */
	258	+ .long xen_entry /* Xen hypervisor */
	259	+ .long default_entry /* Moorestown MID */
	260	+num_subarch_entries = (. - subarch_entries) / 4
	261	+.previous
	262	+#else
	263	+ jmp default_entry
	264	+#endif /* CONFIG_PARAVIRT */
	265	+
265	266	/*
266	267	* Non-boot CPU entry point; entered from trampoline.S
267	268	* We can't lgdt here, because lgdt itself uses a data segment, but
...	...	@@ -282,7 +283,7 @@
282	283	movl %eax,%fs
283	284	movl %eax,%gs
284	285	#endif /* CONFIG_SMP */
285		-3:
	286	+default_entry:
286	287
287	288	/*
288	289	* New page tables may be in 4Mbyte page mode and may
289	290
...	...	@@ -628,13 +629,13 @@
628	629	__PAGE_ALIGNED_BSS
629	630	.align PAGE_SIZE_asm
630	631	#ifdef CONFIG_X86_PAE
631		-ENTRY(initial_pg_pmd)
	632	+initial_pg_pmd:
632	633	.fill 1024*KPMDS,4,0
633	634	#else
634	635	ENTRY(initial_page_table)
635	636	.fill 1024,4,0
636	637	#endif
637		-ENTRY(initial_pg_fixmap)
	638	+initial_pg_fixmap:
638	639	.fill 1024,4,0
639	640	ENTRY(empty_zero_page)
640	641	.fill 4096,1,0
...	...	@@ -4,7 +4,6 @@
4	4	#include <asm/asm-offsets.h>
5	5	#include <asm/thread_info.h>
6	6	#include <asm/processor-flags.h>
7		-#include <asm/pgtable.h>
8	7
9	8	/*G:020
10	9	* Our story starts with the kernel booting into startup_32 in
11	10
...	...	@@ -38,112 +37,8 @@
38	37	/* Set up the initial stack so we can run C code. */
39	38	movl $(init_thread_union+THREAD_SIZE),%esp
40	39
41		- call init_pagetables
42		-
43	40	/* Jumps are relative: we're running __PAGE_OFFSET too low. */
44	41	jmp lguest_init+__PAGE_OFFSET
45		-
46		-/*
47		- * Initialize page tables. This creates a PDE and a set of page
48		- * tables, which are located immediately beyond __brk_base. The variable
49		- * _brk_end is set up to point to the first "safe" location.
50		- * Mappings are created both at virtual address 0 (identity mapping)
51		- * and PAGE_OFFSET for up to _end.
52		- *
53		- * FIXME: This code is taken verbatim from arch/x86/kernel/head_32.S: they
54		- * don't have a stack at this point, so we can't just use call and ret.
55		- */
56		-init_pagetables:
57		-#if PTRS_PER_PMD > 1
58		-#define PAGE_TABLE_SIZE(pages) (((pages) / PTRS_PER_PMD) + PTRS_PER_PGD)
59		-#else
60		-#define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
61		-#endif
62		-#define pa(X) ((X) - __PAGE_OFFSET)
63		-
64		-/* Enough space to fit pagetables for the low memory linear map */
65		-MAPPING_BEYOND_END = \
66		- PAGE_TABLE_SIZE(((1<<32) - __PAGE_OFFSET) >> PAGE_SHIFT) << PAGE_SHIFT
67		-#ifdef CONFIG_X86_PAE
68		-
69		- /*
70		- * In PAE mode initial_page_table is statically defined to contain
71		- * enough entries to cover the VMSPLIT option (that is the top 1, 2 or 3
72		- * entries). The identity mapping is handled by pointing two PGD entries
73		- * to the first kernel PMD.
74		- *
75		- * Note the upper half of each PMD or PTE are always zero at this stage.
76		- */
77		-
78		-#define KPMDS (((-__PAGE_OFFSET) >> 30) & 3) /* Number of kernel PMDs */
79		-
80		- xorl %ebx,%ebx /* %ebx is kept at zero */
81		-
82		- movl $pa(__brk_base), %edi
83		- movl $pa(initial_pg_pmd), %edx
84		- movl $PTE_IDENT_ATTR, %eax
85		-10:
86		- leal PDE_IDENT_ATTR(%edi),%ecx /* Create PMD entry */
87		- movl %ecx,(%edx) /* Store PMD entry */
88		- /* Upper half already zero */
89		- addl $8,%edx
90		- movl $512,%ecx
91		-11:
92		- stosl
93		- xchgl %eax,%ebx
94		- stosl
95		- xchgl %eax,%ebx
96		- addl $0x1000,%eax
97		- loop 11b
98		-
99		- /*
100		- * End condition: we must map up to the end + MAPPING_BEYOND_END.
101		- */
102		- movl $pa(_end) + MAPPING_BEYOND_END + PTE_IDENT_ATTR, %ebp
103		- cmpl %ebp,%eax
104		- jb 10b
105		-1:
106		- addl $__PAGE_OFFSET, %edi
107		- movl %edi, pa(_brk_end)
108		- shrl $12, %eax
109		- movl %eax, pa(max_pfn_mapped)
110		-
111		- /* Do early initialization of the fixmap area */
112		- movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax
113		- movl %eax,pa(initial_pg_pmd+0x1000*KPMDS-8)
114		-#else /* Not PAE */
115		-
116		-page_pde_offset = (__PAGE_OFFSET >> 20);
117		-
118		- movl $pa(__brk_base), %edi
119		- movl $pa(initial_page_table), %edx
120		- movl $PTE_IDENT_ATTR, %eax
121		-10:
122		- leal PDE_IDENT_ATTR(%edi),%ecx /* Create PDE entry */
123		- movl %ecx,(%edx) /* Store identity PDE entry */
124		- movl %ecx,page_pde_offset(%edx) /* Store kernel PDE entry */
125		- addl $4,%edx
126		- movl $1024, %ecx
127		-11:
128		- stosl
129		- addl $0x1000,%eax
130		- loop 11b
131		- /*
132		- * End condition: we must map up to the end + MAPPING_BEYOND_END.
133		- */
134		- movl $pa(_end) + MAPPING_BEYOND_END + PTE_IDENT_ATTR, %ebp
135		- cmpl %ebp,%eax
136		- jb 10b
137		- addl $__PAGE_OFFSET, %edi
138		- movl %edi, pa(_brk_end)
139		- shrl $12, %eax
140		- movl %eax, pa(max_pfn_mapped)
141		-
142		- /* Do early initialization of the fixmap area */
143		- movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax
144		- movl %eax,pa(initial_page_table+0xffc)
145		-#endif
146		- ret
147	42
148	43	/*G:055
149	44	* We create a macro which puts the assembler code between lgstart_ and lgend_