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Diffstat (limited to 'arch/m68k/atari/stram.c')
| -rw-r--r-- | arch/m68k/atari/stram.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/arch/m68k/atari/stram.c b/arch/m68k/atari/stram.c new file mode 100644 index 000000000..ce79b322a --- /dev/null +++ b/arch/m68k/atari/stram.c @@ -0,0 +1,202 @@ +/* + * Functions for ST-RAM allocations + * + * Copyright 1994-97 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/kdev_t.h> +#include <linux/major.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/pagemap.h> +#include <linux/memblock.h> +#include <linux/mount.h> +#include <linux/blkdev.h> +#include <linux/module.h> +#include <linux/ioport.h> + +#include <asm/setup.h> +#include <asm/machdep.h> +#include <asm/page.h> +#include <asm/atarihw.h> +#include <asm/atari_stram.h> +#include <asm/io.h> + + +/* + * The ST-RAM allocator allocates memory from a pool of reserved ST-RAM of + * configurable size, set aside on ST-RAM init. + * As long as this pool is not exhausted, allocation of real ST-RAM can be + * guaranteed. + */ + +/* set if kernel is in ST-RAM */ +static int kernel_in_stram; + +static struct resource stram_pool = { + .name = "ST-RAM Pool" +}; + +static unsigned long pool_size = 1024*1024; + +static unsigned long stram_virt_offset; + +static int __init atari_stram_setup(char *arg) +{ + if (!MACH_IS_ATARI) + return 0; + + pool_size = memparse(arg, NULL); + return 0; +} + +early_param("stram_pool", atari_stram_setup); + + +/* + * This init function is called very early by atari/config.c + * It initializes some internal variables needed for stram_alloc() + */ +void __init atari_stram_init(void) +{ + int i; + + /* + * determine whether kernel code resides in ST-RAM + * (then ST-RAM is the first memory block at virtual 0x0) + */ + kernel_in_stram = (m68k_memory[0].addr == 0); + + for (i = 0; i < m68k_num_memory; ++i) { + if (m68k_memory[i].addr == 0) { + return; + } + } + + /* Should never come here! (There is always ST-Ram!) */ + panic("atari_stram_init: no ST-RAM found!"); +} + + +/* + * This function is called from setup_arch() to reserve the pages needed for + * ST-RAM management, if the kernel resides in ST-RAM. + */ +void __init atari_stram_reserve_pages(void *start_mem) +{ + if (kernel_in_stram) { + pr_debug("atari_stram pool: kernel in ST-RAM, using alloc_bootmem!\n"); + stram_pool.start = (resource_size_t)memblock_alloc_low(pool_size, + PAGE_SIZE); + if (!stram_pool.start) + panic("%s: Failed to allocate %lu bytes align=%lx\n", + __func__, pool_size, PAGE_SIZE); + + stram_pool.end = stram_pool.start + pool_size - 1; + request_resource(&iomem_resource, &stram_pool); + stram_virt_offset = 0; + pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n", + pool_size, &stram_pool); + pr_debug("atari_stram pool: stram_virt_offset = %lx\n", + stram_virt_offset); + } +} + + +/* + * This function is called as arch initcall to reserve the pages needed for + * ST-RAM management, if the kernel does not reside in ST-RAM. + */ +int __init atari_stram_map_pages(void) +{ + if (!kernel_in_stram) { + /* + * Skip page 0, as the fhe first 2 KiB are supervisor-only! + */ + pr_debug("atari_stram pool: kernel not in ST-RAM, using ioremap!\n"); + stram_pool.start = PAGE_SIZE; + stram_pool.end = stram_pool.start + pool_size - 1; + request_resource(&iomem_resource, &stram_pool); + stram_virt_offset = (unsigned long) ioremap(stram_pool.start, + resource_size(&stram_pool)) - stram_pool.start; + pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n", + pool_size, &stram_pool); + pr_debug("atari_stram pool: stram_virt_offset = %lx\n", + stram_virt_offset); + } + return 0; +} +arch_initcall(atari_stram_map_pages); + + +void *atari_stram_to_virt(unsigned long phys) +{ + return (void *)(phys + stram_virt_offset); +} +EXPORT_SYMBOL(atari_stram_to_virt); + + +unsigned long atari_stram_to_phys(void *virt) +{ + return (unsigned long)(virt - stram_virt_offset); +} +EXPORT_SYMBOL(atari_stram_to_phys); + + +void *atari_stram_alloc(unsigned long size, const char *owner) +{ + struct resource *res; + int error; + + pr_debug("atari_stram_alloc: allocate %lu bytes\n", size); + + /* round up */ + size = PAGE_ALIGN(size); + + res = kzalloc(sizeof(struct resource), GFP_KERNEL); + if (!res) + return NULL; + + res->name = owner; + error = allocate_resource(&stram_pool, res, size, 0, UINT_MAX, + PAGE_SIZE, NULL, NULL); + if (error < 0) { + pr_err("atari_stram_alloc: allocate_resource() failed %d!\n", + error); + kfree(res); + return NULL; + } + + pr_debug("atari_stram_alloc: returning %pR\n", res); + return atari_stram_to_virt(res->start); +} +EXPORT_SYMBOL(atari_stram_alloc); + + +void atari_stram_free(void *addr) +{ + unsigned long start = atari_stram_to_phys(addr); + struct resource *res; + unsigned long size; + + res = lookup_resource(&stram_pool, start); + if (!res) { + pr_err("atari_stram_free: trying to free nonexistent region " + "at %p\n", addr); + return; + } + + size = resource_size(res); + pr_debug("atari_stram_free: free %lu bytes at %p\n", size, addr); + release_resource(res); + kfree(res); +} +EXPORT_SYMBOL(atari_stram_free); |