On 7/4/2014 6:35 AM, Thierry Reding wrote:
> On Wed, Jul 02, 2014 at 11:03:38AM -0700, Laura Abbott wrote:
> [...]
>> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
> [...]
>> +static struct gen_pool *atomic_pool;
>> +
>> +#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
>> +static size_t atomic_pool_size = DEFAULT_DMA_COHERENT_POOL_SIZE;
>
> There doesn't seem to be much use for this since it can't be overridden
> via init_dma_coherent_pool_size like on ARM.
>
There is still the command line option coherent_pool=<size> though
[...]
>> + if (page) {
>> + int ret;
>> +
>> + atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
>> + if (!atomic_pool)
>> + goto free_page;
>> +
>> + addr = dma_common_contiguous_remap(page, atomic_pool_size,
>> + VM_USERMAP, prot, atomic_pool_init);
>> +
>> + if (!addr)
>> + goto destroy_genpool;
>> +
>> + memset(addr, 0, atomic_pool_size);
>> + __dma_flush_range(addr, addr + atomic_pool_size);
>> +
>> + ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
>> + page_to_phys(page),
>> + atomic_pool_size, -1);
>> + if (ret)
>> + goto remove_mapping;
>> +
>> + gen_pool_set_algo(atomic_pool,
>> + gen_pool_first_fit_order_align, NULL);
>> +
>> + pr_info("DMA: preallocated %zd KiB pool for atomic allocations\n",
>
> I think this should be "%zu" because atomic_pool_size is a size_t, not a
> ssize_t.
>
Yes, will fix.
>> + atomic_pool_size / 1024);
>> + return 0;
>> + }
>> + goto out;
>> +
>> +remove_mapping:
>> + dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
>> +destroy_genpool:
>> + gen_pool_destroy(atomic_pool);
>> + atomic_pool == NULL;
>
> This probably doesn't belong here.
>
Dastardly typo.
>> +free_page:
>> + if (!dma_release_from_contiguous(NULL, page, nr_pages))
>> + __free_pages(page, get_order(atomic_pool_size));
>
> You use get_order(atomic_pool_size) a lot, perhaps it should be a
> temporary variable?
>
Yes, three usages is probably enough.
>> +out:
>> + pr_err("DMA: failed to allocate %zx KiB pool for atomic coherent allocation\n",
>> + atomic_pool_size / 1024);
>
> Print in decimal rather than hexadecimal?
>
I actually prefer hexadecimal but I should at least be consistent between
error and non-error paths.
> Thierry
>
Thanks,
Laura
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