Re: [PATCH] gurantee DMA area for alloc_bootmem_low()

[Yasunori Goto <y-goto@jp.fujitsu.com>]

> I was thinking more about something like the following to eliminate
> all the users of __pa(MAX_DMA_ADDRESS).  This patch is NOT complete
> as I didn't change arch dependent code using __pa(MAX_DMA_ADDRESS).
> 
> Just curious if people think this is overkill, or is there a better
> way to address this?

There is no objection at present, I suppose this patch is 
the best way. :)

Thanks.

> diff -Naupr linux-2.6.13-rc2-mm2/include/linux/bootmem.h linux-2.6.13-rc2-mm2.work/include/linux/bootmem.h
> --- linux-2.6.13-rc2-mm2/include/linux/bootmem.h	2005-07-06 03:46:33.000000000 +0000
> +++ linux-2.6.13-rc2-mm2.work/include/linux/bootmem.h	2005-07-13 21:14:14.000000000 +0000
> @@ -40,6 +40,14 @@ typedef struct bootmem_data {
>  					 * up searching */
>  } bootmem_data_t;
>  
> +#ifndef MAX_DMA_PHYSADDR
> +#if MAX_DMA_ADDRESS = ~0UL
> +#define MAX_DMA_PHYSADDR MAX_DMA_ADDRESS
> +#else
> +#define MAX_DMA_PHYSADDR (__pa(MAX_DMA_ADDRESS))
> +#endif
> +#endif
> +
>  extern unsigned long __init bootmem_bootmap_pages (unsigned long);
>  extern unsigned long __init init_bootmem (unsigned long addr, unsigned long memend);
>  extern void __init free_bootmem (unsigned long addr, unsigned long size);
> @@ -47,11 +55,11 @@ extern void * __init __alloc_bootmem (un
>  #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
>  extern void __init reserve_bootmem (unsigned long addr, unsigned long size);
>  #define alloc_bootmem(x) \
> -	__alloc_bootmem((x), SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))
> +	__alloc_bootmem((x), SMP_CACHE_BYTES, MAX_DMA_PHYSADDR)
>  #define alloc_bootmem_low(x) \
>  	__alloc_bootmem((x), SMP_CACHE_BYTES, 0)
>  #define alloc_bootmem_pages(x) \
> -	__alloc_bootmem((x), PAGE_SIZE, __pa(MAX_DMA_ADDRESS))
> +	__alloc_bootmem((x), PAGE_SIZE, MAX_DMA_PHYSADDR)
>  #define alloc_bootmem_low_pages(x) \
>  	__alloc_bootmem((x), PAGE_SIZE, 0)
>  #endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
> @@ -64,9 +72,9 @@ extern unsigned long __init free_all_boo
>  extern void * __init __alloc_bootmem_node (pg_data_t *pgdat, unsigned long size, unsigned long align, unsigned long goal);
>  #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
>  #define alloc_bootmem_node(pgdat, x) \
> -	__alloc_bootmem_node((pgdat), (x), SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))
> +	__alloc_bootmem_node((pgdat), (x), SMP_CACHE_BYTES, MAX_DMA_PHYSADDR)
>  #define alloc_bootmem_pages_node(pgdat, x) \
> -	__alloc_bootmem_node((pgdat), (x), PAGE_SIZE, __pa(MAX_DMA_ADDRESS))
> +	__alloc_bootmem_node((pgdat), (x), PAGE_SIZE, MAX_DMA_PHYSADDR)
>  #define alloc_bootmem_low_pages_node(pgdat, x) \
>  	__alloc_bootmem_node((pgdat), (x), PAGE_SIZE, 0)
>  #endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
> diff -Naupr linux-2.6.13-rc2-mm2/mm/bootmem.c linux-2.6.13-rc2-mm2.work/mm/bootmem.c
> --- linux-2.6.13-rc2-mm2/mm/bootmem.c	2005-07-06 03:46:33.000000000 +0000
> +++ linux-2.6.13-rc2-mm2.work/mm/bootmem.c	2005-07-13 21:18:40.000000000 +0000
> @@ -387,10 +387,16 @@ void * __init __alloc_bootmem (unsigned 
>  	pg_data_t *pgdat = pgdat_list;
>  	void *ptr;
>  
> -	for_each_pgdat(pgdat)
> +	for_each_pgdat(pgdat){
> +
> +		if (goal < MAX_DMA_PHYSADDR &&
> +		    pgdat->bdata->node_boot_start >= MAX_DMA_PHYSADDR)
> +			continue; /* Skip No DMA node */
> +
>  		if ((ptr = __alloc_bootmem_core(pgdat->bdata, size,
>  						align, goal)))
>  			return(ptr);
> +	}
>  
>  	/*
>  	 * Whoops, we cannot satisfy the allocation request.

-- 
Yasunori Goto