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

Elliot Berman
2019-11-05T01:28:29Z

Per [1], legacy calling convention supports up to 5 arguments and
3 return values. Create one function to support this combination.

[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@codeaurora.org>
---
drivers/firmware/qcom_scm-32.c | 109 +++++++++++++++++++++++++----------------
1 file changed, 67 insertions(+), 42 deletions(-)

diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
index 9811560..533c68a 100644
--- a/drivers/firmware/qcom_scm-32.c
+++ b/drivers/firmware/qcom_scm-32.c
@@ -257,6 +257,8 @@ static int qcom_scm_call(struct device *dev, struct qcom_scm_desc *desc)
return ret;
}

+#define LEGACY_ATOMIC_N_REG_ARGS 5
+#define LEGACY_ATOMIC_FIRST_REG_IDX 2
#define LEGACY_CLASS_REGISTER (0x2 << 8)
#define LEGACY_MASK_IRQS BIT(5)
#define LEGACY_ATOMIC(svc, cmd, n) ((LEGACY_FUNCNUM(svc, cmd) << 12) | \
@@ -265,52 +267,34 @@ static int qcom_scm_call(struct device *dev, 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
*
* 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(struct qcom_scm_desc *desc)
{
int context_id;
struct arm_smccc_args smc = {0};
struct arm_smccc_res res;
+ size_t i, arglen = desc->arginfo & 0xf;

- smc.a[0] = LEGACY_ATOMIC(svc, cmd, 1);
- smc.a[1] = (unsigned long)&context_id;
- smc.a[2] = arg1;
- arm_smccc_smc(smc.a[0], smc.a[1], smc.a[2], smc.a[3],
- smc.a[4], smc.a[5], smc.a[6], smc.a[7], &res);
+ BUG_ON(arglen > LEGACY_ATOMIC_N_REG_ARGS);

- return res.a0;
-}
+ smc.a[0] = LEGACY_ATOMIC(desc->svc, desc->cmd, arglen);
+ smc.a[1] = (unsigned long)&context_id;

-/**
- * 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_args smc = {0};
- struct arm_smccc_res res;
+ for (i = 0; i < arglen; i++)
+ smc.a[i + LEGACY_ATOMIC_FIRST_REG_IDX] = desc->args[i];

- smc.a[0] = LEGACY_ATOMIC(svc, cmd, 2);
- smc.a[1] = (unsigned long)&context_id;
- smc.a[2] = arg1;
- smc.a[3] = arg2;
arm_smccc_smc(smc.a[0], smc.a[1], smc.a[2], smc.a[3],
smc.a[4], smc.a[5], smc.a[6], smc.a[7], &res);

+ desc->res[0] = res.a1;
+ desc->res[1] = res.a2;
+ desc->res[2] = res.a3;
+
return res.a0;
}

@@ -332,6 +316,11 @@ 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,
+ .owner = ARM_SMCCC_OWNER_SIP,
+ };

if (!cpus || (cpus && cpumask_empty(cpus)))
return -EINVAL;
@@ -343,8 +332,11 @@ 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);
}

/**
@@ -402,8 +394,15 @@ 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),
+ .owner = ARM_SMCCC_OWNER_SIP,
+ };
+
+ qcom_scm_call_atomic(&desc);
}

int __qcom_scm_set_remote_state(struct device *dev, u32 state, u32 id)
@@ -426,8 +425,17 @@ int __qcom_scm_set_remote_state(struct device *dev, u32 state, u32 id)

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,
+ .owner = ARM_SMCCC_OWNER_SIP,
+ };
+
+ 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);
}

bool __qcom_scm_pas_supported(struct device *dev, u32 peripheral)
@@ -539,18 +547,35 @@ 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,
+ .owner = ARM_SMCCC_OWNER_SIP,
+ };

- ret = qcom_scm_call_atomic1(QCOM_SCM_SVC_IO, QCOM_SCM_IO_READ, addr);
+ desc.args[0] = addr;
+ desc.arginfo = QCOM_SCM_ARGS(1);
+
+ ret = qcom_scm_call_atomic(&desc);
if (ret >= 0)
- *val = ret;
+ *val = desc.res[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,
+ .owner = ARM_SMCCC_OWNER_SIP,
+ };
+
+ desc.args[0] = addr;
+ desc.args[1] = val;
+ desc.arginfo = QCOM_SCM_ARGS(2);
+
+ return qcom_scm_call_atomic(&desc);
}

int __qcom_scm_is_call_available(struct device *dev, u32 svc_id, u32 cmd_id)
@@ -631,4 +656,4 @@ int __qcom_scm_qsmmu500_wait_safe_toggle(struct device *dev, bool enable)

void __qcom_scm_init(void)
{
-}
\ No newline at end of file
+}