[PATCH v5 04/11] lib: utils/cache: Add fdt cmo helpers
Anup Patel
anup at brainfault.org
Mon Sep 1 23:13:21 PDT 2025
On Tue, Sep 2, 2025 at 7:48 AM Nick Hu <nick.hu at sifive.com> wrote:
>
> Add the helpers to build up the cache hierarchy via FDT and provide some
> cmo functions for the user who want to flush the entire cache.
>
> Signed-off-by: Nick Hu <nick.hu at sifive.com>
> Reviewed-by: Samuel Holland <samuel.holland at sifive.com>
> Reviewed-by: Anup Patel <anup at brainfault.org>
> ---
> include/sbi_utils/cache/fdt_cmo_helper.h | 34 ++++++++++
> lib/utils/cache/fdt_cmo_helper.c | 112 +++++++++++++++++++++++++++++++
> lib/utils/cache/objects.mk | 1 +
> platform/generic/platform.c | 3 +-
> 4 files changed, 149 insertions(+), 1 deletion(-)
>
> diff --git a/include/sbi_utils/cache/fdt_cmo_helper.h b/include/sbi_utils/cache/fdt_cmo_helper.h
> new file mode 100644
> index 0000000000000000000000000000000000000000..4275725e1e299625306198beb2a268af9c56703c
> --- /dev/null
> +++ b/include/sbi_utils/cache/fdt_cmo_helper.h
> @@ -0,0 +1,34 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2025 SiFive Inc.
> + */
> +
> +#ifndef __FDT_CMO_HELPER_H__
> +#define __FDT_CMO_HELPER_H__
> +
> +/**
> + * Flush the private first level cache of the current hart
> + *
> + * @return 0 on success, or a negative error code on failure
> + */
> +int fdt_cmo_private_flc_flush_all(void);
> +
> +/**
> + * Flush the last level cache of the current hart
> + *
> + * @return 0 on success, or a negative error code on failure
> + */
> +int fdt_cmo_llc_flush_all(void);
> +
> +/**
> + * Initialize the cache devices for each hart
> + *
> + * @param fdt devicetree blob
> + * @param cold_boot cold init or warm init
> + *
> + * @return 0 on success, or a negative error code on failure
> + */
> +int fdt_cmo_init(bool cold_boot);
We need dummy inline flavor of fdt_cmo_init() for the case
where CONFIG_FDT_CACHE is disabled to avoid compile
errors in platform/generic/platform.c
> +
> +#endif
> diff --git a/lib/utils/cache/fdt_cmo_helper.c b/lib/utils/cache/fdt_cmo_helper.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..6d2e853dd735735092c57db2398f97a64de3ab5e
> --- /dev/null
> +++ b/lib/utils/cache/fdt_cmo_helper.c
> @@ -0,0 +1,112 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2025 SiFive Inc.
> + */
> +
> +#include <libfdt.h>
> +#include <sbi/sbi_error.h>
> +#include <sbi/sbi_scratch.h>
> +#include <sbi_utils/cache/fdt_cache.h>
> +#include <sbi_utils/cache/fdt_cmo_helper.h>
> +#include <sbi_utils/fdt/fdt_helper.h>
> +
> +static unsigned long flc_offset;
> +
> +#define get_hart_flc(_s) \
> + sbi_scratch_read_type(_s, struct cache_device *, flc_offset)
> +#define set_hart_flc(_s, _p) \
> + sbi_scratch_write_type(_s, struct cache_device *, flc_offset, _p)
> +
> +int fdt_cmo_private_flc_flush_all(void)
> +{
> + struct cache_device *flc = get_hart_flc(sbi_scratch_thishart_ptr());
> +
> + if (!flc || !flc->cpu_private)
> + return SBI_ENODEV;
> +
> + return cache_flush_all(flc);
> +}
> +
> +int fdt_cmo_llc_flush_all(void)
> +{
> + struct cache_device *llc = get_hart_flc(sbi_scratch_thishart_ptr());
> +
> + if (!llc)
> + return SBI_ENODEV;
> +
> + while (llc->next)
> + llc = llc->next;
> +
> + return cache_flush_all(llc);
> +}
> +
> +static int fdt_cmo_cold_init(const void *fdt)
> +{
> + struct sbi_scratch *scratch;
> + struct cache_device *dev;
> + int cpu_offset, cpus_offset, rc;
> + u32 hartid;
> +
> + cpus_offset = fdt_path_offset(fdt, "/cpus");
> + if (cpus_offset < 0)
> + return SBI_EINVAL;
> +
> + fdt_for_each_subnode(cpu_offset, fdt, cpus_offset) {
> + rc = fdt_parse_hart_id(fdt, cpu_offset, &hartid);
> + if (rc)
> + continue;
> +
> + scratch = sbi_hartid_to_scratch(hartid);
> + if (!scratch)
> + continue;
> +
> + rc = fdt_next_cache_get(fdt, cpu_offset, &dev);
> + if (rc)
> + return rc;
> +
> + set_hart_flc(scratch, dev);
> + }
> +
> + return SBI_OK;
> +}
> +
> +static int fdt_cmo_warm_init(void)
> +{
> + struct cache_device *cur = get_hart_flc(sbi_scratch_thishart_ptr());
> + int rc;
> +
> + while (cur) {
> + if (cur->ops && cur->ops->warm_init) {
> + rc = cur->ops->warm_init(cur);
> + if (rc)
> + return rc;
> + }
> +
> + cur = cur->next;
> + }
> +
> + return SBI_OK;
> +}
> +
> +int fdt_cmo_init(bool cold_boot)
> +{
> + const void *fdt = fdt_get_address();
> + int rc;
> +
> + if (cold_boot) {
> + flc_offset = sbi_scratch_alloc_type_offset(struct cache_device *);
> + if (!flc_offset)
> + return SBI_ENOMEM;
> +
> + rc = fdt_cmo_cold_init(fdt);
> + if (rc)
> + return rc;
> + }
> +
> + rc = fdt_cmo_warm_init();
> + if (rc)
> + return rc;
> +
> + return SBI_OK;
> +}
> diff --git a/lib/utils/cache/objects.mk b/lib/utils/cache/objects.mk
> index a343eb8c4bd495a1596845c1fd02420277023430..6829a966784732127d93180b3eb46ed24de5bc7d 100644
> --- a/lib/utils/cache/objects.mk
> +++ b/lib/utils/cache/objects.mk
> @@ -6,6 +6,7 @@
>
> libsbiutils-objs-$(CONFIG_FDT_CACHE) += cache/fdt_cache.o
> libsbiutils-objs-$(CONFIG_FDT_CACHE) += cache/fdt_cache_drivers.carray.o
> +libsbiutils-objs-$(CONFIG_FDT_CACHE) += cache/fdt_cmo_helper.o
>
> carray-fdt_cache_drivers-$(CONFIG_FDT_CACHE_SIFIVE_CCACHE) += fdt_sifive_ccache
> libsbiutils-objs-$(CONFIG_FDT_CACHE_SIFIVE_CCACHE) += cache/fdt_sifive_ccache.o
> diff --git a/platform/generic/platform.c b/platform/generic/platform.c
> index 889d69052108ba5d45625180a55594ccaf6ba466..15d2e8c04eef67f0b37bec913447d3d5c34cda4b 100644
> --- a/platform/generic/platform.c
> +++ b/platform/generic/platform.c
> @@ -17,6 +17,7 @@
> #include <sbi/sbi_string.h>
> #include <sbi/sbi_system.h>
> #include <sbi/sbi_tlb.h>
> +#include <sbi_utils/cache/fdt_cmo_helper.h>
> #include <sbi_utils/fdt/fdt_domain.h>
> #include <sbi_utils/fdt/fdt_driver.h>
> #include <sbi_utils/fdt/fdt_fixup.h>
> @@ -231,7 +232,7 @@ int generic_early_init(bool cold_boot)
> fdt_driver_init_all(fdt, fdt_early_drivers);
> }
>
> - return 0;
> + return fdt_cmo_init(cold_boot);
> }
>
> int generic_final_init(bool cold_boot)
>
> --
> 2.34.1
>
Regards,
Anup
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