On Fri 22 Apr 15:17 PDT 2016, Andy Gross wrote: [..] > diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c [..] > + > +/** > + * struct qcom_scm_desc > + * @arginfo: Metadata describing the arguments in args[] > + * @args: The array of arguments for the secure syscall > + * @res: The values returned by the secure syscall > + * @extra_args_virt: The buffer containing extra arguments > + (that don't fit in available registers) > + * @extra_args_phys: The physical address of the extra arguments @alloc_size > + */ > +struct qcom_scm_desc { > + u32 arginfo; > + u64 args[MAX_QCOM_SCM_ARGS]; > + struct arm_smccc_res res; > + > + /* private */ > + void *extra_args_virt; > + dma_addr_t extra_args_phys; > + size_t alloc_size; > +}; > + > +static u64 qcom_smccc_convention = -1; > +static DEFINE_MUTEX(qcom_scm_lock); > + > +#define QCOM_SCM_EBUSY_WAIT_MS 30 > +#define QCOM_SCM_EBUSY_MAX_RETRY 20 > + > +#define N_EXT_QCOM_SCM_ARGS 7 > +#define FIRST_EXT_ARG_IDX 3 > +#define N_REGISTER_ARGS (MAX_QCOM_SCM_ARGS - N_EXT_QCOM_SCM_ARGS + 1) > + > +/** > + * qcom_scm_call() - Invoke a syscall in the secure world > + * @svc_id: service identifier > + * @cmd_id: command identifier > + * @fn_id: The function ID for this syscall > + * @desc: Descriptor structure containing arguments and return values > + * > + * Sends a command to the SCM and waits for the command to finish processing. > + * This should *only* be called in pre-emptible context. > + * > +*/ Extra empty line in comment and odd indentation. > +static int qcom_scm_call(u32 svc_id, u32 cmd_id, struct qcom_scm_desc *desc) > +{ > + int arglen = desc->arginfo & 0xf; > + int ret, retry_count = 0, i; > + u32 fn_id = QCOM_SCM_FNID(svc_id, cmd_id); > + u64 cmd, x5 = desc->args[FIRST_EXT_ARG_IDX]; > + > + if (unlikely(arglen > N_REGISTER_ARGS)) { > + desc->alloc_size = N_EXT_QCOM_SCM_ARGS * sizeof(u64); > + desc->extra_args_virt = alloc_size, extra_args_virt and extra_args_phys doesn't seem to outlive this function, can't they be made local variable? > + qcom_scm_alloc_buffer(desc->alloc_size, > + &desc->extra_args_phys, > + GFP_KERNEL); > + if (!desc->extra_args_virt) > + return qcom_scm_remap_error(-ENOMEM); > + > + if (qcom_smccc_convention == ARM_SMCCC_SMC_32) { > + u32 *args = desc->extra_args_virt; > + > + for (i = 0; i < N_EXT_QCOM_SCM_ARGS; i++) > + args[i] = desc->args[i + FIRST_EXT_ARG_IDX]; > + } else { > + u64 *args = desc->extra_args_virt; > + > + for (i = 0; i < N_EXT_QCOM_SCM_ARGS; i++) > + args[i] = desc->args[i + FIRST_EXT_ARG_IDX]; > + } > + > + x5 = desc->extra_args_phys; > + } > + > + do { > + mutex_lock(&qcom_scm_lock); > + > + cmd = ARM_SMCCC_CALL_VAL(ARM_SMCCC_STD_CALL, > + qcom_smccc_convention, > + ARM_SMCCC_OWNER_SIP, fn_id); > + > + do { > + arm_smccc_smc(cmd, arglen, desc->args[0], desc->args[1], > + desc->args[2], x5, 0, 0, &desc->res); > + } while (desc->res.a0 == QCOM_SCM_INTERRUPTED); > + > + mutex_unlock(&qcom_scm_lock); > + > + if (desc->res.a0 == QCOM_SCM_V2_EBUSY) { > + if (retry_count++ > QCOM_SCM_EBUSY_MAX_RETRY) > + break; > + msleep(QCOM_SCM_EBUSY_WAIT_MS); > + } > + } while (desc->res.a0 == QCOM_SCM_V2_EBUSY); > + > + if (desc->extra_args_virt) > + qcom_scm_free_buffer(desc->alloc_size, desc->extra_args_virt, > + desc->extra_args_phys); > + > + if (desc->res.a0 < 0) > + return qcom_scm_remap_error(ret); > + > + return 0; > +} > > /** > * qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus > @@ -50,14 +186,68 @@ int __qcom_scm_set_warm_boot_addr(void *entry, const cpumask_t *cpus) > */ > void __qcom_scm_cpu_power_down(u32 flags) > { > + return; We can't have this empty? > } > > int __qcom_scm_is_call_available(u32 svc_id, u32 cmd_id) > { > - return -ENOTSUPP; > + int ret; > + struct qcom_scm_desc desc = {0}; > + > + desc.arginfo = QCOM_SCM_ARGS(1); > + desc.args[0] = QCOM_SCM_FNID(svc_id, cmd_id) | Are we not playing the endian game om arm64? > + (ARM_SMCCC_OWNER_SIP << ARM_SMCCC_OWNER_SHIFT); > + > + ret = qcom_scm_call(QCOM_SCM_SVC_INFO, QCOM_IS_CALL_AVAIL_CMD, > + &desc); > + > + if (ret) > + return ret; > + > + return desc.res.a1; We use the following construct elsewhere in scm: return ret ? : desc.res.a1; > } > [..] > diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c > index 8e1eeb8..7d7b12b 100644 [..] > > +static void qcom_scm_init(void) > +{ > + __qcom_scm_init(); > +} > + > static int qcom_scm_probe(struct platform_device *pdev) > { > struct qcom_scm *scm; > @@ -208,6 +213,8 @@ static int qcom_scm_probe(struct platform_device *pdev) > __scm = scm; > __scm->dev = &pdev->dev; > > + qcom_scm_init(); > + Why don't you call __qcom_scm_init() directly here? > return 0; > } > > diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h [..] > +#define QCOM_SCM_V2_EBUSY -12 > #define QCOM_SCM_ENOMEM -5 > #define QCOM_SCM_EOPNOTSUPP -4 > #define QCOM_SCM_EINVAL_ADDR -3 > @@ -56,6 +58,8 @@ static inline int qcom_scm_remap_error(int err) > return -EOPNOTSUPP; > case QCOM_SCM_ENOMEM: > return -ENOMEM; > + case QCOM_SCM_V2_EBUSY: > + return err; I don't think return -ENOMEM is the right thing to do here. > } > return -EINVAL; > } Regards, Bjorn -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html