1) Defines messaging protocol for handling Transfer Descriptor
in both UL/DL direction.
2) Ring buffer management.
Signed-off-by: M Chetan Kumar <m.chetan.kumar@xxxxxxxxx>
---
v5: no change.
v4: no change.
v3: no change.
v2:
* Endianness type correction for Host-device protocol structure.
* Function signature documentation correction.
* Streamline multiple returns using goto.
---
drivers/net/wwan/iosm/iosm_ipc_protocol.c | 283 ++++++++++++++++++++++
drivers/net/wwan/iosm/iosm_ipc_protocol.h | 237 ++++++++++++++++++
2 files changed, 520 insertions(+)
create mode 100644 drivers/net/wwan/iosm/iosm_ipc_protocol.c
create mode 100644 drivers/net/wwan/iosm/iosm_ipc_protocol.h
diff --git a/drivers/net/wwan/iosm/iosm_ipc_protocol.c b/drivers/net/wwan/iosm/iosm_ipc_protocol.c
new file mode 100644
index 000000000000..834d8b146a94
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_protocol.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#include "iosm_ipc_imem.h"
+#include "iosm_ipc_protocol.h"
+#include "iosm_ipc_protocol_ops.h"
+#include "iosm_ipc_pm.h"
+#include "iosm_ipc_task_queue.h"
+
+int ipc_protocol_tq_msg_send(struct iosm_protocol *ipc_protocol,
+ enum ipc_msg_prep_type msg_type,
+ union ipc_msg_prep_args *prep_args,
+ struct ipc_rsp *response)
+{
+ int index = ipc_protocol_msg_prep(ipc_protocol->imem, msg_type,
+ prep_args);
+
+ /* Store reference towards caller specified response in response ring
+ * and signal CP
+ */
+ if (index >= 0 && index < IPC_MEM_MSG_ENTRIES) {
+ ipc_protocol->rsp_ring[index] = response;
+ ipc_protocol_msg_hp_update(ipc_protocol->imem);
+ }
+
+ return index;
+}
+
+/* Callback for message send */
+static int ipc_protocol_tq_msg_send_cb(struct iosm_imem *ipc_imem, int arg,
+ void *msg, size_t size)
+{
+ struct ipc_call_msg_send_args *send_args = msg;
+ struct iosm_protocol *ipc_protocol = ipc_imem->ipc_protocol;
+
+ return ipc_protocol_tq_msg_send(ipc_protocol, send_args->msg_type,
+ send_args->prep_args,
+ send_args->response);
+}
+
+/* Remove reference to a response. This is typically used when a requestor timed
+ * out and is no longer interested in the response.
+ */
+static int ipc_protocol_tq_msg_remove(struct iosm_imem *ipc_imem, int arg,
+ void *msg, size_t size)
+{
+ struct iosm_protocol *ipc_protocol = ipc_imem->ipc_protocol;
+
+ ipc_protocol->rsp_ring[arg] = NULL;
+ return 0;
+}
+
+int ipc_protocol_msg_send(struct iosm_protocol *ipc_protocol,
+ enum ipc_msg_prep_type prep,
+ union ipc_msg_prep_args *prep_args)
+{
+ struct ipc_call_msg_send_args send_args;
+ unsigned int exec_timeout;
+ struct ipc_rsp response;
+ int index;
+
+ exec_timeout = (ipc_protocol_get_ap_exec_stage(ipc_protocol) ==
+ IPC_MEM_EXEC_STAGE_RUN ?
+ IPC_MSG_COMPLETE_RUN_DEFAULT_TIMEOUT :
+ IPC_MSG_COMPLETE_BOOT_DEFAULT_TIMEOUT);
+
+ /* Trap if called from non-preemptible context */
+ might_sleep();
+
+ response.status = IPC_MEM_MSG_CS_INVALID;
+ init_completion(&response.completion);
+
+ send_args.msg_type = prep;
+ send_args.prep_args = prep_args;
+ send_args.response = &response;
+
+ /* Allocate and prepare message to be sent in tasklet context.
+ * A positive index returned form tasklet_call references the message
+ * in case it needs to be cancelled when there is a timeout.
+ */
+ index = ipc_task_queue_send_task(ipc_protocol->imem,
+ ipc_protocol_tq_msg_send_cb, 0,
+ &send_args, 0, true);
+
+ if (index < 0) {
+ dev_err(ipc_protocol->dev, "msg %d failed", prep);
+ return index;
+ }
+
+ /* Wait for the device to respond to the message */
+ switch (wait_for_completion_timeout(&response.completion,
+ msecs_to_jiffies(exec_timeout))) {
+ case 0:
+ /* Timeout, there was no response from the device.
+ * Remove the reference to the local response completion
+ * object as we are no longer interested in the response.
+ */
+ ipc_task_queue_send_task(ipc_protocol->imem,
+ ipc_protocol_tq_msg_remove, index,
+ NULL, 0, true);
+ dev_err(ipc_protocol->dev, "msg timeout");
+ ipc_uevent_send(ipc_protocol->pcie->dev, UEVENT_MDM_TIMEOUT);
+ break;
+ default:
+ /* We got a response in time; check completion status: */
+ if (response.status != IPC_MEM_MSG_CS_SUCCESS) {
+ dev_err(ipc_protocol->dev,
+ "msg completion status error %d",
+ response.status);
+ return -EIO;
+ }
+ }
+
+ return 0;
+}
+
+static int ipc_protocol_msg_send_host_sleep(struct iosm_protocol *ipc_protocol,
+ u32 state)
+{
+ union ipc_msg_prep_args prep_args = {
+ .sleep.target = 0,
+ .sleep.state = state,
+ };
+
+ return ipc_protocol_msg_send(ipc_protocol, IPC_MSG_PREP_SLEEP,
+ &prep_args);
+}
+
+void ipc_protocol_doorbell_trigger(struct iosm_protocol *ipc_protocol,
+ u32 identifier)
+{
+ ipc_pm_signal_hpda_doorbell(&ipc_protocol->pm, identifier, true);
+}
+
+bool ipc_protocol_pm_dev_sleep_handle(struct iosm_protocol *ipc_protocol)
+{
+ u32 ipc_status = ipc_protocol_get_ipc_status(ipc_protocol);
+ u32 requested;
+
+ if (ipc_status != IPC_MEM_DEVICE_IPC_RUNNING) {
+ dev_err(ipc_protocol->dev,
+ "irq ignored, CP IPC state is %d, should be RUNNING",
+ ipc_status);
+
+ /* Stop further processing. */
+ return false;
+ }
+
+ /* Get a copy of the requested PM state by the device and the local
+ * device PM state.
+ */
+ requested = ipc_protocol_pm_dev_get_sleep_notification(ipc_protocol);
+
+ return ipc_pm_dev_slp_notification(&ipc_protocol->pm, requested);
+}
+
+static int ipc_protocol_tq_wakeup_dev_slp(struct iosm_imem *ipc_imem, int arg,
+ void *msg, size_t size)
+{
+ struct iosm_pm *ipc_pm = &ipc_imem->ipc_protocol->pm;
+
+ /* Wakeup from device sleep if it is not ACTIVE */
+ ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_HS, true);
+
+ ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_HS, false);
+
+ return 0;
+}
+
+void ipc_protocol_s2idle_sleep(struct iosm_protocol *ipc_protocol, bool sleep)
+{
+ ipc_pm_set_s2idle_sleep(&ipc_protocol->pm, sleep);
+}
+
+bool ipc_protocol_suspend(struct iosm_protocol *ipc_protocol)
+{
+ if (!ipc_pm_prepare_host_sleep(&ipc_protocol->pm))
+ goto err;
+
+ ipc_task_queue_send_task(ipc_protocol->imem,
+ ipc_protocol_tq_wakeup_dev_slp, 0, NULL, 0,
+ true);
+
+ if (!ipc_pm_wait_for_device_active(&ipc_protocol->pm)) {
+ ipc_uevent_send(ipc_protocol->pcie->dev, UEVENT_MDM_TIMEOUT);
+ goto err;
+ }
+
+ /* Send the sleep message for sync sys calls. */
+ dev_dbg(ipc_protocol->dev, "send TARGET_HOST, ENTER_SLEEP");
+ if (ipc_protocol_msg_send_host_sleep(ipc_protocol,
+ IPC_HOST_SLEEP_ENTER_SLEEP)) {
+ /* Sending ENTER_SLEEP message failed, we are still active */
+ ipc_protocol->pm.host_pm_state = IPC_MEM_HOST_PM_ACTIVE;
+ goto err;
+ }
+
+ ipc_protocol->pm.host_pm_state = IPC_MEM_HOST_PM_SLEEP;
+ return true;
+err:
+ return false;
+}
+
+bool ipc_protocol_resume(struct iosm_protocol *ipc_protocol)
+{
+ if (!ipc_pm_prepare_host_active(&ipc_protocol->pm))
+ return false;
+
+ dev_dbg(ipc_protocol->dev, "send TARGET_HOST, EXIT_SLEEP");
+ if (ipc_protocol_msg_send_host_sleep(ipc_protocol,
+ IPC_HOST_SLEEP_EXIT_SLEEP)) {
+ ipc_protocol->pm.host_pm_state = IPC_MEM_HOST_PM_SLEEP;
+ return false;
+ }
+
+ ipc_protocol->pm.host_pm_state = IPC_MEM_HOST_PM_ACTIVE;
+
+ return true;
+}
+
+struct iosm_protocol *ipc_protocol_init(struct iosm_imem *ipc_imem)
+{
+ struct iosm_protocol *ipc_protocol =
+ kzalloc(sizeof(*ipc_protocol), GFP_KERNEL);
+ struct ipc_protocol_context_info *p_ci;
+ u64 addr;
+
+ if (!ipc_protocol)
+ return NULL;
+
+ ipc_protocol->dev = ipc_imem->dev;
+ ipc_protocol->pcie = ipc_imem->pcie;
+ ipc_protocol->imem = ipc_imem;
+ ipc_protocol->p_ap_shm = NULL;
+ ipc_protocol->phy_ap_shm = 0;
+
+ ipc_protocol->old_msg_tail = 0;
+
+ ipc_protocol->p_ap_shm =
+ pci_alloc_consistent(ipc_protocol->pcie->pci,
+ sizeof(*ipc_protocol->p_ap_shm),
+ &ipc_protocol->phy_ap_shm);
+
+ if (!ipc_protocol->p_ap_shm) {
+ dev_err(ipc_protocol->dev, "pci shm alloc error");
+ kfree(ipc_protocol);
+ return NULL;
+ }
+
+ /* Prepare the context info for CP. */
+ addr = ipc_protocol->phy_ap_shm;
+ p_ci = &ipc_protocol->p_ap_shm->ci;
+ p_ci->device_info_addr =
+ addr + offsetof(struct ipc_protocol_ap_shm, device_info);
+ p_ci->head_array =
+ addr + offsetof(struct ipc_protocol_ap_shm, head_array);
+ p_ci->tail_array =
+ addr + offsetof(struct ipc_protocol_ap_shm, tail_array);
+ p_ci->msg_head = addr + offsetof(struct ipc_protocol_ap_shm, msg_head);
+ p_ci->msg_tail = addr + offsetof(struct ipc_protocol_ap_shm, msg_tail);
+ p_ci->msg_ring_addr =
+ addr + offsetof(struct ipc_protocol_ap_shm, msg_ring);
+ p_ci->msg_ring_entries = cpu_to_le16(IPC_MEM_MSG_ENTRIES);
+ p_ci->msg_irq_vector = IPC_MSG_IRQ_VECTOR;
+ p_ci->device_info_irq_vector = IPC_DEVICE_IRQ_VECTOR;
+
+ ipc_mmio_set_contex_info_addr(ipc_imem->mmio, addr);
+
+ ipc_pm_init(ipc_protocol);
+
+ return ipc_protocol;
+}
+
+void ipc_protocol_deinit(struct iosm_protocol *proto)
+{
+ pci_free_consistent(proto->pcie->pci, sizeof(*proto->p_ap_shm),
+ proto->p_ap_shm, proto->phy_ap_shm);
+
+ ipc_pm_deinit(proto);
+ kfree(proto);
+}
diff --git a/drivers/net/wwan/iosm/iosm_ipc_protocol.h b/drivers/net/wwan/iosm/iosm_ipc_protocol.h
new file mode 100644
index 000000000000..9b3a6d86ece7
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_protocol.h
@@ -0,0 +1,237 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#ifndef IOSM_IPC_PROTOCOL_H
+#define IOSM_IPC_PROTOCOL_H
+
+#include "iosm_ipc_imem.h"
+#include "iosm_ipc_pm.h"
+#include "iosm_ipc_protocol_ops.h"
+
+/* Trigger the doorbell interrupt on CP. */
+#define IPC_DOORBELL_IRQ_HPDA 0
+#define IPC_DOORBELL_IRQ_IPC 1
+#define IPC_DOORBELL_IRQ_SLEEP 2
+
+/* IRQ vector number. */
+#define IPC_DEVICE_IRQ_VECTOR 0
+#define IPC_MSG_IRQ_VECTOR 0
+#define IPC_UL_PIPE_IRQ_VECTOR 0
+#define IPC_DL_PIPE_IRQ_VECTOR 0
+
+#define IPC_MEM_MSG_ENTRIES 128
+
+/* Default time out for sending IPC messages like open pipe, close pipe etc.
+ * during run mode.
+ *
+ * If the message interface lock to CP times out, the link to CP is broken.
+ * mode : run mode (IPC_MEM_EXEC_STAGE_RUN)
+ * unit : milliseconds
+ */
+#define IPC_MSG_COMPLETE_RUN_DEFAULT_TIMEOUT 500 /* 0.5 seconds */
+
+/* Default time out for sending IPC messages like open pipe, close pipe etc.
+ * during boot mode.
+ *
+ * If the message interface lock to CP times out, the link to CP is broken.
+ * mode : boot mode
+ * (IPC_MEM_EXEC_STAGE_BOOT | IPC_MEM_EXEC_STAGE_PSI | IPC_MEM_EXEC_STAGE_EBL)
+ * unit : milliseconds
+ */
+#define IPC_MSG_COMPLETE_BOOT_DEFAULT_TIMEOUT 500 /* 0.5 seconds */
+
+/**
+ * struct ipc_protocol_context_info - Structure of the context info
+ * @device_info_addr: 64 bit address to device info
+ * @head_array: 64 bit address to head pointer arr for the pipes
+ * @tail_array: 64 bit address to tail pointer arr for the pipes
+ * @msg_head: 64 bit address to message head pointer
+ * @msg_tail: 64 bit address to message tail pointer
+ * @msg_ring_addr: 64 bit pointer to the message ring buffer
+ * @msg_ring_entries: This field provides the number of entries which
+ * the MR can hold
+ * @msg_irq_vector: This field provides the IRQ which shall be
+ * generated by the EP device when generating
+ * completion for Messages.
+ * @device_info_irq_vector: This field provides the IRQ which shall be
+ * generated by the EP dev after updating Dev. Info
+ */
+struct ipc_protocol_context_info {
+ phys_addr_t device_info_addr;
+ phys_addr_t head_array;
+ phys_addr_t tail_array;
+ phys_addr_t msg_head;
+ phys_addr_t msg_tail;
+ phys_addr_t msg_ring_addr;
+ __le16 msg_ring_entries;
+ u8 msg_irq_vector;
+ u8 device_info_irq_vector;
+};
+
+/**
+ * struct ipc_protocol_device_info - Structure for the device information
+ * @execution_stage: CP execution stage
+ * @ipc_status: IPC states
+ * @device_sleep_notification: Requested device pm states
+ */
+struct ipc_protocol_device_info {
+ __le32 execution_stage;
+ __le32 ipc_status;
+ __le32 device_sleep_notification;
+};
+
+/**
+ * struct ipc_protocol_ap_shm - Protocol Shared Memory Structure
+ * @ci: Context information struct
+ * @device_info: Device information struct
+ * @msg_head: Point to msg head
+ * @head_array: Array of head pointer
+ * @msg_tail: Point to msg tail
+ * @tail_array: Array of tail pointer
+ * @msg_ring: Circular buffers for the read/tail and write/head
+ * indeces.
+ */
+struct ipc_protocol_ap_shm {
+ struct ipc_protocol_context_info ci;
+ struct ipc_protocol_device_info device_info;
+ __le32 msg_head;
+ __le32 head_array[IPC_MEM_MAX_PIPES];
+ __le32 msg_tail;
+ __le32 tail_array[IPC_MEM_MAX_PIPES];
+ union ipc_mem_msg_entry msg_ring[IPC_MEM_MSG_ENTRIES];
+};
+
+/**
+ * struct iosm_protocol - Structure for IPC protocol.
+ * @p_ap_shm: Pointer to Protocol Shared Memory Structure
+ * @pm: Instance to struct iosm_pm
+ * @pcie: Pointer to struct iosm_pcie
+ * @imem: Pointer to struct iosm_imem
+ * @rsp_ring: Array of OS completion objects to be triggered once CP
+ * acknowledges a request in the message ring
+ * @dev: Pointer to device structure
+ * @phy_ap_shm: Physical/Mapped representation of the shared memory info
+ * @old_msg_tail: Old msg tail ptr, until AP has handled ACK's from CP
+ */
+struct iosm_protocol {
+ struct ipc_protocol_ap_shm *p_ap_shm;
+ struct iosm_pm pm;
+ struct iosm_pcie *pcie;
+ struct iosm_imem *imem;
+ struct ipc_rsp *rsp_ring[IPC_MEM_MSG_ENTRIES];
+ struct device *dev;
+ phys_addr_t phy_ap_shm;
+ u32 old_msg_tail;
+};
+
+/**
+ * struct ipc_call_msg_send_args - Structure for message argument for
+ * tasklet function.
+ * @prep_args: Arguments for message preparation function
+ * @response: Can be NULL if result can be ignored
+ * @msg_type: Message Type
+ */
+struct ipc_call_msg_send_args {
+ union ipc_msg_prep_args *prep_args;
+ struct ipc_rsp *response;
+ enum ipc_msg_prep_type msg_type;
+};
+
+/**
+ * ipc_protocol_tq_msg_send - prepare the msg and send to CP
+ * @ipc_protocol: Pointer to ipc_protocol instance
+ * @msg_type: Message type
+ * @prep_args: Message arguments
+ * @response: Pointer to a response object which has a
+ * completion object and return code.
+ *
+ * Returns: 0 on success and failure value on error
+ */
+int ipc_protocol_tq_msg_send(struct iosm_protocol *ipc_protocol,
+ enum ipc_msg_prep_type msg_type,
+ union ipc_msg_prep_args *prep_args,
+ struct ipc_rsp *response);
+
+/**
+ * ipc_protocol_msg_send - Send ipc control message to CP and wait for response
+ * @ipc_protocol: Pointer to ipc_protocol instance
+ * @prep: Message type
+ * @prep_args: Message arguments
+ *
+ * Returns: 0 on success and failure value on error
+ */
+int ipc_protocol_msg_send(struct iosm_protocol *ipc_protocol,
+ enum ipc_msg_prep_type prep,
+ union ipc_msg_prep_args *prep_args);
+
+/**
+ * ipc_protocol_suspend - Signal to CP that host wants to go to sleep (suspend).
+ * @ipc_protocol: Pointer to ipc_protocol instance
+ *
+ * Returns: true if host can suspend, false if suspend must be aborted.
+ */
+bool ipc_protocol_suspend(struct iosm_protocol *ipc_protocol);
+
+/**
+ * ipc_protocol_s2idle_sleep - Call PM function to set PM variables in s2idle
+ * sleep/active case
+ * @ipc_protocol: Pointer to ipc_protocol instance
+ * @sleep: True for sleep/False for active
+ */
+void ipc_protocol_s2idle_sleep(struct iosm_protocol *ipc_protocol, bool sleep);
+
+/**
+ * ipc_protocol_resume - Signal to CP that host wants to resume operation.
+ * @ipc_protocol: Pointer to ipc_protocol instance
+ *
+ * Returns: true if host can resume, false if there is a problem.
+ */
+bool ipc_protocol_resume(struct iosm_protocol *ipc_protocol);
+
+/**
+ * ipc_protocol_pm_dev_sleep_handle - Handles the Device Sleep state change
+ * notification.
+ * @ipc_protocol: Pointer to ipc_protocol instance.
+ *
+ * Returns: true if sleep notification handled, false otherwise.
+ */
+bool ipc_protocol_pm_dev_sleep_handle(struct iosm_protocol *ipc_protocol);
+
+/**
+ * ipc_protocol_doorbell_trigger - Wrapper for PM function which wake up the
+ * device if it is in low power mode
+ * and trigger a head pointer update interrupt.
+ * @ipc_protocol: Pointer to ipc_protocol instance.
+ * @identifier: Specifies what component triggered hpda
+ * update irq
+ */
+void ipc_protocol_doorbell_trigger(struct iosm_protocol *ipc_protocol,
+ u32 identifier);
+
+/**
+ * ipc_protocol_sleep_notification_string - Returns last Sleep Notification as
+ * string.
+ * @ipc_protocol: Instance pointer of Protocol module.
+ *
+ * Returns: Pointer to string.
+ */
+const char *
+ipc_protocol_sleep_notification_string(struct iosm_protocol *ipc_protocol);
+
+/**
+ * ipc_protocol_init - Allocates IPC protocol instance
+ * @ipc_imem: Pointer to iosm_imem structure
+ *
+ * Returns: Address of IPC protocol instance on success & NULL on failure.
+ */
+struct iosm_protocol *ipc_protocol_init(struct iosm_imem *ipc_imem);
+
+/**
+ * ipc_protocol_deinit - Deallocates IPC protocol instance
+ * @ipc_protocol: pointer to the IPC protocol instance
+ */
+void ipc_protocol_deinit(struct iosm_protocol *ipc_protocol);
+
+#endif
--
2.25.1
