MIPS: Two-level pagetables for 64-bit kernels with 64KB pages.

For 64-bit kernels with 64KB pages and two level page tables, there are 42 bits worth of virtual address space This is larger than the 40 bits of virtual address space obtained with the default 4KB Page size and three levels, so there are no draw backs for using two level tables with this configuration. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/761/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Two-level pagetables for 64-bit kernels with 64KB pages.
For 64-bit kernels with 64KB pages and two level page tables, there are 42 bits worth of virtual address space This is larger than the 40 bits of virtual address space obtained with the default 4KB Page size and three levels, so there are no draw backs for using two level tables with this configuration. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/761/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
David Daney · Ralf Baechle
1 parent ef6c1fd662
Showing 8 changed files with 71 additions and 35 deletions Side-by-side Diff
arch/mips/include/asm/page.h
arch/mips/include/asm/pgalloc.h
arch/mips/include/asm/pgtable-64.h
arch/mips/include/asm/pgtable.h
arch/mips/kernel/asm-offsets.c
arch/mips/mm/init.c
arch/mips/mm/pgtable-64.c
arch/mips/mm/tlbex.c
@@ -107,18 +107,6 @@
 typedef struct page *pgtable_t;
  
 /*
- * For 3-level pagetables we defines these ourselves, for 2-level the
- * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
- */
-#ifdef CONFIG_64BIT
-
-typedef struct { unsigned long pmd; } pmd_t;
-#define pmd_val(x)	((x).pmd)
-#define __pmd(x)	((pmd_t) { (x) } )
-
-#endif
-
-/*
  * Right now we don't support 4-level pagetables, so all pud-related
  * definitions come from <asm-generic/pgtable-nopud.h>.
  */
@@ -31,7 +31,7 @@
  */
 extern void pmd_init(unsigned long page, unsigned long pagetable);
  
-#ifdef CONFIG_64BIT
+#ifndef __PAGETABLE_PMD_FOLDED
  
 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 {
@@ -104,7 +104,7 @@
 	tlb_remove_page((tlb), pte);			\
 } while (0)
  
-#ifdef CONFIG_64BIT
+#ifndef __PAGETABLE_PMD_FOLDED
  
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 {
@@ -16,7 +16,11 @@
 #include <asm/cachectl.h>
 #include <asm/fixmap.h>
  
+#ifdef CONFIG_PAGE_SIZE_64KB
+#include <asm-generic/pgtable-nopmd.h>
+#else
 #include <asm-generic/pgtable-nopud.h>
+#endif
  
 /*
  * Each address space has 2 4K pages as its page directory, giving 1024
  
  
@@ -37,13 +41,20 @@
  * fault address - VMALLOC_START.
  */
  
+
+/* PGDIR_SHIFT determines what a third-level page table entry can map */
+#ifdef __PAGETABLE_PMD_FOLDED
+#define PGDIR_SHIFT	(PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3)
+#else
+
 /* PMD_SHIFT determines the size of the area a second-level page table can map */
 #define PMD_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
 #define PMD_SIZE	(1UL << PMD_SHIFT)
 #define PMD_MASK	(~(PMD_SIZE-1))
  
-/* PGDIR_SHIFT determines what a third-level page table entry can map */
+
 #define PGDIR_SHIFT	(PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3))
+#endif
 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
  
  
  
@@ -92,12 +103,14 @@
 #ifdef CONFIG_PAGE_SIZE_64KB
 #define PGD_ORDER		0
 #define PUD_ORDER		aieeee_attempt_to_allocate_pud
-#define PMD_ORDER		0
+#define PMD_ORDER		aieeee_attempt_to_allocate_pmd
 #define PTE_ORDER		0
 #endif
  
 #define PTRS_PER_PGD	((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
+#ifndef __PAGETABLE_PMD_FOLDED
 #define PTRS_PER_PMD	((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t))
+#endif
 #define PTRS_PER_PTE	((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
  
 #if PGDIR_SIZE >= TASK_SIZE
  
  
  
@@ -122,15 +135,30 @@
  
 #define pte_ERROR(e) \
 	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
+#ifndef __PAGETABLE_PMD_FOLDED
 #define pmd_ERROR(e) \
 	printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
+#endif
 #define pgd_ERROR(e) \
 	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
  
 extern pte_t invalid_pte_table[PTRS_PER_PTE];
 extern pte_t empty_bad_page_table[PTRS_PER_PTE];
+
+
+#ifndef __PAGETABLE_PMD_FOLDED
+/*
+ * For 3-level pagetables we defines these ourselves, for 2-level the
+ * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
+ */
+typedef struct { unsigned long pmd; } pmd_t;
+#define pmd_val(x)	((x).pmd)
+#define __pmd(x)	((pmd_t) { (x) } )
+
+
 extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
 extern pmd_t empty_bad_pmd_table[PTRS_PER_PMD];
+#endif
  
 /*
  * Empty pgd/pmd entries point to the invalid_pte_table.
@@ -151,6 +179,7 @@
 {
 	pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
 }
+#ifndef __PAGETABLE_PMD_FOLDED
  
 /*
  * Empty pud entries point to the invalid_pmd_table.
@@ -174,6 +203,7 @@
 {
 	pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
 }
+#endif
  
 #define pte_page(x)		pfn_to_page(pte_pfn(x))
  
@@ -198,6 +228,7 @@
 /* to find an entry in a page-table-directory */
 #define pgd_offset(mm, addr)	((mm)->pgd + pgd_index(addr))
  
+#ifndef __PAGETABLE_PMD_FOLDED
 static inline unsigned long pud_page_vaddr(pud_t pud)
 {
 	return pud_val(pud);
@@ -210,6 +241,7 @@
 {
 	return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address);
 }
+#endif
  
 /* Find an entry in the third-level page table.. */
 #define __pte_offset(address)						\
@@ -177,7 +177,7 @@
  */
 #define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while(0)
  
-#ifdef CONFIG_64BIT
+#ifndef __PAGETABLE_PMD_FOLDED
 /*
  * (puds are folded into pgds so this doesn't get actually called,
  * but the define is needed for a generic inline function.)
@@ -188,11 +188,15 @@
 	DEFINE(_PTE_T_SIZE, sizeof(pte_t));
 	BLANK();
 	DEFINE(_PGD_T_LOG2, PGD_T_LOG2);
+#ifndef __PAGETABLE_PMD_FOLDED
 	DEFINE(_PMD_T_LOG2, PMD_T_LOG2);
+#endif
 	DEFINE(_PTE_T_LOG2, PTE_T_LOG2);
 	BLANK();
 	DEFINE(_PGD_ORDER, PGD_ORDER);
+#ifndef __PAGETABLE_PMD_FOLDED
 	DEFINE(_PMD_ORDER, PMD_ORDER);
+#endif
 	DEFINE(_PTE_ORDER, PTE_ORDER);
 	BLANK();
 	DEFINE(_PMD_SHIFT, PMD_SHIFT);
@@ -477,7 +477,7 @@
  * will officially be retired.
  */
 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
-#ifdef CONFIG_64BIT
+#ifndef __PAGETABLE_PMD_FOLDED
 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
 #endif
 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);
@@ -15,23 +15,31 @@
 void pgd_init(unsigned long page)
 {
 	unsigned long *p, *end;
+	unsigned long entry;
  
+#ifdef __PAGETABLE_PMD_FOLDED
+	entry = (unsigned long)invalid_pte_table;
+#else
+	entry = (unsigned long)invalid_pmd_table;
+#endif
+
  	p = (unsigned long *) page;
 	end = p + PTRS_PER_PGD;
  
 	while (p < end) {
-		p[0] = (unsigned long) invalid_pmd_table;
-		p[1] = (unsigned long) invalid_pmd_table;
-		p[2] = (unsigned long) invalid_pmd_table;
-		p[3] = (unsigned long) invalid_pmd_table;
-		p[4] = (unsigned long) invalid_pmd_table;
-		p[5] = (unsigned long) invalid_pmd_table;
-		p[6] = (unsigned long) invalid_pmd_table;
-		p[7] = (unsigned long) invalid_pmd_table;
+		p[0] = entry;
+		p[1] = entry;
+		p[2] = entry;
+		p[3] = entry;
+		p[4] = entry;
+		p[5] = entry;
+		p[6] = entry;
+		p[7] = entry;
 		p += 8;
 	}
 }
  
+#ifndef __PAGETABLE_PMD_FOLDED
 void pmd_init(unsigned long addr, unsigned long pagetable)
 {
 	unsigned long *p, *end;
  
@@ -40,17 +48,18 @@
 	end = p + PTRS_PER_PMD;
  
 	while (p < end) {
-		p[0] = (unsigned long)pagetable;
-		p[1] = (unsigned long)pagetable;
-		p[2] = (unsigned long)pagetable;
-		p[3] = (unsigned long)pagetable;
-		p[4] = (unsigned long)pagetable;
-		p[5] = (unsigned long)pagetable;
-		p[6] = (unsigned long)pagetable;
-		p[7] = (unsigned long)pagetable;
+		p[0] = pagetable;
+		p[1] = pagetable;
+		p[2] = pagetable;
+		p[3] = pagetable;
+		p[4] = pagetable;
+		p[5] = pagetable;
+		p[6] = pagetable;
+		p[7] = pagetable;
 		p += 8;
 	}
 }
+#endif
  
 void __init pagetable_init(void)
 {
  
@@ -59,8 +68,9 @@
  
 	/* Initialize the entire pgd.  */
 	pgd_init((unsigned long)swapper_pg_dir);
+#ifndef __PAGETABLE_PMD_FOLDED
 	pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table);
-
+#endif
 	pgd_base = swapper_pg_dir;
 	/*
 	 * Fixed mappings:
@@ -549,11 +549,13 @@
  
 	uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
 	uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
+#ifndef __PAGETABLE_PMD_FOLDED
 	uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
 	uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */
 	uasm_i_dsrl(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
 	uasm_i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
 	uasm_i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
+#endif
 }
  
 /*
...	...	@@ -107,18 +107,6 @@
107	107	typedef struct page *pgtable_t;
108	108
109	109	/*
110		- * For 3-level pagetables we defines these ourselves, for 2-level the
111		- * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
112		- */
113		-#ifdef CONFIG_64BIT
114		-
115		-typedef struct { unsigned long pmd; } pmd_t;
116		-#define pmd_val(x) ((x).pmd)
117		-#define __pmd(x) ((pmd_t) { (x) } )
118		-
119		-#endif
120		-
121		-/*
122	110	* Right now we don't support 4-level pagetables, so all pud-related
123	111	* definitions come from <asm-generic/pgtable-nopud.h>.
124	112	*/
...	...	@@ -31,7 +31,7 @@
31	31	*/
32	32	extern void pmd_init(unsigned long page, unsigned long pagetable);
33	33
34		-#ifdef CONFIG_64BIT
	34	+#ifndef __PAGETABLE_PMD_FOLDED
35	35
36	36	static inline void pud_populate(struct mm_struct mm, pud_t pud, pmd_t *pmd)
37	37	{
...	...	@@ -104,7 +104,7 @@
104	104	tlb_remove_page((tlb), pte); \
105	105	} while (0)
106	106
107		-#ifdef CONFIG_64BIT
	107	+#ifndef __PAGETABLE_PMD_FOLDED
108	108
109	109	static inline pmd_t pmd_alloc_one(struct mm_struct mm, unsigned long address)
110	110	{
...	...	@@ -16,7 +16,11 @@
16	16	#include <asm/cachectl.h>
17	17	#include <asm/fixmap.h>
18	18
	19	+#ifdef CONFIG_PAGE_SIZE_64KB
	20	+#include <asm-generic/pgtable-nopmd.h>
	21	+#else
19	22	#include <asm-generic/pgtable-nopud.h>
	23	+#endif
20	24
21	25	/*
22	26	* Each address space has 2 4K pages as its page directory, giving 1024
23	27
24	28
...	...	@@ -37,13 +41,20 @@
37	41	* fault address - VMALLOC_START.
38	42	*/
39	43
	44	+
	45	+/* PGDIR_SHIFT determines what a third-level page table entry can map */
	46	+#ifdef __PAGETABLE_PMD_FOLDED
	47	+#define PGDIR_SHIFT (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3)
	48	+#else
	49	+
40	50	/* PMD_SHIFT determines the size of the area a second-level page table can map */
41	51	#define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
42	52	#define PMD_SIZE (1UL << PMD_SHIFT)
43	53	#define PMD_MASK (~(PMD_SIZE-1))
44	54
45		-/* PGDIR_SHIFT determines what a third-level page table entry can map */
	55	+
46	56	#define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3))
	57	+#endif
47	58	#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
48	59	#define PGDIR_MASK (~(PGDIR_SIZE-1))
49	60
50	61
51	62
...	...	@@ -92,12 +103,14 @@
92	103	#ifdef CONFIG_PAGE_SIZE_64KB
93	104	#define PGD_ORDER 0
94	105	#define PUD_ORDER aieeee_attempt_to_allocate_pud
95		-#define PMD_ORDER 0
	106	+#define PMD_ORDER aieeee_attempt_to_allocate_pmd
96	107	#define PTE_ORDER 0
97	108	#endif
98	109
99	110	#define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
	111	+#ifndef __PAGETABLE_PMD_FOLDED
100	112	#define PTRS_PER_PMD ((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t))
	113	+#endif
101	114	#define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
102	115
103	116	#if PGDIR_SIZE >= TASK_SIZE
104	117
105	118
106	119
...	...	@@ -122,15 +135,30 @@
122	135
123	136	#define pte_ERROR(e) \
124	137	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
	138	+#ifndef __PAGETABLE_PMD_FOLDED
125	139	#define pmd_ERROR(e) \
126	140	printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
	141	+#endif
127	142	#define pgd_ERROR(e) \
128	143	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
129	144
130	145	extern pte_t invalid_pte_table[PTRS_PER_PTE];
131	146	extern pte_t empty_bad_page_table[PTRS_PER_PTE];
	147	+
	148	+
	149	+#ifndef __PAGETABLE_PMD_FOLDED
	150	+/*
	151	+ * For 3-level pagetables we defines these ourselves, for 2-level the
	152	+ * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
	153	+ */
	154	+typedef struct { unsigned long pmd; } pmd_t;
	155	+#define pmd_val(x) ((x).pmd)
	156	+#define __pmd(x) ((pmd_t) { (x) } )
	157	+
	158	+
132	159	extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
133	160	extern pmd_t empty_bad_pmd_table[PTRS_PER_PMD];
	161	+#endif
134	162
135	163	/*
136	164	* Empty pgd/pmd entries point to the invalid_pte_table.
...	...	@@ -151,6 +179,7 @@
151	179	{
152	180	pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
153	181	}
	182	+#ifndef __PAGETABLE_PMD_FOLDED
154	183
155	184	/*
156	185	* Empty pud entries point to the invalid_pmd_table.
...	...	@@ -174,6 +203,7 @@
174	203	{
175	204	pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
176	205	}
	206	+#endif
177	207
178	208	#define pte_page(x) pfn_to_page(pte_pfn(x))
179	209
...	...	@@ -198,6 +228,7 @@
198	228	/* to find an entry in a page-table-directory */
199	229	#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
200	230
	231	+#ifndef __PAGETABLE_PMD_FOLDED
201	232	static inline unsigned long pud_page_vaddr(pud_t pud)
202	233	{
203	234	return pud_val(pud);
...	...	@@ -210,6 +241,7 @@
210	241	{
211	242	return (pmd_t ) pud_page_vaddr(pud) + pmd_index(address);
212	243	}
	244	+#endif
213	245
214	246	/* Find an entry in the third-level page table.. */
215	247	#define __pte_offset(address) \
...	...	@@ -177,7 +177,7 @@
177	177	*/
178	178	#define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while(0)
179	179
180		-#ifdef CONFIG_64BIT
	180	+#ifndef __PAGETABLE_PMD_FOLDED
181	181	/*
182	182	* (puds are folded into pgds so this doesn't get actually called,
183	183	* but the define is needed for a generic inline function.)
...	...	@@ -188,11 +188,15 @@
188	188	DEFINE(_PTE_T_SIZE, sizeof(pte_t));
189	189	BLANK();
190	190	DEFINE(_PGD_T_LOG2, PGD_T_LOG2);
	191	+#ifndef __PAGETABLE_PMD_FOLDED
191	192	DEFINE(_PMD_T_LOG2, PMD_T_LOG2);
	193	+#endif
192	194	DEFINE(_PTE_T_LOG2, PTE_T_LOG2);
193	195	BLANK();
194	196	DEFINE(_PGD_ORDER, PGD_ORDER);
	197	+#ifndef __PAGETABLE_PMD_FOLDED
195	198	DEFINE(_PMD_ORDER, PMD_ORDER);
	199	+#endif
196	200	DEFINE(_PTE_ORDER, PTE_ORDER);
197	201	BLANK();
198	202	DEFINE(_PMD_SHIFT, PMD_SHIFT);
...	...	@@ -477,7 +477,7 @@
477	477	* will officially be retired.
478	478	*/
479	479	pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
480		-#ifdef CONFIG_64BIT
	480	+#ifndef __PAGETABLE_PMD_FOLDED
481	481	pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
482	482	#endif
483	483	pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);
...	...	@@ -15,23 +15,31 @@
15	15	void pgd_init(unsigned long page)
16	16	{
17	17	unsigned long p, end;
	18	+ unsigned long entry;
18	19
	20	+#ifdef __PAGETABLE_PMD_FOLDED
	21	+ entry = (unsigned long)invalid_pte_table;
	22	+#else
	23	+ entry = (unsigned long)invalid_pmd_table;
	24	+#endif
	25	+
19	26	p = (unsigned long *) page;
20	27	end = p + PTRS_PER_PGD;
21	28
22	29	while (p < end) {
23		- p[0] = (unsigned long) invalid_pmd_table;
24		- p[1] = (unsigned long) invalid_pmd_table;
25		- p[2] = (unsigned long) invalid_pmd_table;
26		- p[3] = (unsigned long) invalid_pmd_table;
27		- p[4] = (unsigned long) invalid_pmd_table;
28		- p[5] = (unsigned long) invalid_pmd_table;
29		- p[6] = (unsigned long) invalid_pmd_table;
30		- p[7] = (unsigned long) invalid_pmd_table;
	30	+ p[0] = entry;
	31	+ p[1] = entry;
	32	+ p[2] = entry;
	33	+ p[3] = entry;
	34	+ p[4] = entry;
	35	+ p[5] = entry;
	36	+ p[6] = entry;
	37	+ p[7] = entry;
31	38	p += 8;
32	39	}
33	40	}
34	41
	42	+#ifndef __PAGETABLE_PMD_FOLDED
35	43	void pmd_init(unsigned long addr, unsigned long pagetable)
36	44	{
37	45	unsigned long p, end;
38	46
...	...	@@ -40,17 +48,18 @@
40	48	end = p + PTRS_PER_PMD;
41	49
42	50	while (p < end) {
43		- p[0] = (unsigned long)pagetable;
44		- p[1] = (unsigned long)pagetable;
45		- p[2] = (unsigned long)pagetable;
46		- p[3] = (unsigned long)pagetable;
47		- p[4] = (unsigned long)pagetable;
48		- p[5] = (unsigned long)pagetable;
49		- p[6] = (unsigned long)pagetable;
50		- p[7] = (unsigned long)pagetable;
	51	+ p[0] = pagetable;
	52	+ p[1] = pagetable;
	53	+ p[2] = pagetable;
	54	+ p[3] = pagetable;
	55	+ p[4] = pagetable;
	56	+ p[5] = pagetable;
	57	+ p[6] = pagetable;
	58	+ p[7] = pagetable;
51	59	p += 8;
52	60	}
53	61	}
	62	+#endif
54	63
55	64	void __init pagetable_init(void)
56	65	{
57	66
...	...	@@ -59,8 +68,9 @@
59	68
60	69	/* Initialize the entire pgd. */
61	70	pgd_init((unsigned long)swapper_pg_dir);
	71	+#ifndef __PAGETABLE_PMD_FOLDED
62	72	pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table);
63		-
	73	+#endif
64	74	pgd_base = swapper_pg_dir;
65	75	/*
66	76	* Fixed mappings:
...	...	@@ -549,11 +549,13 @@
549	549
550	550	uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
551	551	uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
	552	+#ifndef __PAGETABLE_PMD_FOLDED
552	553	uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
553	554	uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */
554	555	uasm_i_dsrl(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
555	556	uasm_i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
556	557	uasm_i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
	558	+#endif
557	559	}
558	560
559	561	/*