[PATCH v2 13/13] ARM: stm32mp: add RIFSC system bus driver for STM32MP25
Patrice CHOTARD
patrice.chotard at foss.st.com
Mon Apr 28 15:22:06 CEST 2025
On 4/22/25 15:12, Patrice Chotard wrote:
> From: Patrick Delaunay <patrick.delaunay at foss.st.com>
>
> This driver is checking the access rights of the different
> peripherals connected to the RIFSC bus. If access is denied,
> the associated device is not binded.
>
> Signed-off-by: Gatien Chevallier <gatien.chevallier at foss.st.com>
> Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
> Reviewed-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
>
> ---
>
> Changes in v2:
> - Replace LOG_CATEGORY UCLASS_SIMPLE_BUS by UCLASS_NOP in both
> /arch/arm/mach-stm32mp/stm32mp2/rifsc.c and
> /arch/arm/mach-stm32mp/stm32mp1/etzpc.c.
> - Update board/st/stm32mp1/MAINTAINERS.
> - Fix DSI clock ssetting.
>
> arch/arm/mach-stm32mp/include/mach/rif.h | 26 ++
> arch/arm/mach-stm32mp/stm32mp2/Makefile | 1 +
> arch/arm/mach-stm32mp/stm32mp2/rifsc.c | 364 +++++++++++++++++++++++
> 3 files changed, 391 insertions(+)
> create mode 100644 arch/arm/mach-stm32mp/include/mach/rif.h
> create mode 100644 arch/arm/mach-stm32mp/stm32mp2/rifsc.c
>
> diff --git a/arch/arm/mach-stm32mp/include/mach/rif.h b/arch/arm/mach-stm32mp/include/mach/rif.h
> new file mode 100644
> index 00000000000..10b22108120
> --- /dev/null
> +++ b/arch/arm/mach-stm32mp/include/mach/rif.h
> @@ -0,0 +1,26 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause */
> +/*
> + * Copyright (C) 2023, STMicroelectronics - All Rights Reserved
> + */
> +
> +#ifndef MACH_RIF_H
> +#define MACH_RIF_H
> +
> +#include <linux/types.h>
> +
> +/**
> + * stm32_rifsc_check_access - Check RIF accesses for given device node
> + *
> + * @device_node Node of the device for which the accesses are checked
> + */
> +int stm32_rifsc_check_access(ofnode device_node);
> +
> +/**
> + * stm32_rifsc_check_access - Check RIF accesses for given id
> + *
> + * @device_node Node of the device to get a reference on RIFSC
> + * @id ID of the resource to check
> + */
> +int stm32_rifsc_check_access_by_id(ofnode device_node, u32 id);
> +
> +#endif /* MACH_RIF_H*/
> diff --git a/arch/arm/mach-stm32mp/stm32mp2/Makefile b/arch/arm/mach-stm32mp/stm32mp2/Makefile
> index b579ce5a800..5dbf75daa76 100644
> --- a/arch/arm/mach-stm32mp/stm32mp2/Makefile
> +++ b/arch/arm/mach-stm32mp/stm32mp2/Makefile
> @@ -5,5 +5,6 @@
>
> obj-y += cpu.o
> obj-y += arm64-mmu.o
> +obj-y += rifsc.o
> obj-$(CONFIG_OF_SYSTEM_SETUP) += fdt.o
> obj-$(CONFIG_STM32MP25X) += stm32mp25x.o
> diff --git a/arch/arm/mach-stm32mp/stm32mp2/rifsc.c b/arch/arm/mach-stm32mp/stm32mp2/rifsc.c
> new file mode 100644
> index 00000000000..50dececf77b
> --- /dev/null
> +++ b/arch/arm/mach-stm32mp/stm32mp2/rifsc.c
> @@ -0,0 +1,364 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause
> +/*
> + * Copyright (C) 2023, STMicroelectronics - All Rights Reserved
> + */
> +
> +#define LOG_CATEGORY UCLASS_NOP
> +
> +#include <dm.h>
> +#include <asm/io.h>
> +#include <dm/device.h>
> +#include <dm/device_compat.h>
> +#include <dm/lists.h>
> +#include <linux/bitfield.h>
> +#include <mach/rif.h>
> +
> +/* RIFSC offset register */
> +#define RIFSC_RISC_SECCFGR0(id) (0x10 + 0x4 * (id))
> +#define RIFSC_RISC_PER0_CIDCFGR(id) (0x100 + 0x8 * (id))
> +#define RIFSC_RISC_PER0_SEMCR(id) (0x104 + 0x8 * (id))
> +
> +/*
> + * SEMCR register
> + */
> +#define SEMCR_MUTEX BIT(0)
> +
> +/* RIFSC miscellaneous */
> +#define RIFSC_RISC_SCID_MASK GENMASK(6, 4)
> +#define RIFSC_RISC_SEMWL_MASK GENMASK(23, 16)
> +
> +#define IDS_PER_RISC_SEC_PRIV_REGS 32
> +
> +/*
> + * CIDCFGR register fields
> + */
> +#define CIDCFGR_CFEN BIT(0)
> +#define CIDCFGR_SEMEN BIT(1)
> +
> +#define SEMWL_SHIFT 16
> +
> +#define STM32MP25_RIFSC_ENTRIES 178
> +
> +/* Compartiment IDs */
> +#define RIF_CID0 0x0
> +#define RIF_CID1 0x1
> +
> +/*
> + * struct stm32_rifsc_plat: Information about RIFSC device
> + *
> + * @base: Base address of RIFSC
> + */
> +struct stm32_rifsc_plat {
> + void *base;
> +};
> +
> +/*
> + * struct stm32_rifsc_child_plat: Information about each child
> + *
> + * @domain_id: Domain id
> + */
> +struct stm32_rifsc_child_plat {
> + u32 domain_id;
> +};
> +
> +static bool stm32_rif_is_semaphore_available(void *base, u32 id)
> +{
> + void *addr = base + RIFSC_RISC_PER0_SEMCR(id);
> +
> + return !(readl(addr) & SEMCR_MUTEX);
> +}
> +
> +static int stm32_rif_acquire_semaphore(void *base, u32 id)
> +{
> + void *addr = base + RIFSC_RISC_PER0_SEMCR(id);
> +
> + /* Check that the semaphore is available */
> + if (!stm32_rif_is_semaphore_available(base, id))
> + return -EACCES;
> +
> + setbits_le32(addr, SEMCR_MUTEX);
> +
> + /* Check that CID1 has the semaphore */
> + if (stm32_rif_is_semaphore_available(base, id) ||
> + FIELD_GET(RIFSC_RISC_SCID_MASK, (readl(addr)) != RIF_CID1))
> + return -EACCES;
> +
> + return 0;
> +}
> +
> +static int stm32_rif_release_semaphore(void *base, u32 id)
> +{
> + void *addr = base + RIFSC_RISC_PER0_SEMCR(id);
> +
> + if (stm32_rif_is_semaphore_available(base, id))
> + return 0;
> +
> + clrbits_le32(addr, SEMCR_MUTEX);
> +
> + /* Ok if another compartment takes the semaphore before the check */
> + if (!stm32_rif_is_semaphore_available(base, id) &&
> + FIELD_GET(RIFSC_RISC_SCID_MASK, (readl(addr)) == RIF_CID1))
> + return -EACCES;
> +
> + return 0;
> +}
> +
> +static int rifsc_parse_access_controller(ofnode node, struct ofnode_phandle_args *args)
> +{
> + int ret;
> +
> + ret = ofnode_parse_phandle_with_args(node, "access-controllers",
> + "#access-controller-cells", 0,
> + 0, args);
> + if (ret) {
> + log_debug("failed to parse access-controller (%d)\n", ret);
> + return ret;
> + }
> +
> + if (args->args_count != 1) {
> + log_debug("invalid domain args_count: %d\n", args->args_count);
> + return -EINVAL;
> + }
> +
> + if (args->args[0] >= STM32MP25_RIFSC_ENTRIES) {
> + log_err("Invalid sys bus ID for %s\n", ofnode_get_name(node));
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int rifsc_check_access(void *base, u32 id)
> +{
> + u32 reg_offset, reg_id, sec_reg_value, cid_reg_value, sem_reg_value;
> +
> + /*
> + * RIFSC_RISC_PRIVCFGRx and RIFSC_RISC_SECCFGRx both handle configuration access for
> + * 32 peripherals. On the other hand, there is one _RIFSC_RISC_PERx_CIDCFGR register
> + * per peripheral
> + */
> + reg_id = id / IDS_PER_RISC_SEC_PRIV_REGS;
> + reg_offset = id % IDS_PER_RISC_SEC_PRIV_REGS;
> + sec_reg_value = readl(base + RIFSC_RISC_SECCFGR0(reg_id));
> + cid_reg_value = readl(base + RIFSC_RISC_PER0_CIDCFGR(id));
> + sem_reg_value = readl(base + RIFSC_RISC_PER0_SEMCR(id));
> +
> + /*
> + * First check conditions for semaphore mode, which doesn't take into
> + * account static CID.
> + */
> + if (cid_reg_value & CIDCFGR_SEMEN)
> + goto skip_cid_check;
> +
> + /*
> + * Skip cid check if CID filtering isn't enabled or filtering is enabled on CID0, which
> + * corresponds to whatever CID.
> + */
> + if (!(cid_reg_value & CIDCFGR_CFEN) ||
> + FIELD_GET(RIFSC_RISC_SCID_MASK, cid_reg_value) == RIF_CID0)
> + goto skip_cid_check;
> +
> + /* Coherency check with the CID configuration */
> + if (FIELD_GET(RIFSC_RISC_SCID_MASK, cid_reg_value) != RIF_CID1) {
> + log_debug("Invalid CID configuration for peripheral %d\n", id);
> + return -EACCES;
> + }
> +
> + /* Check semaphore accesses */
> + if (cid_reg_value & CIDCFGR_SEMEN) {
> + if (!(FIELD_GET(RIFSC_RISC_SEMWL_MASK, cid_reg_value) & BIT(RIF_CID1))) {
> + log_debug("Not in semaphore whitelist for peripheral %d\n", id);
> + return -EACCES;
> + }
> + if (!stm32_rif_is_semaphore_available(base, id) &&
> + !(FIELD_GET(RIFSC_RISC_SCID_MASK, sem_reg_value) & BIT(RIF_CID1))) {
> + log_debug("Semaphore unavailable for peripheral %d\n", id);
> + return -EACCES;
> + }
> + }
> +
> +skip_cid_check:
> + /* Check security configuration */
> + if (sec_reg_value & BIT(reg_offset)) {
> + log_debug("Invalid security configuration for peripheral %d\n", id);
> + return -EACCES;
> + }
> +
> + return 0;
> +}
> +
> +int stm32_rifsc_check_access_by_id(ofnode device_node, u32 id)
> +{
> + struct ofnode_phandle_args args;
> + int err;
> +
> + if (id >= STM32MP25_RIFSC_ENTRIES)
> + return -EINVAL;
> +
> + err = rifsc_parse_access_controller(device_node, &args);
> + if (err)
> + return err;
> +
> + return rifsc_check_access((void *)ofnode_get_addr(args.node), id);
> +}
> +
> +int stm32_rifsc_check_access(ofnode device_node)
> +{
> + struct ofnode_phandle_args args;
> + int err;
> +
> + err = rifsc_parse_access_controller(device_node, &args);
> + if (err)
> + return err;
> +
> + return rifsc_check_access((void *)ofnode_get_addr(args.node), args.args[0]);
> +}
> +
> +static int stm32_rifsc_child_pre_probe(struct udevice *dev)
> +{
> + struct stm32_rifsc_plat *plat = dev_get_plat(dev->parent);
> + struct stm32_rifsc_child_plat *child_plat = dev_get_parent_plat(dev);
> + u32 cid_reg_value;
> + int err;
> + u32 id = child_plat->domain_id;
> +
> + cid_reg_value = readl(plat->base + RIFSC_RISC_PER0_CIDCFGR(id));
> +
> + /*
> + * If the peripheral is in semaphore mode, take the semaphore so that
> + * the CID1 has the ownership.
> + */
> + if (cid_reg_value & CIDCFGR_SEMEN &&
> + (FIELD_GET(RIFSC_RISC_SEMWL_MASK, cid_reg_value) & BIT(RIF_CID1))) {
> + err = stm32_rif_acquire_semaphore(plat->base, id);
> + if (err) {
> + dev_err(dev, "Couldn't acquire RIF semaphore for peripheral %d (%d)\n",
> + id, err);
> + return err;
> + }
> + dev_dbg(dev, "Acquiring semaphore for peripheral %d\n", id);
> + }
> +
> + return 0;
> +}
> +
> +static int stm32_rifsc_child_post_remove(struct udevice *dev)
> +{
> + struct stm32_rifsc_plat *plat = dev_get_plat(dev->parent);
> + struct stm32_rifsc_child_plat *child_plat = dev_get_parent_plat(dev);
> + u32 cid_reg_value;
> + int err;
> + u32 id = child_plat->domain_id;
> +
> + cid_reg_value = readl(plat->base + RIFSC_RISC_PER0_CIDCFGR(id));
> +
> + /*
> + * If the peripheral is in semaphore mode, release the semaphore so that
> + * there's no ownership.
> + */
> + if (cid_reg_value & CIDCFGR_SEMEN &&
> + (FIELD_GET(RIFSC_RISC_SEMWL_MASK, cid_reg_value) & BIT(RIF_CID1))) {
> + err = stm32_rif_release_semaphore(plat->base, id);
> + if (err)
> + dev_err(dev, "Couldn't release rif semaphore for peripheral %d (%d)\n",
> + id, err);
> + }
> +
> + return 0;
> +}
> +
> +static int stm32_rifsc_child_post_bind(struct udevice *dev)
> +{
> + struct stm32_rifsc_child_plat *child_plat = dev_get_parent_plat(dev);
> + struct ofnode_phandle_args args;
> + int ret;
> +
> + if (!dev_has_ofnode(dev))
> + return -EPERM;
> +
> + ret = rifsc_parse_access_controller(dev_ofnode(dev), &args);
> + if (ret)
> + return ret;
> +
> + child_plat->domain_id = args.args[0];
> +
> + return 0;
> +}
> +
> +static int stm32_rifsc_bind(struct udevice *dev)
> +{
> + struct stm32_rifsc_plat *plat = dev_get_plat(dev);
> + struct ofnode_phandle_args args;
> + int ret = 0, err = 0;
> + ofnode node;
> +
> + plat->base = dev_read_addr_ptr(dev);
> + if (!plat->base) {
> + dev_err(dev, "can't get registers base address\n");
> + return -ENOENT;
> + }
> +
> + for (node = ofnode_first_subnode(dev_ofnode(dev));
> + ofnode_valid(node);
> + node = ofnode_next_subnode(node)) {
> + const char *node_name = ofnode_get_name(node);
> +
> + if (!ofnode_is_enabled(node))
> + continue;
> +
> + err = rifsc_parse_access_controller(node, &args);
> + if (err) {
> + dev_dbg(dev, "%s failed to parse child on bus (%d)\n", node_name, err);
> + continue;
> + }
> +
> + err = rifsc_check_access(plat->base, args.args[0]);
> + if (err) {
> + dev_info(dev, "%s not allowed on bus (%d)\n", node_name, err);
> + continue;
> + }
> +
> + err = lists_bind_fdt(dev, node, NULL, NULL,
> + gd->flags & GD_FLG_RELOC ? false : true);
> + if (err && !ret) {
> + ret = err;
> + dev_err(dev, "%s failed to bind on bus (%d)\n", node_name, ret);
> + }
> + }
> +
> + if (ret)
> + dev_err(dev, "Some child failed to bind (%d)\n", ret);
> +
> + return ret;
> +}
> +
> +static int stm32_rifsc_remove(struct udevice *bus)
> +{
> + struct udevice *dev;
> +
> + /* Deactivate all child devices not yet removed */
> + for (device_find_first_child(bus, &dev); dev; device_find_next_child(&dev))
> + if (device_active(dev))
> + stm32_rifsc_child_post_remove(dev);
> +
> + return 0;
> +}
> +
> +static const struct udevice_id stm32_rifsc_ids[] = {
> + { .compatible = "st,stm32mp25-rifsc" },
> + {},
> +};
> +
> +U_BOOT_DRIVER(stm32_rifsc) = {
> + .name = "stm32_rifsc",
> + .id = UCLASS_NOP,
> + .of_match = stm32_rifsc_ids,
> + .bind = stm32_rifsc_bind,
> + .remove = stm32_rifsc_remove,
> + .child_post_bind = stm32_rifsc_child_post_bind,
> + .child_pre_probe = stm32_rifsc_child_pre_probe,
> + .child_post_remove = stm32_rifsc_child_post_remove,
> + .plat_auto = sizeof(struct stm32_rifsc_plat),
> + .per_child_plat_auto = sizeof(struct stm32_rifsc_child_plat),
> + .flags = DM_FLAG_OS_PREPARE,
> +};
Applied to u-boot-stm32/master
Thanks
Patrice
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