Re: [PATCH V2] genalloc: add support to specify the physical address

Russell King - ARM Linux
2011-04-28T08:16:13Z

On Wed, Apr 20, 2011 at 08:54:15AM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote:
> so we specify the virtual address as base of the pool chunk and then
> get the physical address for hardware IP
>
> as example on at91 we will use on spi, uart or macb
>
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> Cc: Patrice VILCHEZ <patrice.vilchez@atmel.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> ---
> Hi Andrew,
> I integrate the documentation fix
> could replace the previous one with this one
>
> V2:
> update documentation
> use phys_addr_t for physical addr
> Best Regards,

I notice no comments on this - maybe it needs to be Cc'd to linux-mm too?

Andrew - do you have any views on this?

> J.
> include/linux/genalloc.h | 22 +++++++++++++++++++++-
> lib/genalloc.c | 45 +++++++++++++++++++++++++++++++++++++--------
> 2 files changed, 58 insertions(+), 9 deletions(-)
>
> diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
> index b1c70f1..5bbebda 100644
> --- a/include/linux/genalloc.h
> +++ b/include/linux/genalloc.h
> @@ -26,13 +26,33 @@ struct gen_pool {
> struct gen_pool_chunk {
> spinlock_t lock;
> struct list_head next_chunk; /* next chunk in pool */
> + phys_addr_t phys_addr; /* physical starting address of memory chunk */
> unsigned long start_addr; /* starting address of memory chunk */
> unsigned long end_addr; /* ending address of memory chunk */
> unsigned long bits[0]; /* bitmap for allocating memory chunk */
> };
>
> extern struct gen_pool *gen_pool_create(int, int);
> -extern int gen_pool_add(struct gen_pool *, unsigned long, size_t, int);
> +extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long);
> +extern int gen_pool_add_virt(struct gen_pool *, unsigned long, phys_addr_t,
> + size_t, int);
> +/**
> + * gen_pool_add - add a new chunk of special memory to the pool
> + * @pool: pool to add new memory chunk to
> + * @addr: starting address of memory chunk to add to pool
> + * @size: size in bytes of the memory chunk to add to pool
> + * @nid: node id of the node the chunk structure and bitmap should be
> + * allocated on, or -1
> + *
> + * Add a new chunk of special memory to the specified pool.
> + *
> + * Returns 0 on success or a -ve errno on failure.
> + */
> +static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr,
> + size_t size, int nid)
> +{
> + return gen_pool_add_virt(pool, addr, -1, size, nid);
> +}
> extern void gen_pool_destroy(struct gen_pool *);
> extern unsigned long gen_pool_alloc(struct gen_pool *, size_t);
> extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);
> diff --git a/lib/genalloc.c b/lib/genalloc.c
> index 1923f14..577ddf8 100644
> --- a/lib/genalloc.c
> +++ b/lib/genalloc.c
> @@ -39,17 +39,20 @@ struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
> EXPORT_SYMBOL(gen_pool_create);
>
> /**
> - * gen_pool_add - add a new chunk of special memory to the pool
> + * gen_pool_add_virt - add a new chunk of special memory to the pool
> * @pool: pool to add new memory chunk to
> - * @addr: starting address of memory chunk to add to pool
> + * @virt: virtual starting address of memory chunk to add to pool
> + * @phys: physical starting address of memory chunk to add to pool
> * @size: size in bytes of the memory chunk to add to pool
> * @nid: node id of the node the chunk structure and bitmap should be
> * allocated on, or -1
> *
> * Add a new chunk of special memory to the specified pool.
> + *
> + * Returns 0 on success or a -ve errno on failure.
> */
> -int gen_pool_add(struct gen_pool *pool, unsigned long addr, size_t size,
> - int nid)
> +int gen_pool_add_virt(struct gen_pool *pool, unsigned long virt, phys_addr_t phys,
> + size_t size, int nid)
> {
> struct gen_pool_chunk *chunk;
> int nbits = size >> pool->min_alloc_order;
> @@ -58,11 +61,12 @@ int gen_pool_add(struct gen_pool *pool, unsigned long addr, size_t size,
>
> chunk = kmalloc_node(nbytes, GFP_KERNEL | __GFP_ZERO, nid);
> if (unlikely(chunk == NULL))
> - return -1;
> + return -ENOMEM;
>
> spin_lock_init(&chunk->lock);
> - chunk->start_addr = addr;
> - chunk->end_addr = addr + size;
> + chunk->phys_addr = phys;
> + chunk->start_addr = virt;
> + chunk->end_addr = virt + size;
>
> write_lock(&pool->lock);
> list_add(&chunk->next_chunk, &pool->chunks);
> @@ -70,7 +74,32 @@ int gen_pool_add(struct gen_pool *pool, unsigned long addr, size_t size,
>
> return 0;
> }
> -EXPORT_SYMBOL(gen_pool_add);
> +EXPORT_SYMBOL(gen_pool_add_virt);
> +
> +/**
> + * gen_pool_virt_to_phys - return the physical address of memory
> + * @pool: pool to allocate from
> + * @addr: starting address of memory
> + *
> + * Returns the physical address on success, or -1 on error.
> + */
> +phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long addr)
> +{
> + struct list_head *_chunk;
> + struct gen_pool_chunk *chunk;
> +
> + read_lock(&pool->lock);
> + list_for_each(_chunk, &pool->chunks) {
> + chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
> +
> + if (addr >= chunk->start_addr && addr < chunk->end_addr)
> + return chunk->phys_addr + addr - chunk->start_addr;
> + }
> + read_unlock(&pool->lock);
> +
> + return -1;
> +}
> +EXPORT_SYMBOL(gen_pool_virt_to_phys);
>
> /**
> * gen_pool_destroy - destroy a special memory pool
> --
> 1.7.4.1
>
>
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