i386/ucla/src/lab3/kern/pmap.h

   1 /* See COPYRIGHT for copyright information. */
   2
   3 #ifndef JOS_KERN_PMAP_H
   4 #define JOS_KERN_PMAP_H
   5 #ifndef JOS_KERNEL
   6 # error "This is a JOS kernel header; user programs should not #include it"
   7 #endif
   8
   9 #include <inc/memlayout.h>
  10 #include <inc/assert.h>
  11 struct Env;
  12
  13
  14 /* This macro takes a kernel virtual address -- an address that points above
  15  * KERNBASE, where the machine's maximum 256MB of physical memory is mapped --
  16  * and returns the corresponding physical address.  It panics if you pass it a
  17  * non-kernel virtual address.
  18  */
  19 #define PADDR(kva)                                              \
  20 ({                                                              \
  21         physaddr_t __m_kva = (physaddr_t) (kva);                \
  22         if (__m_kva < KERNBASE)                                 \
  23                 panic("PADDR called with invalid kva %08lx", __m_kva);\
  24         __m_kva - KERNBASE;                                     \
  25 })
  26
  27 /* This macro takes a physical address and returns the corresponding kernel
  28  * virtual address.  It panics if you pass an invalid physical address. */
  29 #define KADDR(pa)                                               \
  30 ({                                                              \
  31         physaddr_t __m_pa = (pa);                               \
  32         uint32_t __m_ppn = PGNUM(__m_pa);                       \
  33         if (__m_ppn >= npages)                                  \
  34                 panic("KADDR called with invalid pa %08lx", __m_pa);\
  35         (void*) (__m_pa + KERNBASE);                            \
  36 })
  37
  38
  39 // Page structures.
  40 // Each Page describes one physical page.
  41 // The pages[] array keeps track of the state of physical memory.
  42 // Entry pages[N] holds information about physical page #N.
  43 // The machine has 'npages' pages of physical memory space.
  44 extern struct Page *pages;
  45 extern size_t npages;
  46
  47 struct Page {
  48         // Next page on the free list.
  49         Page *pp_link;
  50
  51         // Count of pointers to this page (usually in page table entries).
  52         // Reserved pages may not have valid reference counts.
  53         uint16_t pp_ref;
  54 };
  55
  56 extern pde_t *kern_pgdir;
  57
  58 extern struct Segdesc gdt[];
  59 extern struct Pseudodesc gdt_pd;
  60
  61 void    mem_init(void);
  62
  63 void    page_init(void);
  64 struct Page *page_alloc(void);
  65 void    page_free(struct Page *pp);
  66 int     page_insert(pde_t *pgdir, struct Page *pp, uintptr_t va, pte_t perm);
  67 void    page_remove(pde_t *pgdir, uintptr_t va);
  68 struct Page *page_lookup(pde_t *pgdir, uintptr_t va, pte_t **pte_store);
  69 void    page_decref(struct Page *pp);
  70
  71 void    tlb_invalidate(pde_t *pgdir, uintptr_t va);
  72
  73 int     user_mem_check(struct Env *env, uintptr_t va, size_t len, pte_t perm);
  74 void    user_mem_assert(struct Env *env, uintptr_t va, size_t len, pte_t perm);
  75
  76 static inline physaddr_t
  77 page2pa(struct Page *pp)
  78 {
  79         return (pp - pages) << PGSHIFT;
  80 }
  81
  82 static inline struct Page *
  83 pa2page(physaddr_t pa)
  84 {
  85         if (PGNUM(pa) >= npages)
  86                 panic("pa2page called with invalid pa");
  87         return &pages[PGNUM(pa)];
  88 }
  89
  90 static inline void *
  91 page2kva(struct Page *pp)
  92 {
  93         return KADDR(page2pa(pp));
  94 }
  95
  96 static inline struct Page *
  97 kva2page(void *kva)
  98 {
  99         return pa2page(PADDR(kva));
 100 }
 101
 102 pte_t *pgdir_walk(pde_t *pgdir, uintptr_t va, int create);
 103
 104 #endif /* !JOS_KERN_PMAP_H */