diff options
Diffstat (limited to 'drivers/firmware/qcom_scm-smc.c')
| -rw-r--r-- | drivers/firmware/qcom_scm-smc.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/firmware/qcom_scm-smc.c b/drivers/firmware/qcom_scm-smc.c new file mode 100644 index 000000000000..497c13ba98d6 --- /dev/null +++ b/drivers/firmware/qcom_scm-smc.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2015,2019 The Linux Foundation. All rights reserved. + */ + +#include <linux/io.h> +#include <linux/errno.h> +#include <linux/delay.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/qcom_scm.h> +#include <linux/arm-smccc.h> +#include <linux/dma-mapping.h> + +#include "qcom_scm.h" + +/** + * struct arm_smccc_args + * @args: The array of values used in registers in smc instruction + */ +struct arm_smccc_args { + unsigned long args[8]; +}; + +static DEFINE_MUTEX(qcom_scm_lock); + +#define QCOM_SCM_EBUSY_WAIT_MS 30 +#define QCOM_SCM_EBUSY_MAX_RETRY 20 + +#define SCM_SMC_N_REG_ARGS 4 +#define SCM_SMC_FIRST_EXT_IDX (SCM_SMC_N_REG_ARGS - 1) +#define SCM_SMC_N_EXT_ARGS (MAX_QCOM_SCM_ARGS - SCM_SMC_N_REG_ARGS + 1) +#define SCM_SMC_FIRST_REG_IDX 2 +#define SCM_SMC_LAST_REG_IDX (SCM_SMC_FIRST_REG_IDX + SCM_SMC_N_REG_ARGS - 1) + +static void __scm_smc_do_quirk(const struct arm_smccc_args *smc, + struct arm_smccc_res *res) +{ + unsigned long a0 = smc->args[0]; + struct arm_smccc_quirk quirk = { .id = ARM_SMCCC_QUIRK_QCOM_A6 }; + + quirk.state.a6 = 0; + + do { + arm_smccc_smc_quirk(a0, smc->args[1], smc->args[2], + smc->args[3], smc->args[4], smc->args[5], + quirk.state.a6, smc->args[7], res, &quirk); + + if (res->a0 == QCOM_SCM_INTERRUPTED) + a0 = res->a0; + + } while (res->a0 == QCOM_SCM_INTERRUPTED); +} + +static void __scm_smc_do(const struct arm_smccc_args *smc, + struct arm_smccc_res *res, bool atomic) +{ + int retry_count = 0; + + if (atomic) { + __scm_smc_do_quirk(smc, res); + return; + } + + do { + mutex_lock(&qcom_scm_lock); + + __scm_smc_do_quirk(smc, res); + + mutex_unlock(&qcom_scm_lock); + + if (res->a0 == QCOM_SCM_V2_EBUSY) { + if (retry_count++ > QCOM_SCM_EBUSY_MAX_RETRY) + break; + msleep(QCOM_SCM_EBUSY_WAIT_MS); + } + } while (res->a0 == QCOM_SCM_V2_EBUSY); +} + +int scm_smc_call(struct device *dev, const struct qcom_scm_desc *desc, + struct qcom_scm_res *res, bool atomic) +{ + int arglen = desc->arginfo & 0xf; + int i; + dma_addr_t args_phys = 0; + void *args_virt = NULL; + size_t alloc_len; + gfp_t flag = atomic ? GFP_ATOMIC : GFP_KERNEL; + u32 smccc_call_type = atomic ? ARM_SMCCC_FAST_CALL : ARM_SMCCC_STD_CALL; + u32 qcom_smccc_convention = + (qcom_scm_convention == SMC_CONVENTION_ARM_32) ? + ARM_SMCCC_SMC_32 : ARM_SMCCC_SMC_64; + struct arm_smccc_res smc_res; + struct arm_smccc_args smc = {0}; + + smc.args[0] = ARM_SMCCC_CALL_VAL( + smccc_call_type, + qcom_smccc_convention, + desc->owner, + SCM_SMC_FNID(desc->svc, desc->cmd)); + smc.args[1] = desc->arginfo; + for (i = 0; i < SCM_SMC_N_REG_ARGS; i++) + smc.args[i + SCM_SMC_FIRST_REG_IDX] = desc->args[i]; + + if (unlikely(arglen > SCM_SMC_N_REG_ARGS)) { + alloc_len = SCM_SMC_N_EXT_ARGS * sizeof(u64); + args_virt = kzalloc(PAGE_ALIGN(alloc_len), flag); + + if (!args_virt) + return -ENOMEM; + + if (qcom_smccc_convention == ARM_SMCCC_SMC_32) { + __le32 *args = args_virt; + + for (i = 0; i < SCM_SMC_N_EXT_ARGS; i++) + args[i] = cpu_to_le32(desc->args[i + + SCM_SMC_FIRST_EXT_IDX]); + } else { + __le64 *args = args_virt; + + for (i = 0; i < SCM_SMC_N_EXT_ARGS; i++) + args[i] = cpu_to_le64(desc->args[i + + SCM_SMC_FIRST_EXT_IDX]); + } + + args_phys = dma_map_single(dev, args_virt, alloc_len, + DMA_TO_DEVICE); + + if (dma_mapping_error(dev, args_phys)) { + kfree(args_virt); + return -ENOMEM; + } + + smc.args[SCM_SMC_LAST_REG_IDX] = args_phys; + } + + __scm_smc_do(&smc, &smc_res, atomic); + + if (args_virt) { + dma_unmap_single(dev, args_phys, alloc_len, DMA_TO_DEVICE); + kfree(args_virt); + } + + if (res) { + res->result[0] = smc_res.a1; + res->result[1] = smc_res.a2; + res->result[2] = smc_res.a3; + } + + return (long)smc_res.a0 ? qcom_scm_remap_error(smc_res.a0) : 0; +} |