Initial commit

tasks/mm0/include/vm_area.h

@@ -0,0 +1,128 @@
+/*
+ * Virtual memory area descriptors. No page cache yet.
+ *
+ * Copyright (C) 2007 Bahadir Balban
+ */
+#ifndef __VM_AREA_H__
+#define __VM_AREA_H__
+
+#include <stdio.h>
+#include <task.h>
+#include <l4/macros.h>
+#include <l4/config.h>
+#include <l4/types.h>
+#include <arch/mm.h>
+#include <lib/spinlock.h>
+
+/* Protection flags */
+#define VM_NONE				(1 << 0)
+#define VM_READ				(1 << 1)
+#define VM_WRITE			(1 << 2)
+#define VM_EXEC				(1 << 3)
+#define VM_PROT_MASK			(VM_READ | VM_WRITE | VM_EXEC)
+#define VM_SWAPPED			(1 << 4)
+
+/* VMA flags */
+#define VMA_SHARED			(1 << 3)
+/* VMA that's not file-backed, always ZI */
+#define VMA_ANON			(1 << 4)
+/* Private copy of a file VMA, can be ZI */
+#define VMA_COW				(1 << 5)
+/* This marks shadow vmas */
+#define VMA_SHADOW			(1 << 6)
+
+struct page {
+	int count;		/* Refcount */
+	struct spinlock lock;	/* Page lock. */
+	struct list_head list;  /* For list of a file's in-memory pages */
+	unsigned long virtual;	/* If refs >1, first mapper's virtual address */
+	struct vm_file *owner;	/* The file it belongs to */
+	unsigned int flags;	/* Flags associated with the page. */
+	unsigned long f_offset; /* The offset page resides in its owner */
+};
+extern struct page *page_array;
+
+#define page_refcnt(x)		((x)->count + 1)
+#define virtual(x)		((x)->virtual)
+#define phys_to_page(x)		(page_array + __pfn(x))
+#define page_to_phys(x)		__pfn_to_addr((((void *)x) - \
+					       (void *)page_array) \
+					      / sizeof(struct page))
+
+/* Fault data specific to this task + ptr to kernel's data */
+struct fault_data {
+	fault_kdata_t *kdata;		/* Generic data flonged by the kernel */
+	unsigned int reason;		/* Generic fault reason flags */
+	unsigned int address;		/* Aborted address */
+	struct vm_area *vma;		/* Inittask-related fault data */
+	struct tcb *task;		/* Inittask-related fault data */
+};
+
+struct vm_pager_ops {
+	void (*read_page)(struct fault_data *f, void *);
+	void (*write_page)(struct fault_data *f, void *);
+};
+
+/* Describes the pager task that handles a vm_area. */
+struct vm_pager {
+	struct vm_pager_ops ops;	/* The ops the pager does on area */
+};
+
+/*
+ * TODO: Since there's no vfs yet, an inode's i_addr field is the
+ * virtual memory address of a file which uniquely identifies that file.
+ */
+struct inode {
+	unsigned long i_addr;	/* The unique, global resource id. */
+};
+
+/*
+ * Describes the in-memory representation of a file. This could
+ * point at a file or another resource, e.g. a device area or swapper space.
+ */
+struct vm_file {
+	struct inode inode;
+	unsigned long length;
+
+	/* This is the cache of physical pages that this file has in memory. */
+	struct list_head page_cache_list;
+	struct vm_pager *pager;
+};
+
+/*
+ * Describes a virtually contiguous chunk of memory region in a task. It covers
+ * a unique virtual address area within its task, meaning that it does not
+ * overlap with other regions in the same task. The region could be backed by a
+ * file or various other resources. This is managed by the region's pager.
+ */
+struct vm_area {
+	struct list_head list;		/* Vma list */
+	struct list_head shadow_list;	/* Head for shadow list. See fault.c */
+	unsigned long pfn_start;	/* Region start virtual pfn */
+	unsigned long pfn_end;		/* Region end virtual pfn, exclusive */
+	unsigned long flags;		/* Protection flags. */
+	unsigned long f_offset;		/* File offset in pfns */
+	struct vm_file *owner;		/* File that backs the area. */
+};
+
+static inline struct vm_area *find_vma(unsigned long addr,
+				       struct list_head *vm_area_list)
+{
+	struct vm_area *vma;
+	unsigned long pfn = __pfn(addr);
+
+	list_for_each_entry(vma, vm_area_list, list)
+		if ((pfn >= vma->pfn_start) && (pfn < vma->pfn_end))
+			return vma;
+	return 0;
+}
+
+/* Pagers */
+extern struct vm_pager default_file_pager;
+extern struct vm_pager swap_pager;
+
+
+/* Main page fault entry point */
+void page_fault_handler(l4id_t tid, fault_kdata_t *fkdata);
+
+#endif /* __VM_AREA_H__ */