zynqmp.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Xilinx Zynq MPSoC Firmware layer
 *
 *  Copyright (C) 2014-2018 Xilinx, Inc.
 *
 *  Michal Simek <michal.simek@xilinx.com>
 *  Davorin Mista <davorin.mista@aggios.com>
 *  Jolly Shah <jollys@xilinx.com>
 *  Rajan Vaja <rajanv@xilinx.com>
 */

#include <linux/arm-smccc.h>
#include <linux/compiler.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/uaccess.h>

#include <linux/firmware/xlnx-zynqmp.h>

/**
 * zynqmp_pm_ret_code() - Convert PMU-FW error codes to Linux error codes
 * @ret_status:		PMUFW return code
 *
 * Return: corresponding Linux error code
 */
static int zynqmp_pm_ret_code(u32 ret_status)
{
	switch (ret_status) {
	case XST_PM_SUCCESS:
	case XST_PM_DOUBLE_REQ:
		return 0;
	case XST_PM_NO_ACCESS:
		return -EACCES;
	case XST_PM_ABORT_SUSPEND:
		return -ECANCELED;
	case XST_PM_INTERNAL:
	case XST_PM_CONFLICT:
	case XST_PM_INVALID_NODE:
	default:
		return -EINVAL;
	}
}

static noinline int do_fw_call_fail(u64 arg0, u64 arg1, u64 arg2,
				    u32 *ret_payload)
{
	return -ENODEV;
}

/*
 * PM function call wrapper
 * Invoke do_fw_call_smc or do_fw_call_hvc, depending on the configuration
 */
static int (*do_fw_call)(u64, u64, u64, u32 *ret_payload) = do_fw_call_fail;

/**
 * do_fw_call_smc() - Call system-level platform management layer (SMC)
 * @arg0:		Argument 0 to SMC call
 * @arg1:		Argument 1 to SMC call
 * @arg2:		Argument 2 to SMC call
 * @ret_payload:	Returned value array
 *
 * Invoke platform management function via SMC call (no hypervisor present).
 *
 * Return: Returns status, either success or error+reason
 */
static noinline int do_fw_call_smc(u64 arg0, u64 arg1, u64 arg2,
				   u32 *ret_payload)
{
	struct arm_smccc_res res;

	arm_smccc_smc(arg0, arg1, arg2, 0, 0, 0, 0, 0, &res);

	if (ret_payload) {
		ret_payload[0] = lower_32_bits(res.a0);
		ret_payload[1] = upper_32_bits(res.a0);
		ret_payload[2] = lower_32_bits(res.a1);
		ret_payload[3] = upper_32_bits(res.a1);
	}

	return zynqmp_pm_ret_code((enum pm_ret_status)res.a0);
}

/**
 * do_fw_call_hvc() - Call system-level platform management layer (HVC)
 * @arg0:		Argument 0 to HVC call
 * @arg1:		Argument 1 to HVC call
 * @arg2:		Argument 2 to HVC call
 * @ret_payload:	Returned value array
 *
 * Invoke platform management function via HVC
 * HVC-based for communication through hypervisor
 * (no direct communication with ATF).
 *
 * Return: Returns status, either success or error+reason
 */
static noinline int do_fw_call_hvc(u64 arg0, u64 arg1, u64 arg2,
				   u32 *ret_payload)
{
	struct arm_smccc_res res;

	arm_smccc_hvc(arg0, arg1, arg2, 0, 0, 0, 0, 0, &res);

	if (ret_payload) {
		ret_payload[0] = lower_32_bits(res.a0);
		ret_payload[1] = upper_32_bits(res.a0);
		ret_payload[2] = lower_32_bits(res.a1);
		ret_payload[3] = upper_32_bits(res.a1);
	}

	return zynqmp_pm_ret_code((enum pm_ret_status)res.a0);
}

/**
 * zynqmp_pm_invoke_fn() - Invoke the system-level platform management layer
 *			   caller function depending on the configuration
 * @pm_api_id:		Requested PM-API call
 * @arg0:		Argument 0 to requested PM-API call
 * @arg1:		Argument 1 to requested PM-API call
 * @arg2:		Argument 2 to requested PM-API call
 * @arg3:		Argument 3 to requested PM-API call
 * @ret_payload:	Returned value array
 *
 * Invoke platform management function for SMC or HVC call, depending on
 * configuration.
 * Following SMC Calling Convention (SMCCC) for SMC64:
 * Pm Function Identifier,
 * PM_SIP_SVC + PM_API_ID =
 *	((SMC_TYPE_FAST << FUNCID_TYPE_SHIFT)
 *	((SMC_64) << FUNCID_CC_SHIFT)
 *	((SIP_START) << FUNCID_OEN_SHIFT)
 *	((PM_API_ID) & FUNCID_NUM_MASK))
 *
 * PM_SIP_SVC	- Registered ZynqMP SIP Service Call.
 * PM_API_ID	- Platform Management API ID.
 *
 * Return: Returns status, either success or error+reason
 */
int zynqmp_pm_invoke_fn(u32 pm_api_id, u32 arg0, u32 arg1,
			u32 arg2, u32 arg3, u32 *ret_payload)
{
	/*
	 * Added SIP service call Function Identifier
	 * Make sure to stay in x0 register
	 */
	u64 smc_arg[4];

	smc_arg[0] = PM_SIP_SVC | pm_api_id;
	smc_arg[1] = ((u64)arg1 << 32) | arg0;
	smc_arg[2] = ((u64)arg3 << 32) | arg2;

	return do_fw_call(smc_arg[0], smc_arg[1], smc_arg[2], ret_payload);
}

static u32 pm_api_version;
static u32 pm_tz_version;

/**
 * zynqmp_pm_get_api_version() - Get version number of PMU PM firmware
 * @version:	Returned version value
 *
 * Return: Returns status, either success or error+reason
 */
static int zynqmp_pm_get_api_version(u32 *version)
{
	u32 ret_payload[PAYLOAD_ARG_CNT];
	int ret;

	if (!version)
		return -EINVAL;

	/* Check is PM API version already verified */
	if (pm_api_version > 0) {
		*version = pm_api_version;
		return 0;
	}
	ret = zynqmp_pm_invoke_fn(PM_GET_API_VERSION, 0, 0, 0, 0, ret_payload);
	*version = ret_payload[1];

	return ret;
}

/**
 * zynqmp_pm_get_trustzone_version() - Get secure trustzone firmware version
 * @version:	Returned version value
 *
 * Return: Returns status, either success or error+reason
 */
static int zynqmp_pm_get_trustzone_version(u32 *version)
{
	u32 ret_payload[PAYLOAD_ARG_CNT];
	int ret;

	if (!version)
		return -EINVAL;

	/* Check is PM trustzone version already verified */
	if (pm_tz_version > 0) {
		*version = pm_tz_version;
		return 0;
	}
	ret = zynqmp_pm_invoke_fn(PM_GET_TRUSTZONE_VERSION, 0, 0,
				  0, 0, ret_payload);
	*version = ret_payload[1];

	return ret;
}

/**
 * get_set_conduit_method() - Choose SMC or HVC based communication
 * @np:		Pointer to the device_node structure
 *
 * Use SMC or HVC-based functions to communicate with EL2/EL3.
 *
 * Return: Returns 0 on success or error code
 */
static int get_set_conduit_method(struct device_node *np)
{
	const char *method;

	if (of_property_read_string(np, "method", &method)) {
		pr_warn("%s missing \"method\" property\n", __func__);
		return -ENXIO;
	}

	if (!strcmp("hvc", method)) {
		do_fw_call = do_fw_call_hvc;
	} else if (!strcmp("smc", method)) {
		do_fw_call = do_fw_call_smc;
	} else {
		pr_warn("%s Invalid \"method\" property: %s\n",
			__func__, method);
		return -EINVAL;
	}

	return 0;
}

static const struct zynqmp_eemi_ops eemi_ops = {
	.get_api_version = zynqmp_pm_get_api_version,
};

/**
 * zynqmp_pm_get_eemi_ops - Get eemi ops functions
 *
 * Return: Pointer of eemi_ops structure
 */
const struct zynqmp_eemi_ops *zynqmp_pm_get_eemi_ops(void)
{
	return &eemi_ops;
}
EXPORT_SYMBOL_GPL(zynqmp_pm_get_eemi_ops);

static int zynqmp_firmware_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np;
	int ret;

	np = of_find_compatible_node(NULL, NULL, "xlnx,zynqmp");
	if (!np)
		return 0;
	of_node_put(np);

	ret = get_set_conduit_method(dev->of_node);
	if (ret)
		return ret;

	/* Check PM API version number */
	zynqmp_pm_get_api_version(&pm_api_version);
	if (pm_api_version < ZYNQMP_PM_VERSION) {
		panic("%s Platform Management API version error. Expected: v%d.%d - Found: v%d.%d\n",
		      __func__,
		      ZYNQMP_PM_VERSION_MAJOR, ZYNQMP_PM_VERSION_MINOR,
		      pm_api_version >> 16, pm_api_version & 0xFFFF);
	}

	pr_info("%s Platform Management API v%d.%d\n", __func__,
		pm_api_version >> 16, pm_api_version & 0xFFFF);

	/* Check trustzone version number */
	ret = zynqmp_pm_get_trustzone_version(&pm_tz_version);
	if (ret)
		panic("Legacy trustzone found without version support\n");

	if (pm_tz_version < ZYNQMP_TZ_VERSION)
		panic("%s Trustzone version error. Expected: v%d.%d - Found: v%d.%d\n",
		      __func__,
		      ZYNQMP_TZ_VERSION_MAJOR, ZYNQMP_TZ_VERSION_MINOR,
		      pm_tz_version >> 16, pm_tz_version & 0xFFFF);

	pr_info("%s Trustzone version v%d.%d\n", __func__,
		pm_tz_version >> 16, pm_tz_version & 0xFFFF);

	return of_platform_populate(dev->of_node, NULL, NULL, dev);
}

static int zynqmp_firmware_remove(struct platform_device *pdev)
{
	return 0;
}

static const struct of_device_id zynqmp_firmware_of_match[] = {
	{.compatible = "xlnx,zynqmp-firmware"},
	{},
};
MODULE_DEVICE_TABLE(of, zynqmp_firmware_of_match);

static struct platform_driver zynqmp_firmware_driver = {
	.driver = {
		.name = "zynqmp_firmware",
		.of_match_table = zynqmp_firmware_of_match,
	},
	.probe = zynqmp_firmware_probe,
	.remove = zynqmp_firmware_remove,
};
module_platform_driver(zynqmp_firmware_driver);