[PATCH v3 1/4] lib: sbi: add support for firmware features extension
Anup Patel
anup at brainfault.org
Wed Jun 19 05:47:47 PDT 2024
On Wed, Jun 19, 2024 at 3:13 PM Clément Léger <cleger at rivosinc.com> wrote:
>
> This extension allows the software running in supervisor mode to control
> the behavior of various features of the SBI [1]. Implement the support
> for such extension.
>
> Link: https://lists.riscv.org/g/tech-prs/message/924 [1]
> Signed-off-by: Clément Léger <cleger at rivosinc.com>
I had already reviewed the previous revision of this patch.
Reviewed-by: Anup Patel <anup at brainfault.org>
Applied this patch to the riscv/opensbi repo.
Thanks,
Anup
> ---
> include/sbi/sbi_ecall_interface.h | 27 +++++
> include/sbi/sbi_fwft.h | 23 ++++
> lib/sbi/objects.mk | 1 +
> lib/sbi/sbi_fwft.c | 178 ++++++++++++++++++++++++++++++
> lib/sbi/sbi_init.c | 11 ++
> 5 files changed, 240 insertions(+)
> create mode 100644 include/sbi/sbi_fwft.h
> create mode 100644 lib/sbi/sbi_fwft.c
>
> diff --git a/include/sbi/sbi_ecall_interface.h b/include/sbi/sbi_ecall_interface.h
> index 2600b66..e9a8167 100644
> --- a/include/sbi/sbi_ecall_interface.h
> +++ b/include/sbi/sbi_ecall_interface.h
> @@ -34,6 +34,7 @@
> #define SBI_EXT_CPPC 0x43505043
> #define SBI_EXT_DBTR 0x44425452
> #define SBI_EXT_SSE 0x535345
> +#define SBI_EXT_FWFT 0x46574654
>
> /* SBI function IDs for BASE extension*/
> #define SBI_EXT_BASE_GET_SPEC_VERSION 0x0
> @@ -117,6 +118,32 @@
> #define SBI_EXT_DBTR_TRIGGER_ENABLE 0x6
> #define SBI_EXT_DBTR_TRIGGER_DISABLE 0x7
>
> +/* SBI function IDs for FW feature extension */
> +#define SBI_EXT_FWFT_SET 0x0
> +#define SBI_EXT_FWFT_GET 0x1
> +
> +enum sbi_fwft_feature_t {
> + SBI_FWFT_MISALIGNED_EXC_DELEG = 0x0,
> + SBI_FWFT_LANDING_PAD = 0x1,
> + SBI_FWFT_SHADOW_STACK = 0x2,
> + SBI_FWFT_DOUBLE_TRAP = 0x3,
> + SBI_FWFT_PTE_AD_HW_UPDATING = 0x4,
> + SBI_FWFT_LOCAL_RESERVED_START = 0x5,
> + SBI_FWFT_LOCAL_RESERVED_END = 0x3fffffff,
> + SBI_FWFT_LOCAL_PLATFORM_START = 0x40000000,
> + SBI_FWFT_LOCAL_PLATFORM_END = 0x7fffffff,
> +
> + SBI_FWFT_GLOBAL_RESERVED_START = 0x80000000,
> + SBI_FWFT_GLOBAL_RESERVED_END = 0xbfffffff,
> + SBI_FWFT_GLOBAL_PLATFORM_START = 0xc0000000,
> + SBI_FWFT_GLOBAL_PLATFORM_END = 0xffffffff,
> +};
> +
> +#define SBI_FWFT_GLOBAL_FEATURE_BIT (1 << 31)
> +#define SBI_FWFT_PLATFORM_FEATURE_BIT (1 << 30)
> +
> +#define SBI_FWFT_SET_FLAG_LOCK (1 << 0)
> +
> /** General pmu event codes specified in SBI PMU extension */
> enum sbi_pmu_hw_generic_events_t {
> SBI_PMU_HW_NO_EVENT = 0,
> diff --git a/include/sbi/sbi_fwft.h b/include/sbi/sbi_fwft.h
> new file mode 100644
> index 0000000..2148820
> --- /dev/null
> +++ b/include/sbi/sbi_fwft.h
> @@ -0,0 +1,23 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2024 Rivos Inc.
> + *
> + * Authors:
> + * Clément Léger <cleger at rivosinc.com>
> + */
> +
> +#ifndef __SBI_FW_FEATURE_H__
> +#define __SBI_FW_FEATURE_H__
> +
> +#include <sbi/sbi_ecall_interface.h>
> +
> +struct sbi_scratch;
> +
> +int sbi_fwft_set(enum sbi_fwft_feature_t feature, unsigned long value,
> + unsigned long flags);
> +int sbi_fwft_get(enum sbi_fwft_feature_t feature, unsigned long *out_val);
> +
> +int sbi_fwft_init(struct sbi_scratch *scratch, bool cold_boot);
> +
> +#endif
> diff --git a/lib/sbi/objects.mk b/lib/sbi/objects.mk
> index b1c4a50..221e72c 100644
> --- a/lib/sbi/objects.mk
> +++ b/lib/sbi/objects.mk
> @@ -65,6 +65,7 @@ libsbi-objs-y += sbi_domain_context.o
> libsbi-objs-y += sbi_domain.o
> libsbi-objs-y += sbi_emulate_csr.o
> libsbi-objs-y += sbi_fifo.o
> +libsbi-objs-y += sbi_fwft.o
> libsbi-objs-y += sbi_hart.o
> libsbi-objs-y += sbi_heap.o
> libsbi-objs-y += sbi_math.o
> diff --git a/lib/sbi/sbi_fwft.c b/lib/sbi/sbi_fwft.c
> new file mode 100644
> index 0000000..b302b5d
> --- /dev/null
> +++ b/lib/sbi/sbi_fwft.c
> @@ -0,0 +1,178 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2024 Rivos Inc.
> + *
> + * Authors:
> + * Clément Léger <cleger at rivosinc.com>
> + */
> +
> +#include <sbi/sbi_console.h>
> +#include <sbi/sbi_bitmap.h>
> +#include <sbi/sbi_ecall_interface.h>
> +#include <sbi/sbi_error.h>
> +#include <sbi/sbi_hart.h>
> +#include <sbi/sbi_heap.h>
> +#include <sbi/sbi_scratch.h>
> +#include <sbi/sbi_string.h>
> +#include <sbi/sbi_types.h>
> +
> +#include <sbi/riscv_asm.h>
> +#include <sbi/riscv_encoding.h>
> +
> +/** Offset of pointer to FWFT HART state in scratch space */
> +static unsigned long fwft_ptr_offset;
> +
> +#define fwft_get_hart_state_ptr(__scratch) \
> + sbi_scratch_read_type((__scratch), void *, fwft_ptr_offset)
> +
> +#define fwft_thishart_state_ptr() \
> + fwft_get_hart_state_ptr(sbi_scratch_thishart_ptr())
> +
> +#define fwft_set_hart_state_ptr(__scratch, __phs) \
> + sbi_scratch_write_type((__scratch), void *, fwft_ptr_offset, (__phs))
> +
> +struct fwft_config;
> +
> +struct fwft_feature {
> + enum sbi_fwft_feature_t id;
> + int (*supported)(struct fwft_config *conf);
> + int (*set)(struct fwft_config *conf, unsigned long value);
> + int (*get)(struct fwft_config *conf, unsigned long *value);
> +};
> +
> +struct fwft_config {
> + const struct fwft_feature *feature;
> + unsigned long flags;
> +};
> +
> +struct fwft_hart_state {
> + unsigned int config_count;
> + struct fwft_config configs[];
> +};
> +
> +static const unsigned long fwft_defined_features[] = {
> + SBI_FWFT_MISALIGNED_EXC_DELEG,
> + SBI_FWFT_LANDING_PAD,
> + SBI_FWFT_SHADOW_STACK,
> + SBI_FWFT_DOUBLE_TRAP,
> + SBI_FWFT_PTE_AD_HW_UPDATING,
> +};
> +
> +static bool fwft_is_defined_feature(enum sbi_fwft_feature_t feature)
> +{
> + int i;
> +
> + for (i = 0; i < array_size(fwft_defined_features); i++) {
> + if (fwft_defined_features[i] == feature)
> + return true;
> + }
> +
> + return false;
> +}
> +
> +static struct fwft_config* get_feature_config(enum sbi_fwft_feature_t feature)
> +{
> + int i;
> + struct fwft_hart_state *fhs = fwft_thishart_state_ptr();
> +
> + if (feature & SBI_FWFT_GLOBAL_FEATURE_BIT)
> + return NULL;
> +
> + for (i = 0; i < fhs->config_count; i++){
> + if (feature == fhs->configs[i].feature->id)
> + return &fhs->configs[i];
> + }
> +
> + return NULL;
> +}
> +
> +static int fwft_get_feature(enum sbi_fwft_feature_t feature,
> + struct fwft_config **conf)
> +{
> + int ret;
> + struct fwft_config *tconf;
> +
> + tconf = get_feature_config(feature);
> + if (!tconf) {
> + if (fwft_is_defined_feature(feature))
> + return SBI_ENOTSUPP;
> +
> + return SBI_EDENIED;
> + }
> +
> + if (tconf->feature->supported) {
> + ret = tconf->feature->supported(tconf);
> + if (ret)
> + return ret;
> + }
> + *conf = tconf;
> +
> + return SBI_SUCCESS;
> +}
> +
> +int sbi_fwft_set(enum sbi_fwft_feature_t feature, unsigned long value,
> + unsigned long flags)
> +{
> + int ret;
> + struct fwft_config *conf;
> +
> + ret = fwft_get_feature(feature, &conf);
> + if (ret)
> + return ret;
> +
> + if ((flags & ~SBI_FWFT_SET_FLAG_LOCK) != 0)
> + return SBI_ERR_INVALID_PARAM;
> +
> + if (conf->flags & SBI_FWFT_SET_FLAG_LOCK)
> + return SBI_EDENIED;
> +
> + ret = conf->feature->set(conf, value);
> + if (ret)
> + return ret;
> +
> + conf->flags = flags;
> +
> + return SBI_OK;
> +}
> +
> +int sbi_fwft_get(enum sbi_fwft_feature_t feature, unsigned long *out_val)
> +{
> + int ret;
> + struct fwft_config *conf;
> +
> + ret = fwft_get_feature(feature, &conf);
> + if (ret)
> + return ret;
> +
> + return conf->feature->get(conf, out_val);
> +}
> +
> +static const struct fwft_feature features[] = {};
> +
> +int sbi_fwft_init(struct sbi_scratch *scratch, bool cold_boot)
> +{
> + int i;
> + struct fwft_hart_state *fhs;
> +
> + if (cold_boot) {
> + fwft_ptr_offset = sbi_scratch_alloc_type_offset(void *);
> + if (!fwft_ptr_offset)
> + return SBI_ENOMEM;
> + }
> +
> + fhs = fwft_get_hart_state_ptr(scratch);
> + if (!fhs) {
> + fhs = sbi_zalloc(sizeof(fhs) + array_size(features) * sizeof(struct fwft_config));
> + if (!fhs)
> + return SBI_ENOMEM;
> +
> + fhs->config_count = array_size(features);
> + for (i = 0; i < array_size(features); i++)
> + fhs->configs[i].feature = &features[i];
> +
> + fwft_set_hart_state_ptr(scratch, fhs);
> + }
> +
> + return 0;
> +}
> diff --git a/lib/sbi/sbi_init.c b/lib/sbi/sbi_init.c
> index 389172a..0f9e14c 100644
> --- a/lib/sbi/sbi_init.c
> +++ b/lib/sbi/sbi_init.c
> @@ -14,6 +14,7 @@
> #include <sbi/sbi_cppc.h>
> #include <sbi/sbi_domain.h>
> #include <sbi/sbi_ecall.h>
> +#include <sbi/sbi_fwft.h>
> #include <sbi/sbi_hart.h>
> #include <sbi/sbi_hartmask.h>
> #include <sbi/sbi_heap.h>
> @@ -308,6 +309,12 @@ static void __noreturn init_coldboot(struct sbi_scratch *scratch, u32 hartid)
> sbi_hart_hang();
> }
>
> + rc = sbi_fwft_init(scratch, true);
> + if (rc) {
> + sbi_printf("%s: fwft init failed (error %d)\n", __func__, rc);
> + sbi_hart_hang();
> + }
> +
> /*
> * Note: Finalize domains after HSM initialization so that we
> * can startup non-root domains.
> @@ -423,6 +430,10 @@ static void __noreturn init_warm_startup(struct sbi_scratch *scratch,
> if (rc)
> sbi_hart_hang();
>
> + rc = sbi_fwft_init(scratch, false);
> + if (rc)
> + sbi_hart_hang();
> +
> rc = sbi_platform_final_init(plat, false);
> if (rc)
> sbi_hart_hang();
> --
> 2.45.2
>
>
> --
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