[LV-kern-commit] CVS: kernel-2.4/include/asm-vax/mm pgalloc.h,1.3,1.4

[Dave A. <ai...@us...>]

Update of /cvsroot/linux-vax/kernel-2.4/include/asm-vax/mm
In directory usw-pr-cvs1:/tmp/cvs-serv28407/include/asm-vax/mm

Modified Files:
	pgalloc.h 
Log Message:
DA: extensive changes to pgalloc.h 

allocates p0 + p1 page tables at correct place in system for 2.4
implement pte_alloc_kernel + pte_alloc in a much simplified fashion
fixed process size... needs #defining properly..


Index: pgalloc.h
===================================================================
RCS file: /cvsroot/linux-vax/kernel-2.4/include/asm-vax/mm/pgalloc.h,v
retrieving revision 1.3
retrieving revision 1.4
diff -u -r1.3 -r1.4
--- pgalloc.h	2001/02/15 01:17:23	1.3
+++ pgalloc.h	2001/05/19 12:05:51	1.4
@@ -13,12 +13,15 @@
  *      pgds into a single page, and add pages as needed. The quicklists
  *      structure can be hijacked for this. Or at least one per pagelet...
  */
-
+/* 
+ * (c) Copyright Dave Airlie 2001 - ai...@li...
+ *     --  re-write for fixed sized processes 
+ */
 #include <asm/processor.h>
 #include <linux/threads.h>
 #include <asm/mm/virtmap.h>
+#include <linux/vmalloc.h>
 
-
 #ifndef CONFIG_SMP
 extern struct pgtable_cache_struct {
 	unsigned long *pgd_cache;
@@ -31,7 +34,6 @@
 #define quicklists cpu_data[smp_processor_id()]
 
 #endif
-
 #define pgd_quicklist (quicklists.pgd_cache)
 #define pmd_quicklist ((unsigned long *)0)
 #define pte_quicklist (quicklists.pte_cache)
@@ -63,7 +65,9 @@
  * used to allocate a kernel page table - this turns on ASN bits
  * if any.
  */
-
+#if 0
+extern  pgd_t *get_pgd_slow(void);
+#else
 extern __inline__ pgd_t *get_pgd_slow(void)
 {
    	/* 
@@ -75,13 +79,22 @@
 	pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL);
 
 	if (ret) {
-	        /* set p0 and p1 regions to empty values */
-		memset(ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
-	        /* set the s0 region, from the master copy in swapper_pg_dir */
-		memcpy(ret + USER_PTRS_PER_PGD, swapper_pg_dir + USER_PTRS_PER_PGD, (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+	  /* Allocate space for the p0/p1 page tables */
+	  /* allocate 192 pages at 4096 bytes each for page tables? */
+	  ret[0].br = (unsigned long)vmalloc(192 * PAGE_SIZE);
+	  ret[0].lr = ((160*PAGE_SIZE)>>SIZEOF_PTE_LOG2); 
+	  /* the p1br needs to be set back from the end of the p1 ptes */
+	  ret[1].br = (ret[0].br - 0x800000) + (192*PAGE_SIZE);
+	  ret[1].lr = 0x40000-((32*PAGE_SIZE)>>SIZEOF_PTE_LOG2);
+
+	  printk("get_pgd: p0: %8lX, %8lX, p1: %8lX, %8lx\n", ret[0].br, ret[0].lr, ret[1].br, ret[1].lr);
+	  
+	  /* set the s0 region, from the master copy in swapper_pg_dir */
+	  memcpy(ret + USER_PTRS_PER_PGD, swapper_pg_dir + USER_PTRS_PER_PGD, (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
 	}
 	return ret;
 }
+#endif
 
 extern __inline__ pgd_t *get_pgd_fast(void)
 {
@@ -93,6 +106,7 @@
 		pgtable_cache_size--;
 	} else
 		ret = (unsigned long *)get_pgd_slow();
+
 	return (pgd_t *)ret;
 }
 
@@ -179,12 +193,21 @@
  * 
  *  - At present I'm ducking this. We fix the S0 page table size at  
  *  boot time, and disallow dynamic expansion. atp Feb 2001. 
+ * 
+ *  - we still need to implement this ... linux still calls it .. 
+ *  - D.A. May 2001.
  */
 extern inline pte_t * pte_alloc_kernel(pmd_t * pmd, unsigned long address)
 {
-   return NULL;
-}
+  pgd_t *pgdptr = (pgd_t *)pmd;
 
+  /* note the lr in the system pgd is in PAGELETS.... shift it down to 
+     give page view */
+  if ((address >> PAGE_SHIFT) < (pgdptr->lr>>3)) 
+    return pte_offset(pmd, address);
+  else
+    return NULL;
+}
 
 /* 
  * allocate a page, to hold page table entries. 
@@ -195,7 +218,45 @@
  */
 extern inline pte_t * pte_alloc(pmd_t * pmd, unsigned long address)
 {
-   
+  unsigned long pte_number, pte_page, pte_page_offset;
+  pgd_t *pgdptr = (pgd_t *)pmd;
+  pte_t *newpte= NULL;
+  
+  /* Deal with P0 vs P1 spaces */
+  /* need to handle error cases */
+  if (address < 0x40000000)
+    {
+      pte_number = (address >> PAGE_SHIFT);
+      pte_page   = (pte_number >> SIZEOF_PTE_LOG2);
+      pte_page_offset = pte_number & (PTRS_PER_PTE - 1);
+      if ((pte_number) < (pgdptr->lr)) {
+	newpte = pte_offset(pmd, address);
+      }
+    }
+  else
+    {
+      address-=0x40000000;
+      pte_number = (address>>PAGE_SHIFT);
+      pte_page = (pte_number >> SIZEOF_PTE_LOG2);
+      pte_page_offset = pte_number & (PTRS_PER_PTE - 1);
+      if ((pte_number) > (pgdptr->lr)) {
+	newpte = pte_offset(pmd, address);
+      }
+
+    }
+
+  if (newpte)
+    {
+      remap_and_clear_pte_page((pgd_t *)pmd, newpte, pte_page);
+      pte_clear(newpte);
+      /* make sure a page in S0 space is mapped */
+
+    }
+  return newpte;
+
+  /* old 2.2 code commented out for now .. in case it is of any use 
+     to anyone later - D.A. May 2001 */  
+#if 0   
   /* calculate the offset of the requested pte in this pagetable page */
   unsigned long pte_number, pte_page, pte_page_offset;
   pgd_t *pgdptr = (pgd_t *)pmd;
@@ -209,6 +270,7 @@
   /* do we have a pgd base and length set ? */
   /* The p0br and p1br should be setup at process initialisation. */
   if (pmd_none(*pmd)) {
+    printk("Got pmd_none\n");
      		return NULL;
   } 
 
@@ -248,6 +310,7 @@
      pgdptr->lr += PTRS_PER_PTE;
   }
   return (pte_t *)( pgdptr->br + pte_number*BYTES_PER_PTE_T);
+#endif /* if 0 */
 }