Moved all pager page-mapping routines to memory.c

Added a new virtual address pool for contiguous virtual addresses for the pager.
This will help in mapping multi-page user buffers and files.

tasks/mm0/include/file.h

@@ -19,6 +19,8 @@ int file_open(struct tcb *opener, int fd);
 
 struct vm_file *do_open2(struct tcb *task, int fd, unsigned long vnum, unsigned long length);
 int flush_file_pages(struct vm_file *f);
+int read_file_pages(struct vm_file *vmfile, unsigned long pfn_start,
+		    unsigned long pfn_end);
 
 struct vfs_file_data {
 	unsigned long vnum;

tasks/mm0/include/memory.h

@@ -21,4 +21,12 @@ void init_mm_descriptors(struct page_bitmap *page_map,
 			 struct bootdesc *bootdesc, struct membank *membank);
 void init_physmem(struct initdata *initdata, struct membank *membank);
 
+int pager_address_pool_init(void);
+void *pager_new_address(int npages);
+int pager_delete_address(void *virt_addr, int npages);
+void *pager_map_pages(struct vm_file *f, unsigned long page_offset, unsigned long npages);
+void pager_unmap_pages(void *addr, unsigned long npages);
+void *pager_map_page(struct vm_file *f, unsigned long page_offset);
+void pager_unmap_page(void *addr);
+
 #endif /* __MEMORY_H__ */

tasks/mm0/src/file.c

@@ -21,6 +21,7 @@
 #include <user.h>
 #include <test.h>
 
+
 /* Copy from one page's buffer into another page */
 int page_copy(struct page *dst, struct page *src,
 	      unsigned long dst_offset, unsigned long src_offset,
@@ -308,27 +309,6 @@ int read_file_pages(struct vm_file *vmfile, unsigned long pfn_start,
 	return 0;
 }
 
-/* Maps a page from a vm_file to the pager's address space */
-void *pager_map_page(struct vm_file *f, unsigned long page_offset)
-{
-	int err;
-	struct page *p;
-
-	if ((err = read_file_pages(f, page_offset, page_offset + 1)) < 0)
-		return PTR_ERR(err);
-
-	if ((p = find_page(&f->vm_obj, page_offset)))
-		return (void *)l4_map_helper((void *)page_to_phys(p), 1);
-	else
-		return 0;
-}
-
-/* Unmaps a page's virtual address from the pager's address space */
-void pager_unmap_page(void *addr)
-{
-	l4_unmap_helper(addr, 1);
-}
-
 int vfs_write(unsigned long vnum, unsigned long file_offset,
 	      unsigned long npages, void *pagebuf)
 {

tasks/mm0/src/init.c

@@ -174,6 +174,10 @@ void init_mm(struct initdata *initdata)
 		printf("UTCB initialisation failed.\n");
 		BUG();
 	}
+
+	/* For supplying contiguous virtual addresses to pager */
+	pager_address_pool_init();
+
 	// printf("%s: Initialised utcb address pool.\n", __TASKNAME__);
 
 	/* Give the kernel some memory to use for its allocators */

tasks/mm0/src/lib/elf/elf.c

@@ -24,6 +24,13 @@ int elf_probe(struct elf_header *header)
 		return -1;
 }
 
+static inline void *pager_map_file_offset(struct vm_file *f, unsigned long f_offset)
+{
+	void *page = pager_map_page(f, __pfn(f_offset));
+
+	return (void *)((unsigned long)page | (PAGE_MASK & f_offset));
+}
+
 /*
  * Loading an ELF file:
  *
@@ -59,8 +66,14 @@ int elf_parse_executable(struct tcb *task, struct vm_file *file,
 	}
 
 	/* Get the section header table */
-	sect_header = (struct elf_section_header *)
+	if (__pfn(elf_header->e_shoff) > 0)
-		      ((void *)elf_header + elf_header->e_shoff);
+		sect_header = pager_map_file_offset(file, elf_header->e_shoff);
+	else
+		sect_header = (struct elf_section_header *)
+			      ((void *)elf_header + elf_header->e_shoff);
+
+	/* Determine if we cross a page boundary during traversal */
+	if (elf_header->e_shentsize * elf_header->e_shnum > TILL_PAGE_ENDS(sect_header))
 
 	/*
 	 * Sift through sections and copy their marks to tcb and efd

tasks/mm0/src/memory.c

@@ -8,15 +8,19 @@
 #include <l4/macros.h>
 #include <l4/config.h>
 #include <l4/types.h>
+#include <l4/api/errno.h>
 #include <l4/generic/space.h>
 #include <l4lib/arch/syslib.h>
 #include INC_GLUE(memory.h)
 #include INC_SUBARCH(mm.h)
 #include <memory.h>
+#include <file.h>
 
 struct membank membank[1];
 struct page *page_array;
 
+struct address_pool pager_vaddr_pool;
+
 void *phys_to_virt(void *addr)
 {
 	return addr + INITTASK_OFFSET;
@@ -90,3 +94,82 @@ void init_physmem(struct initdata *initdata, struct membank *membank)
 	page_array = membank[0].page_array;
 }
 
+/* Maps a page from a vm_file to the pager's address space */
+void *pager_map_page(struct vm_file *f, unsigned long page_offset)
+{
+	int err;
+	struct page *p;
+
+	if ((err = read_file_pages(f, page_offset, page_offset + 1)) < 0)
+		return PTR_ERR(err);
+
+	if ((p = find_page(&f->vm_obj, page_offset)))
+		return (void *)l4_map_helper((void *)page_to_phys(p), 1);
+	else
+		return 0;
+}
+
+/* Unmaps a page's virtual address from the pager's address space */
+void pager_unmap_page(void *addr)
+{
+	l4_unmap_helper(addr, 1);
+}
+
+int pager_address_pool_init(void)
+{
+	int err;
+
+	/* Initialise the global shm virtual address pool */
+	if ((err = address_pool_init(&pager_vaddr_pool,
+				     (unsigned long)0xD0000000,
+				     (unsigned long)0xE0000000)) < 0) {
+		printf("Pager virtual address pool initialisation failed.\n");
+		return err;
+	}
+	return 0;
+}
+
+void *pager_new_address(int npages)
+{
+	return address_new(&pager_vaddr_pool, npages);
+}
+
+int pager_delete_address(void *virt_addr, int npages)
+{
+	return address_del(&pager_vaddr_pool, virt_addr, npages);
+}
+
+/* Maps a page from a vm_file to the pager's address space */
+void *pager_map_pages(struct vm_file *f, unsigned long page_offset, unsigned long npages)
+{
+	int err;
+	struct page *p;
+	void *addr_start, *addr;
+
+	/* Get the pages */
+	if ((err = read_file_pages(f, page_offset, page_offset + npages)) < 0)
+		return PTR_ERR(err);
+
+	/* Get the address range */
+	if (!(addr_start = pager_new_address(npages)))
+		return PTR_ERR(-ENOMEM);
+	addr = addr_start;
+
+	/* Map pages contiguously one by one */
+	for (unsigned long pfn = page_offset; pfn < page_offset + npages; pfn++) {
+		BUG_ON(!(p = find_page(&f->vm_obj, page_offset)))
+			l4_map((void *)page_to_phys(p), addr, 1, MAP_USR_RW_FLAGS, self_tid());
+			addr += PAGE_SIZE;
+	}
+
+	return addr_start;
+}
+
+/* Unmaps a page's virtual address from the pager's address space */
+void pager_unmap_pages(void *addr, unsigned long npages)
+{
+	l4_unmap_helper(addr, npages);
+	pager_delete_address(addr, npages);
+}
+
+