Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 190 insertions, 0 deletions

diff --git a/drivers/pci/pcie/rcec.c b/drivers/pci/pcie/rcec.c
new file mode 100644
index 0000000000..d0bcd141ac
--- /dev/null
+++ b/drivers/pci/pcie/rcec.c
@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Root Complex Event Collector Support
+ *
+ * Authors:
+ *  Sean V Kelley <sean.v.kelley@intel.com>
+ *  Qiuxu Zhuo <qiuxu.zhuo@intel.com>
+ *
+ * Copyright (C) 2020 Intel Corp.
+ */
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/pci_regs.h>
+
+#include "../pci.h"
+
+struct walk_rcec_data {
+	struct pci_dev *rcec;
+	int (*user_callback)(struct pci_dev *dev, void *data);
+	void *user_data;
+};
+
+static bool rcec_assoc_rciep(struct pci_dev *rcec, struct pci_dev *rciep)
+{
+	unsigned long bitmap = rcec->rcec_ea->bitmap;
+	unsigned int devn;
+
+	/* An RCiEP found on a different bus in range */
+	if (rcec->bus->number != rciep->bus->number)
+		return true;
+
+	/* Same bus, so check bitmap */
+	for_each_set_bit(devn, &bitmap, 32)
+		if (devn == PCI_SLOT(rciep->devfn))
+			return true;
+
+	return false;
+}
+
+static int link_rcec_helper(struct pci_dev *dev, void *data)
+{
+	struct walk_rcec_data *rcec_data = data;
+	struct pci_dev *rcec = rcec_data->rcec;
+
+	if ((pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) &&
+	    rcec_assoc_rciep(rcec, dev)) {
+		dev->rcec = rcec;
+		pci_dbg(dev, "PME & error events signaled via %s\n",
+			pci_name(rcec));
+	}
+
+	return 0;
+}
+
+static int walk_rcec_helper(struct pci_dev *dev, void *data)
+{
+	struct walk_rcec_data *rcec_data = data;
+	struct pci_dev *rcec = rcec_data->rcec;
+
+	if ((pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) &&
+	    rcec_assoc_rciep(rcec, dev))
+		rcec_data->user_callback(dev, rcec_data->user_data);
+
+	return 0;
+}
+
+static void walk_rcec(int (*cb)(struct pci_dev *dev, void *data),
+		      void *userdata)
+{
+	struct walk_rcec_data *rcec_data = userdata;
+	struct pci_dev *rcec = rcec_data->rcec;
+	u8 nextbusn, lastbusn;
+	struct pci_bus *bus;
+	unsigned int bnr;
+
+	if (!rcec->rcec_ea)
+		return;
+
+	/* Walk own bus for bitmap based association */
+	pci_walk_bus(rcec->bus, cb, rcec_data);
+
+	nextbusn = rcec->rcec_ea->nextbusn;
+	lastbusn = rcec->rcec_ea->lastbusn;
+
+	/* All RCiEP devices are on the same bus as the RCEC */
+	if (nextbusn == 0xff && lastbusn == 0x00)
+		return;
+
+	for (bnr = nextbusn; bnr <= lastbusn; bnr++) {
+		/* No association indicated (PCIe 5.0-1, 7.9.10.3) */
+		if (bnr == rcec->bus->number)
+			continue;
+
+		bus = pci_find_bus(pci_domain_nr(rcec->bus), bnr);
+		if (!bus)
+			continue;
+
+		/* Find RCiEP devices on the given bus ranges */
+		pci_walk_bus(bus, cb, rcec_data);
+	}
+}
+
+/**
+ * pcie_link_rcec - Link RCiEP devices associated with RCEC.
+ * @rcec: RCEC whose RCiEP devices should be linked.
+ *
+ * Link the given RCEC to each RCiEP device found.
+ */
+void pcie_link_rcec(struct pci_dev *rcec)
+{
+	struct walk_rcec_data rcec_data;
+
+	if (!rcec->rcec_ea)
+		return;
+
+	rcec_data.rcec = rcec;
+	rcec_data.user_callback = NULL;
+	rcec_data.user_data = NULL;
+
+	walk_rcec(link_rcec_helper, &rcec_data);
+}
+
+/**
+ * pcie_walk_rcec - Walk RCiEP devices associating with RCEC and call callback.
+ * @rcec:	RCEC whose RCiEP devices should be walked
+ * @cb:		Callback to be called for each RCiEP device found
+ * @userdata:	Arbitrary pointer to be passed to callback
+ *
+ * Walk the given RCEC. Call the callback on each RCiEP found.
+ *
+ * If @cb returns anything other than 0, break out.
+ */
+void pcie_walk_rcec(struct pci_dev *rcec, int (*cb)(struct pci_dev *, void *),
+		    void *userdata)
+{
+	struct walk_rcec_data rcec_data;
+
+	if (!rcec->rcec_ea)
+		return;
+
+	rcec_data.rcec = rcec;
+	rcec_data.user_callback = cb;
+	rcec_data.user_data = userdata;
+
+	walk_rcec(walk_rcec_helper, &rcec_data);
+}
+
+void pci_rcec_init(struct pci_dev *dev)
+{
+	struct rcec_ea *rcec_ea;
+	u32 rcec, hdr, busn;
+	u8 ver;
+
+	/* Only for Root Complex Event Collectors */
+	if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_EC)
+		return;
+
+	rcec = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_RCEC);
+	if (!rcec)
+		return;
+
+	rcec_ea = kzalloc(sizeof(*rcec_ea), GFP_KERNEL);
+	if (!rcec_ea)
+		return;
+
+	pci_read_config_dword(dev, rcec + PCI_RCEC_RCIEP_BITMAP,
+			      &rcec_ea->bitmap);
+
+	/* Check whether RCEC BUSN register is present */
+	pci_read_config_dword(dev, rcec, &hdr);
+	ver = PCI_EXT_CAP_VER(hdr);
+	if (ver >= PCI_RCEC_BUSN_REG_VER) {
+		pci_read_config_dword(dev, rcec + PCI_RCEC_BUSN, &busn);
+		rcec_ea->nextbusn = PCI_RCEC_BUSN_NEXT(busn);
+		rcec_ea->lastbusn = PCI_RCEC_BUSN_LAST(busn);
+	} else {
+		/* Avoid later ver check by setting nextbusn */
+		rcec_ea->nextbusn = 0xff;
+		rcec_ea->lastbusn = 0x00;
+	}
+
+	dev->rcec_ea = rcec_ea;
+}
+
+void pci_rcec_exit(struct pci_dev *dev)
+{
+	kfree(dev->rcec_ea);
+	dev->rcec_ea = NULL;
+}