From 217bbd81885587b462311fab1b04172926c59f1e Mon Sep 17 00:00:00 2001 From: Michael Schmitz Date: Mon, 1 Nov 2010 19:54:00 +0100 Subject: 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 [Andreas Schwab : Use memparse()] [Geert: Use the resource subsystem instead of a custom allocator] Signed-off-by: Geert Uytterhoeven --- arch/m68k/atari/stram.c | 354 ++++++++++-------------------------------------- 1 file changed, 69 insertions(+), 285 deletions(-) (limited to 'arch/m68k/atari') 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 * @@ -30,91 +30,35 @@ #include #include -#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 -#include -#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: - */ -- cgit