[LV-kern-commit] CVS: kernel-2.4/include/asm-vax/mm pgalloc.h,1.7,1.8

[Andy P. <at...@us...>]

Update of /cvsroot/linux-vax/kernel-2.4/include/asm-vax/mm
In directory usw-pr-cvs1:/tmp/cvs-serv19188/mm

Modified Files:
	pgalloc.h 
Log Message:
machine check implementation


Index: pgalloc.h
===================================================================
RCS file: /cvsroot/linux-vax/kernel-2.4/include/asm-vax/mm/pgalloc.h,v
retrieving revision 1.7
retrieving revision 1.8
diff -u -r1.7 -r1.8
--- pgalloc.h	2001/06/17 12:39:19	1.7
+++ pgalloc.h	2001/06/26 19:01:11	1.8
@@ -166,162 +166,10 @@
 #define pgd_free(pgd)	   free_pgd_slow(pgd)
 #define pgd_alloc()	     get_pgd_fast()
 
+/* atp jun 01, moved these to arch/vax/mm/pgalloc.c */
 /* Allocate a new page for a page table for the kernel */
-/* It is called from mm/vmalloc.c in  alloc_area_pmd() 
- * 
- * It needs to be physically contiguous with the rest of the 
- * system page table. 
- * Things to consider: 
- *   If you want to allocate a pagetable to hold a pte for a given
- *   new S0 address, (where this address is higher than SBR+SLR) then that
- *   new page table page must be allocated at the exact physical page 
- *   That maps that S0 address. I.e. 
- *    To map a virtual address X you need to allocate the physical
- *   page containing the address
- * 
- *               PFN = ( (X-PAGE_OFFSET) >> PAGE_SHIFT) 
- *   PTE address (physical memory) = (PFN*4)+SBR 
- *   Physical page address = (PTE address) & ~(PAGE_MASK) 
- *              SLR  = ((Physical page address + (1<<PAGE_SHIFT)) - SBR) / 4.
- * 
- * 
- *   If that physical page is already occupied, the contents must
- * be ejected.  This takes time, and can lead to deadlock, particularly
- * if a dirty page needs to be written to disk/swap. 
- *   Also, any physical pages that are in between the previous end of the 
- * system page table, and the new end (SBR+SLR) will need to be cleared,
- * otherwise random rubbish will end up in the system page table. 
- *   One way to do this by "locking up the machine", moving the contents
- * of the physical pages needed to pages on the freelist, rewriting the PTE's 
- * to point at the new physical pages, and then allocating and expanding 
- * the system page table. No scheduling allowed.  Also how you locate all
- * of the references to a given physical page so that you can rewrite them
- * without conducting a thorough search of all page tables (possibly
- * incurring page faults for those P0 page tables that have been swapped out)
- * is not clear. 
- * 						 
- * 
- *  - 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)
-{
-  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. 
- * for a user process. 
- * We grab a random page. The only catch is that it must be virtually
- * contiguous within the P0 or P1 page tables, which are held in S0
- * space. So, we remap the page table area in S0 space too. 
- */
-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);
-      /* 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;
-  unsigned long t2;
-  pte_t *page;
-  
-  pte_number = (address >> PAGE_SHIFT);
-  pte_page   = (pte_number >> SIZEOF_PTE_LOG2);
-  pte_page_offset = pte_number & (PTRS_PER_PTE - 1);
-     
-  /* 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;
-  } 
-
-   /* do we need to allocate another page(s) */
-   
-  
-    /* this is already inside the page table region, and allocated */
-    /* return the virtual address of the pte. (base registers for p0 and p1 */
-    /* refer to virtual addresses in S0 space) so no _va() is needed */
-  if (pte_number < (pgdptr->lr)) {
-    return (pte_t *) (pgdptr->br + pte_number*BYTES_PER_PTE_T);
-  }
-   
-  /* The address lies outside the current page table - by how much?*/
-  /* FIXME: Maximum task size, defined by max p0 pagetable size */
-  
-  /* number of pages to allocate */
-  t2 = ((pte_number - pgdptr->lr) >> SIZEOF_PTE_LOG2) + 1 ;
-
-  while (t2--) {
-     /* grab a page off the quicklist */
-     page = get_pte_fast();
-     /* or allocate a new one if none left */
-     if (!page) page = get_pte_slow(pmd, address);
-     
-     /* run out of pages - out of memory */ 
-     /* FIXME: is there anything else we need to do to signal failure?*/
-     if (!page) {
-	printk("%s:%d: run out of free pages building page table at pte %08lx.\n", __FILE__, __LINE__, pgdptr->lr);
-	return NULL;
-     }
-     /* map this page into the S0 page table at the right point */
-     remap_and_clear_pte_page((pgd_t *)pmd, page, pte_page);
-     
-     /* add this page of PTEs to the length register */
-     /* FIXME: handle reverse P1 region... */
-     pgdptr->lr += PTRS_PER_PTE;
-  }
-  return (pte_t *)( pgdptr->br + pte_number*BYTES_PER_PTE_T);
-#endif /* if 0 */
-}
-
+extern pte_t *pte_alloc_kernel(pmd_t *pmd, unsigned long address);
+extern pte_t *pte_alloc(pmd_t *pmd, unsigned long address); 
 
 /*
  * allocating and freeing a pmd is trivial: the 1-entry pmd is