[PATCH v8] platform: generic: renesas: rzfive: Add SBI EXT to check for enabling IOCP errata
Anup Patel
anup at brainfault.org
Wed Apr 5 21:53:38 PDT 2023
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.
> +
> +#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().
> +{
> + switch (funcid) {
> + case SBI_EXT_ANDES_IOCP_SW_WORKAROUND:
> + *out_value = andes45_apply_iocp_sw_workaround();
> + break;
> +
> + default:
> + return SBI_EINVAL;
> + }
> +
> + return 0;
> +}
> +
> int renesas_rzfive_early_init(bool cold_boot, const struct fdt_match *match)
> {
> /*
> @@ -55,4 +75,5 @@ const struct platform_override renesas_rzfive = {
> .match_table = renesas_rzfive_match,
> .early_init = renesas_rzfive_early_init,
> .final_init = renesas_rzfive_final_init,
> + .vendor_ext_provider = renesas_rzfive_vendor_ext_provider,
> };
> --
> 2.17.1
>
Regards,
Anup
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