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firmware: qcom_scm-64: Add atomic version of qcom_scm_call

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There are scnenarios where drivers are required to make a
scm call in atomic context, such as in one of the qcom's
arm-smmu-500 errata [1].

[1] ("https://source.codeaurora.org/quic/la/kernel/msm-4.9/
      tree/drivers/iommu/arm-smmu.c?h=msm-4.9#n4842")

Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Andy Gross <agross@kernel.org>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Vivek Gautam 2019-09-20 13:34:27 +05:30 committed by Will Deacon
parent ff34f3cce2
commit 1a5ea3b7a6
1 changed files with 94 additions and 44 deletions
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138
drivers/firmware/qcom_scm-64.c
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@ -62,32 +62,72 @@ static DEFINE_MUTEX(qcom_scm_lock);
#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
* @dev: device
* @svc_id: service identifier
* @cmd_id: command identifier
* @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.
*/
static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
const struct qcom_scm_desc *desc,
struct arm_smccc_res *res)
static void __qcom_scm_call_do(const struct qcom_scm_desc *desc,
struct arm_smccc_res *res, u32 fn_id,
u64 x5, u32 type)
{
u64 cmd;
struct arm_smccc_quirk quirk = { .id = ARM_SMCCC_QUIRK_QCOM_A6 };
cmd = ARM_SMCCC_CALL_VAL(type, qcom_smccc_convention,
ARM_SMCCC_OWNER_SIP, fn_id);
quirk.state.a6 = 0;
do {
arm_smccc_smc_quirk(cmd, desc->arginfo, desc->args[0],
desc->args[1], desc->args[2], x5,
quirk.state.a6, 0, res, &quirk);
if (res->a0 == QCOM_SCM_INTERRUPTED)
cmd = res->a0;
} while (res->a0 == QCOM_SCM_INTERRUPTED);
}
static void qcom_scm_call_do(const struct qcom_scm_desc *desc,
struct arm_smccc_res *res, u32 fn_id,
u64 x5, bool atomic)
{
int retry_count = 0;
if (atomic) {
__qcom_scm_call_do(desc, res, fn_id, x5, ARM_SMCCC_FAST_CALL);
return;
}
do {
mutex_lock(&qcom_scm_lock);
__qcom_scm_call_do(desc, res, fn_id, x5,
ARM_SMCCC_STD_CALL);
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);
}
static int ___qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
const struct qcom_scm_desc *desc,
struct arm_smccc_res *res, bool atomic)
{
int arglen = desc->arginfo & 0xf;
int retry_count = 0, i;
int i;
u32 fn_id = QCOM_SCM_FNID(svc_id, cmd_id);
u64 cmd, x5 = desc->args[FIRST_EXT_ARG_IDX];
u64 x5 = desc->args[FIRST_EXT_ARG_IDX];
dma_addr_t args_phys = 0;
void *args_virt = NULL;
size_t alloc_len;
struct arm_smccc_quirk quirk = {.id = ARM_SMCCC_QUIRK_QCOM_A6};
gfp_t flag = atomic ? GFP_ATOMIC : GFP_KERNEL;
if (unlikely(arglen > N_REGISTER_ARGS)) {
alloc_len = N_EXT_QCOM_SCM_ARGS * sizeof(u64);
args_virt = kzalloc(PAGE_ALIGN(alloc_len), GFP_KERNEL);
args_virt = kzalloc(PAGE_ALIGN(alloc_len), flag);
if (!args_virt)
return -ENOMEM;
@ -117,33 +157,7 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
x5 = 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);
quirk.state.a6 = 0;
do {
arm_smccc_smc_quirk(cmd, desc->arginfo, desc->args[0],
desc->args[1], desc->args[2], x5,
quirk.state.a6, 0, res, &quirk);
if (res->a0 == QCOM_SCM_INTERRUPTED)
cmd = res->a0;
} while (res->a0 == QCOM_SCM_INTERRUPTED);
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);
qcom_scm_call_do(desc, res, fn_id, x5, atomic);
if (args_virt) {
dma_unmap_single(dev, args_phys, alloc_len, DMA_TO_DEVICE);
@ -156,6 +170,42 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
return 0;
}
/**
* qcom_scm_call() - Invoke a syscall in the secure world
* @dev: device
* @svc_id: service identifier
* @cmd_id: command identifier
* @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.
*/
static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
const struct qcom_scm_desc *desc,
struct arm_smccc_res *res)
{
might_sleep();
return ___qcom_scm_call(dev, svc_id, cmd_id, desc, res, false);
}
/**
* qcom_scm_call_atomic() - atomic variation of qcom_scm_call()
* @dev: device
* @svc_id: service identifier
* @cmd_id: command identifier
* @desc: Descriptor structure containing arguments and return values
* @res: Structure containing results from SMC/HVC call
*
* Sends a command to the SCM and waits for the command to finish processing.
* This can be called in atomic context.
*/
static int qcom_scm_call_atomic(struct device *dev, u32 svc_id, u32 cmd_id,
const struct qcom_scm_desc *desc,
struct arm_smccc_res *res)
{
return ___qcom_scm_call(dev, svc_id, cmd_id, desc, res, true);
}
/**
* qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus
* @entry: Entry point function for the cpus