Merge tag 'platform-drivers-x86-v5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

Pull x86 platform driver updates from Hans de Goede:
  "New drivers:
    - AMD Host System Management Port (HSMP)
    - Intel Software Defined Silicon

  Removed drivers (functionality folded into other drivers):
    - intel_cht_int33fe_microb
    - surface3_button

  amd-pmc:
    - s2idle bug-fixes
    - Support for AMD Spill to DRAM STB feature

  hp-wmi:
    - Fix SW_TABLET_MODE detection method (and other fixes)
    - Support omen thermal profile policy v1

  serial-multi-instantiate:
    - Add SPI device support
    - Add support for CS35L41 amplifiers used in new laptops

  think-lmi:
    - syfs-class-firmware-attributes Certificate authentication support

  thinkpad_acpi:
    - Fixes + quirks
    - Add platform_profile support on AMD based ThinkPads

  x86-android-tablets:
    - Improve Asus ME176C / TF103C support
    - Support Nextbook Ares 8, Lenovo Tab 2 830 and 1050 tablets

  Lots of various other small fixes and hardware-id additions"

* tag 'platform-drivers-x86-v5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (60 commits)
  platform/x86: think-lmi: Certificate authentication support
  Documentation: syfs-class-firmware-attributes: Lenovo Certificate support
  platform/x86: amd-pmc: Only report STB errors when STB enabled
  platform/x86: amd-pmc: Drop CPU QoS workaround
  platform/x86: amd-pmc: Output error codes in messages
  platform/x86: amd-pmc: Move to later in the suspend process
  ACPI / x86: Add support for LPS0 callback handler
  platform/x86: thinkpad_acpi: consistently check fan_get_status return.
  platform/x86: hp-wmi: support omen thermal profile policy v1
  platform/x86: hp-wmi: Changing bios_args.data to be dynamically allocated
  platform/x86: hp-wmi: Fix 0x05 error code reported by several WMI calls
  platform/x86: hp-wmi: Fix SW_TABLET_MODE detection method
  platform/x86: hp-wmi: Fix hp_wmi_read_int() reporting error (0x05)
  platform/x86: amd-pmc: Validate entry into the deepest state on resume
  platform/x86: thinkpad_acpi: Don't use test_bit on an integer
  platform/x86: thinkpad_acpi: Fix compiler warning about uninitialized err variable
  platform/x86: thinkpad_acpi: clean up dytc profile convert
  platform/x86: x86-android-tablets: Depend on EFI and SPI
  platform/x86: amd-pmc: uninitialized variable in amd_pmc_s2d_init()
  platform/x86: intel-uncore-freq: fix uncore_freq_common_init() error codes
  ...

2 files changed, 87 insertions, 0 deletions

diff --git a/Documentation/x86/amd_hsmp.rst b/Documentation/x86/amd_hsmp.rst
new file mode 100644
index 000000000000..440e4b645a1c
--- /dev/null
+++ b/Documentation/x86/amd_hsmp.rst
@@ -0,0 +1,86 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================================
+AMD HSMP interface
+============================================
+
+Newer Fam19h EPYC server line of processors from AMD support system
+management functionality via HSMP (Host System Management Port).
+
+The Host System Management Port (HSMP) is an interface to provide
+OS-level software with access to system management functions via a
+set of mailbox registers.
+
+More details on the interface can be found in chapter
+"7 Host System Management Port (HSMP)" of the family/model PPR
+Eg: https://www.amd.com/system/files/TechDocs/55898_B1_pub_0.50.zip
+
+HSMP interface is supported on EPYC server CPU models only.
+
+
+HSMP device
+============================================
+
+amd_hsmp driver under the drivers/platforms/x86/ creates miscdevice
+/dev/hsmp to let user space programs run hsmp mailbox commands.
+
+$ ls -al /dev/hsmp
+crw-r--r-- 1 root root 10, 123 Jan 21 21:41 /dev/hsmp
+
+Characteristics of the dev node:
+ * Write mode is used for running set/configure commands
+ * Read mode is used for running get/status monitor commands
+
+Access restrictions:
+ * Only root user is allowed to open the file in write mode.
+ * The file can be opened in read mode by all the users.
+
+In-kernel integration:
+ * Other subsystems in the kernel can use the exported transport
+   function hsmp_send_message().
+ * Locking across callers is taken care by the driver.
+
+
+An example
+==========
+
+To access hsmp device from a C program.
+First, you need to include the headers::
+
+  #include <linux/amd_hsmp.h>
+
+Which defines the supported messages/message IDs.
+
+Next thing, open the device file, as follows::
+
+  int file;
+
+  file = open("/dev/hsmp", O_RDWR);
+  if (file < 0) {
+    /* ERROR HANDLING; you can check errno to see what went wrong */
+    exit(1);
+  }
+
+The following IOCTL is defined:
+
+``ioctl(file, HSMP_IOCTL_CMD, struct hsmp_message *msg)``
+  The argument is a pointer to a::
+
+    struct hsmp_message {
+    	__u32	msg_id;				/* Message ID */
+    	__u16	num_args;			/* Number of input argument words in message */
+    	__u16	response_sz;			/* Number of expected output/response words */
+    	__u32	args[HSMP_MAX_MSG_LEN];		/* argument/response buffer */
+    	__u16	sock_ind;			/* socket number */
+    };
+
+The ioctl would return a non-zero on failure; you can read errno to see
+what happened. The transaction returns 0 on success.
+
+More details on the interface and message definitions can be found in chapter
+"7 Host System Management Port (HSMP)" of the respective family/model PPR
+eg: https://www.amd.com/system/files/TechDocs/55898_B1_pub_0.50.zip
+
+User space C-APIs are made available by linking against the esmi library,
+which is provided by the E-SMS project https://developer.amd.com/e-sms/.
+See: https://github.com/amd/esmi_ib_library
diff --git a/Documentation/x86/index.rst b/Documentation/x86/index.rst
index 982c8af853b9..91b2fa456618 100644
--- a/Documentation/x86/index.rst
+++ b/Documentation/x86/index.rst
@@ -25,6 +25,7 @@ x86-specific Documentation
    intel-iommu
    intel_txt
    amd-memory-encryption
+   amd_hsmp
    pti
    mds
    microcode