integrate memory areas in process and MMU subsystems (d7ffb14c) · Commits · FiXos core team / FiXos

arch/sh/exception.c

+34 −0

Original line number	Diff line number	Diff line
		@@ -13,6 +13,7 @@
		#include <sys/memory.h>
		#include <utils/log.h>
		#include <sys/kdebug.h>
		#include <sys/mem_area.h>


		//void exception_handler() __attribute__ ((interrupt_handler, section(".handler.exception")));
		@@ -156,6 +157,39 @@ void tlbmiss_handler()
		page = mem_find_page(curpr->dir_list,
		(void*)(vpn << PM_PAGE_ORDER) );

		// if page is not in dir list (or is invalid), maybe it exists in memory
		// area (allocate it)
		// FIXME not working for shared pages
		if(page == NULL \|\| !(page->private.flags & MEM_PAGE_VALID)) {
		struct mem_area *area;
		void *virtaddr;

		virtaddr = PM_PHYSICAL_ADDR(vpn);
		area = mem_area_find(curpr, virtaddr);
		if(area != NULL) {
		union pm_page pmpage;
		void *pmaddr;

		// 'major' page fault, create and fill it
		// FIXME UNCACHED due to temporary hack to be sure nothing is retained in cache
		pmaddr = arch_pm_get_free_page(MEM_PM_UNCACHED);
		if(pmaddr != NULL) {
		pmpage.private.ppn = PM_PHYSICAL_PAGE(pmaddr);
		pmpage.private.flags = MEM_PAGE_PRIVATE \| MEM_PAGE_VALID; // \| MEM_PAGE_CACHED;
		mem_insert_page(& curpr->dir_list, &pmpage, virtaddr);

		// FIXME get min(PM_PAGE_BYTES, max allowed) bytes
		mem_area_copy_raw(area, (virtaddr - area->address), pmaddr, PM_PAGE_BYTES);

		// not optimized, but ensure page points to a valid page struct
		page = mem_find_page(curpr->dir_list, virtaddr);

		printk(LOG_DEBUG, "tlb major fault: page inserted (virt %p -> phy %p)\n",
		virtaddr, PM_PHYSICAL_ADDR(page->private.ppn));
		}
		}
		}

		if(page != NULL) {
		unsigned int flags;
		uint32 ppn = 0;

init.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -38,6 +38,7 @@
		#include "sys/console.h"

		#include "sys/sysctl.h"
		#include "sys/mem_area.h"

		extern char cmdargs_begin;
		extern char cmdargs_end;
		@@ -131,6 +132,7 @@ void init() {

		//DBG_WAIT;


		// Initializing VFS and device sub-sytems, mount platform filesystems,
		// register platform devices...

		@@ -215,6 +217,10 @@ void init() {
		test_vfs();
		*/

		// memory area subsystem
		mem_area_init();


		process_init();
		sched_init();
		test_process();

sys/mem_area.c

+22 −2

Original line number	Diff line number	Diff line
		@@ -87,16 +87,36 @@ int mem_area_copy_raw(struct mem_area area, size_t offset, void dest, size_t s

		if(area->flags & MEM_AREA_TYPE_ANON) {
		// anonymous area, the current implementation do nothing...
		if(offset + size > area->max_size) {
		printk(LOG_ERR, "mem_area: attempt to copy extra bytes (anon)\n");
		}
		else {
		if(offset + size > area->anon.size && (area->flags & MEM_AREA_MAYGROW)) {
		printk(LOG_DEBUG, "mem_area: extends area (%d->%d)\n",
		area->anon.size, offset + size);
		}
		ret = 0;
		}
		}
		else if(area->flags & MEM_AREA_TYPE_FILE) {
		// file mapped to memory, for now use a generic way to handle them
		// TODO improve this with map_area_ops struct to allow "override"
		size_t nbread;

		vfs_lseek(area->file.filep, SEEK_SET, offset);
		vfs_lseek(area->file.filep, area->file.origin + offset, SEEK_SET);
		nbread = vfs_read(area->file.filep, dest, size);
		ret = nbread == size ? 0 : -1;

		if(ret) {
		printk(LOG_ERR, "mem_area: failed loading %d bytes from offset 0x%x"
		" [absolute 0x%x] (read returns %d)\n",
		size, offset, area->file.origin + offset, nbread);
		}
		else {
		printk(LOG_DEBUG, "mem_area: loaded %d bytes @%p from file\n", size, dest);
		}

		//print_memory(LOG_DEBUG, dest, nbread);
		}

		return ret;

sys/process.c

+42 −0

Original line number	Diff line number	Diff line
		@@ -196,6 +196,20 @@ void process_terminate(struct process *proc, int status) {

		// FIXME controlling terminal is process was session leader


		// remove all memory areas
		struct list_head *cur_area;

		cur_area = proc->mem_areas.next;
		while(cur_area != & proc->mem_areas) {
		struct list_head *next_area = cur_area->next;
		struct mem_area *area = container_of(cur_area, struct mem_area, list);
		mem_area_free(area);
		cur_area = next_area;
		}
		INIT_LIST_HEAD(& proc->mem_areas);


		// release the used address space, and free each allocated physical pages
		arch_adrsp_release(& proc->addr_space);
		for(curdir = proc->dir_list; curdir != NULL; curdir = nextdir) {
		@@ -263,6 +277,20 @@ pid_t sys_fork() {

		newproc->ctty = cur->ctty;

		// copy each memory area
		struct list_head *area_list;

		list_for_each(area_list, & cur->mem_areas) {
		// duplicate it
		// FIXME file should be duplicated? Or a counter need to be used?
		struct mem_area *old_area = container_of(area_list, struct mem_area, list);
		struct mem_area *new_area;

		new_area = mem_area_alloc();
		new_area = old_area;
		mem_area_insert(newproc, new_area);
		}

		// copy each memory page with same virtual addresses
		// TODO copy-on-write system!
		for(dir = cur->dir_list; dir != NULL; dir = dir->next) {
		@@ -427,6 +455,20 @@ int sys_execve(const char filename, char const argv[], char *const envp[]) {
		cur->sig_array[i].sa_handler = SIG_DFL;
		}


		// remove all memory areas
		struct list_head *cur_area;

		cur_area = cur->mem_areas.next;
		while(cur_area != & cur->mem_areas) {
		struct list_head *next_area = cur_area->next;
		struct mem_area *area = container_of(cur_area, struct mem_area, list);
		mem_area_free(area);
		cur_area = next_area;
		}
		INIT_LIST_HEAD(& cur->mem_areas);


		// use a new address space to avoid to use old TLB records
		arch_adrsp_release(& cur->addr_space);