metalsvm/mm/memory.c

/* 
 * Copyright 2010 Stefan Lankes, Chair for Operating Systems,
 *                               RWTH Aachen University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * This file is part of MetalSVM. 
 */

#include <metalsvm/stdio.h>
#include <metalsvm/string.h>
#include <metalsvm/stdlib.h>
#include <metalsvm/memory.h>
#include <metalsvm/spinlock.h>
#include <metalsvm/time.h>
#include <metalsvm/processor.h>
#include <metalsvm/page.h>
#include <metalsvm/errno.h>
#ifdef CONFIG_MULTIBOOT
#include <asm/multiboot.h>
#endif
#ifdef CONFIG_ROCKCREEK
#include <asm/RCCE.h>
#include <asm/RCCE_lib.h>
#include <asm/SCC_API.h>
#include <asm/icc.h>
#endif

/* 
 * Set whole address space as occupied:
 * 0 => free, 1 => occupied
 */
static uint8_t bitmap[BITMAP_SIZE] = {[0 ... BITMAP_SIZE-1] = 0xFF};
static spinlock_t bitmap_lock = SPINLOCK_INIT;

atomic_int32_t total_pages = ATOMIC_INIT(0);
atomic_int32_t total_allocated_pages = ATOMIC_INIT(0);
atomic_int32_t total_available_pages = ATOMIC_INIT(0);

/* 
 * Note that linker symbols are not variables, they have no memory allocated for
 * maintaining a value, rather their address is their value.
 */
extern const void kernel_start;
extern const void kernel_end;

inline static int page_marked(size_t i)
{
	size_t index = i >> 3;
	size_t mod = i & 0x7;

	return  (bitmap[index] & (1 << mod));
}

inline static void page_set_mark(size_t i)
{
	size_t index = i >> 3;
	size_t mod = i & 0x7;

	bitmap[index] = bitmap[index] | (1 << mod);
}

inline static void page_clear_mark(size_t i)
{
	size_t index = i / 8;
	size_t mod = i % 8;

	bitmap[index] = bitmap[index] & ~(1 << mod);
}

size_t get_pages(size_t npages)
{
	size_t cnt, off;

	if (BUILTIN_EXPECT(!npages, 0))
		return 0;
	if (BUILTIN_EXPECT(npages > atomic_int32_read(&total_available_pages), 0))
		return 0;

	spinlock_lock(&bitmap_lock);

	off = 1;
	while (off <= BITMAP_SIZE*8 - npages) {
		for (cnt=0; cnt<npages; cnt++) {
			if (page_marked(off+cnt))
				goto next;
		}

		for (cnt=0; cnt<npages; cnt++) {
			page_set_mark(off+cnt);
		}

		spinlock_unlock(&bitmap_lock);

		atomic_int32_add(&total_allocated_pages, npages);
		atomic_int32_sub(&total_available_pages, npages);

		return off << PAGE_BITS;

next:		off += cnt+1;
	}

	spinlock_unlock(&bitmap_lock);

	return 0;
}

int put_pages(size_t phyaddr, size_t npages)
{
	size_t i, ret = 0;
	size_t base = phyaddr >> PAGE_BITS;

	if (BUILTIN_EXPECT(!phyaddr, 0))
		return -EINVAL;
	if (BUILTIN_EXPECT(!npages, 0))
		return -EINVAL;

	spinlock_lock(&bitmap_lock);

	for (i=0; i<npages; i++) {
		if (page_marked(base+i)) {
			page_clear_mark(base+i);
			ret++;
		}
	}

	spinlock_unlock(&bitmap_lock);

	atomic_int32_sub(&total_allocated_pages, ret);
	atomic_int32_add(&total_available_pages, ret);

	kprintf("put_pages: phyaddr=%#lx, npages = %d, ret = %d\n",
		phyaddr, npages, ret); // TODO: remove

	return ret;
}

int copy_page(size_t pdest, size_t psrc)
{
	static size_t viraddr;
	if (!viraddr) { // statically allocate virtual memory area
		viraddr = vma_alloc(2 * PAGE_SIZE, VMA_HEAP);
		if (BUILTIN_EXPECT(!viraddr, 0))
			return -ENOMEM;
	}

	// map pages
	size_t vsrc = map_region(viraddr, psrc, 1, MAP_KERNEL_SPACE);
	size_t vdest = map_region(viraddr + PAGE_SIZE, pdest, 1, MAP_KERNEL_SPACE);
	if (BUILTIN_EXPECT(!vsrc || !vdest, 0)) {
		unmap_region(viraddr, 2);
		return -ENOMEM;
	}

	kprintf("copy_page: copy page frame from: %#lx (%#lx) to %#lx (%#lx)\n", vsrc, psrc, vdest, pdest); // TODO remove

	// copy the whole page
	memcpy((void*) vdest, (void*) vsrc, PAGE_SIZE);

	// householding
	unmap_region(viraddr, 2);

	return 0;
}

int mmu_init(void)
{
	unsigned int i; 
	size_t addr;
	int ret = 0;

#ifdef CONFIG_MULTIBOOT
	if (mb_info) {
		if (mb_info->flags & MULTIBOOT_INFO_MEM_MAP) {
			multiboot_memory_map_t* mmap = (multiboot_memory_map_t*) ((size_t) mb_info->mmap_addr);
			multiboot_memory_map_t* mmap_end = (void*) ((size_t) mb_info->mmap_addr + mb_info->mmap_length);

			// mark available memory as free
			while (mmap < mmap_end) {
				if (mmap->type == MULTIBOOT_MEMORY_AVAILABLE) {
					for (addr=mmap->addr; addr < mmap->addr + mmap->len; addr += PAGE_SIZE) {
						page_clear_mark(addr >> PAGE_BITS);
						atomic_int32_inc(&total_pages);
						atomic_int32_inc(&total_available_pages);
					}
				}
				mmap++;
			}
		}
		else if (mb_info->flags & MULTIBOOT_INFO_MEM) {
			size_t page;
			size_t pages_lower = mb_info->mem_lower >> 2; /* KiB to page number */
			size_t pages_upper = mb_info->mem_upper >> 2;

			for (page=0; page<pages_lower; page++)
				page_clear_mark(page);

			for (page=0; page<pages_upper; page++)
				page_clear_mark(page + 256); /* 1 MiB == 256 pages offset */

			atomic_int32_add(&total_pages, pages_lower + pages_upper);
			atomic_int32_add(&total_available_pages, pages_lower + pages_upper);
		}
		else {
			kputs("Unable to initialize the memory management subsystem\n");
			while (1) HALT;
		}

		// mark mb_info as used
		page_set_mark((size_t) mb_info >> PAGE_BITS);
		atomic_int32_inc(&total_allocated_pages);
		atomic_int32_dec(&total_available_pages);

		// mark modules list as used
		if (mb_info->flags & MULTIBOOT_INFO_MODS) {
			for(addr=mb_info->mods_addr; addr<mb_info->mods_addr+mb_info->mods_count*sizeof(multiboot_module_t); addr+=PAGE_SIZE) {
				page_set_mark(addr >> PAGE_BITS);
				atomic_int32_inc(&total_allocated_pages);
				atomic_int32_dec(&total_available_pages);
			}
		}
	}
#elif defined(CONFIG_ROCKCREEK)
	// of course, the first slots belong to the private memory
	for(addr=0x00; addr<1*0x1000000; addr+=PAGE_SIZE) {
		page_clear_mark(addr >> PAGE_BITS);
		if (addr > addr + PAGE_SIZE)
			break;
		atomic_int32_inc(&total_pages);
		atomic_int32_inc(&total_available_pages);
	}

	// Note: The last slot belongs always to the private memory.
	for(addr=0xFF000000; addr<0xFFFFFFFF; addr+=PAGE_SIZE) {
		page_clear_mark(addr >> PAGE_BITS);
		if (addr > addr + PAGE_SIZE)
			break;
		atomic_int32_inc(&total_pages);
		atomic_int32_inc(&total_available_pages);
	}

	// mark the bootinfo as used.
	page_set_mark((size_t)bootinfo >> PAGE_BITS);
	atomic_int32_inc(&total_allocated_pages);
	atomic_int32_dec(&total_available_pages);
#else
	#error Currently, MetalSVM supports only the Multiboot specification or the RockCreek processor!
#endif

	// mark kernel as used
	for(addr=(size_t) &kernel_start; addr<(size_t) &kernel_end; addr+=PAGE_SIZE) {
		page_set_mark(addr >> PAGE_BITS);
		atomic_int32_inc(&total_allocated_pages);
		atomic_int32_dec(&total_available_pages);
	}

#if MAX_CORES > 1
	page_set_mark(SMP_SETUP_ADDR >> PAGE_BITS);
	atomic_int32_inc(&total_allocated_pages);
	atomic_int32_dec(&total_available_pages);
#endif

	// enable paging and map SMP, VGA, Multiboot modules etc.
	ret = paging_init();
	if (BUILTIN_EXPECT(ret, 0)) {
		kprintf("Failed to initialize paging: %d\n", ret);
		return ret;
	}

	ret = vma_init();
	if (BUILTIN_EXPECT(ret, 0)) {
		kprintf("Failed to initialize VMA regions: %d\n", ret);
		return ret;
	}

#ifdef CONFIG_MULTIBOOT
	/* 
	 * Modules like the init ram disk are already loaded.
	 * Therefore, we set these pages as used.
	 */
	if (mb_info && (mb_info->flags & MULTIBOOT_INFO_MODS)) {
		multiboot_module_t* mmodule = (multiboot_module_t*) ((size_t) mb_info->mods_addr);
		for(i=0; i<mb_info->mods_count; i++) {
			for(addr=mmodule[i].mod_start; addr<mmodule[i].mod_end; addr+=PAGE_SIZE) {
				page_set_mark(addr >> PAGE_BITS);
				atomic_int32_inc(&total_allocated_pages);
				atomic_int32_dec(&total_available_pages);
			}
		}
	}
#elif defined(CONFIG_ROCKCREEK)
	/*
	 * Now, we are able to read the FPGA registers and to
	 * determine the number of slots for private memory.
	 */
	uint32_t slots = *((volatile uint8_t*) (FPGA_BASE + 0x8244));
	if (slots == 0)
		slots = 1;

	kprintf("MetalSVM use %d slots for private memory\n", slots);

	// define the residual private slots as free
	for(addr=1*0x1000000; addr<slots*0x1000000; addr+=PAGE_SIZE) {
		page_clear_mark(addr >> PAGE_BITS);
		if (addr > addr + PAGE_SIZE)
			break;
		atomic_int32_inc(&total_pages);
		atomic_int32_inc(&total_available_pages);
	}

	/* 
	 * The init ram disk are already loaded.
	 * Therefore, we set these pages as used.
	 */
	for(addr=bootinfo->addr; addr<bootinfo->addr+bootinfo->size; addr+=PAGE_SIZE) {
		// this area is already mapped, so we need to virt_to_phys() these addresses.
		page_set_mark(virt_to_phys(addr) >> PAGE_BITS);
		atomic_int32_inc(&total_allocated_pages);
		atomic_int32_dec(&total_available_pages);
	}
#endif

	return ret;
}