HI Padmarao, On Fri, Dec 11, 2020 at 4:23 PM Padmarao Begari <padmara...@gmail.com> wrote: > > Hi Bin, > > On Fri, Dec 11, 2020 at 1:22 PM Bin Meng <bmeng...@gmail.com> wrote: >> >> Hi Padmarao, >> >> On Fri, Dec 11, 2020 at 3:10 PM Padmarao Begari <padmara...@gmail.com> wrote: >> > >> > Hi Bin, >> > >> > On Thu, Dec 10, 2020 at 4:11 PM Bin Meng <bmeng...@gmail.com> wrote: >> >> >> >> Hi Padmarao, >> >> >> >> On Thu, Dec 3, 2020 at 4:43 AM Padmarao Begari >> >> <padmarao.beg...@microchip.com> wrote: >> >> > >> >> > dma_addr_t holds any valid DMA address. If the DMA API only uses >> >> > 32/64-bit >> >> > addresses, dma_addr_t need only be 32/64 bits wide. >> >> > >> >> > Signed-off-by: Padmarao Begari <padmarao.beg...@microchip.com> >> >> > Reviewed-by: Anup Patel <anup.pa...@wdc.com> >> >> > --- >> >> > arch/riscv/Kconfig | 4 ++++ >> >> > arch/riscv/include/asm/types.h | 4 ++++ >> >> > 2 files changed, 8 insertions(+) >> >> > >> >> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >> >> > index 30b05408b1..55eaee2da6 100644 >> >> > --- a/arch/riscv/Kconfig >> >> > +++ b/arch/riscv/Kconfig >> >> > @@ -152,6 +152,10 @@ config 32BIT >> >> > config 64BIT >> >> > bool >> >> > >> >> > +config DMA_ADDR_T_64BIT >> >> > + bool >> >> > + default y if 64BIT >> >> > + >> >> > config SIFIVE_CLINT >> >> > bool >> >> > depends on RISCV_MMODE || SPL_RISCV_MMODE >> >> > diff --git a/arch/riscv/include/asm/types.h >> >> > b/arch/riscv/include/asm/types.h >> >> > index 403cf9a48f..b800b2d221 100644 >> >> > --- a/arch/riscv/include/asm/types.h >> >> > +++ b/arch/riscv/include/asm/types.h >> >> > @@ -29,7 +29,11 @@ typedef unsigned short umode_t; >> >> > >> >> > #include <stddef.h> >> >> > >> >> > +#ifdef CONFIG_DMA_ADDR_T_64BIT >> >> > +typedef u64 dma_addr_t; >> >> > +#else >> >> > typedef u32 dma_addr_t; >> >> > +#endif >> >> >> >> Why is this patch needed for U-Boot? >> >> >> > >> > Initially this patch was created for the MACB driver dependency and now >> > the MACB driver is not dependent on CONFIG_DMA_ADDR_T_64BIT. >> > But We created this patch the same as the ARM 64-bit kconfig and the >> > 'CONFIG_DMA_ADDR_T_64BIT' is used when the MMC driver is configured with >> > DMA. >> > >> >> But in U-Boot there is no 64-bit address. The DMA address should be >> under 4G. Both MACB and MMC driver should work with the 32-bit DMA >> addresses, no? >> > > We will use 64-bit addresses in the future.
But U-Boot does not generate 64-bit addresses for DMA at present. > Both MACB and MMC drivers work with 64-bit DMA addresses in the PolarFire SoC. So I think the patch to enable 64-bit DMA in U-Boot is not necessary. Regards, Bin
