Merge tag 'platform-drivers-x86-v6.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

Pull x86 platform driver updates from Hans de Goede:

 - Microsoft Surface:
     - SSAM hot unplug support
     - Surface Pro 8 keyboard cover support
     - Tablet mode switch support for Surface Pro 8 and Surface Laptop
       Studio

 - thinkpad_acpi:
     - AMD Automatice Mode Transitions (AMT) support

 - Mellanox:
     - Vulcan chassis COMe NVSwitch management support
     - XH3000 support

 - New generic/shared Intel P2SB (Primary to Sideband) support

 - Lots of small cleanups

 - Various small bugfixes

 - Various new hardware ids / quirks additions

* tag 'platform-drivers-x86-v6.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (105 commits)
  platform/x86/intel/vsec: Fix wrong type for local status variables
  platform/x86: p2sb: Move out of X86_PLATFORM_DEVICES dependency
  platform/x86: pmc_atom: Fix comment typo
  platform/surface: gpe: Add support for 13" Intel version of Surface Laptop 4
  platform/olpc: Fix uninitialized data in debugfs write
  platform/mellanox: mlxreg-lc: Fix error flow and extend verbosity
  platform/x86: pmc_atom: Match all Lex BayTrail boards with critclk_systems DMI table
  platform/x86: sony-laptop: Remove useless comparisons in sony_pic_read_possible_resource()
  tools/power/x86/intel-speed-select: Remove unneeded semicolon
  tools/power/x86/intel-speed-select: Fix off by one check
  platform/surface: tabletsw: Fix __le32 integer access
  Documentation/ABI: Add new attributes for mlxreg-io sysfs interfaces
  Documentation/ABI: mlxreg-io: Fix contact info
  platform/mellanox: mlxreg-io: Add locking for io operations
  platform/x86: mlx-platform: Add COME board revision register
  platform/x86: mlx-platform: Add support for new system XH3000
  platform/x86: mlx-platform: Introduce support for COMe NVSwitch management module for Vulcan chassis
  platform/x86: mlx-platform: Add support for systems equipped with two ASICs
  platform/x86: mlx-platform: Add cosmetic changes for alignment
  platform/x86: mlx-platform: Make activation of some drivers conditional
  ...

1 files changed, 133 insertions, 0 deletions

diff --git a/drivers/platform/x86/p2sb.c b/drivers/platform/x86/p2sb.c
new file mode 100644
index 000000000000..fb2e141f3eb8
--- /dev/null
+++ b/drivers/platform/x86/p2sb.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Primary to Sideband (P2SB) bridge access support
+ *
+ * Copyright (c) 2017, 2021-2022 Intel Corporation.
+ *
+ * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *	    Jonathan Yong <jonathan.yong@intel.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/export.h>
+#include <linux/pci.h>
+#include <linux/platform_data/x86/p2sb.h>
+
+#include <asm/cpu_device_id.h>
+#include <asm/intel-family.h>
+
+#define P2SBC			0xe0
+#define P2SBC_HIDE		BIT(8)
+
+static const struct x86_cpu_id p2sb_cpu_ids[] = {
+	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT,	PCI_DEVFN(13, 0)),
+	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_D,	PCI_DEVFN(31, 1)),
+	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_D,	PCI_DEVFN(31, 1)),
+	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE,		PCI_DEVFN(31, 1)),
+	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE_L,		PCI_DEVFN(31, 1)),
+	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE,		PCI_DEVFN(31, 1)),
+	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_L,		PCI_DEVFN(31, 1)),
+	{}
+};
+
+static int p2sb_get_devfn(unsigned int *devfn)
+{
+	const struct x86_cpu_id *id;
+
+	id = x86_match_cpu(p2sb_cpu_ids);
+	if (!id)
+		return -ENODEV;
+
+	*devfn = (unsigned int)id->driver_data;
+	return 0;
+}
+
+static int p2sb_read_bar0(struct pci_dev *pdev, struct resource *mem)
+{
+	/* Copy resource from the first BAR of the device in question */
+	*mem = pdev->resource[0];
+	return 0;
+}
+
+static int p2sb_scan_and_read(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
+{
+	struct pci_dev *pdev;
+	int ret;
+
+	pdev = pci_scan_single_device(bus, devfn);
+	if (!pdev)
+		return -ENODEV;
+
+	ret = p2sb_read_bar0(pdev, mem);
+
+	pci_stop_and_remove_bus_device(pdev);
+	return ret;
+}
+
+/**
+ * p2sb_bar - Get Primary to Sideband (P2SB) bridge device BAR
+ * @bus: PCI bus to communicate with
+ * @devfn: PCI slot and function to communicate with
+ * @mem: memory resource to be filled in
+ *
+ * The BIOS prevents the P2SB device from being enumerated by the PCI
+ * subsystem, so we need to unhide and hide it back to lookup the BAR.
+ *
+ * if @bus is NULL, the bus 0 in domain 0 will be used.
+ * If @devfn is 0, it will be replaced by devfn of the P2SB device.
+ *
+ * Caller must provide a valid pointer to @mem.
+ *
+ * Locking is handled by pci_rescan_remove_lock mutex.
+ *
+ * Return:
+ * 0 on success or appropriate errno value on error.
+ */
+int p2sb_bar(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
+{
+	struct pci_dev *pdev_p2sb;
+	unsigned int devfn_p2sb;
+	u32 value = P2SBC_HIDE;
+	int ret;
+
+	/* Get devfn for P2SB device itself */
+	ret = p2sb_get_devfn(&devfn_p2sb);
+	if (ret)
+		return ret;
+
+	/* if @bus is NULL, use bus 0 in domain 0 */
+	bus = bus ?: pci_find_bus(0, 0);
+
+	/*
+	 * Prevent concurrent PCI bus scan from seeing the P2SB device and
+	 * removing via sysfs while it is temporarily exposed.
+	 */
+	pci_lock_rescan_remove();
+
+	/* Unhide the P2SB device, if needed */
+	pci_bus_read_config_dword(bus, devfn_p2sb, P2SBC, &value);
+	if (value & P2SBC_HIDE)
+		pci_bus_write_config_dword(bus, devfn_p2sb, P2SBC, 0);
+
+	pdev_p2sb = pci_scan_single_device(bus, devfn_p2sb);
+	if (devfn)
+		ret = p2sb_scan_and_read(bus, devfn, mem);
+	else
+		ret = p2sb_read_bar0(pdev_p2sb, mem);
+	pci_stop_and_remove_bus_device(pdev_p2sb);
+
+	/* Hide the P2SB device, if it was hidden */
+	if (value & P2SBC_HIDE)
+		pci_bus_write_config_dword(bus, devfn_p2sb, P2SBC, P2SBC_HIDE);
+
+	pci_unlock_rescan_remove();
+
+	if (ret)
+		return ret;
+
+	if (mem->flags == 0)
+		return -ENODEV;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(p2sb_bar);