[PATCH 4/9] firmware: arm_ffa: Add support for querying FF-A features

Sudeep Holla
2022-08-30T10:12:21Z

Add support for FFA_FEATURES to discover properties supported at the
FF-A interface. This interface can be used to query:
- If an FF-A interface is implemented by the component at the higher EL,
- If an implemented FF-A interface also implements any optional features
described in its interface definition, and
- Any implementation details exported by an implemented FF-A interface
as described in its interface definition.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
drivers/firmware/arm_ffa/driver.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index 04e7cbb1b9aa..de94073f4109 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -571,6 +571,29 @@ static int ffa_memory_reclaim(u64 g_handle, u32 flags)
return 0;
}

+static int ffa_features(u32 func_feat_id, u32 input_props, u32 *if_props)
+{
+ ffa_value_t id;
+
+ if (!ARM_SMCCC_IS_FAST_CALL(func_feat_id) && input_props) {
+ pr_err("%s: Invalid Parameters: %x, %x", __func__,
+ func_feat_id, input_props);
+ return ffa_to_linux_errno(FFA_RET_INVALID_PARAMETERS);
+ }
+
+ invoke_ffa_fn((ffa_value_t){
+ .a0 = FFA_FEATURES, .a1 = func_feat_id, .a2 = input_props,
+ }, &id);
+
+ if (id.a0 == FFA_ERROR)
+ return ffa_to_linux_errno((int)id.a2);
+
+ if (if_props)
+ *if_props = id.a2;
+
+ return 0;
+}
+
static u32 ffa_api_version_get(void)
{
return drv_info->version;
--
2.37.2