161 строка
3.6 KiB
C
161 строка
3.6 KiB
C
/*
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* Functions for ST-RAM allocations
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*
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* Copyright 1994-97 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/kdev_t.h>
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#include <linux/major.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/pagemap.h>
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#include <linux/bootmem.h>
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#include <linux/mount.h>
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#include <linux/blkdev.h>
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#include <linux/module.h>
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#include <asm/setup.h>
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#include <asm/machdep.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/atarihw.h>
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#include <asm/atari_stram.h>
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#include <asm/io.h>
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/*
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* The ST-RAM allocator allocates memory from a pool of reserved ST-RAM of
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* configurable size, set aside on ST-RAM init.
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* As long as this pool is not exhausted, allocation of real ST-RAM can be
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* guaranteed.
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*/
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/* set if kernel is in ST-RAM */
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static int kernel_in_stram;
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static struct resource stram_pool = {
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.name = "ST-RAM Pool"
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};
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static unsigned long pool_size = 1024*1024;
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static int __init atari_stram_setup(char *arg)
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{
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if (!MACH_IS_ATARI)
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return 0;
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pool_size = memparse(arg, NULL);
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return 0;
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}
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early_param("stram_pool", atari_stram_setup);
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/*
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* This init function is called very early by atari/config.c
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* It initializes some internal variables needed for stram_alloc()
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*/
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void __init atari_stram_init(void)
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{
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int i;
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void *stram_start;
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/*
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* determine whether kernel code resides in ST-RAM
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* (then ST-RAM is the first memory block at virtual 0x0)
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*/
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stram_start = phys_to_virt(0);
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kernel_in_stram = (stram_start == 0);
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for (i = 0; i < m68k_num_memory; ++i) {
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if (m68k_memory[i].addr == 0) {
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return;
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}
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}
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/* Should never come here! (There is always ST-Ram!) */
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panic("atari_stram_init: no ST-RAM found!");
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}
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/*
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* This function is called from setup_arch() to reserve the pages needed for
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* ST-RAM management.
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*/
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void __init atari_stram_reserve_pages(void *start_mem)
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{
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/*
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* always reserve first page of ST-RAM, the first 2 KiB are
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* supervisor-only!
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*/
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if (!kernel_in_stram)
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reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT);
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stram_pool.start = (resource_size_t)alloc_bootmem_low_pages(pool_size);
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stram_pool.end = stram_pool.start + pool_size - 1;
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request_resource(&iomem_resource, &stram_pool);
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pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
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pool_size, &stram_pool);
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}
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void *atari_stram_alloc(unsigned long size, const char *owner)
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{
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struct resource *res;
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int error;
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pr_debug("atari_stram_alloc: allocate %lu bytes\n", size);
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/* round up */
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size = PAGE_ALIGN(size);
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res = kzalloc(sizeof(struct resource), GFP_KERNEL);
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if (!res)
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return NULL;
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res->name = owner;
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error = allocate_resource(&stram_pool, res, size, 0, UINT_MAX,
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PAGE_SIZE, NULL, NULL);
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if (error < 0) {
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pr_err("atari_stram_alloc: allocate_resource() failed %d!\n",
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error);
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kfree(res);
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return NULL;
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}
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pr_debug("atari_stram_alloc: returning %pR\n", res);
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return (void *)res->start;
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}
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EXPORT_SYMBOL(atari_stram_alloc);
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void atari_stram_free(void *addr)
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{
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unsigned long start = (unsigned long)addr;
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struct resource *res;
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unsigned long size;
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res = lookup_resource(&stram_pool, start);
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if (!res) {
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pr_err("atari_stram_free: trying to free nonexistent region "
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"at %p\n", addr);
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return;
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}
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size = resource_size(res);
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pr_debug("atari_stram_free: free %lu bytes at %p\n", size, addr);
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release_resource(res);
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kfree(res);
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}
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EXPORT_SYMBOL(atari_stram_free);
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