Re: [PATCH] allocate multiple contiguous pages via uncached allocator

[Jes Sorensen <jes@sgi.com>]

Dean Nelson wrote:
> Enable the uncached allocator to allocate multiple pages of contiguous
> uncached memory.
>  
> Signed-off-by: Dean Nelson <dcn@sgi.com>

Acked-by: Jes Sorensen <jes@sgi.com>


> ---
>  
>  arch/ia64/kernel/uncached.c |   21 ++++++++++++---------
>  drivers/char/mspec.c        |   12 ++++++------
>  include/asm-ia64/uncached.h |    4 ++--
>  3 files changed, 20 insertions(+), 17 deletions(-)
> 
> Index: linux-2.6/arch/ia64/kernel/uncached.c
> =================================> --- linux-2.6.orig/arch/ia64/kernel/uncached.c	2007-10-04 06:52:20.000000000 -0500
> +++ linux-2.6/arch/ia64/kernel/uncached.c	2007-11-08 12:14:31.408258515 -0600
> @@ -177,12 +177,13 @@
>   * uncached_alloc_page
>   *
>   * @starting_nid: node id of node to start with, or -1
> + * @n_pages: number of contiguous pages to allocate
>   *
> - * Allocate 1 uncached page. Allocates on the requested node. If no
> - * uncached pages are available on the requested node, roundrobin starting
> - * with the next higher node.
> + * Allocate the specified number of contiguous uncached pages on the
> + * the requested node. If not enough contiguous uncached pages are available
> + * on the requested node, roundrobin starting with the next higher node.
>   */
> -unsigned long uncached_alloc_page(int starting_nid)
> +unsigned long uncached_alloc_page(int starting_nid, int n_pages)
>  {
>  	unsigned long uc_addr;
>  	struct uncached_pool *uc_pool;
> @@ -202,7 +203,8 @@
>  		if (uc_pool->pool = NULL)
>  			continue;
>  		do {
> -			uc_addr = gen_pool_alloc(uc_pool->pool, PAGE_SIZE);
> +			uc_addr = gen_pool_alloc(uc_pool->pool,
> +						 n_pages * PAGE_SIZE);
>  			if (uc_addr != 0)
>  				return uc_addr;
>  		} while (uncached_add_chunk(uc_pool, nid) = 0);
> @@ -217,11 +219,12 @@
>  /*
>   * uncached_free_page
>   *
> - * @uc_addr: uncached address of page to free
> + * @uc_addr: uncached address of first page to free
> + * @n_pages: number of contiguous pages to free
>   *
> - * Free a single uncached page.
> + * Free the specified number of uncached pages.
>   */
> -void uncached_free_page(unsigned long uc_addr)
> +void uncached_free_page(unsigned long uc_addr, int n_pages)
>  {
>  	int nid = paddr_to_nid(uc_addr - __IA64_UNCACHED_OFFSET);
>  	struct gen_pool *pool = uncached_pools[nid].pool;
> @@ -232,7 +235,7 @@
>  	if ((uc_addr & (0XFUL << 60)) != __IA64_UNCACHED_OFFSET)
>  		panic("uncached_free_page invalid address %lx\n", uc_addr);
>  
> -	gen_pool_free(pool, uc_addr, PAGE_SIZE);
> +	gen_pool_free(pool, uc_addr, n_pages * PAGE_SIZE);
>  }
>  EXPORT_SYMBOL(uncached_free_page);
>  
> Index: linux-2.6/drivers/char/mspec.c
> =================================> --- linux-2.6.orig/drivers/char/mspec.c	2007-10-04 06:52:21.000000000 -0500
> +++ linux-2.6/drivers/char/mspec.c	2007-11-08 12:07:17.458415225 -0600
> @@ -180,7 +180,7 @@
>  		my_page = vdata->maddr[index];
>  		vdata->maddr[index] = 0;
>  		if (!mspec_zero_block(my_page, PAGE_SIZE))
> -			uncached_free_page(my_page);
> +			uncached_free_page(my_page, 1);
>  		else
>  			printk(KERN_WARNING "mspec_close(): "
>  			       "failed to zero page %ld\n", my_page);
> @@ -209,7 +209,7 @@
>  	index = (address - vdata->vm_start) >> PAGE_SHIFT;
>  	maddr = (volatile unsigned long) vdata->maddr[index];
>  	if (maddr = 0) {
> -		maddr = uncached_alloc_page(numa_node_id());
> +		maddr = uncached_alloc_page(numa_node_id(), 1);
>  		if (maddr = 0)
>  			return NOPFN_OOM;
>  
> @@ -218,7 +218,7 @@
>  			vdata->count++;
>  			vdata->maddr[index] = maddr;
>  		} else {
> -			uncached_free_page(maddr);
> +			uncached_free_page(maddr, 1);
>  			maddr = vdata->maddr[index];
>  		}
>  		spin_unlock(&vdata->lock);
> @@ -367,7 +367,7 @@
>  				int nasid;
>  				unsigned long phys;
>  
> -				scratch_page[nid] = uncached_alloc_page(nid);
> +				scratch_page[nid] = uncached_alloc_page(nid, 1);
>  				if (scratch_page[nid] = 0)
>  					goto free_scratch_pages;
>  				phys = __pa(scratch_page[nid]);
> @@ -414,7 +414,7 @@
>   free_scratch_pages:
>  	for_each_node(nid) {
>  		if (scratch_page[nid] != 0)
> -			uncached_free_page(scratch_page[nid]);
> +			uncached_free_page(scratch_page[nid], 1);
>  	}
>  	return ret;
>  }
> @@ -431,7 +431,7 @@
>  
>  		for_each_node(nid) {
>  			if (scratch_page[nid] != 0)
> -				uncached_free_page(scratch_page[nid]);
> +				uncached_free_page(scratch_page[nid], 1);
>  		}
>  	}
>  }
> Index: linux-2.6/include/asm-ia64/uncached.h
> =================================> --- linux-2.6.orig/include/asm-ia64/uncached.h	2007-10-04 06:52:25.000000000 -0500
> +++ linux-2.6/include/asm-ia64/uncached.h	2007-11-08 12:05:00.633469891 -0600
> @@ -8,5 +8,5 @@
>   * Prototypes for the uncached page allocator
>   */
>  
> -extern unsigned long uncached_alloc_page(int nid);
> -extern void uncached_free_page(unsigned long);
> +extern unsigned long uncached_alloc_page(int, int);
> +extern void uncached_free_page(unsigned long, int);