LinuxKPI: extend pci.h by various functions for wireless driver

Add dummy functions for dealing with "HotPlug" events which we currently
do not support.

Add pci_dev_get(), pci_find_ext_capability() and pci_pme_capable().

The added pcie_find_root_port() is a bit special as we need to create
another linux pci device;  for that make lkpinew_pci_dev() public
which is also helpful for other cases when we want to use the Linux
routines to check for device identifiers only and need a container
for the "bsddev" to use natively.  This has proven to avoid basic
checking code for the sake of rewriting it to native field names
elsewhere.  Given we cache the newly created "root" we also need to
make sure we clean it up.

Sponsored by:	The FreeBSD Foundation
Reviewed by:	hselasky
Differential Revision: https://reviews.freebsd.org/D30521

(cherry picked from commit 8e106c5230c1f0683ffc473db5c2e0d01b2bfeea)

2 files changed, 93 insertions, 1 deletions

diff --git a/sys/compat/linuxkpi/common/include/linux/pci.h b/sys/compat/linuxkpi/common/include/linux/pci.h
index 36a82e81b4bc..b8a801ac9f70 100644
--- a/sys/compat/linuxkpi/common/include/linux/pci.h
+++ b/sys/compat/linuxkpi/common/include/linux/pci.h
@@ -221,6 +221,7 @@ struct pci_dev {
 	struct list_head	links;
 	struct pci_driver	*pdrv;
 	struct pci_bus		*bus;
+	struct pci_dev		*root;
 	uint16_t		device;
 	uint16_t		vendor;
 	uint16_t		subsystem_vendor;
@@ -236,6 +237,10 @@ struct pci_dev {
 	TAILQ_HEAD(, pci_mmio_region)	mmio;
 };
 
+/* Internal helper function(s). */
+struct pci_dev *lkpinew_pci_dev(device_t);
+
+
 static inline struct resource_list_entry *
 linux_pci_get_rle(struct pci_dev *pdev, int type, int rid)
 {
@@ -327,6 +332,15 @@ pci_set_drvdata(struct pci_dev *pdev, void *data)
 	dev_set_drvdata(&pdev->dev, data);
 }
 
+static inline struct pci_dev *
+pci_dev_get(struct pci_dev *pdev)
+{
+
+	if (pdev != NULL)
+		get_device(&pdev->dev);
+	return (pdev);
+}
+
 static __inline void
 pci_dev_put(struct pci_dev *pdev)
 {
@@ -497,6 +511,48 @@ static inline int pci_pcie_cap(struct pci_dev *dev)
 }
 
 static inline int
+pci_find_ext_capability(struct pci_dev *pdev, int capid)
+{
+	int reg;
+
+	if (pci_find_extcap(pdev->dev.bsddev, capid, &reg))
+		return (0);
+	return (reg);
+}
+
+#define	PCIM_PCAP_PME_SHIFT	11
+static __inline bool
+pci_pme_capable(struct pci_dev *pdev, uint32_t flag)
+{
+	struct pci_devinfo *dinfo;
+	pcicfgregs *cfg;
+
+	if (flag > (PCIM_PCAP_D3PME_COLD >> PCIM_PCAP_PME_SHIFT))
+		return (false);
+
+	dinfo = device_get_ivars(pdev->dev.bsddev);
+	cfg = &dinfo->cfg;
+
+	if (cfg->pp.pp_cap == 0)
+		return (false);
+
+	if ((cfg->pp.pp_cap & (1 << (PCIM_PCAP_PME_SHIFT + flag))) != 0)
+		return (true);
+
+	return (false);
+}
+
+static inline int
+pci_disable_link_state(struct pci_dev *pdev, uint32_t flags)
+{
+
+	if (!pci_enable_aspm)
+		return (-EPERM);
+
+	return (-ENXIO);
+}
+
+static inline int
 pci_read_config_byte(struct pci_dev *pdev, int where, u8 *val)
 {
 
@@ -1052,6 +1108,38 @@ pcie_bandwidth_available(struct pci_dev *pdev,
 	return (nwidth * PCIE_SPEED2MBS_ENC(nspeed));
 }
 
+static inline struct pci_dev *
+pcie_find_root_port(struct pci_dev *pdev)
+{
+	device_t root;
+
+	if (pdev->root != NULL)
+		return (pdev->root);
+
+	root = pci_find_pcie_root_port(pdev->dev.bsddev);
+	if (root == NULL)
+		return (NULL);
+
+	pdev->root = lkpinew_pci_dev(root);
+	return (pdev->root);
+}
+
+/* This is needed when people rip out the device "HotPlug". */
+static inline void
+pci_lock_rescan_remove(void)
+{
+}
+
+static inline void
+pci_unlock_rescan_remove(void)
+{
+}
+
+static __inline void
+pci_stop_and_remove_bus_device(struct pci_dev *pdev)
+{
+}
+
 /*
  * The following functions can be used to attach/detach the LinuxKPI's
  * PCI device runtime. The pci_driver and pci_device_id pointer is
diff --git a/sys/compat/linuxkpi/common/src/linux_pci.c b/sys/compat/linuxkpi/common/src/linux_pci.c
index 7aa159600faa..030951175a42 100644
--- a/sys/compat/linuxkpi/common/src/linux_pci.c
+++ b/sys/compat/linuxkpi/common/src/linux_pci.c
@@ -243,11 +243,13 @@ lkpinew_pci_dev_release(struct device *dev)
 	struct pci_dev *pdev;
 
 	pdev = to_pci_dev(dev);
+	if (pdev->root != NULL)
+		pci_dev_put(pdev->root);
 	free(pdev->bus, M_DEVBUF);
 	free(pdev, M_DEVBUF);
 }
 
-static struct pci_dev *
+struct pci_dev *
 lkpinew_pci_dev(device_t dev)
 {
 	struct pci_dev *pdev;
@@ -408,6 +410,8 @@ linux_pci_detach_device(struct pci_dev *pdev)
 	if (pdev->pdrv != NULL)
 		pdev->pdrv->remove(pdev);
 
+	if (pdev->root != NULL)
+		pci_dev_put(pdev->root);
 	free(pdev->bus, M_DEVBUF);
 	linux_pdev_dma_uninit(pdev);