Hi Prabhakar, Am Montag, 24. Oktober 2022, 13:55:00 CEST schrieb Lad, Prabhakar: > Hi Conor, > > On Fri, Oct 21, 2022 at 11:32 PM Conor Dooley <conor@xxxxxxxxxx> wrote: > > > > On Fri, Oct 21, 2022 at 11:05:40PM +0100, Lad, Prabhakar wrote: > > > Hi Rob, > > > > > > Thank you for the review. > > > > > > On Fri, Oct 21, 2022 at 3:05 AM Rob Herring <robh@xxxxxxxxxx> wrote: > > > > > > > > On Wed, Oct 19, 2022 at 11:02:42PM +0100, Prabhakar wrote: > > > > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > > > > > > > > > > On the AX45MP core, cache coherency is a specification option so it may > > > > > not be supported. In this case DMA will fail. As a workaround, firstly we > > > > > allocate a global dma coherent pool from which DMA allocations are taken > > > > > and marked as non-cacheable + bufferable using the PMA region as specified > > > > > in the device tree. Synchronization callbacks are implemented to > > > > > synchronize when doing DMA transactions. > > > > > > > > > > The Andes AX45MP core has a Programmable Physical Memory Attributes (PMA) > > > > > block that allows dynamic adjustment of memory attributes in the runtime. > > > > > It contains a configurable amount of PMA entries implemented as CSR > > > > > registers to control the attributes of memory locations in interest. > > > > > > > > > > Below are the memory attributes supported: > > > > > * Device, Non-bufferable > > > > > * Device, bufferable > > > > > * Memory, Non-cacheable, Non-bufferable > > > > > * Memory, Non-cacheable, Bufferable > > > > > * Memory, Write-back, No-allocate > > > > > * Memory, Write-back, Read-allocate > > > > > * Memory, Write-back, Write-allocate > > > > > * Memory, Write-back, Read and Write-allocate > > > > > > > > > > This patch adds support to configure the memory attributes of the memory > > > > > regions as passed from the l2 cache node and exposes the cache management > > > > > ops. > > > > > > > > > > More info about PMA (section 10.3): > > > > > http://www.andestech.com/wp-content/uploads/AX45MP-1C-Rev.-5.0.0-Datasheet.pdf > > > > > > > > > > This feature is based on the work posted [0] by Vincent Chen > > > > > <vincentc@xxxxxxxxxxxxx> for the Andes AndeStart RISC-V CPU. > > > > > > > > > > [0] https://lore.kernel.org/lkml/1540982130-28248-1-git-send-email-vincentc@xxxxxxxxxxxxx/ > > > > > > > > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > > > > > --- > > > > > arch/riscv/include/asm/cacheflush.h | 8 + > > > > > arch/riscv/include/asm/errata_list.h | 2 + > > > > > arch/riscv/mm/dma-noncoherent.c | 20 ++ > > > > > drivers/soc/renesas/Kconfig | 5 + > > > > > drivers/soc/renesas/Makefile | 4 + > > > > > drivers/soc/renesas/rzf/Kconfig | 6 + > > > > > drivers/soc/renesas/rzf/Makefile | 3 + > > > > > drivers/soc/renesas/rzf/ax45mp_cache.c | 431 +++++++++++++++++++++++++ > > > > > > > > How many cache drivers do we have around now? I've seen a few bindings > > > > go by. I'm guessing it is time to stop putting the drivers in the > > > > drivers/soc/ dumping ground. > > > > > > > The main reason this driver is not in arch/riscv is that it has vendor > > > specific extensions. Due to this reason it was agreed during the LPC > > > that vendor specific extension should be maintained by SoC vendors and > > > was agreed that this can go into drivers/soc/renesas folder instead. > > > > Does not in drivers/soc mean they need to go into arch/riscv? > I was under the impression Rob wanted them arch/riscv, sorry for the confusion. > > > The outcome of the chat at the LPC BoF was more that the cache drivers > > themselves should not be be routed via the arch maintainers, no? > > > Indeed. > > > > > > > > > drivers/soc/renesas/rzf/ax45mp_sbi.h | 29 ++ > > > > > 9 files changed, 508 insertions(+) > > > > > create mode 100644 drivers/soc/renesas/rzf/Kconfig > > > > > create mode 100644 drivers/soc/renesas/rzf/Makefile > > > > > create mode 100644 drivers/soc/renesas/rzf/ax45mp_cache.c > > > > > create mode 100644 drivers/soc/renesas/rzf/ax45mp_sbi.h > > > > > > > > > > diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h > > > > > index 8a5c246b0a21..40aa790be9a3 100644 > > > > > --- a/arch/riscv/include/asm/cacheflush.h > > > > > +++ b/arch/riscv/include/asm/cacheflush.h > > > > > @@ -65,6 +65,14 @@ static inline void riscv_noncoherent_supported(void) {} > > > > > #define SYS_RISCV_FLUSH_ICACHE_LOCAL 1UL > > > > > #define SYS_RISCV_FLUSH_ICACHE_ALL (SYS_RISCV_FLUSH_ICACHE_LOCAL) > > > > > > > > > > +#ifdef CONFIG_AX45MP_L2_CACHE > > > > > +void ax45mp_cpu_dma_inval_range(void *vaddr, size_t end); > > > > > +void ax45mp_cpu_dma_wb_range(void *vaddr, size_t end); > > > > > + > > > > > +#define ALT_CMO_OP(_op, _start, _size, _cachesize) \ > > > > > + _op(_start, _size) > > > > > +#endif > > > > > + > > > > > #include <asm-generic/cacheflush.h> > > > > > > > > > > #endif /* _ASM_RISCV_CACHEFLUSH_H */ > > > > > diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h > > > > > index 19a771085781..d9cbf60c3b65 100644 > > > > > --- a/arch/riscv/include/asm/errata_list.h > > > > > +++ b/arch/riscv/include/asm/errata_list.h > > > > > @@ -89,6 +89,7 @@ asm volatile(ALTERNATIVE( \ > > > > > #define ALT_THEAD_PMA(_val) > > > > > #endif > > > > > > > > > > +#ifdef CONFIG_ERRATA_THEAD_CMO > > > > > /* > > > > > * dcache.ipa rs1 (invalidate, physical address) > > > > > * | 31 - 25 | 24 - 20 | 19 - 15 | 14 - 12 | 11 - 7 | 6 - 0 | > > > > > @@ -143,5 +144,6 @@ asm volatile(ALTERNATIVE_2( \ > > > > > : "a0") > > > > > > > > > > #endif /* __ASSEMBLY__ */ > > > > > +#endif > > > > > > > > > > #endif > > > > > diff --git a/arch/riscv/mm/dma-noncoherent.c b/arch/riscv/mm/dma-noncoherent.c > > > > > index b0add983530a..5270acca6766 100644 > > > > > --- a/arch/riscv/mm/dma-noncoherent.c > > > > > +++ b/arch/riscv/mm/dma-noncoherent.c > > > > > @@ -24,13 +24,25 @@ void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, > > > > > > > > > > switch (dir) { > > > > > case DMA_TO_DEVICE: > > > > > +#ifdef CONFIG_ERRATA_THEAD_CMO > > > > > ALT_CMO_OP(clean, vaddr, size, riscv_cbom_block_size); > > > > > +#elif CONFIG_AX45MP_L2_CACHE > > > > > + ALT_CMO_OP(ax45mp_cpu_dma_wb_range, vaddr, size, 0x0); > > > > > +#endif > > > > > > > > How do you support more than one platform in a build? > > > > > > > Yes, that's one concern which I have mentioned in the cover letter too > > > (At that moment it's just a single platform). Suggestions welcome! > > > > I think I said it on one of the earlier version, but it needs to be > > implemented w/ runtime patching via alternatives just like the thead > > stuff patches in their functions. > > > I'm a bit stumped with alternatives() usage. > > Currently I am just replacing the ALT_CMO_OP() macro if > CONFIG_AX45MP_L2_CACHE is enabled. For AX45MP currently we have two > exported functions ax45mp_cpu_dma_inval_range/ax45mp_cpu_dma_wb_range. > If I switch to > ALTERNATIVE() macro usage then I'll have to use the assembly version > of the above two mentioned functions? The overarching goal should always be the unified-kernel-image. So hardware-specific compile-time #ifeefs are normally a no-no :-) . So yes, it most likely should be assembly-based, and you'll "just" need to introduce an ALTERNATIVE_3 macro, similar to what ALTERNAITVE_2 does. That is actually the really nice part of alternatives, that you can have as many variants as you like. Heiko
