1 files changed, 197 insertions, 0 deletions
diff --git a/arch/x86/machine/pmap.h b/arch/x86/machine/pmap.h
new file mode 100644
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--- /dev/null
+++ b/arch/x86/machine/pmap.h
@@ -0,0 +1,197 @@
+/*
+ * Copyright (c) 2010, 2011, 2012 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _X86_PMAP_H
+#define _X86_PMAP_H
+
+#include <kern/param.h>
+#include <kern/types.h>
+#include <lib/stdint.h>
+
+/*
+ * Page directory/table properties.
+ */
+#ifdef PAE
+#define PMAP_PDE_SHIFT  21
+#define PMAP_PT_SHIFT   9
+#define PMAP_NR_PDT     4
+#define PMAP_PTE_PMASK  0x0000000ffffff000ULL
+#else /* PAE */
+#define PMAP_PDE_SHIFT  22
+#define PMAP_PT_SHIFT   10
+#define PMAP_NR_PDT     1
+#define PMAP_PTE_PMASK  (~PAGE_MASK)
+#endif /* PAE */
+
+#define PMAP_PTE_SHIFT 12
+
+/*
+ * The amount of virtual memory described by a page directory/table entry.
+ */
+#define PMAP_PDE_MAPSIZE    (1 << PMAP_PDE_SHIFT)
+#define PMAP_PTE_MAPSIZE    (1 << PMAP_PTE_SHIFT)
+
+/*
+ * Number of entries in a page directory/table.
+ */
+#define PMAP_PTE_PER_PT (1 << PMAP_PT_SHIFT)
+
+/*
+ * PDE/PTE flags.
+ */
+#define PMAP_PTE_PRESENT        0x001
+#define PMAP_PTE_WRITE          0x002
+#define PMAP_PTE_USER           0x004
+#define PMAP_PTE_WRITE_THROUGH  0x008
+#define PMAP_PTE_CACHE_DISABLE  0x010
+#define PMAP_PTE_ACCESSED       0x020
+#define PMAP_PTE_DIRTY          0x040
+#define PMAP_PTE_GLOBAL         0x100
+#define PMAP_PTE_AVAIL1         0x200
+#define PMAP_PTE_AVAIL2         0x400
+#define PMAP_PTE_AVAIL3         0x800
+
+/*
+ * Flags related to page protection.
+ */
+#define PMAP_PTE_PROT_MASK PMAP_PTE_WRITE
+
+/*
+ * Index of the first PDE for the kernel address space.
+ */
+#define PMAP_PDE_KERN (VM_MIN_KERNEL_ADDRESS >> PMAP_PDE_SHIFT)
+
+/*
+ * PDE index for the page directory.
+ */
+#define PMAP_PDE_PTE (VM_MAX_KERNEL_ADDRESS >> PMAP_PDE_SHIFT)
+
+/*
+ * Page table entry (also usable as a page directory entry or page directory
+ * pointer table entry).
+ */
+#ifdef PAE
+typedef uint64_t pmap_pte_t;
+#else /* PAE */
+typedef uint32_t pmap_pte_t;
+#endif /* PAE */
+
+/*
+ * Base virtual address of the linear mapping of PTEs.
+ */
+#define PMAP_PTE_BASE   ((pmap_pte_t *)(PMAP_PDE_PTE << PMAP_PDE_SHIFT))
+
+/*
+ * Base virtual address of the page directory, in the linear mapping of PTEs.
+ */
+#define PMAP_PDP_BASE   (PMAP_PTE_BASE + (PMAP_PDE_PTE * PMAP_PTE_PER_PT))
+
+/*
+ * Virtual address of the PDE that points to the PDP.
+ */
+#define PMAP_PDP_PDE    (PMAP_PDP_BASE + PMAP_PDE_PTE)
+
+/*
+ * Number of pages to reserve for the pmap module after the kernel.
+ *
+ * This pool of pure virtual memory can be used to reserve virtual addresses
+ * before the VM system is initialized.
+ */
+#define PMAP_RESERVED_PAGES 2
+
+/*
+ * Physical address map.
+ */
+struct pmap {
+    pmap_pte_t *pdir;   /* Page directory virtual address */
+    vm_phys_t pdir_pa;  /* Page directory physical address */
+#ifdef PAE
+    pmap_pte_t *pdpt;   /* Page directory pointer table physical address */
+#endif /* PAE */
+};
+
+/*
+ * The kernel pmap.
+ */
+extern struct pmap *kernel_pmap;
+
+/*
+ * Kernel page directory.
+ */
+extern pmap_pte_t pmap_kpdir[PMAP_NR_PDT * PMAP_PTE_PER_PT];
+
+#ifdef PAE
+/*
+ * Kernel page directory pointer table.
+ */
+extern pmap_pte_t pmap_kpdpt[PMAP_NR_PDT];
+#endif /* PAE */
+
+/*
+ * Address below which using the low level kernel pmap functions is safe.
+ * Its value is adjusted by calling pmap_growkernel().
+ */
+extern unsigned long pmap_klimit;
+
+/*
+ * Early initialization of the pmap module.
+ *
+ * When this function is called, basic paging is enabled and the kernel
+ * already runs at virtual addresses.
+ */
+void pmap_bootstrap(void);
+
+/*
+ * Allocate pure virtual memory.
+ *
+ * This memory is obtained from a very small pool of reserved pages located
+ * immediately after the kernel. Its purpose is to allow early mappings to
+ * be created before the VM system is available.
+ */
+unsigned long pmap_bootalloc(unsigned int nr_pages);
+
+/*
+ * Return the available kernel virtual space in virt_start and virt_end.
+ *
+ * This function is called early, during initialization of the VM system, and
+ * can't be used after since the VM has taken control of the kernel address
+ * space.
+ */
+void pmap_virtual_space(unsigned long *virt_start, unsigned long *virt_end);
+
+/*
+ * Preallocate resources so that addresses up to va can be mapped safely in
+ * the kernel pmap.
+ */
+void pmap_growkernel(unsigned long va);
+
+/*
+ * Kernel specific mapping functions.
+ *
+ * Resources for the new mappings must be preallocated.
+ */
+void pmap_kenter(unsigned long va, vm_phys_t pa);
+void pmap_kremove(unsigned long start, unsigned long end);
+void pmap_kprotect(unsigned long start, unsigned long end, int prot);
+vm_phys_t pmap_kextract(unsigned long va);
+
+/*
+ * Zero a page at the given physical address.
+ */
+void pmap_zero_page(vm_phys_t pa);
+
+#endif /* _X86_PMAP_H */