Adds support for sending a FF-A direct request. Checks that the SP also
supports handling a 32-bit direct request. 64-bit direct requests are
not used by the mediator itself so there is not need to check for that.
Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
---
xen/arch/arm/tee/ffa.c | 112 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 112 insertions(+)
diff --git a/xen/arch/arm/tee/ffa.c b/xen/arch/arm/tee/ffa.c
index f129879c5b81..f2cce955d981 100644
--- a/xen/arch/arm/tee/ffa.c
+++ b/xen/arch/arm/tee/ffa.c
@@ -181,6 +181,56 @@ static bool ffa_get_version(uint32_t *vers)
return true;
}
+static int32_t get_ffa_ret_code(const struct arm_smccc_1_2_regs *resp)
+{
+ switch ( resp->a0 )
+ {
+ case FFA_ERROR:
+ if ( resp->a2 )
+ return resp->a2;
+ else
+ return FFA_RET_NOT_SUPPORTED;
+ case FFA_SUCCESS_32:
+ case FFA_SUCCESS_64:
+ return FFA_RET_OK;
+ default:
+ return FFA_RET_NOT_SUPPORTED;
+ }
+}
+
+static int32_t ffa_simple_call(uint32_t fid, register_t a1, register_t a2,
+ register_t a3, register_t a4)
+{
+ const struct arm_smccc_1_2_regs arg = {
+ .a0 = fid,
+ .a1 = a1,
+ .a2 = a2,
+ .a3 = a3,
+ .a4 = a4,
+ };
+ struct arm_smccc_1_2_regs resp;
+
+ arm_smccc_1_2_smc(&arg, &resp);
+
+ return get_ffa_ret_code(&resp);
+}
+
+static int32_t ffa_features(uint32_t id)
+{
+ return ffa_simple_call(FFA_FEATURES, id, 0, 0, 0);
+}
+
+static bool check_mandatory_feature(uint32_t id)
+{
+ int32_t ret = ffa_features(id);
+
+ if (ret)
+ printk(XENLOG_ERR "ffa: mandatory feature id %#x missing: error %d\n",
+ id, ret);
+
+ return !ret;
+}
+
static uint16_t get_vm_id(const struct domain *d)
{
/* +1 since 0 is reserved for the hypervisor in FF-A */
@@ -222,6 +272,57 @@ static void handle_version(struct cpu_user_regs *regs)
set_regs(regs, vers, 0, 0, 0, 0, 0, 0, 0);
}
+static void handle_msg_send_direct_req(struct cpu_user_regs *regs, uint32_t fid)
+{
+ struct arm_smccc_1_2_regs arg = { .a0 = fid, };
+ struct arm_smccc_1_2_regs resp = { };
+ struct domain *d = current->domain;
+ uint32_t src_dst;
+ uint64_t mask;
+
+ if ( smccc_is_conv_64(fid) )
+ mask = GENMASK_ULL(63, 0);
+ else
+ mask = GENMASK_ULL(31, 0);
+
+ src_dst = get_user_reg(regs, 1);
+ if ( (src_dst >> 16) != get_vm_id(d) )
+ {
+ resp.a0 = FFA_ERROR;
+ resp.a2 = FFA_RET_INVALID_PARAMETERS;
+ goto out;
+ }
+
+ arg.a1 = src_dst;
+ arg.a2 = get_user_reg(regs, 2) & mask;
+ arg.a3 = get_user_reg(regs, 3) & mask;
+ arg.a4 = get_user_reg(regs, 4) & mask;
+ arg.a5 = get_user_reg(regs, 5) & mask;
+ arg.a6 = get_user_reg(regs, 6) & mask;
+ arg.a7 = get_user_reg(regs, 7) & mask;
+
+ arm_smccc_1_2_smc(&arg, &resp);
+ switch ( resp.a0 )
+ {
+ case FFA_ERROR:
+ case FFA_SUCCESS_32:
+ case FFA_SUCCESS_64:
+ case FFA_MSG_SEND_DIRECT_RESP_32:
+ case FFA_MSG_SEND_DIRECT_RESP_64:
+ break;
+ default:
+ /* Bad fid, report back. */
+ memset(&arg, 0, sizeof(arg));
+ arg.a0 = FFA_ERROR;
+ arg.a1 = src_dst;
+ arg.a2 = FFA_RET_ABORTED;
+ }
+
+out:
+ set_regs(regs, resp.a0, resp.a1 & mask, resp.a2 & mask, resp.a3 & mask,
+ resp.a4 & mask, resp.a5 & mask, resp.a6 & mask, resp.a7 & mask);
+}
+
static bool ffa_handle_call(struct cpu_user_regs *regs)
{
uint32_t fid = get_user_reg(regs, 0);
@@ -239,6 +340,10 @@ static bool ffa_handle_call(struct cpu_user_regs *regs)
case FFA_ID_GET:
set_regs_success(regs, get_vm_id(d), 0);
return true;
+ case FFA_MSG_SEND_DIRECT_REQ_32:
+ case FFA_MSG_SEND_DIRECT_REQ_64:
+ handle_msg_send_direct_req(regs, fid);
+ return true;
default:
gprintk(XENLOG_ERR, "ffa: unhandled fid 0x%x\n", fid);
@@ -326,6 +431,13 @@ static bool ffa_probe(void)
printk(XENLOG_INFO "ARM FF-A Firmware version %u.%u\n",
major_vers, minor_vers);
+ /*
+ * TODO save result of checked features and use that information to
+ * accept or reject requests from guests.
+ */
