firmware: add Intel Stratix10 service layer driver

Some features of the Intel Stratix10 SoC require a level of privilege
higher than the kernel is granted. Such secure features include
FPGA programming. In terms of the ARMv8 architecture, the kernel runs
at Exception Level 1 (EL1), access to the features requires
Exception Level 3 (EL3).

The Intel Stratix10 SoC service layer provides an in kernel API for
drivers to request access to the secure features. The requests are queued
and processed one by one. ARM’s SMCCC is used to pass the execution
of the requests on to a secure monitor (EL3).

The header file stratix10-sve-client.h defines the interface between
service providers (FPGA manager is one of them) and service layer.

The header file stratix10-smc.h defines the secure monitor call (SMC)
message protocols used for service layer driver in normal world
(EL1) to communicate with secure monitor SW in secure monitor exception
level 3 (EL3).

Signed-off-by: Richard Gong <richard.gong@intel.com>
Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1013 insertions, 0 deletions

diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c
new file mode 100644
index 000000000000..168f52314963
--- /dev/null
+++ b/drivers/firmware/stratix10-svc.c
@@ -0,0 +1,1013 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017-2018, Intel Corporation
+ */
+
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/genalloc.h>
+#include <linux/io.h>
+#include <linux/kfifo.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/firmware/intel/stratix10-smc.h>
+#include <linux/firmware/intel/stratix10-svc-client.h>
+#include <linux/types.h>
+
+/**
+ * SVC_NUM_DATA_IN_FIFO - number of struct stratix10_svc_data in the FIFO
+ *
+ * SVC_NUM_CHANNEL - number of channel supported by service layer driver
+ *
+ * FPGA_CONFIG_DATA_CLAIM_TIMEOUT_MS - claim back the submitted buffer(s)
+ * from the secure world for FPGA manager to reuse, or to free the buffer(s)
+ * when all bit-stream data had be send.
+ *
+ * FPGA_CONFIG_STATUS_TIMEOUT_SEC - poll the FPGA configuration status,
+ * service layer will return error to FPGA manager when timeout occurs,
+ * timeout is set to 30 seconds (30 * 1000) at Intel Stratix10 SoC.
+ */
+#define SVC_NUM_DATA_IN_FIFO                    32
+#define SVC_NUM_CHANNEL                         1
+#define FPGA_CONFIG_DATA_CLAIM_TIMEOUT_MS       200
+#define FPGA_CONFIG_STATUS_TIMEOUT_SEC          30
+
+typedef void (svc_invoke_fn)(unsigned long, unsigned long, unsigned long,
+                             unsigned long, unsigned long, unsigned long,
+                             unsigned long, unsigned long,
+                             struct arm_smccc_res *);
+struct stratix10_svc_chan;
+
+/**
+ * struct stratix10_svc_sh_memory - service shared memory structure
+ * @sync_complete: state for a completion
+ * @addr: physical address of shared memory block
+ * @size: size of shared memory block
+ * @invoke_fn: function to issue secure monitor or hypervisor call
+ *
+ * This struct is used to save physical address and size of shared memory
+ * block. The shared memory blocked is allocated by secure monitor software
+ * at secure world.
+ *
+ * Service layer driver uses the physical address and size to create a memory
+ * pool, then allocates data buffer from that memory pool for service client.
+ */
+struct stratix10_svc_sh_memory {
+        struct completion sync_complete;
+        unsigned long addr;
+        unsigned long size;
+        svc_invoke_fn *invoke_fn;
+};
+
+/**
+ * struct stratix10_svc_data_mem - service memory structure
+ * @vaddr: virtual address
+ * @paddr: physical address
+ * @size: size of memory
+ * @node: link list head node
+ *
+ * This struct is used in a list that keeps track of buffers which have
+ * been allocated or freed from the memory pool. Service layer driver also
+ * uses this struct to transfer physical address to virtual address.
+ */
+struct stratix10_svc_data_mem {
+        void *vaddr;
+        phys_addr_t paddr;
+        size_t size;
+        struct list_head node;
+};
+
+/**
+ * struct stratix10_svc_data - service data structure
+ * @chan: service channel
+ * @paddr: playload physical address
+ * @size: playload size
+ * @command: service command requested by client
+ * @flag: configuration type (full or partial)
+ * @arg: args to be passed via registers and not physically mapped buffers
+ *
+ * This struct is used in service FIFO for inter-process communication.
+ */
+struct stratix10_svc_data {
+        struct stratix10_svc_chan *chan;
+        phys_addr_t paddr;
+        size_t size;
+        u32 command;
+        u32 flag;
+        u64 arg[3];
+};
+
+/**
+ * struct stratix10_svc_controller - service controller
+ * @dev: device
+ * @chans: array of service channels
+ * @num_chans: number of channels in 'chans' array
+ * @num_active_client: number of active service client
+ * @node: list management
+ * @genpool: memory pool pointing to the memory region
+ * @task: pointer to the thread task which handles SMC or HVC call
+ * @svc_fifo: a queue for storing service message data
+ * @complete_status: state for completion
+ * @svc_fifo_lock: protect access to service message data queue
+ * @invoke_fn: function to issue secure monitor call or hypervisor call
+ *
+ * This struct is used to create communication channels for service clients, to
+ * handle secure monitor or hypervisor call.
+ */
+struct stratix10_svc_controller {
+        struct device *dev;
+        struct stratix10_svc_chan *chans;
+        int num_chans;
+        int num_active_client;
+        struct list_head node;
+        struct gen_pool *genpool;
+        struct task_struct *task;
+        struct kfifo svc_fifo;
+        struct completion complete_status;
+        spinlock_t svc_fifo_lock;
+        svc_invoke_fn *invoke_fn;
+};
+
+/**
+ * struct stratix10_svc_chan - service communication channel
+ * @ctrl: pointer to service controller which is the provider of this channel
+ * @scl: pointer to service client which owns the channel
+ * @name: service client name associated with the channel
+ * @lock: protect access to the channel
+ *
+ * This struct is used by service client to communicate with service layer, each
+ * service client has its own channel created by service controller.
+ */
+struct stratix10_svc_chan {
+        struct stratix10_svc_controller *ctrl;
+        struct stratix10_svc_client *scl;
+        char *name;
+        spinlock_t lock;
+};
+
+static LIST_HEAD(svc_ctrl);
+static LIST_HEAD(svc_data_mem);
+
+/**
+ * svc_pa_to_va() - translate physical address to virtual address
+ * @addr: to be translated physical address
+ *
+ * Return: valid virtual address or NULL if the provided physical
+ * address doesn't exist.
+ */
+static void *svc_pa_to_va(unsigned long addr)
+{
+        struct stratix10_svc_data_mem *pmem;
+
+        pr_debug("claim back P-addr=0x%016x\n", (unsigned int)addr);
+        list_for_each_entry(pmem, &svc_data_mem, node)
+                if (pmem->paddr == addr)
+                        return pmem->vaddr;
+
+        /* physical address is not found */
+        return NULL;
+}
+
+/**
+ * svc_thread_cmd_data_claim() - claim back buffer from the secure world
+ * @ctrl: pointer to service layer controller
+ * @p_data: pointer to service data structure
+ * @cb_data: pointer to callback data structure to service client
+ *
+ * Claim back the submitted buffers from the secure world and pass buffer
+ * back to service client (FPGA manager, etc) for reuse.
+ */
+static void svc_thread_cmd_data_claim(struct stratix10_svc_controller *ctrl,
+                                      struct stratix10_svc_data *p_data,
+                                      struct stratix10_svc_cb_data *cb_data)
+{
+        struct arm_smccc_res res;
+        unsigned long timeout;
+
+        reinit_completion(&ctrl->complete_status);
+        timeout = msecs_to_jiffies(FPGA_CONFIG_DATA_CLAIM_TIMEOUT_MS);
+
+        pr_debug("%s: claim back the submitted buffer\n", __func__);
+        do {
+                ctrl->invoke_fn(INTEL_SIP_SMC_FPGA_CONFIG_COMPLETED_WRITE,
+                                0, 0, 0, 0, 0, 0, 0, &res);
+
+                if (res.a0 == INTEL_SIP_SMC_STATUS_OK) {
+                        if (!res.a1) {
+                                complete(&ctrl->complete_status);
+                                break;
+                        }
+                        cb_data->status = BIT(SVC_STATUS_RECONFIG_BUFFER_DONE);
+                        cb_data->kaddr1 = svc_pa_to_va(res.a1);
+                        cb_data->kaddr2 = (res.a2) ?
+                                          svc_pa_to_va(res.a2) : NULL;
+                        cb_data->kaddr3 = (res.a3) ?
+                                          svc_pa_to_va(res.a3) : NULL;
+                        p_data->chan->scl->receive_cb(p_data->chan->scl,
+                                                      cb_data);
+                } else {
+                        pr_debug("%s: secure world busy, polling again\n",
+                                 __func__);
+                }
+        } while (res.a0 == INTEL_SIP_SMC_STATUS_OK ||
+                 res.a0 == INTEL_SIP_SMC_FPGA_CONFIG_STATUS_BUSY ||
+                 wait_for_completion_timeout(&ctrl->complete_status, timeout));
+}
+
+/**
+ * svc_thread_cmd_config_status() - check configuration status
+ * @ctrl: pointer to service layer controller
+ * @p_data: pointer to service data structure
+ * @cb_data: pointer to callback data structure to service client
+ *
+ * Check whether the secure firmware at secure world has finished the FPGA
+ * configuration, and then inform FPGA manager the configuration status.
+ */
+static void svc_thread_cmd_config_status(struct stratix10_svc_controller *ctrl,
+                                         struct stratix10_svc_data *p_data,
+                                         struct stratix10_svc_cb_data *cb_data)
+{
+        struct arm_smccc_res res;
+        int count_in_sec;
+
+        cb_data->kaddr1 = NULL;
+        cb_data->kaddr2 = NULL;
+        cb_data->kaddr3 = NULL;
+        cb_data->status = BIT(SVC_STATUS_RECONFIG_ERROR);
+
+        pr_debug("%s: polling config status\n", __func__);
+
+        count_in_sec = FPGA_CONFIG_STATUS_TIMEOUT_SEC;
+        while (count_in_sec) {
+                ctrl->invoke_fn(INTEL_SIP_SMC_FPGA_CONFIG_ISDONE,
+                                0, 0, 0, 0, 0, 0, 0, &res);
+                if ((res.a0 == INTEL_SIP_SMC_STATUS_OK) ||
+                    (res.a0 == INTEL_SIP_SMC_FPGA_CONFIG_STATUS_ERROR))
+                        break;
+
+                /*
+                 * configuration is still in progress, wait one second then
+                 * poll again
+                 */
+                msleep(1000);
+                count_in_sec--;
+        };
+
+        if (res.a0 == INTEL_SIP_SMC_STATUS_OK && count_in_sec)
+                cb_data->status = BIT(SVC_STATUS_RECONFIG_COMPLETED);
+
+        p_data->chan->scl->receive_cb(p_data->chan->scl, cb_data);
+}
+
+/**
+ * svc_thread_recv_status_ok() - handle the successful status
+ * @p_data: pointer to service data structure
+ * @cb_data: pointer to callback data structure to service client
+ * @res: result from SMC or HVC call
+ *
+ * Send back the correspond status to the service client (FPGA manager etc).
+ */
+static void svc_thread_recv_status_ok(struct stratix10_svc_data *p_data,
+                                      struct stratix10_svc_cb_data *cb_data,
+                                      struct arm_smccc_res res)
+{
+        cb_data->kaddr1 = NULL;
+        cb_data->kaddr2 = NULL;
+        cb_data->kaddr3 = NULL;
+
+        switch (p_data->command) {
+        case COMMAND_RECONFIG:
+                cb_data->status = BIT(SVC_STATUS_RECONFIG_REQUEST_OK);
+                break;
+        case COMMAND_RECONFIG_DATA_SUBMIT:
+                cb_data->status = BIT(SVC_STATUS_RECONFIG_BUFFER_SUBMITTED);
+                break;
+        case COMMAND_NOOP:
+                cb_data->status = BIT(SVC_STATUS_RECONFIG_BUFFER_SUBMITTED);
+                cb_data->kaddr1 = svc_pa_to_va(res.a1);
+                break;
+        case COMMAND_RECONFIG_STATUS:
+                cb_data->status = BIT(SVC_STATUS_RECONFIG_COMPLETED);
+                break;
+        default:
+                pr_warn("it shouldn't happen\n");
+                break;
+        }
+
+        pr_debug("%s: call receive_cb\n", __func__);
+        p_data->chan->scl->receive_cb(p_data->chan->scl, cb_data);
+}
+
+/**
+ * svc_normal_to_secure_thread() - the function to run in the kthread
+ * @data: data pointer for kthread function
+ *
+ * Service layer driver creates stratix10_svc_smc_hvc_call kthread on CPU
+ * node 0, its function stratix10_svc_secure_call_thread is used to handle
+ * SMC or HVC calls between kernel driver and secure monitor software.
+ *
+ * Return: 0 for success or -ENOMEM on error.
+ */
+static int svc_normal_to_secure_thread(void *data)
+{
+        struct stratix10_svc_controller
+                        *ctrl = (struct stratix10_svc_controller *)data;
+        struct stratix10_svc_data *pdata;
+        struct stratix10_svc_cb_data *cbdata;
+        struct arm_smccc_res res;
+        unsigned long a0, a1, a2;
+        int ret_fifo = 0;
+
+        pdata =  kmalloc(sizeof(*pdata), GFP_KERNEL);
+        if (!pdata)
+                return -ENOMEM;
+
+        cbdata = kmalloc(sizeof(*cbdata), GFP_KERNEL);
+        if (!cbdata) {
+                kfree(pdata);
+                return -ENOMEM;
+        }
+
+        /* default set, to remove build warning */
+        a0 = INTEL_SIP_SMC_FPGA_CONFIG_LOOPBACK;
+        a1 = 0;
+        a2 = 0;
+
+        pr_debug("smc_hvc_shm_thread is running\n");
+
+        while (!kthread_should_stop()) {
+                ret_fifo = kfifo_out_spinlocked(&ctrl->svc_fifo,
+                                                pdata, sizeof(*pdata),
+                                                &ctrl->svc_fifo_lock);
+
+                if (!ret_fifo)
+                        continue;
+
+                pr_debug("get from FIFO pa=0x%016x, command=%u, size=%u\n",
+                         (unsigned int)pdata->paddr, pdata->command,
+                         (unsigned int)pdata->size);
+
+                switch (pdata->command) {
+                case COMMAND_RECONFIG_DATA_CLAIM:
+                        svc_thread_cmd_data_claim(ctrl, pdata, cbdata);
+                        continue;
+                case COMMAND_RECONFIG:
+                        a0 = INTEL_SIP_SMC_FPGA_CONFIG_START;
+                        pr_debug("conf_type=%u\n", (unsigned int)pdata->flag);
+                        a1 = pdata->flag;
+                        a2 = 0;
+                        break;
+                case COMMAND_RECONFIG_DATA_SUBMIT:
+                        a0 = INTEL_SIP_SMC_FPGA_CONFIG_WRITE;
+                        a1 = (unsigned long)pdata->paddr;
+                        a2 = (unsigned long)pdata->size;
+                        break;
+                case COMMAND_RECONFIG_STATUS:
+                        a0 = INTEL_SIP_SMC_FPGA_CONFIG_ISDONE;
+                        a1 = 0;
+                        a2 = 0;
+                        break;
+                default:
+                        pr_warn("it shouldn't happen\n");
+                        break;
+                }
+                pr_debug("%s: before SMC call -- a0=0x%016x a1=0x%016x",
+                         __func__, (unsigned int)a0, (unsigned int)a1);
+                pr_debug(" a2=0x%016x\n", (unsigned int)a2);
+
+                ctrl->invoke_fn(a0, a1, a2, 0, 0, 0, 0, 0, &res);
+
+                pr_debug("%s: after SMC call -- res.a0=0x%016x",
+                         __func__, (unsigned int)res.a0);
+                pr_debug(" res.a1=0x%016x, res.a2=0x%016x",
+                         (unsigned int)res.a1, (unsigned int)res.a2);
+                pr_debug(" res.a3=0x%016x\n", (unsigned int)res.a3);
+
+                switch (res.a0) {
+                case INTEL_SIP_SMC_STATUS_OK:
+                        svc_thread_recv_status_ok(pdata, cbdata, res);
+                        break;
+                case INTEL_SIP_SMC_FPGA_CONFIG_STATUS_BUSY:
+                        switch (pdata->command) {
+                        case COMMAND_RECONFIG_DATA_SUBMIT:
+                                svc_thread_cmd_data_claim(ctrl,
+                                                          pdata, cbdata);
+                                break;
+                        case COMMAND_RECONFIG_STATUS:
+                                svc_thread_cmd_config_status(ctrl,
+                                                             pdata, cbdata);
+                                break;
+                        default:
+                                pr_warn("it shouldn't happen\n");
+                                break;
+                        }
+                        break;
+                case INTEL_SIP_SMC_FPGA_CONFIG_STATUS_REJECTED:
+                        pr_debug("%s: STATUS_REJECTED\n", __func__);
+                        break;
+                case INTEL_SIP_SMC_FPGA_CONFIG_STATUS_ERROR:
+                        pr_err("%s: STATUS_ERROR\n", __func__);
+                        cbdata->status = BIT(SVC_STATUS_RECONFIG_ERROR);
+                        cbdata->kaddr1 = NULL;
+                        cbdata->kaddr2 = NULL;
+                        cbdata->kaddr3 = NULL;
+                        pdata->chan->scl->receive_cb(pdata->chan->scl, cbdata);
+                        break;
+                default:
+                        pr_warn("it shouldn't happen\n");
+                        break;
+                }
+        };
+
+        kfree(cbdata);
+        kfree(pdata);
+
+        return 0;
+}
+
+/**
+ * svc_normal_to_secure_shm_thread() - the function to run in the kthread
+ * @data: data pointer for kthread function
+ *
+ * Service layer driver creates stratix10_svc_smc_hvc_shm kthread on CPU
+ * node 0, its function stratix10_svc_secure_shm_thread is used to query the
+ * physical address of memory block reserved by secure monitor software at
+ * secure world.
+ *
+ * svc_normal_to_secure_shm_thread() calls do_exit() directly since it is a
+ * standlone thread for which no one will call kthread_stop() or return when
+ * 'kthread_should_stop()' is true.
+ */
+static int svc_normal_to_secure_shm_thread(void *data)
+{
+        struct stratix10_svc_sh_memory
+                        *sh_mem = (struct stratix10_svc_sh_memory *)data;
+        struct arm_smccc_res res;
+
+        /* SMC or HVC call to get shared memory info from secure world */
+        sh_mem->invoke_fn(INTEL_SIP_SMC_FPGA_CONFIG_GET_MEM,
+                          0, 0, 0, 0, 0, 0, 0, &res);
+        if (res.a0 == INTEL_SIP_SMC_STATUS_OK) {
+                sh_mem->addr = res.a1;
+                sh_mem->size = res.a2;
+        } else {
+                pr_err("%s: after SMC call -- res.a0=0x%016x",  __func__,
+                       (unsigned int)res.a0);
+                sh_mem->addr = 0;
+                sh_mem->size = 0;
+        }
+
+        complete(&sh_mem->sync_complete);
+        do_exit(0);
+}
+
+/**
+ * svc_get_sh_memory() - get memory block reserved by secure monitor SW
+ * @pdev: pointer to service layer device
+ * @sh_memory: pointer to service shared memory structure
+ *
+ * Return: zero for successfully getting the physical address of memory block
+ * reserved by secure monitor software, or negative value on error.
+ */
+static int svc_get_sh_memory(struct platform_device *pdev,
+                                    struct stratix10_svc_sh_memory *sh_memory)
+{
+        struct device *dev = &pdev->dev;
+        struct task_struct *sh_memory_task;
+        unsigned int cpu = 0;
+
+        init_completion(&sh_memory->sync_complete);
+
+        /* smc or hvc call happens on cpu 0 bound kthread */
+        sh_memory_task = kthread_create_on_node(svc_normal_to_secure_shm_thread,
+                                               (void *)sh_memory,
+                                                cpu_to_node(cpu),
+                                                "svc_smc_hvc_shm_thread");
+        if (IS_ERR(sh_memory_task)) {
+                dev_err(dev, "fail to create stratix10_svc_smc_shm_thread\n");
+                return -EINVAL;
+        }
+
+        wake_up_process(sh_memory_task);
+
+        if (!wait_for_completion_timeout(&sh_memory->sync_complete, 10 * HZ)) {
+                dev_err(dev,
+                        "timeout to get sh-memory paras from secure world\n");
+                return -ETIMEDOUT;
+        }
+
+        if (!sh_memory->addr || !sh_memory->size) {
+                dev_err(dev,
+                        "fails to get shared memory info from secure world\n");
+                return -ENOMEM;
+        }
+
+        dev_dbg(dev, "SM software provides paddr: 0x%016x, size: 0x%08x\n",
+                (unsigned int)sh_memory->addr,
+                (unsigned int)sh_memory->size);
+
+        return 0;
+}
+
+/**
+ * svc_create_memory_pool() - create a memory pool from reserved memory block
+ * @pdev: pointer to service layer device
+ * @sh_memory: pointer to service shared memory structure
+ *
+ * Return: pool allocated from reserved memory block or ERR_PTR() on error.
+ */
+static struct gen_pool *
+svc_create_memory_pool(struct platform_device *pdev,
+                       struct stratix10_svc_sh_memory *sh_memory)
+{
+        struct device *dev = &pdev->dev;
+        struct gen_pool *genpool;
+        unsigned long vaddr;
+        phys_addr_t paddr;
+        size_t size;
+        phys_addr_t begin;
+        phys_addr_t end;
+        void *va;
+        size_t page_mask = PAGE_SIZE - 1;
+        int min_alloc_order = 3;
+        int ret;
+
+        begin = roundup(sh_memory->addr, PAGE_SIZE);
+        end = rounddown(sh_memory->addr + sh_memory->size, PAGE_SIZE);
+        paddr = begin;
+        size = end - begin;
+        va = memremap(paddr, size, MEMREMAP_WC);
+        if (!va) {
+                dev_err(dev, "fail to remap shared memory\n");
+                return ERR_PTR(-EINVAL);
+        }
+        vaddr = (unsigned long)va;
+        dev_dbg(dev,
+                "reserved memory vaddr: %p, paddr: 0x%16x size: 0x%8x\n",
+                va, (unsigned int)paddr, (unsigned int)size);
+        if ((vaddr & page_mask) || (paddr & page_mask) ||
+            (size & page_mask)) {
+                dev_err(dev, "page is not aligned\n");
+                return ERR_PTR(-EINVAL);
+        }
+        genpool = gen_pool_create(min_alloc_order, -1);
+        if (!genpool) {
+                dev_err(dev, "fail to create genpool\n");
+                return ERR_PTR(-ENOMEM);
+        }
+        gen_pool_set_algo(genpool, gen_pool_best_fit, NULL);
+        ret = gen_pool_add_virt(genpool, vaddr, paddr, size, -1);
+        if (ret) {
+                dev_err(dev, "fail to add memory chunk to the pool\n");
+                gen_pool_destroy(genpool);
+                return ERR_PTR(ret);
+        }
+
+        return genpool;
+}
+
+/**
+ * svc_smccc_smc() - secure monitor call between normal and secure world
+ * @a0: argument passed in registers 0
+ * @a1: argument passed in registers 1
+ * @a2: argument passed in registers 2
+ * @a3: argument passed in registers 3
+ * @a4: argument passed in registers 4
+ * @a5: argument passed in registers 5
+ * @a6: argument passed in registers 6
+ * @a7: argument passed in registers 7
+ * @res: result values from register 0 to 3
+ */
+static void svc_smccc_smc(unsigned long a0, unsigned long a1,
+                          unsigned long a2, unsigned long a3,
+                          unsigned long a4, unsigned long a5,
+                          unsigned long a6, unsigned long a7,
+                          struct arm_smccc_res *res)
+{
+        arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
+}
+
+/**
+ * svc_smccc_hvc() - hypervisor call between normal and secure world
+ * @a0: argument passed in registers 0
+ * @a1: argument passed in registers 1
+ * @a2: argument passed in registers 2
+ * @a3: argument passed in registers 3
+ * @a4: argument passed in registers 4
+ * @a5: argument passed in registers 5
+ * @a6: argument passed in registers 6
+ * @a7: argument passed in registers 7
+ * @res: result values from register 0 to 3
+ */
+static void svc_smccc_hvc(unsigned long a0, unsigned long a1,
+                          unsigned long a2, unsigned long a3,
+                          unsigned long a4, unsigned long a5,
+                          unsigned long a6, unsigned long a7,
+                          struct arm_smccc_res *res)
+{
+        arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
+}
+
+/**
+ * get_invoke_func() - invoke SMC or HVC call
+ * @dev: pointer to device
+ *
+ * Return: function pointer to svc_smccc_smc or svc_smccc_hvc.
+ */
+static svc_invoke_fn *get_invoke_func(struct device *dev)
+{
+        const char *method;
+
+        if (of_property_read_string(dev->of_node, "method", &method)) {
+                dev_warn(dev, "missing \"method\" property\n");
+                return ERR_PTR(-ENXIO);
+        }
+
+        if (!strcmp(method, "smc"))
+                return svc_smccc_smc;
+        if (!strcmp(method, "hvc"))
+                return svc_smccc_hvc;
+
+        dev_warn(dev, "invalid \"method\" property: %s\n", method);
+
+        return ERR_PTR(-EINVAL);
+}
+
+/**
+ * stratix10_svc_request_channel_byname() - request a service channel
+ * @client: pointer to service client
+ * @name: service client name
+ *
+ * This function is used by service client to request a service channel.
+ *
+ * Return: a pointer to channel assigned to the client on success,
+ * or ERR_PTR() on error.
+ */
+struct stratix10_svc_chan *stratix10_svc_request_channel_byname(
+        struct stratix10_svc_client *client, const char *name)
+{
+        struct device *dev = client->dev;
+        struct stratix10_svc_controller *controller;
+        struct stratix10_svc_chan *chan = NULL;
+        unsigned long flag;
+        int i;
+
+        /* if probe was called after client's, or error on probe */
+        if (list_empty(&svc_ctrl))
+                return ERR_PTR(-EPROBE_DEFER);
+
+        controller = list_first_entry(&svc_ctrl,
+                                      struct stratix10_svc_controller, node);
+        for (i = 0; i < SVC_NUM_CHANNEL; i++) {
+                if (!strcmp(controller->chans[i].name, name)) {
+                        chan = &controller->chans[i];
+                        break;
+                }
+        }
+
+        /* if there was no channel match */
+        if (i == SVC_NUM_CHANNEL) {
+                dev_err(dev, "%s: channel not allocated\n", __func__);
+                return ERR_PTR(-EINVAL);
+        }
+
+        if (chan->scl || !try_module_get(controller->dev->driver->owner)) {
+                dev_dbg(dev, "%s: svc not free\n", __func__);
+                return ERR_PTR(-EBUSY);
+        }
+
+        spin_lock_irqsave(&chan->lock, flag);
+        chan->scl = client;
+        chan->ctrl->num_active_client++;
+        spin_unlock_irqrestore(&chan->lock, flag);
+
+        return chan;
+}
+EXPORT_SYMBOL_GPL(stratix10_svc_request_channel_byname);
+
+/**
+ * stratix10_svc_free_channel() - free service channel
+ * @chan: service channel to be freed
+ *
+ * This function is used by service client to free a service channel.
+ */
+void stratix10_svc_free_channel(struct stratix10_svc_chan *chan)
+{
+        unsigned long flag;
+
+        spin_lock_irqsave(&chan->lock, flag);
+        chan->scl = NULL;
+        chan->ctrl->num_active_client--;
+        module_put(chan->ctrl->dev->driver->owner);
+        spin_unlock_irqrestore(&chan->lock, flag);
+}
+EXPORT_SYMBOL_GPL(stratix10_svc_free_channel);
+
+/**
+ * stratix10_svc_send() - send a message data to the remote
+ * @chan: service channel assigned to the client
+ * @msg: message data to be sent, in the format of
+ * "struct stratix10_svc_client_msg"
+ *
+ * This function is used by service client to add a message to the service
+ * layer driver's queue for being sent to the secure world.
+ *
+ * Return: 0 for success, -ENOMEM or -ENOBUFS on error.
+ */
+int stratix10_svc_send(struct stratix10_svc_chan *chan, void *msg)
+{
+        struct stratix10_svc_client_msg
+                *p_msg = (struct stratix10_svc_client_msg *)msg;
+        struct stratix10_svc_data_mem *p_mem;
+        struct stratix10_svc_data *p_data;
+        int ret = 0;
+        unsigned int cpu = 0;
+
+        p_data = kzalloc(sizeof(*p_data), GFP_KERNEL);
+        if (!p_data)
+                return -ENOMEM;
+
+        /* first client will create kernel thread */
+        if (!chan->ctrl->task) {
+                chan->ctrl->task =
+                        kthread_create_on_node(svc_normal_to_secure_thread,
+                                              (void *)chan->ctrl,
+                                              cpu_to_node(cpu),
+                                              "svc_smc_hvc_thread");
+                        if (IS_ERR(chan->ctrl->task)) {
+                                dev_err(chan->ctrl->dev,
+                                        "fails to create svc_smc_hvc_thread\n");
+                                kfree(p_data);
+                                return -EINVAL;
+                        }
+                kthread_bind(chan->ctrl->task, cpu);
+                wake_up_process(chan->ctrl->task);
+        }
+
+        pr_debug("%s: sent P-va=%p, P-com=%x, P-size=%u\n", __func__,
+                 p_msg->payload, p_msg->command,
+                 (unsigned int)p_msg->payload_length);
+
+        if (list_empty(&svc_data_mem)) {
+                if (p_msg->command == COMMAND_RECONFIG) {
+                        struct stratix10_svc_command_config_type *ct =
+                                (struct stratix10_svc_command_config_type *)
+                                p_msg->payload;
+                        p_data->flag = ct->flags;
+                }
+        } else {
+                list_for_each_entry(p_mem, &svc_data_mem, node)
+                        if (p_mem->vaddr == p_msg->payload) {
+                                p_data->paddr = p_mem->paddr;
+                                break;
+                        }
+        }
+
+        p_data->command = p_msg->command;
+        p_data->arg[0] = p_msg->arg[0];
+        p_data->arg[1] = p_msg->arg[1];
+        p_data->arg[2] = p_msg->arg[2];
+        p_data->size = p_msg->payload_length;
+        p_data->chan = chan;
+        pr_debug("%s: put to FIFO pa=0x%016x, cmd=%x, size=%u\n", __func__,
+               (unsigned int)p_data->paddr, p_data->command,
+               (unsigned int)p_data->size);
+        ret = kfifo_in_spinlocked(&chan->ctrl->svc_fifo, p_data,
+                                  sizeof(*p_data),
+                                  &chan->ctrl->svc_fifo_lock);
+
+        kfree(p_data);
+
+        if (!ret)
+                return -ENOBUFS;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(stratix10_svc_send);
+
+/**
+ * stratix10_svc_done() - complete service request transactions
+ * @chan: service channel assigned to the client
+ *
+ * This function should be called when client has finished its request
+ * or there is an error in the request process. It allows the service layer
+ * to stop the running thread to have maximize savings in kernel resources.
+ */
+void stratix10_svc_done(struct stratix10_svc_chan *chan)
+{
+        /* stop thread when thread is running AND only one active client */
+        if (chan->ctrl->task && chan->ctrl->num_active_client <= 1) {
+                pr_debug("svc_smc_hvc_shm_thread is stopped\n");
+                kthread_stop(chan->ctrl->task);
+                chan->ctrl->task = NULL;
+        }
+}
+EXPORT_SYMBOL_GPL(stratix10_svc_done);
+
+/**
+ * stratix10_svc_allocate_memory() - allocate memory
+ * @chan: service channel assigned to the client
+ * @size: memory size requested by a specific service client
+ *
+ * Service layer allocates the requested number of bytes buffer from the
+ * memory pool, service client uses this function to get allocated buffers.
+ *
+ * Return: address of allocated memory on success, or ERR_PTR() on error.
+ */
+void *stratix10_svc_allocate_memory(struct stratix10_svc_chan *chan,
+                                    size_t size)
+{
+        struct stratix10_svc_data_mem *pmem;
+        unsigned long va;
+        phys_addr_t pa;
+        struct gen_pool *genpool = chan->ctrl->genpool;
+        size_t s = roundup(size, 1 << genpool->min_alloc_order);
+
+        pmem = devm_kzalloc(chan->ctrl->dev, sizeof(*pmem), GFP_KERNEL);
+        if (!pmem)
+                return ERR_PTR(-ENOMEM);
+
+        va = gen_pool_alloc(genpool, s);
+        if (!va)
+                return ERR_PTR(-ENOMEM);
+
+        memset((void *)va, 0, s);
+        pa = gen_pool_virt_to_phys(genpool, va);
+
+        pmem->vaddr = (void *)va;
+        pmem->paddr = pa;
+        pmem->size = s;
+        list_add_tail(&pmem->node, &svc_data_mem);
+        pr_debug("%s: va=%p, pa=0x%016x\n", __func__,
+                 pmem->vaddr, (unsigned int)pmem->paddr);
+
+        return (void *)va;
+}
+EXPORT_SYMBOL_GPL(stratix10_svc_allocate_memory);
+
+/**
+ * stratix10_svc_free_memory() - free allocated memory
+ * @chan: service channel assigned to the client
+ * @kaddr: memory to be freed
+ *
+ * This function is used by service client to free allocated buffers.
+ */
+void stratix10_svc_free_memory(struct stratix10_svc_chan *chan, void *kaddr)
+{
+        struct stratix10_svc_data_mem *pmem;
+        size_t size = 0;
+
+        list_for_each_entry(pmem, &svc_data_mem, node)
+                if (pmem->vaddr == kaddr) {
+                        size = pmem->size;
+                        break;
+                }
+
+        gen_pool_free(chan->ctrl->genpool, (unsigned long)kaddr, size);
+        pmem->vaddr = NULL;
+        list_del(&pmem->node);
+}
+EXPORT_SYMBOL_GPL(stratix10_svc_free_memory);
+
+static const struct of_device_id stratix10_svc_drv_match[] = {
+        {.compatible = "intel,stratix10-svc"},
+        {},
+};
+
+static int stratix10_svc_drv_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct stratix10_svc_controller *controller;
+        struct stratix10_svc_chan *chans;
+        struct gen_pool *genpool;
+        struct stratix10_svc_sh_memory *sh_memory;
+        svc_invoke_fn *invoke_fn;
+        size_t fifo_size;
+        int ret;
+
+        /* get SMC or HVC function */
+        invoke_fn = get_invoke_func(dev);
+        if (IS_ERR(invoke_fn))
+                return -EINVAL;
+
+        sh_memory = devm_kzalloc(dev, sizeof(*sh_memory), GFP_KERNEL);
+        if (!sh_memory)
+                return -ENOMEM;
+
+        sh_memory->invoke_fn = invoke_fn;
+        ret = svc_get_sh_memory(pdev, sh_memory);
+        if (ret)
+                return ret;
+
+        genpool = svc_create_memory_pool(pdev, sh_memory);
+        if (!genpool)
+                return -ENOMEM;
+
+        /* allocate service controller and supporting channel */
+        controller = devm_kzalloc(dev, sizeof(*controller), GFP_KERNEL);
+        if (!controller)
+                return -ENOMEM;
+
+        chans = devm_kmalloc_array(dev, SVC_NUM_CHANNEL,
+                                   sizeof(*chans), GFP_KERNEL | __GFP_ZERO);
+        if (!chans)
+                return -ENOMEM;
+
+        controller->dev = dev;
+        controller->num_chans = SVC_NUM_CHANNEL;
+        controller->num_active_client = 0;
+        controller->chans = chans;
+        controller->genpool = genpool;
+        controller->task = NULL;
+        controller->invoke_fn = invoke_fn;
+        init_completion(&controller->complete_status);
+
+        fifo_size = sizeof(struct stratix10_svc_data) * SVC_NUM_DATA_IN_FIFO;
+        ret = kfifo_alloc(&controller->svc_fifo, fifo_size, GFP_KERNEL);
+        if (ret) {
+                dev_err(dev, "fails to allocate FIFO\n");
+                return ret;
+        }
+        spin_lock_init(&controller->svc_fifo_lock);
+
+        chans[0].scl = NULL;
+        chans[0].ctrl = controller;
+        chans[0].name = SVC_CLIENT_FPGA;
+        spin_lock_init(&chans[0].lock);
+
+        list_add_tail(&controller->node, &svc_ctrl);
+        platform_set_drvdata(pdev, controller);
+
+        pr_info("Intel Service Layer Driver Initialized\n");
+
+        return ret;
+}
+
+static int stratix10_svc_drv_remove(struct platform_device *pdev)
+{
+        struct stratix10_svc_controller *ctrl = platform_get_drvdata(pdev);
+
+        kfifo_free(&ctrl->svc_fifo);
+        if (ctrl->task) {
+                kthread_stop(ctrl->task);
+                ctrl->task = NULL;
+        }
+        if (ctrl->genpool)
+                gen_pool_destroy(ctrl->genpool);
+        list_del(&ctrl->node);
+
+        return 0;
+}
+
+static struct platform_driver stratix10_svc_driver = {
+        .probe = stratix10_svc_drv_probe,
+        .remove = stratix10_svc_drv_remove,
+        .driver = {
+                .name = "stratix10-svc",
+                .of_match_table = stratix10_svc_drv_match,
+        },
+};
+
+static int __init stratix10_svc_init(void)
+{
+        struct device_node *fw_np;
+        struct device_node *np;
+        int ret;
+
+        fw_np = of_find_node_by_name(NULL, "firmware");
+        if (!fw_np)
+                return -ENODEV;
+
+        np = of_find_matching_node(fw_np, stratix10_svc_drv_match);
+        if (!np) {
+                of_node_put(fw_np);
+                return -ENODEV;
+        }
+
+        of_node_put(np);
+        ret = of_platform_populate(fw_np, stratix10_svc_drv_match, NULL, NULL);
+        of_node_put(fw_np);
+        if (ret)
+                return ret;
+
+        return platform_driver_register(&stratix10_svc_driver);
+}
+
+static void __exit stratix10_svc_exit(void)
+{
+        return platform_driver_unregister(&stratix10_svc_driver);
+}
+
+subsys_initcall(stratix10_svc_init);
+module_exit(stratix10_svc_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel Stratix10 Service Layer Driver");
+MODULE_AUTHOR("Richard Gong <richard.gong@intel.com>");
+MODULE_ALIAS("platform:stratix10-svc");