2017-11-08 16:36 GMT+08:00 Arnd Bergmann <arnd@xxxxxxxx>: > On Wed, Nov 8, 2017 at 6:54 AM, Greentime Hu <green.hu@xxxxxxxxx> wrote: > >> +/* >> + * The DMA mask corresponding to the maximum bus address allocatable >> + * using GFP_DMA. The default here places no restriction on DMA >> + * allocations. This must be the smallest DMA mask in the system, >> + * so a successful GFP_DMA allocation will always satisfy this. >> + */ >> +#ifndef ISA_DMA_THRESHOLD >> +#define ISA_DMA_THRESHOLD (0xffffffffULL) >> +#endif > > I see this one only in powerpc, I think it can be removed. Thanks. I will remove it in next version patch. > >> + >> +/* >> + * Optional device DMA address remapping. Do _not_ use directly! >> + * We should really eliminate virt_to_bus() here - it's deprecated. >> + */ >> +#define page_to_dma(dev, page) ((dma_addr_t)__virt_to_phys((unsigned long)page_address(page))) >> +#define dma_to_virt(dev, addr) ((void *)__phys_to_virt(addr)) >> +#define virt_to_dma(dev, addr) ((dma_addr_t)__virt_to_phys((unsigned long)(addr))) > > This looks like an older comment, I think we have eliminated them from the > mainline kernel in all drivers, so you should remove them here too. Thanks. I will remove it in next version patch. >> diff --git a/arch/nds32/include/asm/shmparam.h b/arch/nds32/include/asm/shmparam.h >> new file mode 100644 >> index 0000000..5679648 >> --- /dev/null >> +++ b/arch/nds32/include/asm/shmparam.h > >> + >> +/* >> + * This should be the size of the virtually indexed cache/ways, >> + * whichever is greater since the cache aliases every size/ways >> + * bytes. >> + */ >> +#define SHMLBA (4 * PAGE_SIZE) /* attach addr a multiple of this */ >> +#define REALSHMLBA SHMLBA > > I don't see REALSHMLBA anywhere in the kernel, do you need it? > > For SHMLBA, I think it should be defined as an absolute number, using > the maximum > that you might need for any possible value of PAGE_SIZE. Otherwise user space > has a much harder time figuring out what it should use. Thanks. I will remove REALSHMLBA. I will consider to use 8KB or larger page size in the next version patch.
