Vmalloc/vfree fixes: use swapper_pg_dir[0] for the vmalloc range

translations, use a kernel pmd table that points into the kptbl[].
This is to make the generic part of vmalloc()/vfree() find pgd/pmd/pte
that it expects.

4 files changed, 18 insertions, 4 deletions

diff --git a/arch/mips64/kernel/head.S b/arch/mips64/kernel/head.S
index 74d3c34ef..f87366d21 100644
--- a/arch/mips64/kernel/head.S
+++ b/arch/mips64/kernel/head.S
@@ -173,4 +173,5 @@ NESTED(bootstrap, 16, sp)
 	page	empty_bad_pmd_table, 1
 	page	kptbl, KPTBL_PAGE_ORDER
 	.globl	ekptbl
+	page	kpmdtbl, 0
 ekptbl:
diff --git a/arch/mips64/kernel/setup.c b/arch/mips64/kernel/setup.c
index 93f7f8a78..691e88d20 100644
--- a/arch/mips64/kernel/setup.c
+++ b/arch/mips64/kernel/setup.c
@@ -154,8 +154,10 @@ void __init setup_arch(char **cmdline_p)
 	unsigned long tmp;
 	unsigned long *initrd_header;
 #endif
+	int i;
+	pmd_t *pmd = kpmdtbl;
+	pte_t *pte = kptbl;
 
-	memset((void *)kptbl, 0, PAGE_SIZE << KPTBL_PAGE_ORDER);
 	cpu_probe();
 	load_mmu();
 
@@ -193,4 +195,10 @@ void __init setup_arch(char **cmdline_p)
 #endif
 
 	paging_init();
+
+	memset((void *)kptbl, 0, PAGE_SIZE << KPTBL_PAGE_ORDER);
+	memset((void *)kpmdtbl, 0, PAGE_SIZE);
+	pgd_set(swapper_pg_dir, kpmdtbl);
+	for (i = 0; i < (1 << KPTBL_PAGE_ORDER); pmd++,i++,pte+=PTRS_PER_PTE)
+		pmd_val(*pmd) = (unsigned long)pte;
 }
diff --git a/include/asm-mips64/pgalloc.h b/include/asm-mips64/pgalloc.h
index 8d091227a..d9a766097 100644
--- a/include/asm-mips64/pgalloc.h
+++ b/include/asm-mips64/pgalloc.h
@@ -192,9 +192,9 @@ extern inline pmd_t *pmd_alloc(pgd_t * pgd, unsigned long address)
 }
 
 extern pte_t kptbl[(PAGE_SIZE<<KPTBL_PAGE_ORDER)/sizeof(pte_t)];
+extern pmd_t kpmdtbl[PTRS_PER_PMD];
 
-#define MAGIC_PMD_VAL		((pmd_t *)0x1234)
-#define pmd_alloc_kernel(d,a)	MAGIC_PMD_VAL
+#define pmd_alloc_kernel(d,a)	(pmd_t *)kpmdtbl
 
 extern inline pte_t * pte_alloc_kernel(pmd_t * pmd, unsigned long address)
 {
diff --git a/include/asm-mips64/pgtable.h b/include/asm-mips64/pgtable.h
index e3f688c8a..6e6212a06 100644
--- a/include/asm-mips64/pgtable.h
+++ b/include/asm-mips64/pgtable.h
@@ -64,6 +64,11 @@ do {									\
  * that the failure is recognized later on. Linux does not seem to 
  * handle these failures very well though. The empty_bad_page_table has
  * invalid pte entries in it, to force page faults.
+ * Vmalloc handling: vmalloc uses swapper_pg_dir[0] (returned by 
+ * pgd_offset_k), which is initalized to point to kpmdtbl. kpmdtbl is 
+ * the only single page pmd in the system. kpmdtbl entries point into 
+ * kptbl[] array. We reserve 1<<KPTBL_PAGE_ORDER pages to hold the
+ * vmalloc range translations, which the fault handler looks at.
  */
 
 #endif /* !defined (_LANGUAGE_ASSEMBLY) */
@@ -442,7 +447,7 @@ extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 #define page_pte(page) page_pte_prot(page, __pgprot(0))
 
 /* to find an entry in a kernel page-table-directory */
-#define pgd_offset_k(address) pgd_offset(&init_mm, address)
+#define pgd_offset_k(address) pgd_offset(&init_mm, 0)
 
 #define pgd_index(address)	((address >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))