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-rw-r--r--arch/m68k/atari/stram.c202
1 files changed, 202 insertions, 0 deletions
diff --git a/arch/m68k/atari/stram.c b/arch/m68k/atari/stram.c
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+++ b/arch/m68k/atari/stram.c
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+/*
+ * 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);