[PATCH v5 6/7] firmware: arm_ffa: Setup in-kernel users of FFA partitions

[Sudeep Holla <sudeep.holla@arm.com>]

Parse the FFA nodes from the device-tree and register all the partitions
whose services will be used in the kernel.

In order to also enable in-kernel users of FFA interface, let us add
simple set of operations for such devices.

The in-kernel users are registered without the character device interface.

Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/arm_ffa/common.h |   2 +
 drivers/firmware/arm_ffa/driver.c | 188 ++++++++++++++++++++++++++++++
 include/linux/arm_ffa.h           |  38 +++++-
 3 files changed, 227 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_ffa/common.h b/drivers/firmware/arm_ffa/common.h
index d019348bf67d..eb1371c2b2b8 100644
--- a/drivers/firmware/arm_ffa/common.h
+++ b/drivers/firmware/arm_ffa/common.h
@@ -6,6 +6,7 @@
 #ifndef _FFA_COMMON_H
 #define _FFA_COMMON_H
 
+#include <linux/arm_ffa.h>
 #include <linux/arm-smccc.h>
 #include <linux/err.h>
 
@@ -17,6 +18,7 @@ typedef ffa_res_t
 
 int __init arm_ffa_bus_init(void);
 void __exit arm_ffa_bus_exit(void);
+bool ffa_device_is_valid(struct ffa_device *ffa_dev);
 
 #ifdef CONFIG_ARM_FFA_SMCCC
 int __init ffa_transport_init(ffa_fn **invoke_ffa_fn);
diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index 6d5094ecc0f6..fe81f6b71b6c 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -24,9 +24,13 @@
 
 #include <linux/arm_ffa.h>
 #include <linux/bitfield.h>
+#include <linux/device.h>
 #include <linux/io.h>
+#include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/slab.h>
+#include <linux/uuid.h>
 
 #include "common.h"
 
@@ -183,6 +187,20 @@ static int ffa_version_check(u32 *version)
 	return 0;
 }
 
+static int ffa_rx_release(void)
+{
+	ffa_res_t ret;
+
+	ret = invoke_ffa_fn(FFA_RX_RELEASE, 0, 0, 0, 0, 0, 0, 0);
+
+	if (ret.a0 == FFA_ERROR)
+		return ffa_to_linux_errno((int)ret.a2);
+
+	/* check for ret.a0 == FFA_RX_RELEASE ? */
+
+	return 0;
+}
+
 static int ffa_rxtx_map(phys_addr_t tx_buf, phys_addr_t rx_buf, u32 pg_cnt)
 {
 	ffa_res_t ret;
@@ -209,6 +227,52 @@ static int ffa_rxtx_unmap(u16 vm_id)
 	return 0;
 }
 
+/* buffer must be sizeof(struct ffa_partition_info) * num_partitions */
+static int
+__ffa_partition_info_get(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3,
+			 struct ffa_partition_info **buffer, int num_partitions)
+{
+	int count;
+	ffa_res_t partition_info;
+
+	mutex_lock(&drv_info->rx_lock);
+	partition_info = invoke_ffa_fn(FFA_PARTITION_INFO_GET, uuid0, uuid1,
+				       uuid2, uuid3, 0, 0, 0);
+
+	if (partition_info.a0 == FFA_ERROR)
+		return ffa_to_linux_errno((int)partition_info.a2);
+
+	count = partition_info.a2;
+
+	if (buffer && count <= num_partitions)
+		memcpy(*buffer, drv_info->rx_buffer, sizeof(*buffer) * count);
+
+	ffa_rx_release();
+
+	mutex_unlock(&drv_info->rx_lock);
+
+	return count;
+}
+
+static int ffa_partition_probe(const char *uuid_str,
+			       struct ffa_partition_info *buffer)
+{
+	int count;
+	uuid_t uuid;
+	u32 uuid0_4[4] = { 0 };
+
+	if (uuid_parse(uuid_str, &uuid)) {
+		pr_err("invalid uuid (%s)\n", uuid_str);
+		return -ENODEV;
+	}
+
+	export_uuid((u8 *)uuid0_4, &uuid);
+	count = __ffa_partition_info_get(uuid0_4[0], uuid0_4[1], uuid0_4[2],
+					 uuid0_4[3], &buffer, 1);
+
+	return count != 1;
+}
+
 #define VM_ID_MASK	GENMASK(15, 0)
 static int ffa_id_get(u16 *vm_id)
 {
@@ -224,9 +288,125 @@ static int ffa_id_get(u16 *vm_id)
 	return 0;
 }
 
+static int ffa_msg_send_direct_req(u16 src_id, u16 dst_id, bool mode_32bit,
+				   struct ffa_send_direct_data *data)
+{
+	u32 req_id, resp_id, src_dst_ids = PACK_TARGET_INFO(src_id, dst_id);
+	ffa_res_t ret;
+
+	if (mode_32bit) {
+		req_id = FFA_MSG_SEND_DIRECT_REQ;
+		resp_id = FFA_MSG_SEND_DIRECT_RESP;
+	} else {
+		req_id = FFA_FN_NATIVE(MSG_SEND_DIRECT_REQ);
+		resp_id = FFA_FN_NATIVE(MSG_SEND_DIRECT_RESP);
+	}
+
+	ret = invoke_ffa_fn(req_id, src_dst_ids, 0, data->data0, data->data1,
+			    data->data2, data->data3, data->data4);
+
+	while (ret.a0 == FFA_INTERRUPT)
+		ret = invoke_ffa_fn(FFA_RUN, ret.a1, 0, 0, 0, 0, 0, 0);
+	if (ret.a0 == FFA_ERROR)
+		return ffa_to_linux_errno((int)ret.a2);
+
+	if (ret.a0 == resp_id) {
+		data->data0 = ret.a3;
+		data->data1 = ret.a4;
+		data->data2 = ret.a5;
+		data->data3 = ret.a6;
+		data->data4 = ret.a7;
+	}
+
+	return 0;
+}
+
+static u32 ffa_api_version_get(void)
+{
+	return drv_info->version;
+}
+
+static int ffa_partition_info_get(const char *uuid_str,
+				  struct ffa_partition_info *buffer)
+{
+	if (ffa_partition_probe(uuid_str, buffer))
+		return -ENOENT;
+	return 0;
+}
+
+static void ffa_mode_32bit_set(struct ffa_device *dev)
+{
+	dev->mode_32bit = true;
+}
+
+static int ffa_sync_send_receive(struct ffa_device *dev,
+				 struct ffa_send_direct_data *data)
+{
+	return ffa_msg_send_direct_req(drv_info->vm_id, dev->vm_id,
+				       dev->mode_32bit, data);
+}
+
+static const struct ffa_dev_ops ffa_ops = {
+	.api_version_get = ffa_api_version_get,
+	.partition_info_get = ffa_partition_info_get,
+	.mode_32bit_set = ffa_mode_32bit_set,
+	.sync_send_receive = ffa_sync_send_receive,
+};
+
+const struct ffa_dev_ops *ffa_dev_ops_get(struct ffa_device *dev)
+{
+	if (ffa_device_is_valid(dev))
+		return &ffa_ops;
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(ffa_dev_ops_get);
+
+static void ffa_setup_partitions(struct device_node *np)
+{
+	int ret;
+	struct device_node *child;
+	struct ffa_device *ffa_dev;
+	struct ffa_partition_info pbuf;
+	const char *p_uuid, *pfx = "Ignoring FFA partition";
+	uuid_t uuid = UUID_INIT(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
+
+	for_each_child_of_node(np, child) {
+		if (!of_device_is_compatible(child, "arm,ffa-1.0-partition"))
+			continue;
+
+		if (of_property_read_string(child, "uuid", &p_uuid)) {
+			pr_err("%s: failed to parse \"uuid\" property\n", pfx);
+			continue;
+		}
+
+		if (uuid_parse(p_uuid, &uuid)) {
+			pr_err("%s: invalid \"uuid\" property (%s)\n",
+			       pfx, p_uuid);
+			continue;
+		}
+
+		ret = ffa_partition_probe(p_uuid, &pbuf);
+		if (ret) {
+			pr_err("%s: %s partition info probe failed\n",
+			       pfx, p_uuid);
+			continue;
+		}
+
+		ffa_dev = ffa_device_register(p_uuid, pbuf.id);
+		if (!ffa_dev) {
+			pr_err("%s: failed to register %s\n", pfx, p_uuid);
+			continue;
+		}
+
+		ffa_dev_set_drvdata(ffa_dev, drv_info);
+	}
+}
+
 static int __init ffa_init(void)
 {
 	int ret;
+	struct device_node *np;
 
 	ret = arm_ffa_bus_init();
 	if (ret)
@@ -273,6 +453,14 @@ static int __init ffa_init(void)
 	mutex_init(&drv_info->rx_lock);
 	mutex_init(&drv_info->tx_lock);
 
+	/* Set up all the partitions */
+	np = of_find_compatible_node(NULL, NULL, "arm,ffa-1.0");
+	if (!np)
+		return 0;
+
+	ffa_setup_partitions(np);
+	of_node_put(np);
+
 	return 0;
 free_pages:
 	if (drv_info->tx_buffer)
diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h
index 43f9c0df4114..f0c68f3f1c6a 100644
--- a/include/linux/arm_ffa.h
+++ b/include/linux/arm_ffa.h
@@ -6,7 +6,6 @@
 #ifndef _LINUX_ARM_FFA_H
 #define _LINUX_ARM_FFA_H
 
-#include <linux/cdev.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/types.h>
@@ -15,6 +14,7 @@
 /* FFA Bus/Device/Driver related */
 struct ffa_device {
 	int vm_id;
+	bool mode_32bit;
 	uuid_t uuid;
 	struct device dev;
 };
@@ -48,6 +48,7 @@ int ffa_driver_register(struct ffa_driver *driver, struct module *owner,
 			const char *mod_name);
 void ffa_driver_unregister(struct ffa_driver *driver);
 bool ffa_device_is_valid(struct ffa_device *ffa_dev);
+const struct ffa_dev_ops *ffa_dev_ops_get(struct ffa_device *dev);
 
 #else
 static inline
@@ -70,6 +71,10 @@ static inline void ffa_driver_unregister(struct ffa_driver *driver) {}
 static inline
 bool ffa_device_is_valid(struct ffa_device *ffa_dev) { return false; }
 
+const struct ffa_dev_ops *ffa_dev_ops_get(struct ffa_device *dev)
+{
+	return NULL;
+}
 #endif /* CONFIG_ARM_FFA_TRANSPORT */
 
 #define ffa_register(driver) \
@@ -88,4 +93,35 @@ bool ffa_device_is_valid(struct ffa_device *ffa_dev) { return false; }
 #define module_ffa_driver(__ffa_driver)	\
 	module_driver(__ffa_driver, ffa_register, ffa_unregister)
 
+/* FFA transport related */
+struct ffa_partition_info {
+	u16 id;
+	u16 exec_ctxt;
+/* partition supports receipt of direct requests */
+#define FFA_PARTITION_DIRECT_RECV	BIT(0)
+/* partition can send direct requests. */
+#define FFA_PARTITION_DIRECT_SEND	BIT(1)
+/* partition can send and receive indirect messages. */
+#define FFA_PARTITION_INDIRECT_MSG	BIT(2)
+	u32 properties;
+};
+
+/* For use with FFA_MSG_SEND_DIRECT_{REQ,RESP} which pass data via registers */
+struct ffa_send_direct_data {
+	unsigned long data0; /* w3/x3 */
+	unsigned long data1; /* w4/x4 */
+	unsigned long data2; /* w5/x5 */
+	unsigned long data3; /* w6/x6 */
+	unsigned long data4; /* w7/x7 */
+};
+
+struct ffa_dev_ops {
+	u32 (*api_version_get)(void);
+	int (*partition_info_get)(const char *uuid_str,
+				  struct ffa_partition_info *buffer);
+	void (*mode_32bit_set)(struct ffa_device *dev);
+	int (*sync_send_receive)(struct ffa_device *dev,
+				 struct ffa_send_direct_data *data);
+};
+
 #endif /* _LINUX_ARM_FFA_H */
-- 
2.25.1