[PATCH v4 13/17] firmware: qcom_scm-32: Create common legacy atomic call

From: Elliot Berman
Date: Thu Dec 12 2019 - 13:52:00 EST


Per [1], legacy calling convention supports up to 5 arguments and 3
return values. Create one function to support this combination, and
remove the original "atomic1" and "atomic2" variants for 1 and 2
arguments. This more closely aligns scm_legacy implementation with
scm_smc implementation.

[1]: https://source.codeaurora.org/quic/la/kernel/msm-4.9/tree/drivers/soc/qcom/scm.c?h=kernel.lnx.4.9.r28-rel#n1024

Signed-off-by: Elliot Berman <eberman@xxxxxxxxxxxxxx>
---
drivers/firmware/qcom_scm-32.c | 106 ++++++++++++++++++++++++++---------------
1 file changed, 68 insertions(+), 38 deletions(-)

diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
index acd956f..9729a8a 100644
--- a/drivers/firmware/qcom_scm-32.c
+++ b/drivers/firmware/qcom_scm-32.c
@@ -266,6 +266,8 @@ static int qcom_scm_call(struct device *dev, const struct qcom_scm_desc *desc,
return ret;
}

+#define SCM_LEGACY_ATOMIC_N_REG_ARGS 5
+#define SCM_LEGACY_ATOMIC_FIRST_REG_IDX 2
#define SCM_LEGACY_CLASS_REGISTER (0x2 << 8)
#define SCM_LEGACY_MASK_IRQS BIT(5)
#define SCM_LEGACY_ATOMIC_ID(svc, cmd, n) \
@@ -275,44 +277,35 @@ static int qcom_scm_call(struct device *dev, const struct qcom_scm_desc *desc,
(n & 0xf))

/**
- * qcom_scm_call_atomic1() - Send an atomic SCM command with one argument
- * @svc_id: service identifier
- * @cmd_id: command identifier
- * @arg1: first argument
+ * qcom_scm_call_atomic() - Send an atomic SCM command with up to 5 arguments
+ * and 3 return values
+ * @desc: SCM call descriptor containing arguments
+ * @res: SCM call return values
*
* This shall only be used with commands that are guaranteed to be
* uninterruptable, atomic and SMP safe.
*/
-static s32 qcom_scm_call_atomic1(u32 svc, u32 cmd, u32 arg1)
+static int qcom_scm_call_atomic(const struct qcom_scm_desc *desc,
+ struct qcom_scm_res *res)
{
int context_id;
- struct arm_smccc_res res;
+ struct arm_smccc_res smc_res;
+ size_t arglen = desc->arginfo & 0xf;

- arm_smccc_smc(SCM_LEGACY_ATOMIC_ID(svc, cmd, 1),
- (unsigned long)&context_id, arg1, 0, 0, 0, 0, 0, &res);
+ BUG_ON(arglen > SCM_LEGACY_ATOMIC_N_REG_ARGS);

- return res.a0;
-}
+ arm_smccc_smc(SCM_LEGACY_ATOMIC_ID(desc->svc, desc->cmd, arglen),
+ (unsigned long)&context_id,
+ desc->args[0], desc->args[1], desc->args[2],
+ desc->args[3], desc->args[4], 0, &smc_res);

-/**
- * qcom_scm_call_atomic2() - Send an atomic SCM command with two arguments
- * @svc_id: service identifier
- * @cmd_id: command identifier
- * @arg1: first argument
- * @arg2: second argument
- *
- * This shall only be used with commands that are guaranteed to be
- * uninterruptable, atomic and SMP safe.
- */
-static s32 qcom_scm_call_atomic2(u32 svc, u32 cmd, u32 arg1, u32 arg2)
-{
- int context_id;
- struct arm_smccc_res res;
-
- arm_smccc_smc(SCM_LEGACY_ATOMIC_ID(svc, cmd, 2),
- (unsigned long)&context_id, arg1, 0, 0, 0, 0, 0, &res);
+ if (res) {
+ res->result[0] = smc_res.a1;
+ res->result[1] = smc_res.a2;
+ res->result[2] = smc_res.a3;
+ }

- return res.a0;
+ return smc_res.a0;
}

/**
@@ -333,6 +326,10 @@ int __qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
QCOM_SCM_FLAG_COLDBOOT_CPU2,
QCOM_SCM_FLAG_COLDBOOT_CPU3,
};
+ struct qcom_scm_desc desc = {
+ .svc = QCOM_SCM_SVC_BOOT,
+ .cmd = QCOM_SCM_BOOT_SET_ADDR,
+ };

if (!cpus || (cpus && cpumask_empty(cpus)))
return -EINVAL;
@@ -344,8 +341,11 @@ int __qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
set_cpu_present(cpu, false);
}

- return qcom_scm_call_atomic2(QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_SET_ADDR,
- flags, virt_to_phys(entry));
+ desc.args[0] = flags;
+ desc.args[1] = virt_to_phys(entry);
+ desc.arginfo = QCOM_SCM_ARGS(2);
+
+ return qcom_scm_call_atomic(&desc, NULL);
}

/**
@@ -404,8 +404,14 @@ int __qcom_scm_set_warm_boot_addr(struct device *dev, void *entry,
*/
void __qcom_scm_cpu_power_down(u32 flags)
{
- qcom_scm_call_atomic1(QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_TERMINATE_PC,
- flags & QCOM_SCM_FLUSH_FLAG_MASK);
+ struct qcom_scm_desc desc = {
+ .svc = QCOM_SCM_SVC_BOOT,
+ .cmd = QCOM_SCM_BOOT_TERMINATE_PC,
+ .args[0] = flags & QCOM_SCM_FLUSH_FLAG_MASK,
+ .arginfo = QCOM_SCM_ARGS(1),
+ };
+
+ qcom_scm_call_atomic(&desc, NULL);
}

int __qcom_scm_is_call_available(struct device *dev, u32 svc_id, u32 cmd_id)
@@ -601,8 +607,16 @@ int __qcom_scm_pas_mss_reset(struct device *dev, bool reset)

int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
{
- return qcom_scm_call_atomic2(QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_SET_DLOAD_MODE,
- enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0, 0);
+ struct qcom_scm_desc desc = {
+ .svc = QCOM_SCM_SVC_BOOT,
+ .cmd = QCOM_SCM_BOOT_SET_DLOAD_MODE,
+ };
+
+ desc.args[0] = QCOM_SCM_BOOT_SET_DLOAD_MODE;
+ desc.args[1] = enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0;
+ desc.arginfo = QCOM_SCM_ARGS(2);
+
+ return qcom_scm_call_atomic(&desc, NULL);
}

int __qcom_scm_set_remote_state(struct device *dev, u32 state, u32 id)
@@ -664,18 +678,34 @@ int __qcom_scm_io_readl(struct device *dev, phys_addr_t addr,
unsigned int *val)
{
int ret;
+ struct qcom_scm_desc desc = {
+ .svc = QCOM_SCM_SVC_IO,
+ .cmd = QCOM_SCM_IO_READ,
+ };
+ struct qcom_scm_res res;
+
+ desc.args[0] = addr;
+ desc.arginfo = QCOM_SCM_ARGS(1);

- ret = qcom_scm_call_atomic1(QCOM_SCM_SVC_IO, QCOM_SCM_IO_READ, addr);
+ ret = qcom_scm_call_atomic(&desc, &res);
if (ret >= 0)
- *val = ret;
+ *val = res.result[0];

return ret < 0 ? ret : 0;
}

int __qcom_scm_io_writel(struct device *dev, phys_addr_t addr, unsigned int val)
{
- return qcom_scm_call_atomic2(QCOM_SCM_SVC_IO, QCOM_SCM_IO_WRITE,
- addr, val);
+ struct qcom_scm_desc desc = {
+ .svc = QCOM_SCM_SVC_IO,
+ .cmd = QCOM_SCM_IO_WRITE,
+ };
+
+ desc.args[0] = addr;
+ desc.args[1] = val;
+ desc.arginfo = QCOM_SCM_ARGS(2);
+
+ return qcom_scm_call_atomic(&desc, NULL);
}

int __qcom_scm_qsmmu500_wait_safe_toggle(struct device *dev, bool enable)
--
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