diff options
Diffstat (limited to 'drivers/firmware/smccc/soc_id.c')
| -rw-r--r-- | drivers/firmware/smccc/soc_id.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/drivers/firmware/smccc/soc_id.c b/drivers/firmware/smccc/soc_id.c new file mode 100644 index 000000000000..c24b3fca1cfe --- /dev/null +++ b/drivers/firmware/smccc/soc_id.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2020 Arm Limited + */ + +#define pr_fmt(fmt) "SMCCC: SOC_ID: " fmt + +#include <linux/arm-smccc.h> +#include <linux/bitfield.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/sys_soc.h> + +#define SMCCC_SOC_ID_JEP106_BANK_IDX_MASK GENMASK(30, 24) +/* + * As per the SMC Calling Convention specification v1.2 (ARM DEN 0028C) + * Section 7.4 SMCCC_ARCH_SOC_ID bits[23:16] are JEP-106 identification + * code with parity bit for the SiP. We can drop the parity bit. + */ +#define SMCCC_SOC_ID_JEP106_ID_CODE_MASK GENMASK(22, 16) +#define SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK GENMASK(15, 0) + +#define JEP106_BANK_CONT_CODE(x) \ + (u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_BANK_IDX_MASK, (x))) +#define JEP106_ID_CODE(x) \ + (u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_ID_CODE_MASK, (x))) +#define IMP_DEF_SOC_ID(x) \ + (u16)(FIELD_GET(SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK, (x))) + +static struct soc_device *soc_dev; +static struct soc_device_attribute *soc_dev_attr; + +#ifdef CONFIG_ARM64 + +static char __ro_after_init smccc_soc_id_name[136] = ""; + +static inline void str_fragment_from_reg(char *dst, unsigned long reg) +{ + dst[0] = (reg >> 0) & 0xff; + dst[1] = (reg >> 8) & 0xff; + dst[2] = (reg >> 16) & 0xff; + dst[3] = (reg >> 24) & 0xff; + dst[4] = (reg >> 32) & 0xff; + dst[5] = (reg >> 40) & 0xff; + dst[6] = (reg >> 48) & 0xff; + dst[7] = (reg >> 56) & 0xff; +} + +static char __init *smccc_soc_name_init(void) +{ + struct arm_smccc_1_2_regs args; + struct arm_smccc_1_2_regs res; + size_t len; + + /* + * Issue Number 1.6 of the Arm SMC Calling Convention + * specification introduces an optional "name" string + * to the ARM_SMCCC_ARCH_SOC_ID function. Fetch it if + * available. + */ + args.a0 = ARM_SMCCC_ARCH_SOC_ID; + args.a1 = 2; /* SOC_ID name */ + arm_smccc_1_2_invoke(&args, &res); + + if ((u32)res.a0 == 0) { + /* + * Copy res.a1..res.a17 to the smccc_soc_id_name string + * 8 bytes at a time. As per Issue 1.6 of the Arm SMC + * Calling Convention, the string will be NUL terminated + * and padded, from the end of the string to the end of the + * 136 byte buffer, with NULs. + */ + str_fragment_from_reg(smccc_soc_id_name + 8 * 0, res.a1); + str_fragment_from_reg(smccc_soc_id_name + 8 * 1, res.a2); + str_fragment_from_reg(smccc_soc_id_name + 8 * 2, res.a3); + str_fragment_from_reg(smccc_soc_id_name + 8 * 3, res.a4); + str_fragment_from_reg(smccc_soc_id_name + 8 * 4, res.a5); + str_fragment_from_reg(smccc_soc_id_name + 8 * 5, res.a6); + str_fragment_from_reg(smccc_soc_id_name + 8 * 6, res.a7); + str_fragment_from_reg(smccc_soc_id_name + 8 * 7, res.a8); + str_fragment_from_reg(smccc_soc_id_name + 8 * 8, res.a9); + str_fragment_from_reg(smccc_soc_id_name + 8 * 9, res.a10); + str_fragment_from_reg(smccc_soc_id_name + 8 * 10, res.a11); + str_fragment_from_reg(smccc_soc_id_name + 8 * 11, res.a12); + str_fragment_from_reg(smccc_soc_id_name + 8 * 12, res.a13); + str_fragment_from_reg(smccc_soc_id_name + 8 * 13, res.a14); + str_fragment_from_reg(smccc_soc_id_name + 8 * 14, res.a15); + str_fragment_from_reg(smccc_soc_id_name + 8 * 15, res.a16); + str_fragment_from_reg(smccc_soc_id_name + 8 * 16, res.a17); + + len = strnlen(smccc_soc_id_name, sizeof(smccc_soc_id_name)); + if (len) { + if (len == sizeof(smccc_soc_id_name)) + pr_warn(FW_BUG "Ignoring improperly formatted name\n"); + else + return smccc_soc_id_name; + } + } + + return NULL; +} + +#else + +static char __init *smccc_soc_name_init(void) +{ + return NULL; +} + +#endif + +static int __init smccc_soc_init(void) +{ + int soc_id_rev, soc_id_version; + static char soc_id_str[20], soc_id_rev_str[12]; + static char soc_id_jep106_id_str[12]; + + if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2) + return 0; + + soc_id_version = arm_smccc_get_soc_id_version(); + if (soc_id_version == SMCCC_RET_NOT_SUPPORTED) { + pr_info("ARCH_SOC_ID not implemented, skipping ....\n"); + return 0; + } + + if (soc_id_version < 0) { + pr_err("Invalid SoC Version: %x\n", soc_id_version); + return -EINVAL; + } + + soc_id_rev = arm_smccc_get_soc_id_revision(); + if (soc_id_rev < 0) { + pr_err("Invalid SoC Revision: %x\n", soc_id_rev); + return -EINVAL; + } + + soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL); + if (!soc_dev_attr) + return -ENOMEM; + + sprintf(soc_id_rev_str, "0x%08x", soc_id_rev); + sprintf(soc_id_jep106_id_str, "jep106:%02x%02x", + JEP106_BANK_CONT_CODE(soc_id_version), + JEP106_ID_CODE(soc_id_version)); + sprintf(soc_id_str, "%s:%04x", soc_id_jep106_id_str, + IMP_DEF_SOC_ID(soc_id_version)); + + soc_dev_attr->soc_id = soc_id_str; + soc_dev_attr->revision = soc_id_rev_str; + soc_dev_attr->family = soc_id_jep106_id_str; + soc_dev_attr->machine = smccc_soc_name_init(); + + soc_dev = soc_device_register(soc_dev_attr); + if (IS_ERR(soc_dev)) { + kfree(soc_dev_attr); + return PTR_ERR(soc_dev); + } + + pr_info("ID = %s Revision = %s\n", soc_dev_attr->soc_id, + soc_dev_attr->revision); + + return 0; +} +module_init(smccc_soc_init); + +static void __exit smccc_soc_exit(void) +{ + if (soc_dev) + soc_device_unregister(soc_dev); + kfree(soc_dev_attr); +} +module_exit(smccc_soc_exit); |