[PATCH v8] platform: generic: renesas: rzfive: Add SBI EXT to check for enabling IOCP errata

Lad, Prabhakar prabhakar.csengg at gmail.com
Thu Apr 6 02:37:44 PDT 2023


Hi Anup,

Thank you for the review.

On Thu, Apr 6, 2023 at 5:53 AM Anup Patel <anup at brainfault.org> wrote:
>
> On Fri, Mar 31, 2023 at 11:32 PM Lad Prabhakar
> <prabhakar.mahadev-lad.rj at bp.renesas.com> wrote:
> >
> > I/O Coherence Port (IOCP) provides an AXI interface for connecting
> > external non-caching masters, such as DMA controllers. The accesses
> > from IOCP are coherent with D-Caches and L2 Cache.
> >
> > IOCP is a specification option and is disabled on the Renesas RZ/Five
> > SoC due to this reason IP blocks using DMA will fail.
> >
> > As a workaround for SoCs with IOCP disabled CMO needs to be handled by
> > software. Firstly OpenSBI configures the memory region as
> > "Memory, Non-cacheable, Bufferable" and passes this region as a global
> > shared dma pool as a DT node. With DMA_GLOBAL_POOL enabled all DMA
> > allocations happen from this region and synchronization callbacks are
> > implemented to synchronize when doing DMA transactions.
> >
> > SBI_EXT_ANDES_IOCP_SW_WORKAROUND checks if the IOCP errata should be
> > applied to handle cache management.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
> > Reviewed-by: Yu Chien Peter Lin <peterlin at andestech.com>
> > Reviewed-by: Conor Dooley <conor.dooley at microchip.com>
> > ---
> > v7->v8
> > * Fixed typo controlable -> controllable
> > * Included RB tag from Lin-san and Conor
> >
> > v6->v7
> > * Added a new section for conf and control registers
> > * Made use of misa_extension('U')
> > * For unsupported funcid's now returning SBI_EINVAL
> > * Renamed ANDES_SBI_EXT_IOCP_SW_WORKAROUND -> SBI_EXT_ANDES_IOCP_SW_WORKAROUND
> >
> > v5->v6
> > * Moved ANDES_SBI_EXT_IOCP_SW_WORKAROUND to andes_sbi.h
> > * Moved helpers to check IOCP to common header so that we re-use code
> >
> > v5:
> > https://patchwork.ozlabs.org/project/opensbi/patch/20230213215111.32017-4-prabhakar.mahadev-lad.rj@bp.renesas.com/
> > ---
> >  platform/generic/include/andes/andes45.h   | 23 ++++++++++++++--
> >  platform/generic/include/andes/andes_sbi.h | 32 ++++++++++++++++++++++
> >  platform/generic/renesas/rzfive/rzfive.c   | 21 ++++++++++++++
> >  3 files changed, 74 insertions(+), 2 deletions(-)
> >  create mode 100644 platform/generic/include/andes/andes_sbi.h
> >
> > diff --git a/platform/generic/include/andes/andes45.h b/platform/generic/include/andes/andes45.h
> > index 08b3d18..f570994 100644
> > --- a/platform/generic/include/andes/andes45.h
> > +++ b/platform/generic/include/andes/andes45.h
> > @@ -4,7 +4,26 @@
> >  #define CSR_MARCHID_MICROID 0xfff
> >
> >  /* Memory and Miscellaneous Registers */
> > -#define CSR_MCACHE_CTL 0x7ca
> > -#define CSR_MCCTLCOMMAND 0x7cc
> > +#define CSR_MCACHE_CTL         0x7ca
> > +#define CSR_MCCTLCOMMAND       0x7cc
> > +
> > +/* Configuration Control & Status Registers */
> > +#define CSR_MICM_CFG           0xfc0
> > +#define CSR_MDCM_CFG           0xfc1
> > +#define CSR_MMSC_CFG           0xfc2
> > +
> > +#define MICM_CFG_ISZ_OFFSET            6
> > +#define MICM_CFG_ISZ_MASK              (0x7  << MICM_CFG_ISZ_OFFSET)
> > +
> > +#define MDCM_CFG_DSZ_OFFSET            6
> > +#define MDCM_CFG_DSZ_MASK              (0x7  << MDCM_CFG_DSZ_OFFSET)
> > +
> > +#define MMSC_CFG_CCTLCSR_OFFSET                16
> > +#define MMSC_CFG_CCTLCSR_MASK          (0x1 << MMSC_CFG_CCTLCSR_OFFSET)
> > +#define MMSC_IOCP_OFFSET                       47
> > +#define MMSC_IOCP_MASK                 (0x1ULL << MMSC_IOCP_OFFSET)
> > +
> > +#define MCACHE_CTL_CCTL_SUEN_OFFSET    8
> > +#define MCACHE_CTL_CCTL_SUEN_MASK      (0x1 << MCACHE_CTL_CCTL_SUEN_OFFSET)
> >
> >  #endif /* _RISCV_ANDES45_H */
> > diff --git a/platform/generic/include/andes/andes_sbi.h b/platform/generic/include/andes/andes_sbi.h
> > new file mode 100644
> > index 0000000..12b83c2
> > --- /dev/null
> > +++ b/platform/generic/include/andes/andes_sbi.h
> > @@ -0,0 +1,32 @@
> > +#ifndef _RISCV_ANDES_SBI_H
> > +#define _RISCV_ANDES_SBI_H
> > +
> > +#include <sbi/riscv_asm.h>
> > +
> > +#include "andes45.h"
> > +
> > +enum sbi_ext_andes_fid {
> > +       SBI_EXT_ANDES_FID0 = 0, /* Reserved for future use */
> > +       SBI_EXT_ANDES_IOCP_SW_WORKAROUND,
> > +};
> > +
> > +static bool andes45_cache_controllable(void)
> > +{
> > +       return (((csr_read(CSR_MICM_CFG) & MICM_CFG_ISZ_MASK) ||
> > +                (csr_read(CSR_MDCM_CFG) & MDCM_CFG_DSZ_MASK)) &&
> > +               (csr_read(CSR_MMSC_CFG) & MMSC_CFG_CCTLCSR_MASK) &&
> > +               (csr_read(CSR_MCACHE_CTL) & MCACHE_CTL_CCTL_SUEN_MASK) &&
> > +               misa_extension('U'));
> > +}
> > +
> > +static bool andes45_iocp_disabled(void)
> > +{
> > +       return (csr_read(CSR_MMSC_CFG) & MMSC_IOCP_MASK) ? false : true;
> > +}
> > +
> > +static bool andes45_apply_iocp_sw_workaround(void)
> > +{
> > +       return andes45_cache_controllable() & andes45_iocp_disabled();
> > +}
>
> Instead of having all static functions in the header, I suggest creating a small
> library at platforms/generic/andes/andes_sbi.c with its own Kconfig option.
>
> The Renesas RZ/Five platform can select the andes_sbi library using Kconfig.
>
Sure will do.

> > +
> > +#endif /* _RISCV_ANDES_SBI_H */
> > diff --git a/platform/generic/renesas/rzfive/rzfive.c b/platform/generic/renesas/rzfive/rzfive.c
> > index 4d71d0d..b6df1a7 100644
> > --- a/platform/generic/renesas/rzfive/rzfive.c
> > +++ b/platform/generic/renesas/rzfive/rzfive.c
> > @@ -5,8 +5,10 @@
> >   */
> >
> >  #include <andes/andes45_pma.h>
> > +#include <andes/andes_sbi.h>
> >  #include <platform_override.h>
> >  #include <sbi/sbi_domain.h>
> > +#include <sbi/sbi_error.h>
> >  #include <sbi_utils/fdt/fdt_helper.h>
> >
> >  static const struct andes45_pma_region renesas_rzfive_pma_regions[] = {
> > @@ -28,6 +30,24 @@ static int renesas_rzfive_final_init(bool cold_boot, const struct fdt_match *mat
> >                                          array_size(renesas_rzfive_pma_regions));
> >  }
> >
> > +static int renesas_rzfive_vendor_ext_provider(long funcid,
> > +                                             const struct sbi_trap_regs *regs,
> > +                                             unsigned long *out_value,
> > +                                             struct sbi_trap_info *out_trap,
> > +                                             const struct fdt_match *match)
>
> I think andes_sbi.c should define and implement:
>
> int andes_sbi_vendor_ext_provider(long funcid,
>                                               const struct sbi_trap_regs *regs,
>                                              unsigned long *out_value,
>                                              struct sbi_trap_info *out_trap,
>                                              const struct fdt_match *match);
>
> The renesas_rzfive_vendor_ext_provider() can simply call
> andes_sbi_vendor_ext_provider() or the ".vendor_ext_provider"
> below can be directly set to andes_sbi_vendor_ext_provider().
>
Ok I will move this to andes45_sbi.c.

Cheers,
Prabhakar



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