On Sat, 27 Jan 2018 15:42:47 +0100,
Maciej S. Szmigiero wrote:
>
> Commit a5003fc04113 ("[ALSA] emu10k1 - simplify page allocation for synth")
> switched from using the DMA allocator for synth DMA pages to manually
> calling alloc_page().
> However, this usage has an implicit assumption that the DMA address space
> for the emu10k1-family chip is the same as the CPU physical address space
> which is not true for a system with a IOMMU.
>
> Since this made the synth part of the driver non-functional on such systems
> let's effectively revert that commit.
Let's keep (or re-add after this revert) the simplification with
__synth_free_pages(). Other than that I have no objection to this
change.
thanks,
Takashi
>
> Signed-off-by: Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>
> ---
> Changes from v1: None in this patch.
>
> sound/pci/emu10k1/memory.c | 70 ++++++++++++++++++++++++++--------------------
> 1 file changed, 39 insertions(+), 31 deletions(-)
>
> diff --git a/sound/pci/emu10k1/memory.c b/sound/pci/emu10k1/memory.c
> index fcb04cbbc9ab..5cdffe2d31e1 100644
> --- a/sound/pci/emu10k1/memory.c
> +++ b/sound/pci/emu10k1/memory.c
> @@ -457,49 +457,44 @@ static void get_single_page_range(struct snd_util_memhdr *hdr,
> *last_page_ret = last_page;
> }
>
> -/* release allocated pages */
> -static void __synth_free_pages(struct snd_emu10k1 *emu, int first_page,
> - int last_page)
> -{
> - int page;
> -
> - for (page = first_page; page <= last_page; page++) {
> - free_page((unsigned long)emu->page_ptr_table[page]);
> - emu->page_addr_table[page] = 0;
> - emu->page_ptr_table[page] = NULL;
> - }
> -}
> -
> /*
> * allocate kernel pages
> */
> static int synth_alloc_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
> {
> int page, first_page, last_page;
> + struct snd_dma_buffer dmab;
>
> emu10k1_memblk_init(blk);
> get_single_page_range(emu->memhdr, blk, &first_page, &last_page);
> /* allocate kernel pages */
> for (page = first_page; page <= last_page; page++) {
> - /* first try to allocate from <4GB zone */
> - struct page *p = alloc_page(GFP_KERNEL | GFP_DMA32 |
> - __GFP_NOWARN);
> - if (!p || (page_to_pfn(p) & ~(emu->dma_mask >> PAGE_SHIFT))) {
> - if (p)
> - __free_page(p);
> - /* try to allocate from <16MB zone */
> - p = alloc_page(GFP_ATOMIC | GFP_DMA |
> - __GFP_NORETRY | /* no OOM-killer */
> - __GFP_NOWARN);
> - }
> - if (!p) {
> - __synth_free_pages(emu, first_page, page - 1);
> - return -ENOMEM;
> + if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV,
> + snd_dma_pci_data(emu->pci),
> + PAGE_SIZE, &dmab) < 0)
> + goto __fail;
> + if (!is_valid_page(emu, dmab.addr)) {
> + snd_dma_free_pages(&dmab);
> + goto __fail;
> }
> - emu->page_addr_table[page] = page_to_phys(p);
> - emu->page_ptr_table[page] = page_address(p);
> + emu->page_addr_table[page] = dmab.addr;
> + emu->page_ptr_table[page] = dmab.area;
> }
> return 0;
> +
> +__fail:
> + /* release allocated pages */
> + last_page = page - 1;
> + for (page = first_page; page <= last_page; page++) {
> + dmab.area = emu->page_ptr_table[page];
> + dmab.addr = emu->page_addr_table[page];
> + dmab.bytes = PAGE_SIZE;
> + snd_dma_free_pages(&dmab);
> + emu->page_addr_table[page] = 0;
> + emu->page_ptr_table[page] = NULL;
> + }
> +
> + return -ENOMEM;
> }
>
> /*
> @@ -507,10 +502,23 @@ static int synth_alloc_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk
> */
> static int synth_free_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
> {
> - int first_page, last_page;
> + int page, first_page, last_page;
> + struct snd_dma_buffer dmab;
>
> get_single_page_range(emu->memhdr, blk, &first_page, &last_page);
> - __synth_free_pages(emu, first_page, last_page);
> + dmab.dev.type = SNDRV_DMA_TYPE_DEV;
> + dmab.dev.dev = snd_dma_pci_data(emu->pci);
> + for (page = first_page; page <= last_page; page++) {
> + if (emu->page_ptr_table[page] == NULL)
> + continue;
> + dmab.area = emu->page_ptr_table[page];
> + dmab.addr = emu->page_addr_table[page];
> + dmab.bytes = PAGE_SIZE;
> + snd_dma_free_pages(&dmab);
> + emu->page_addr_table[page] = 0;
> + emu->page_ptr_table[page] = NULL;
> + }
> +
> return 0;
> }
>
>
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