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authorMichael Schmitz <schmitzmic@googlemail.com>2010-11-01 19:54:00 +0100
committerGeert Uytterhoeven <geert@linux-m68k.org>2011-07-30 21:21:39 +0200
commit217bbd81885587b462311fab1b04172926c59f1e (patch)
treec914306226654e239683e3c374c57ba85d9a5d9a /arch/m68k/atari
parentb7785e954348465e1926d9c10ff3e49c207d4ec6 (diff)
downloadblackbird-op-linux-217bbd81885587b462311fab1b04172926c59f1e.tar.gz
blackbird-op-linux-217bbd81885587b462311fab1b04172926c59f1e.zip
m68k/atari: Reserve some ST-RAM early on for device buffer use
Based on an original patch from Michael Schmitz: Because mem_init() is now called before device init, devices that rely on ST-RAM may find all ST-RAM already allocated to other users by the time device init happens. In particular, a large initrd RAM disk may use up enough of ST-RAM to cause atari_stram_alloc() to resort to __get_dma_pages() allocation. In the current state of Atari memory management, all of RAM is marked DMA capable, so __get_dma_pages() may well return RAM that is not in actual fact DMA capable. Using this for frame buffer or SCSI DMA buffer causes subtle failure. The ST-RAM allocator has been changed to allocate memory from a pool of reserved ST-RAM of configurable size, set aside on ST-RAM init (i.e. before mem_init()). As long as this pool is not exhausted, allocation of real ST-RAM can be guaranteed. Other changes: - Replace the custom allocator in the ST-RAM pool by the existing allocator in the resource subsystem, - Remove mem_init_done and its hook, as memory init is now done before device init, - Remove /proc/stram, as ST-RAM usage now shows up under /proc/iomem, e.g. 005f2000-006f1fff : ST-RAM Pool 005f2000-0063dfff : atafb 0063e000-00641fff : ataflop 00642000-00642fff : SCSI Signed-off-by: Michael Schmitz <schmitz@debian.org> [Andreas Schwab <schwab@linux-m68k.org>: Use memparse()] [Geert: Use the resource subsystem instead of a custom allocator] Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k/atari')
-rw-r--r--arch/m68k/atari/stram.c354
1 files changed, 69 insertions, 285 deletions
diff --git a/arch/m68k/atari/stram.c b/arch/m68k/atari/stram.c
index 6ec3b7f33779..0810c8d56e59 100644
--- a/arch/m68k/atari/stram.c
+++ b/arch/m68k/atari/stram.c
@@ -1,5 +1,5 @@
/*
- * arch/m68k/atari/stram.c: Functions for ST-RAM allocations
+ * Functions for ST-RAM allocations
*
* Copyright 1994-97 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
*
@@ -30,91 +30,35 @@
#include <asm/atari_stram.h>
#include <asm/io.h>
-#undef DEBUG
-
-#ifdef DEBUG
-#define DPRINTK(fmt,args...) printk( fmt, ##args )
-#else
-#define DPRINTK(fmt,args...)
-#endif
-
-#if defined(CONFIG_PROC_FS) && defined(CONFIG_STRAM_PROC)
-/* abbrev for the && above... */
-#define DO_PROC
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#endif
/*
- * ++roman:
- *
- * New version of ST-Ram buffer allocation. Instead of using the
- * 1 MB - 4 KB that remain when the ST-Ram chunk starts at $1000
- * (1 MB granularity!), such buffers are reserved like this:
- *
- * - If the kernel resides in ST-Ram anyway, we can take the buffer
- * from behind the current kernel data space the normal way
- * (incrementing start_mem).
- *
- * - If the kernel is in TT-Ram, stram_init() initializes start and
- * end of the available region. Buffers are allocated from there
- * and mem_init() later marks the such used pages as reserved.
- * Since each TT-Ram chunk is at least 4 MB in size, I hope there
- * won't be an overrun of the ST-Ram region by normal kernel data
- * space.
- *
- * For that, ST-Ram may only be allocated while kernel initialization
- * is going on, or exactly: before mem_init() is called. There is also
- * no provision now for freeing ST-Ram buffers. It seems that isn't
- * really needed.
- *
+ * 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.
*/
-/* Start and end (virtual) of ST-RAM */
-static void *stram_start, *stram_end;
-
-/* set after memory_init() executed and allocations via start_mem aren't
- * possible anymore */
-static int mem_init_done;
-
/* set if kernel is in ST-RAM */
static int kernel_in_stram;
-typedef struct stram_block {
- struct stram_block *next;
- void *start;
- unsigned long size;
- unsigned flags;
- const char *owner;
-} BLOCK;
-
-/* values for flags field */
-#define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */
-#define BLOCK_KMALLOCED 0x02 /* structure allocated by kmalloc() */
-#define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */
+static struct resource stram_pool = {
+ .name = "ST-RAM Pool"
+};
-/* list of allocated blocks */
-static BLOCK *alloc_list;
+static unsigned long pool_size = 1024*1024;
-/* We can't always use kmalloc() to allocate BLOCK structures, since
- * stram_alloc() can be called rather early. So we need some pool of
- * statically allocated structures. 20 of them is more than enough, so in most
- * cases we never should need to call kmalloc(). */
-#define N_STATIC_BLOCKS 20
-static BLOCK static_blocks[N_STATIC_BLOCKS];
-/***************************** Prototypes *****************************/
+static int __init atari_stram_setup(char *arg)
+{
+ if (!MACH_IS_ATARI)
+ return 0;
-static BLOCK *add_region( void *addr, unsigned long size );
-static BLOCK *find_region( void *addr );
-static int remove_region( BLOCK *block );
+ pool_size = memparse(arg, NULL);
+ return 0;
+}
-/************************* End of Prototypes **************************/
+early_param("stram_pool", atari_stram_setup);
-
-/* ------------------------------------------------------------------------ */
-/* Public Interface */
-/* ------------------------------------------------------------------------ */
/*
* This init function is called very early by atari/config.c
@@ -123,25 +67,23 @@ static int remove_region( BLOCK *block );
void __init atari_stram_init(void)
{
int i;
+ void *stram_start;
- /* initialize static blocks */
- for( i = 0; i < N_STATIC_BLOCKS; ++i )
- static_blocks[i].flags = BLOCK_FREE;
-
- /* determine whether kernel code resides in ST-RAM (then ST-RAM is the
- * first memory block at virtual 0x0) */
+ /*
+ * determine whether kernel code resides in ST-RAM
+ * (then ST-RAM is the first memory block at virtual 0x0)
+ */
stram_start = phys_to_virt(0);
kernel_in_stram = (stram_start == 0);
- for( i = 0; i < m68k_num_memory; ++i ) {
+ for (i = 0; i < m68k_num_memory; ++i) {
if (m68k_memory[i].addr == 0) {
- /* skip first 2kB or page (supervisor-only!) */
- stram_end = stram_start + m68k_memory[i].size;
return;
}
}
+
/* Should never come here! (There is always ST-Ram!) */
- panic( "atari_stram_init: no ST-RAM found!" );
+ panic("atari_stram_init: no ST-RAM found!");
}
@@ -151,226 +93,68 @@ void __init atari_stram_init(void)
*/
void __init atari_stram_reserve_pages(void *start_mem)
{
- /* always reserve first page of ST-RAM, the first 2 kB are
- * supervisor-only! */
+ /*
+ * always reserve first page of ST-RAM, the first 2 KiB are
+ * supervisor-only!
+ */
if (!kernel_in_stram)
reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT);
-}
+ stram_pool.start = (resource_size_t)alloc_bootmem_low_pages(pool_size);
+ stram_pool.end = stram_pool.start + pool_size - 1;
+ request_resource(&iomem_resource, &stram_pool);
-void atari_stram_mem_init_hook (void)
-{
- mem_init_done = 1;
+ pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
+ pool_size, &stram_pool);
}
-/*
- * This is main public interface: somehow allocate a ST-RAM block
- *
- * - If we're before mem_init(), we have to make a static allocation. The
- * region is taken in the kernel data area (if the kernel is in ST-RAM) or
- * from the start of ST-RAM (if the kernel is in TT-RAM) and added to the
- * rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel
- * address space in the latter case.
- *
- * - If mem_init() already has been called, try with __get_dma_pages().
- * This has the disadvantage that it's very hard to get more than 1 page,
- * and it is likely to fail :-(
- *
- */
-void *atari_stram_alloc(long size, const char *owner)
+void *atari_stram_alloc(unsigned long size, const char *owner)
{
- void *addr = NULL;
- BLOCK *block;
- int flags;
-
- DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner);
-
- if (!mem_init_done)
- return alloc_bootmem_low(size);
- else {
- /* After mem_init(): can only resort to __get_dma_pages() */
- addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size));
- flags = BLOCK_GFP;
- DPRINTK( "atari_stram_alloc: after mem_init, "
- "get_pages=%p\n", addr );
+ 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;
}
- if (addr) {
- if (!(block = add_region( addr, size ))) {
- /* out of memory for BLOCK structure :-( */
- DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- "
- "freeing again\n" );
- free_pages((unsigned long)addr, get_order(size));
- return( NULL );
- }
- block->owner = owner;
- block->flags |= flags;
- }
- return( addr );
+ pr_debug("atari_stram_alloc: returning %pR\n", res);
+ return (void *)res->start;
}
EXPORT_SYMBOL(atari_stram_alloc);
-void atari_stram_free( void *addr )
+void atari_stram_free(void *addr)
{
- BLOCK *block;
-
- DPRINTK( "atari_stram_free(addr=%p)\n", addr );
+ unsigned long start = (unsigned long)addr;
+ struct resource *res;
+ unsigned long size;
- if (!(block = find_region( addr ))) {
- printk( KERN_ERR "Attempt to free non-allocated ST-RAM block at %p "
- "from %p\n", addr, __builtin_return_address(0) );
+ res = lookup_resource(&stram_pool, start);
+ if (!res) {
+ pr_err("atari_stram_free: trying to free nonexistent region "
+ "at %p\n", addr);
return;
}
- DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, "
- "flags=%02x\n", block, block->size, block->owner, block->flags );
-
- if (!(block->flags & BLOCK_GFP))
- goto fail;
- DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n",
- get_order(block->size));
- free_pages((unsigned long)addr, get_order(block->size));
- remove_region( block );
- return;
-
- fail:
- printk( KERN_ERR "atari_stram_free: cannot free block at %p "
- "(called from %p)\n", addr, __builtin_return_address(0) );
+ 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);
-
-
-/* ------------------------------------------------------------------------ */
-/* Region Management */
-/* ------------------------------------------------------------------------ */
-
-
-/* insert a region into the alloced list (sorted) */
-static BLOCK *add_region( void *addr, unsigned long size )
-{
- BLOCK **p, *n = NULL;
- int i;
-
- for( i = 0; i < N_STATIC_BLOCKS; ++i ) {
- if (static_blocks[i].flags & BLOCK_FREE) {
- n = &static_blocks[i];
- n->flags = 0;
- break;
- }
- }
- if (!n && mem_init_done) {
- /* if statics block pool exhausted and we can call kmalloc() already
- * (after mem_init()), try that */
- n = kmalloc( sizeof(BLOCK), GFP_KERNEL );
- if (n)
- n->flags = BLOCK_KMALLOCED;
- }
- if (!n) {
- printk( KERN_ERR "Out of memory for ST-RAM descriptor blocks\n" );
- return( NULL );
- }
- n->start = addr;
- n->size = size;
-
- for( p = &alloc_list; *p; p = &((*p)->next) )
- if ((*p)->start > addr) break;
- n->next = *p;
- *p = n;
-
- return( n );
-}
-
-
-/* find a region (by start addr) in the alloced list */
-static BLOCK *find_region( void *addr )
-{
- BLOCK *p;
-
- for( p = alloc_list; p; p = p->next ) {
- if (p->start == addr)
- return( p );
- if (p->start > addr)
- break;
- }
- return( NULL );
-}
-
-
-/* remove a block from the alloced list */
-static int remove_region( BLOCK *block )
-{
- BLOCK **p;
-
- for( p = &alloc_list; *p; p = &((*p)->next) )
- if (*p == block) break;
- if (!*p)
- return( 0 );
-
- *p = block->next;
- if (block->flags & BLOCK_KMALLOCED)
- kfree( block );
- else
- block->flags |= BLOCK_FREE;
- return( 1 );
-}
-
-
-
-/* ------------------------------------------------------------------------ */
-/* /proc statistics file stuff */
-/* ------------------------------------------------------------------------ */
-
-#ifdef DO_PROC
-
-#define PRINT_PROC(fmt,args...) seq_printf( m, fmt, ##args )
-
-static int stram_proc_show(struct seq_file *m, void *v)
-{
- BLOCK *p;
-
- PRINT_PROC("Total ST-RAM: %8u kB\n",
- (stram_end - stram_start) >> 10);
- PRINT_PROC( "Allocated regions:\n" );
- for( p = alloc_list; p; p = p->next ) {
- PRINT_PROC("0x%08lx-0x%08lx: %s (",
- virt_to_phys(p->start),
- virt_to_phys(p->start+p->size-1),
- p->owner);
- if (p->flags & BLOCK_GFP)
- PRINT_PROC( "page-alloced)\n" );
- else
- PRINT_PROC( "??)\n" );
- }
-
- return 0;
-}
-
-static int stram_proc_open(struct inode *inode, struct file *file)
-{
- return single_open(file, stram_proc_show, NULL);
-}
-
-static const struct file_operations stram_proc_fops = {
- .open = stram_proc_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
-
-static int __init proc_stram_init(void)
-{
- proc_create("stram", 0, NULL, &stram_proc_fops);
- return 0;
-}
-module_init(proc_stram_init);
-#endif
-
-
-/*
- * Local variables:
- * c-indent-level: 4
- * tab-width: 4
- * End:
- */
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