2.4.3-pre6 alpha pte/pmd_alloc update

From: Ivan Kokshaysky (ink@jurassic.park.msu.ru)
Date: Wed Mar 21 2001 - 13:12:32 EST


Surprisingly, it works on lx164. :-)

Ivan.

On Mon, Mar 19, 2001 at 06:46:17PM -0800, Linus Torvalds wrote:
> This has only been tested on i386 without PAE, and is known to break other
> architectures. Ingo, mind checking what PAE needs? Generally, the changes
> are simple, and really only implies changing the pte/pmd allocation
> functions to _only_ allocate (ie removing the stuff that actually modifies
> the page tables, as that is now handled by generic code), and to make sure
> that the "pgd/pmd_populate()" functions do the right thing.
>
> I have also removed the xxx_kernel() functions - for architectures that
> need them, I suspect that the right approach is to just make the
> "populate" funtions notice when "mm" is "init_mm", the kernel context.
> That removed a lot of duplicate code that had little good reason.

diff -urp 2.4.3p6/arch/alpha/mm/init.c linux/arch/alpha/mm/init.c
--- 2.4.3p6/arch/alpha/mm/init.c Wed Nov 29 09:43:39 2000
+++ linux/arch/alpha/mm/init.c Wed Mar 21 20:04:21 2001
@@ -43,20 +43,6 @@ struct thread_struct original_pcb;
 struct pgtable_cache_struct quicklists;
 #endif
 
-void
-__bad_pmd(pgd_t *pgd)
-{
- printk("Bad pgd in pmd_alloc: %08lx\n", pgd_val(*pgd));
- pgd_set(pgd, BAD_PAGETABLE);
-}
-
-void
-__bad_pte(pmd_t *pmd)
-{
- printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd));
- pmd_set(pmd, (pte_t *) BAD_PAGETABLE);
-}
-
 pgd_t *
 get_pgd_slow(void)
 {
@@ -80,66 +66,26 @@ get_pgd_slow(void)
         return ret;
 }
 
-pmd_t *
-get_pmd_slow(pgd_t *pgd, unsigned long offset)
-{
- pmd_t *pmd;
-
- pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
- if (pgd_none(*pgd)) {
- if (pmd) {
- clear_page((void *)pmd);
- pgd_set(pgd, pmd);
- return pmd + offset;
- }
- pgd_set(pgd, BAD_PAGETABLE);
- return NULL;
- }
- free_page((unsigned long)pmd);
- if (pgd_bad(*pgd)) {
- __bad_pmd(pgd);
- return NULL;
- }
- return (pmd_t *) pgd_page(*pgd) + offset;
-}
-
-pte_t *
-get_pte_slow(pmd_t *pmd, unsigned long offset)
-{
- pte_t *pte;
-
- pte = (pte_t *) __get_free_page(GFP_KERNEL);
- if (pmd_none(*pmd)) {
- if (pte) {
- clear_page((void *)pte);
- pmd_set(pmd, pte);
- return pte + offset;
- }
- pmd_set(pmd, (pte_t *) BAD_PAGETABLE);
- return NULL;
- }
- free_page((unsigned long)pte);
- if (pmd_bad(*pmd)) {
- __bad_pte(pmd);
- return NULL;
- }
- return (pte_t *) pmd_page(*pmd) + offset;
-}
-
 int do_check_pgt_cache(int low, int high)
 {
         int freed = 0;
- if(pgtable_cache_size > high) {
- do {
- if(pgd_quicklist)
- free_pgd_slow(get_pgd_fast()), freed++;
- if(pmd_quicklist)
- free_pmd_slow(get_pmd_fast()), freed++;
- if(pte_quicklist)
- free_pte_slow(get_pte_fast()), freed++;
- } while(pgtable_cache_size > low);
- }
- return freed;
+ if(pgtable_cache_size > high) {
+ do {
+ if(pgd_quicklist) {
+ free_pgd_slow(get_pgd_fast());
+ freed++;
+ }
+ if(pmd_quicklist) {
+ pmd_free_slow(pmd_alloc_one_fast());
+ freed++;
+ }
+ if(pte_quicklist) {
+ pte_free_slow(pte_alloc_one_fast());
+ freed++;
+ }
+ } while(pgtable_cache_size > low);
+ }
+ return freed;
 }
 
 /*
diff -urp 2.4.3p6/include/asm-alpha/pgalloc.h linux/include/asm-alpha/pgalloc.h
--- 2.4.3p6/include/asm-alpha/pgalloc.h Sat Dec 30 01:07:23 2000
+++ linux/include/asm-alpha/pgalloc.h Wed Mar 21 19:48:27 2001
@@ -241,6 +241,9 @@ extern struct pgtable_cache_struct {
 #define pte_quicklist (quicklists.pte_cache)
 #define pgtable_cache_size (quicklists.pgtable_cache_sz)
 
+#define pmd_populate(pmd, pte) pmd_set(pmd, pte)
+#define pgd_populate(pgd, pmd) pgd_set(pgd, pmd)
+
 extern pgd_t *get_pgd_slow(void);
 
 static inline pgd_t *get_pgd_fast(void)
@@ -268,9 +271,15 @@ static inline void free_pgd_slow(pgd_t *
         free_page((unsigned long)pgd);
 }
 
-extern pmd_t *get_pmd_slow(pgd_t *pgd, unsigned long address_premasked);
+static inline pmd_t *pmd_alloc_one(void)
+{
+ pmd_t *ret = (pmd_t *)__get_free_page(GFP_KERNEL);
+ if (ret)
+ clear_page(ret);
+ return ret;
+}
 
-static inline pmd_t *get_pmd_fast(void)
+static inline pmd_t *pmd_alloc_one_fast(void)
 {
         unsigned long *ret;
 
@@ -282,21 +291,27 @@ static inline pmd_t *get_pmd_fast(void)
         return (pmd_t *)ret;
 }
 
-static inline void free_pmd_fast(pmd_t *pmd)
+static inline void pmd_free_fast(pmd_t *pmd)
 {
         *(unsigned long *)pmd = (unsigned long) pte_quicklist;
         pte_quicklist = (unsigned long *) pmd;
         pgtable_cache_size++;
 }
 
-static inline void free_pmd_slow(pmd_t *pmd)
+static inline void pmd_free_slow(pmd_t *pmd)
 {
         free_page((unsigned long)pmd);
 }
 
-extern pte_t *get_pte_slow(pmd_t *pmd, unsigned long address_preadjusted);
+static inline pte_t *pte_alloc_one(void)
+{
+ pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL);
+ if (pte)
+ clear_page(pte);
+ return pte;
+}
 
-static inline pte_t *get_pte_fast(void)
+static inline pte_t *pte_alloc_one_fast(void)
 {
         unsigned long *ret;
 
@@ -308,66 +323,22 @@ static inline pte_t *get_pte_fast(void)
         return (pte_t *)ret;
 }
 
-static inline void free_pte_fast(pte_t *pte)
+static inline void pte_free_fast(pte_t *pte)
 {
         *(unsigned long *)pte = (unsigned long) pte_quicklist;
         pte_quicklist = (unsigned long *) pte;
         pgtable_cache_size++;
 }
 
-static inline void free_pte_slow(pte_t *pte)
+static inline void pte_free_slow(pte_t *pte)
 {
         free_page((unsigned long)pte);
 }
 
-extern void __bad_pte(pmd_t *pmd);
-extern void __bad_pmd(pgd_t *pgd);
-
-#define pte_free_kernel(pte) free_pte_fast(pte)
-#define pte_free(pte) free_pte_fast(pte)
-#define pmd_free_kernel(pmd) free_pmd_fast(pmd)
-#define pmd_free(pmd) free_pmd_fast(pmd)
+#define pte_free(pte) pte_free_fast(pte)
+#define pmd_free(pmd) pmd_free_fast(pmd)
 #define pgd_free(pgd) free_pgd_fast(pgd)
 #define pgd_alloc() get_pgd_fast()
-
-static inline pte_t * pte_alloc(pmd_t *pmd, unsigned long address)
-{
- address = (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
- if (pmd_none(*pmd)) {
- pte_t *page = get_pte_fast();
-
- if (!page)
- return get_pte_slow(pmd, address);
- pmd_set(pmd, page);
- return page + address;
- }
- if (pmd_bad(*pmd)) {
- __bad_pte(pmd);
- return NULL;
- }
- return (pte_t *) pmd_page(*pmd) + address;
-}
-
-static inline pmd_t * pmd_alloc(pgd_t *pgd, unsigned long address)
-{
- address = (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
- if (pgd_none(*pgd)) {
- pmd_t *page = get_pmd_fast();
-
- if (!page)
- return get_pmd_slow(pgd, address);
- pgd_set(pgd, page);
- return page + address;
- }
- if (pgd_bad(*pgd)) {
- __bad_pmd(pgd);
- return NULL;
- }
- return (pmd_t *) pgd_page(*pgd) + address;
-}
-
-#define pte_alloc_kernel pte_alloc
-#define pmd_alloc_kernel pmd_alloc
 
 extern int do_check_pgt_cache(int, int);
 
-
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This archive was generated by hypermail 2b29 : Fri Mar 23 2001 - 21:00:16 EST