Edited and added various comments.
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mark
parent
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@ -1,4 +1,4 @@
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/* $NetBSD: pmap.c,v 1.20 1998/04/30 21:22:01 mark Exp $ */
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/* $NetBSD: pmap.c,v 1.21 1998/05/01 15:30:54 mark Exp $ */
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/*
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* Copyright (c) 1994-1997 Mark Brinicombe.
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@ -196,6 +196,10 @@ pmap_debug(level)
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* pages.
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*/
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/*
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* Allocate a new pv_entry structure from the freelist. If the list is
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* empty allocate a new page and fill the freelist.
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*/
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struct pv_entry *
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pmap_alloc_pv()
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{
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@ -235,6 +239,10 @@ pmap_alloc_pv()
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return pv;
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}
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/*
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* Release a pv_entry structure putting it back on the freelist.
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*/
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void
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pmap_free_pv(pv)
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struct pv_entry *pv;
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@ -316,6 +324,9 @@ pmap_collect_pv()
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}
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}
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/*
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* Enter a new physical-virtual mapping into the pv table
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*/
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/*__inline*/ int
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pmap_enter_pv(pmap, va, pind, flags)
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@ -375,6 +386,10 @@ pmap_enter_pv(pmap, va, pind, flags)
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}
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/*
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* Remove a physical-virtual mapping from the pv table
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*/
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/* __inline*/ u_int
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pmap_remove_pv(pmap, va, pind)
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pmap_t pmap;
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@ -438,6 +453,9 @@ pmap_remove_pv(pmap, va, pind)
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return(flags);
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}
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/*
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* Modify a physical-virtual mapping in the pv table
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*/
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/*__inline */ u_int
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pmap_modify_pv(pmap, va, pind, bic_mask, eor_mask)
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@ -501,6 +519,11 @@ pmap_modify_pv(pmap, va, pind, bic_mask, eor_mask)
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}
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/*
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* Map the specified level 2 pagetable into the level 1 page table for
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* the given pmap to cover a chunk of virtual address space starting from the
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* address specified.
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*/
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static /*__inline*/ void
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pmap_map_in_l1(pmap, va, l2pa)
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pmap_t pmap;
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@ -508,6 +531,7 @@ pmap_map_in_l1(pmap, va, l2pa)
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{
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vm_offset_t ptva;
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/* Calculate the index into the L1 page table */
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ptva = (va >> PDSHIFT) & ~3;
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#ifdef PMAP_DEBUG
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if (pmap_debug_level >= 0)
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@ -515,7 +539,7 @@ pmap_map_in_l1(pmap, va, l2pa)
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pmap->pm_pdir, L1_PTE(l2pa), ptva);
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#endif /* PMAP_DEBUG */
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/* Wire page table into the L1 */
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/* Map page table into the L1 */
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pmap->pm_pdir[ptva + 0] = L1_PTE(l2pa + 0x000);
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pmap->pm_pdir[ptva + 1] = L1_PTE(l2pa + 0x400);
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pmap->pm_pdir[ptva + 2] = L1_PTE(l2pa + 0x800);
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@ -531,11 +555,11 @@ pmap_map_in_l1(pmap, va, l2pa)
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*((pt_entry_t *)(pmap->pm_vptpt + ptva)) =
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L2_PTE_NC_NB(l2pa, AP_KRW);
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/* XXX should be a purge */
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cpu_tlb_flushD();
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}
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/*
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* Used to map a range of physical addresses into kernel
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* virtual address space.
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@ -736,7 +760,7 @@ pmap_create(size)
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* pmap_alloc_l1pt()
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*
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* This routine allocates physical and virtual memory for a L1 page table
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* and wires in.
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* and wires it.
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* A l1pt structure is returned to describe the allocated page table.
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*
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* This routine is allowed to fail if the required memory cannot be allocated.
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@ -920,7 +944,7 @@ pmap_allocpagedir(pmap)
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/*
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* Now we get nasty. We need to map the page
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* directory to a standard address in the memory
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* map. This means we can easily find the active
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* map. This means we can easily find the active
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* page directory. This is needed by pmap_pte to
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* hook in an alternate pmap's page tables.
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* This means that a page table is needed in each
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@ -1084,7 +1108,13 @@ pmap_release(pmap)
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/* Remove the zero page mapping */
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pmap_remove(pmap, 0x00000000, 0x00000000 + NBPG);
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/* Free any page tables still mapped */
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/*
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* Free any page tables still mapped
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* This is only temporay until pmap_enter can count the number
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* of mappings made in a page table. Then pmap_remove() can
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* reduce the count and free the pagetable when the count
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* reaches zero.
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*/
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for (loop = 0; loop < 0x3bf; ++loop) {
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pte = (pt_entry_t *)(pmap->pm_vptpt + loop * 4);
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if (*pte != 0) {
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@ -1094,7 +1124,7 @@ pmap_release(pmap)
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#endif /* PMAP_DEBUG */
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page = PHYS_TO_VM_PAGE(pmap_pte_pa(pte));
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if (page == NULL)
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panic("pmap_free_physpage: bogus physical page address");
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panic("pmap_release: bad address for phys page");
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vm_page_free1(page);
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}
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}
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@ -1103,7 +1133,6 @@ pmap_release(pmap)
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}
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/*
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* void pmap_reference(pmap_t pmap)
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*
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@ -2031,7 +2060,7 @@ pmap_enter(pmap, va, pa, prot, wired)
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struct vm_page *page;
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vm_offset_t l2pa;
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/* Allocate a page table to cover the mapping of zero page */
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/* Allocate a page table */
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page = vm_page_alloc1();
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/* XXX should try and free up memory if alloc fails */
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@ -2883,6 +2912,13 @@ pmap_page_attributes(va)
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}
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/*
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* pmap_collect: free resources held by a pmap
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*
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* => optional function.
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* => called when a process is swapped out to free memory.
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*/
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void
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pmap_collect(pmap)
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pmap_t pmap;
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