[RFC,01/18] net: iosm: entry point

diff --git a/drivers/net/wwan/iosm/iosm_ipc_pcie.c b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
new file mode 100644
index 000000000000..9457e889695a
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
@@ -0,0 +1,494 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Intel Corporation.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/module.h>
+
+#include "iosm_ipc_imem.h"
+#include "iosm_ipc_pcie.h"
+
+#define DRV_AUTHOR "Intel Corporation <linuxwwan@intel.com>"
+
+MODULE_AUTHOR(DRV_AUTHOR);
+MODULE_DESCRIPTION("IOSM Driver");
+MODULE_LICENSE("GPL v2");
+
+static void ipc_pcie_resources_release(struct iosm_pcie *ipc_pcie)
+{
+	/* Free the MSI resources. */
+	ipc_release_irq(ipc_pcie);
+
+	/* Free mapped doorbell scratchpad bus memory into CPU space. */
+	iounmap(ipc_pcie->scratchpad);
+	ipc_pcie->scratchpad = NULL;
+
+	/* Free mapped IPC_REGS bus memory into CPU space. */
+	iounmap(ipc_pcie->ipc_regs);
+	ipc_pcie->ipc_regs = NULL;
+
+	/* Releases all PCI I/O and memory resources previously reserved by a
+	 * successful call to pci_request_regions.  Call this function only
+	 * after all use of the PCI regions has ceased.
+	 */
+	pci_release_regions(ipc_pcie->pci);
+}
+
+static void ipc_cleanup(struct iosm_pcie *ipc_pcie)
+{
+	struct pci_dev *pci;
+
+	pci = ipc_pcie->pci;
+
+	/* Free the shared memory resources. */
+	ipc_imem_cleanup(ipc_pcie->imem);
+
+	ipc_pcie_resources_release(ipc_pcie);
+
+	/* Signal to the system that the PCI device is not in use. */
+	if (ipc_pcie->pci)
+		pci_disable_device(pci);
+
+	/*dbg cleanup*/
+	ipc_pcie->dev = NULL;
+}
+
+static void ipc_pcie_deinit(struct iosm_pcie *ipc_pcie)
+{
+	if (ipc_pcie) {
+		kfree(ipc_pcie->imem);
+		kfree(ipc_pcie);
+	}
+}
+
+static void iosm_ipc_remove(struct pci_dev *pci)
+{
+	struct iosm_pcie *ipc_pcie = pci_get_drvdata(pci);
+
+	ipc_cleanup(ipc_pcie);
+
+	ipc_pcie_deinit(ipc_pcie);
+}
+
+static int ipc_pcie_resources_request(struct iosm_pcie *ipc_pcie)
+{
+	struct pci_dev *pci = ipc_pcie->pci;
+	u32 cap;
+	u32 ret;
+
+	/* Reserved PCI I/O and memory resources.
+	 * Mark all PCI regions associated with PCI device pci as
+	 * being reserved by owner IOSM_IPC.
+	 */
+	ret = pci_request_regions(pci, "IOSM_IPC");
+	if (ret) {
+		dev_err(ipc_pcie->dev, "failed pci request regions");
+		goto pci_request_region_fail;
+	}
+
+	/* Reserve the doorbell IPC REGS memory resources.
+	 * Remap the memory into CPU space. Arrange for the physical address
+	 * (BAR) to be visible from this driver.
+	 * pci_ioremap_bar() ensures that the memory is marked uncachable.
+	 */
+	ipc_pcie->ipc_regs = pci_ioremap_bar(pci, ipc_pcie->ipc_regs_bar_nr);
+
+	if (!ipc_pcie->ipc_regs) {
+		dev_err(ipc_pcie->dev, "IPC REGS ioremap error");
+		ret = -EBUSY;
+		goto ipc_regs_remap_fail;
+	}
+
+	/* Reserve the MMIO scratchpad memory resources.
+	 * Remap the memory into CPU space. Arrange for the physical address
+	 * (BAR) to be visible from this driver.
+	 * pci_ioremap_bar() ensures that the memory is marked uncachable.
+	 */
+	ipc_pcie->scratchpad =
+		pci_ioremap_bar(pci, ipc_pcie->scratchpad_bar_nr);
+
+	if (!ipc_pcie->scratchpad) {
+		dev_err(ipc_pcie->dev, "doorbell scratchpad ioremap error");
+		ret = -EBUSY;
+		goto scratch_remap_fail;
+	}
+
+	/* Install the irq handler triggered by CP. */
+	ret = ipc_acquire_irq(ipc_pcie);
+	if (ret) {
+		dev_err(ipc_pcie->dev, "acquiring MSI irq failed!");
+		goto irq_acquire_fail;
+	}
+
+	/* Enable bus-mastering for the IOSM IPC device. */
+	pci_set_master(pci);
+
+	/* Enable LTR if possible
+	 * This is needed for L1.2!
+	 */
+	pcie_capability_read_dword(ipc_pcie->pci, PCI_EXP_DEVCAP2, &cap);
+	if (cap & PCI_EXP_DEVCAP2_LTR)
+		pcie_capability_set_word(ipc_pcie->pci, PCI_EXP_DEVCTL2,
+					 PCI_EXP_DEVCTL2_LTR_EN);
+
+	dev_dbg(ipc_pcie->dev, "link between AP and CP is fully on");
+
+	return ret;
+
+irq_acquire_fail:
+	iounmap(ipc_pcie->scratchpad);
+	ipc_pcie->scratchpad = NULL;
+scratch_remap_fail:
+	iounmap(ipc_pcie->ipc_regs);
+	ipc_pcie->ipc_regs = NULL;
+ipc_regs_remap_fail:
+	pci_release_regions(pci);
+pci_request_region_fail:
+	return ret;
+}
+
+bool ipc_pcie_check_aspm_enabled(struct iosm_pcie *ipc_pcie,
+				 struct pci_dev *pdev)
+{
+	u32 enabled = 0;
+	u16 value = 0;
+
+	if (!ipc_pcie || !pdev)
+		return false;
+
+	pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &value);
+	enabled = value & PCI_EXP_LNKCTL_ASPMC;
+	dev_dbg(ipc_pcie->dev, "ASPM L1: 0x%04X 0x%03X", pdev->device, value);
+
+	return (enabled == PCI_EXP_LNKCTL_ASPM_L1 ||
+		enabled == PCI_EXP_LNKCTL_ASPMC);
+}
+
+bool ipc_pcie_check_data_link_active(struct iosm_pcie *ipc_pcie)
+{
+	struct pci_dev *parent;
+	u16 link_status = 0;
+
+	if (!ipc_pcie || !ipc_pcie->pci) {
+		dev_dbg(ipc_pcie->dev, "device not found");
+		return false;
+	}
+
+	if (!ipc_pcie->pci->bus || !ipc_pcie->pci->bus->self) {
+		dev_err(ipc_pcie->dev, "root port not found");
+		return false;
+	}
+
+	parent = ipc_pcie->pci->bus->self;
+
+	pcie_capability_read_word(parent, PCI_EXP_LNKSTA, &link_status);
+	dev_dbg(ipc_pcie->dev, "Link status: 0x%04X", link_status);
+
+	return link_status & PCI_EXP_LNKSTA_DLLLA;
+}
+
+static bool ipc_pcie_check_aspm_supported(struct iosm_pcie *ipc_pcie,
+					  struct pci_dev *pdev)
+{
+	u32 support = 0;
+	u32 cap = 0;
+
+	pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &cap);
+	support = u32_get_bits(cap, PCI_EXP_LNKCAP_ASPMS);
+	if (support < PCI_EXP_LNKCTL_ASPM_L1) {
+		dev_dbg(ipc_pcie->dev, "ASPM L1 not supported: 0x%04X",
+			pdev->device);
+		return false;
+	}
+	return true;
+}
+
+void ipc_pcie_config_aspm(struct iosm_pcie *ipc_pcie, struct pci_dev *pdev)
+{
+	bool parent_aspm_enabled, dev_aspm_enabled;
+	struct pci_dev *parent;
+
+	if (!pci_is_pcie(pdev)) {
+		dev_err(ipc_pcie->dev, "not a PCIe device");
+		return;
+	}
+
+	parent = pdev->bus->self;
+
+	/* check if both root port and child supports ASPM L1 */
+	if (!ipc_pcie_check_aspm_supported(ipc_pcie, parent) ||
+	    !ipc_pcie_check_aspm_supported(ipc_pcie, pdev))
+		return;
+
+	parent_aspm_enabled = ipc_pcie_check_aspm_enabled(ipc_pcie, parent);
+	dev_aspm_enabled = ipc_pcie_check_aspm_enabled(ipc_pcie, pdev);
+
+	dev_dbg(ipc_pcie->dev, "ASPM parent: %s device: %s",
+		parent_aspm_enabled ? "Enabled" : "Disabled",
+		dev_aspm_enabled ? "Enabled" : "Disabled");
+}
+
+/* Function initializes PCIe endpoint configuration */
+static void ipc_pcie_config_init(struct iosm_pcie *ipc_pcie)
+{
+	/* BAR0 is used for doorbell */
+	ipc_pcie->ipc_regs_bar_nr = IPC_DOORBELL_BAR0;
+
+	/* update HW configuration */
+	ipc_pcie->scratchpad_bar_nr = IPC_SCRATCHPAD_BAR2;
+	ipc_pcie->doorbell_reg_offset = IPC_DOORBELL_CH_OFFSET;
+	ipc_pcie->doorbell_write = IPC_WRITE_PTR_REG_0;
+	ipc_pcie->doorbell_capture = IPC_CAPTURE_PTR_REG_0;
+}
+
+/* The PCI bus has recognized the IOSM IPC device and invokes
+ * iosm_ipc_probe with the assigned resources. pci_id contains
+ * the identification, which need not be verified.
+ */
+static int iosm_ipc_probe(struct pci_dev *pci,
+			  const struct pci_device_id *pci_id)
+{
+	struct iosm_pcie *ipc_pcie;
+
+	pr_debug("Probing device 0x%X from the vendor 0x%X", pci_id->device,
+		 pci_id->vendor);
+
+	ipc_pcie = kzalloc(sizeof(*ipc_pcie), GFP_KERNEL);
+	if (!ipc_pcie)
+		goto ret_fail;
+
+	/* Initialize ipc dbg component for the PCIe device */
+	ipc_pcie->dev = &pci->dev;
+
+	/* Set the driver specific data. */
+	pci_set_drvdata(pci, ipc_pcie);
+
+	/* Save the address of the PCI device configuration. */
+	ipc_pcie->pci = pci;
+
+	/* Update platform configuration */
+	ipc_pcie_config_init(ipc_pcie);
+
+	/* Initialize the device before it is used. Ask low-level code
+	 * to enable I/O and memory. Wake up the device if it was suspended.
+	 */
+	if (pci_enable_device(pci)) {
+		dev_err(ipc_pcie->dev, "failed to enable the AP PCIe device");
+		/* If enable of PCIe device has failed then calling ipc_cleanup
+		 * will panic the system. More over ipc_cleanup() is required to
+		 * be called after ipc_imem_mount()
+		 */
+		goto pci_enable_fail;
+	}
+
+	ipc_pcie_config_aspm(ipc_pcie, pci);
+	dev_dbg(ipc_pcie->dev, "PCIe device enabled.");
+
+	if (ipc_pcie_resources_request(ipc_pcie))
+		goto resources_req_fail;
+
+	/* Establish the link to the imem layer. */
+	ipc_pcie->imem = ipc_imem_init(ipc_pcie, pci->device,
+				       ipc_pcie->scratchpad, ipc_pcie->dev);
+	if (!ipc_pcie->imem) {
+		dev_err(ipc_pcie->dev, "failed to init imem");
+		goto imem_init_fail;
+	}
+
+	clear_bit(IPC_SUSPENDED, &ipc_pcie->pm_flags);
+
+	return 0;
+
+imem_init_fail:
+	ipc_pcie_resources_release(ipc_pcie);
+resources_req_fail:
+	pci_disable_device(pci);
+pci_enable_fail:
+	ipc_pcie_deinit(ipc_pcie);
+ret_fail:
+	return -EIO;
+}
+
+static const struct pci_device_id iosm_ipc_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, INTEL_CP_DEVICE_7560_ID) },
+	{}
+};
+
+int __maybe_unused iosm_ipc_suspend(struct device *dev)
+{
+	struct iosm_pcie *ipc_pcie;
+	struct pci_dev *pdev;
+	int ret;
+
+	pdev = to_pci_dev(dev);
+
+	ipc_pcie = pci_get_drvdata(pdev);
+
+	/* Execute D3 one time. */
+	if (pdev->current_state != PCI_D0) {
+		dev_dbg(ipc_pcie->dev, "done for PM=%d", pdev->current_state);
+		return 0;
+	}
+
+	/* The HAL shall ask the shared memory layer whether D3 is allowed. */
+	ipc_imem_pm_suspend(ipc_pcie->imem);
+
+	/* Save the PCI configuration space of a device before suspending. */
+	ret = pci_save_state(pdev);
+
+	if (ret) {
+		dev_err(ipc_pcie->dev, "pci_save_state error=%d", ret);
+		return ret;
+	}
+
+	/* Set the power state of a PCI device.
+	 * Transition a device to a new power state, using the device's PCI PM
+	 * registers.
+	 */
+	ret = pci_set_power_state(pdev, PCI_D3cold);
+
+	if (ret) {
+		dev_err(ipc_pcie->dev, "pci_set_power_state error=%d", ret);
+		return ret;
+	}
+
+	set_bit(IPC_SUSPENDED, &ipc_pcie->pm_flags);
+
+	dev_dbg(ipc_pcie->dev, "SUSPEND done");
+	return 0;
+}
+
+int __maybe_unused iosm_ipc_resume(struct device *dev)
+{
+	struct iosm_pcie *ipc_pcie;
+	struct pci_dev *pdev;
+	int ret;
+
+	pdev = to_pci_dev(dev);
+
+	ipc_pcie = pci_get_drvdata(pdev);
+
+	/* Set the power state of a PCI device.
+	 * Transition a device to a new power state, using the device's PCI PM
+	 * registers.
+	 */
+	ret = pci_set_power_state(pdev, PCI_D0);
+
+	if (ret) {
+		dev_err(ipc_pcie->dev, "pci_set_power_state error=%d", ret);
+		return ret;
+	}
+
+	pci_restore_state(pdev);
+
+	clear_bit(IPC_SUSPENDED, &ipc_pcie->pm_flags);
+
+	/* The HAL shall inform the shared memory layer that the device is
+	 * active.
+	 */
+	ipc_imem_pm_resume(ipc_pcie->imem);
+
+	dev_dbg(ipc_pcie->dev, "RESUME done");
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(iosm_ipc_pm, iosm_ipc_suspend, iosm_ipc_resume);
+
+static struct pci_driver iosm_ipc_driver = {
+	.name = KBUILD_MODNAME,
+	.probe = iosm_ipc_probe,
+	.remove = iosm_ipc_remove,
+	.driver = {
+		.pm = &iosm_ipc_pm,
+	},
+	.id_table = iosm_ipc_ids,
+};
+
+module_pci_driver(iosm_ipc_driver);
+
+int ipc_pcie_addr_map(struct iosm_pcie *ipc_pcie, void *mem, size_t size,
+		      dma_addr_t *mapping, int direction)
+{
+	if (!ipc_pcie || !mapping)
+		return -EINVAL;
+
+	if (ipc_pcie->pci) {
+		*mapping = dma_map_single(&ipc_pcie->pci->dev, mem, size,
+					  direction);
+		if (dma_mapping_error(&ipc_pcie->pci->dev, *mapping)) {
+			dev_err(ipc_pcie->dev, "dma mapping failed");
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+void ipc_pcie_addr_unmap(struct iosm_pcie *ipc_pcie, size_t size,
+			 dma_addr_t mapping, int direction)
+{
+	if (!ipc_pcie || !mapping)
+		return;
+
+	if (ipc_pcie->pci)
+		dma_unmap_single(&ipc_pcie->pci->dev, mapping, size, direction);
+}
+
+struct sk_buff *ipc_pcie_alloc_local_skb(struct iosm_pcie *ipc_pcie,
+					 gfp_t flags, size_t size)
+{
+	struct sk_buff *skb;
+
+	if (!ipc_pcie || !size) {
+		dev_err(ipc_pcie->dev, "invalid pcie object or size");
+		return NULL;
+	}
+
+	skb = __netdev_alloc_skb(NULL, size, flags);
+	if (!skb)
+		return NULL;
+
+	IPC_CB(skb)->op_type = (u8)UL_DEFAULT;
+	IPC_CB(skb)->mapping = 0;
+
+	return skb;
+}
+
+struct sk_buff *ipc_pcie_alloc_skb(struct iosm_pcie *ipc_pcie, size_t size,
+				   gfp_t flags, dma_addr_t *mapping,
+				   int direction, size_t headroom)
+{
+	struct sk_buff *skb =
+		ipc_pcie_alloc_local_skb(ipc_pcie, flags, size + headroom);
+
+	if (!skb)
+		return NULL;
+
+	if (headroom)
+		skb_reserve(skb, headroom);
+
+	if (ipc_pcie_addr_map(ipc_pcie, skb->data, size, mapping, direction)) {
+		dev_kfree_skb(skb);
+		return NULL;
+	}
+
+	BUILD_BUG_ON(sizeof(*IPC_CB(skb)) > sizeof(skb->cb));
+
+	/* Store the mapping address in skb scratch pad for later usage */
+	IPC_CB(skb)->mapping = *mapping;
+	IPC_CB(skb)->direction = direction;
+	IPC_CB(skb)->len = size;
+
+	return skb;
+}
+
+void ipc_pcie_kfree_skb(struct iosm_pcie *ipc_pcie, struct sk_buff *skb)
+{
+	if (!skb)
+		return;
+
+	ipc_pcie_addr_unmap(ipc_pcie, IPC_CB(skb)->len, IPC_CB(skb)->mapping,
+			    IPC_CB(skb)->direction);
+	IPC_CB(skb)->mapping = 0;
+	dev_kfree_skb(skb);
+}
diff --git a/drivers/net/wwan/iosm/iosm_ipc_pcie.h b/drivers/net/wwan/iosm/iosm_ipc_pcie.h
new file mode 100644
index 000000000000..916c049291cc
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_pcie.h
@@ -0,0 +1,205 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (C) 2020 Intel Corporation.
+ */
+
+#ifndef IOSM_IPC_PCIE_H
+#define IOSM_IPC_PCIE_H
+
+#include <linux/device.h>
+#include <linux/pci.h>
+#include <linux/skbuff.h>
+
+#include "iosm_ipc_irq.h"
+
+/* Device ID */
+#define INTEL_CP_DEVICE_7560_ID 0x7560
+
+/* Define for BAR area usage */
+#define IPC_DOORBELL_BAR0 0
+#define IPC_SCRATCHPAD_BAR2 2
+
+/* Defines for DOORBELL registers information */
+#define IPC_DOORBELL_CH_OFFSET BIT(5)
+#define IPC_WRITE_PTR_REG_0 BIT(4)
+#define IPC_CAPTURE_PTR_REG_0 BIT(3)
+#define IPC_SUSPENDED BIT(0)
+
+/* Number of MSI used for IPC */
+#define IPC_MSI_VECTORS 1
+
+/* Total number of Maximum IPC IRQ vectors used for IPC */
+#define IPC_IRQ_VECTORS IPC_MSI_VECTORS
+
+/**
+ * struct iosm_pcie - IPC_PCIE struct.
+ * @pci:			Address of the device description
+ * @dev:			Pointer to generic device structure
+ * @ipc_regs:			Remapped CP doorbell address of the irq register
+ *				set, to fire the doorbell irq.
+ * @scratchpad:			Remapped CP scratchpad address, to send the
+ *				configuration. tuple and the IPC descriptors
+ *				to CP in the ROM phase. The config tuple
+ *				information are saved on the MSI scratchpad.
+ * @imem:			Pointer to imem data struct
+ * @ipc_regs_bar_nr:		BAR number to be used for IPC doorbell
+ * @scratchpad_bar_nr:		BAR number to be used for Scratchpad
+ * @nvec:			number of requested irq vectors
+ * @doorbell_reg_offset:	doorbell_reg_offset
+ * @doorbell_write:		doorbell write register
+ * @doorbell_capture:		doorbell capture resgister
+ * @pm_flags:			flags for the Power Management
+ */
+struct iosm_pcie {
+	struct pci_dev *pci;
+	struct device *dev;
+	void __iomem *ipc_regs;
+	void __iomem *scratchpad;
+	struct iosm_imem *imem;
+	int ipc_regs_bar_nr;
+	int scratchpad_bar_nr;
+	int nvec;
+	u32 doorbell_reg_offset;
+	u32 doorbell_write;
+	u32 doorbell_capture;
+	unsigned long pm_flags;
+};
+
+/**
+ * struct ipc_skb_cb - State definition of the socket buffer which is mapped to
+ *		       the cb field of sbk
+ * @mapping:	Store physical or IOVA mapped address of skb virtual add.
+ * @direction:	DMA direction
+ * @len:	Length of the DMA mapped region
+ * @op_type:    Expected values are defined about enum ipc_ul_usr_op.
+ */
+struct ipc_skb_cb {
+	dma_addr_t mapping;
+	int direction;
+	int len;
+	u8 op_type;
+};
+
+/**
+ * enum ipc_ul_usr_op - Control information to execute the right operation on
+ *			the user interface.
+ * @UL_USR_OP_BLOCKED:	The uplink app was blocked until CP confirms that the
+ *			uplink buffer was consumed triggered by the IRQ.
+ * @UL_MUX_OP_ADB:	In MUX mode the UL ADB shall be addedd to the free list.
+ * @UL_DEFAULT:		SKB in non muxing mode
+ */
+enum ipc_ul_usr_op {
+	UL_USR_OP_BLOCKED,
+	UL_MUX_OP_ADB,
+	UL_DEFAULT,
+};
+
+/**
+ * ipc_pcie_addr_map - Maps the kernel's virtual address to either IOVA
+ *		       address space or Physical address space, the mapping is
+ *		       stored in the skb's cb.
+ * @ipc_pcie:	Pointer to struct iosm_pcie
+ * @mem:	Skb mem containing data
+ * @size:	Data size
+ * @mapping:	Dma mapping address
+ * @direction:	Data direction
+ *
+ * Returns: 0 on success else error code
+ */
+int ipc_pcie_addr_map(struct iosm_pcie *ipc_pcie, void *mem, size_t size,
+		      dma_addr_t *mapping, int direction);
+
+/**
+ * ipc_pcie_addr_unmap - Unmaps the skb memory region from IOVA address space
+ * @ipc_pcie:	Pointer to struct iosm_pcie
+ * @size:	Data size
+ * @mapping:	Dma mapping address
+ * @direction:	Data direction
+ *
+ * Returns: 0 on success else error code
+ */
+void ipc_pcie_addr_unmap(struct iosm_pcie *ipc_pcie, size_t size,
+			 dma_addr_t mapping, int direction);
+
+/**
+ * ipc_pcie_alloc_skb - Allocate an uplink SKB for the given size.
+ *			This also re-calculates the Start and End addresses
+ *			if PCIe Address Range Check (PARC) is supported.
+ * @ipc_pcie:	Pointer to struct iosm_pcie
+ * @size:	Size of the SKB required.
+ * @flags:	Allocation flags
+ * @mapping:	Copies either mapped IOVA add. or converted Phy address
+ * @direction:	DMA data direction
+ * @headroom:	Header data offset
+ * Returns: Pointer to ipc_skb on Success, NULL on failure.
+ */
+struct sk_buff *ipc_pcie_alloc_skb(struct iosm_pcie *ipc_pcie, size_t size,
+				   gfp_t flags, dma_addr_t *mapping,
+				   int direction, size_t headroom);
+
+/**
+ * ipc_pcie_alloc_local_skb - Allocate a local SKB for the given size.
+ * @ipc_pcie:	Pointer to struct iosm_pcie
+ * @flags:	Allocation flags
+ * @size:	Size of the SKB required.
+ *
+ * Returns: Pointer to ipc_skb on Success, NULL on failure.
+ */
+struct sk_buff *ipc_pcie_alloc_local_skb(struct iosm_pcie *ipc_pcie,
+					 gfp_t flags, size_t size);
+
+/**
+ * ipc_pcie_kfree_skb - Free skb allocated by ipc_pcie_alloc_*_skb().
+ *			Using ipc_pcie_kfree_skb() could cause potential
+ *			Kernel panic if used on skb not allocated by
+ *			ipc_util_alloc_skb() function.
+ * @ipc_pcie:	Pointer to struct iosm_pcie
+ * @skb:	Pointer to the skb
+ */
+void ipc_pcie_kfree_skb(struct iosm_pcie *ipc_pcie, struct sk_buff *skb);
+
+/**
+ * ipc_pcie_check_data_link_active - Check Data Link Layer Active
+ * @ipc_pcie:	Pointer to struct iosm_pcie
+ *
+ * Returns: true if active, otherwise false
+ */
+bool ipc_pcie_check_data_link_active(struct iosm_pcie *ipc_pcie);
+
+/**
+ * iosm_ipc_suspend - Callback invoked by pm_runtime_suspend. It decrements
+ *		     the device's usage count then, carry out a suspend,
+ *		     either synchronous or asynchronous.
+ * @dev:	Pointer to struct device
+ *
+ * Returns: 0 on success else error code
+ */
+int iosm_ipc_suspend(struct device *dev);
+
+/**
+ * iosm_ipc_resume - Callback invoked by pm_runtime_resume. It increments
+ *		    the device's usage count then, carry out a suspend,
+ *		    either synchronous or asynchronous.
+ * @dev:	Pointer to struct device
+ *
+ * Returns: 0 on success else error code
+ */
+int iosm_ipc_resume(struct device *dev);
+
+/**
+ * ipc_pcie_check_aspm_enabled - Check if ASPM L1 is already enabled
+ * @ipc_pcie:			 Pointer to struct iosm_pcie
+ * @pdev:	Pointer to struct pci_dev
+ *
+ * Returns: true if ASPM is already enabled else false
+ */
+bool ipc_pcie_check_aspm_enabled(struct iosm_pcie *ipc_pcie,
+				 struct pci_dev *pdev);
+/**
+ * ipc_pcie_config_aspm - Configure ASPM L1
+ * @ipc_pcie:	Pointer to struct iosm_pcie
+ * @pdev:	Pointer to struct pci_dev
+ */
+void ipc_pcie_config_aspm(struct iosm_pcie *ipc_pcie, struct pci_dev *pdev);
+
+#endif