Merge tag 'cxl-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull CXL (Compute Express Link) updates from Dan Williams:
 "The main new functionality this time is work to allow Linux to
  natively handle CXL link protocol errors signalled via PCIe AER for
  current generation CXL platforms. This required some enlightenment of
  the PCIe AER core to workaround the fact that current generation RCH
  (Restricted CXL Host) platforms physically hide topology details and
  registers via a mechanism called RCRB (Root Complex Register Block).

  The next major highlight is reworks to address bugs in parsing region
  configurations for next generation VH (Virtual Host) topologies. The
  old broken algorithm is replaced with a simpler one that significantly
  increases the number of region configurations supported by Linux. This
  is again relevant for error handling so that forward and reverse
  address translation of memory errors can be carried out by Linux for
  memory regions instantiated by platform firmware.

  As for other cross-tree work, the ACPI table parsing code has been
  refactored for reuse parsing the "CDAT" structure which is an
  ACPI-like data structure that is reported by CXL devices. That work is
  in preparation for v6.8 support for CXL QoS. Think of this as dynamic
  generation of NUMA node topology information generated by Linux rather
  than platform firmware.

  Lastly, a number of internal object lifetime issues have been resolved
  along with misc. fixes and feature updates (decoders_committed sysfs
  ABI).

  Summary:

   - Add support for RCH (Restricted CXL Host) Error recovery

   - Fix several region assembly bugs

   - Fix mem-device lifetime issues relative to the sanitize command and
     RCH topology.

   - Refactor ACPI table parsing for CDAT parsing re-use in preparation
     for CXL QOS support"

* tag 'cxl-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (50 commits)
  lib/fw_table: Remove acpi_parse_entries_array() export
  cxl/pci: Change CXL AER support check to use native AER
  cxl/hdm: Remove broken error path
  cxl/hdm: Fix && vs || bug
  acpi: Move common tables helper functions to common lib
  cxl: Add support for reading CXL switch CDAT table
  cxl: Add checksum verification to CDAT from CXL
  cxl: Export QTG ids from CFMWS to sysfs as qos_class attribute
  cxl: Add decoders_committed sysfs attribute to cxl_port
  cxl: Add cxl_decoders_committed() helper
  cxl/core/regs: Rework cxl_map_pmu_regs() to use map->dev for devm
  cxl/core/regs: Rename phys_addr in cxl_map_component_regs()
  PCI/AER: Unmask RCEC internal errors to enable RCH downstream port error handling
  PCI/AER: Forward RCH downstream port-detected errors to the CXL.mem dev handler
  cxl/pci: Disable root port interrupts in RCH mode
  cxl/pci: Add RCH downstream port error logging
  cxl/pci: Map RCH downstream AER registers for logging protocol errors
  cxl/pci: Update CXL error logging to use RAS register address
  PCI/AER: Refactor cper_print_aer() for use by CXL driver module
  cxl/pci: Add RCH downstream port AER register discovery
  ...

3 files changed, 193 insertions, 0 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index 2d90935d5a21..3ea1c830efab 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -772,3 +772,6 @@ config ASN1_ENCODER
 
 config POLYNOMIAL
        tristate
+
+config FIRMWARE_TABLE
+	bool
diff --git a/lib/Makefile b/lib/Makefile
index 13455f47f9df..6b09731d8e61 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -409,6 +409,8 @@ obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o
 
 obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
 
+obj-$(CONFIG_FIRMWARE_TABLE) += fw_table.o
+
 # FORTIFY_SOURCE compile-time behavior tests
 TEST_FORTIFY_SRCS = $(wildcard $(srctree)/$(src)/test_fortify/*-*.c)
 TEST_FORTIFY_LOGS = $(patsubst $(srctree)/$(src)/%.c, %.log, $(TEST_FORTIFY_SRCS))
diff --git a/lib/fw_table.c b/lib/fw_table.c
new file mode 100644
index 000000000000..b51f30a28e47
--- /dev/null
+++ b/lib/fw_table.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  fw_tables.c - Parsing support for ACPI and ACPI-like tables provided by
+ *                platform or device firmware
+ *
+ *  Copyright (C) 2001 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2023 Intel Corp.
+ */
+#include <linux/errno.h>
+#include <linux/fw_table.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+enum acpi_subtable_type {
+	ACPI_SUBTABLE_COMMON,
+	ACPI_SUBTABLE_HMAT,
+	ACPI_SUBTABLE_PRMT,
+	ACPI_SUBTABLE_CEDT,
+};
+
+struct acpi_subtable_entry {
+	union acpi_subtable_headers *hdr;
+	enum acpi_subtable_type type;
+};
+
+static unsigned long __init_or_acpilib
+acpi_get_entry_type(struct acpi_subtable_entry *entry)
+{
+	switch (entry->type) {
+	case ACPI_SUBTABLE_COMMON:
+		return entry->hdr->common.type;
+	case ACPI_SUBTABLE_HMAT:
+		return entry->hdr->hmat.type;
+	case ACPI_SUBTABLE_PRMT:
+		return 0;
+	case ACPI_SUBTABLE_CEDT:
+		return entry->hdr->cedt.type;
+	}
+	return 0;
+}
+
+static unsigned long __init_or_acpilib
+acpi_get_entry_length(struct acpi_subtable_entry *entry)
+{
+	switch (entry->type) {
+	case ACPI_SUBTABLE_COMMON:
+		return entry->hdr->common.length;
+	case ACPI_SUBTABLE_HMAT:
+		return entry->hdr->hmat.length;
+	case ACPI_SUBTABLE_PRMT:
+		return entry->hdr->prmt.length;
+	case ACPI_SUBTABLE_CEDT:
+		return entry->hdr->cedt.length;
+	}
+	return 0;
+}
+
+static unsigned long __init_or_acpilib
+acpi_get_subtable_header_length(struct acpi_subtable_entry *entry)
+{
+	switch (entry->type) {
+	case ACPI_SUBTABLE_COMMON:
+		return sizeof(entry->hdr->common);
+	case ACPI_SUBTABLE_HMAT:
+		return sizeof(entry->hdr->hmat);
+	case ACPI_SUBTABLE_PRMT:
+		return sizeof(entry->hdr->prmt);
+	case ACPI_SUBTABLE_CEDT:
+		return sizeof(entry->hdr->cedt);
+	}
+	return 0;
+}
+
+static enum acpi_subtable_type __init_or_acpilib
+acpi_get_subtable_type(char *id)
+{
+	if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
+		return ACPI_SUBTABLE_HMAT;
+	if (strncmp(id, ACPI_SIG_PRMT, 4) == 0)
+		return ACPI_SUBTABLE_PRMT;
+	if (strncmp(id, ACPI_SIG_CEDT, 4) == 0)
+		return ACPI_SUBTABLE_CEDT;
+	return ACPI_SUBTABLE_COMMON;
+}
+
+static __init_or_acpilib bool has_handler(struct acpi_subtable_proc *proc)
+{
+	return proc->handler || proc->handler_arg;
+}
+
+static __init_or_acpilib int call_handler(struct acpi_subtable_proc *proc,
+					  union acpi_subtable_headers *hdr,
+					  unsigned long end)
+{
+	if (proc->handler)
+		return proc->handler(hdr, end);
+	if (proc->handler_arg)
+		return proc->handler_arg(hdr, proc->arg, end);
+	return -EINVAL;
+}
+
+/**
+ * acpi_parse_entries_array - for each proc_num find a suitable subtable
+ *
+ * @id: table id (for debugging purposes)
+ * @table_size: size of the root table
+ * @table_header: where does the table start?
+ * @proc: array of acpi_subtable_proc struct containing entry id
+ *        and associated handler with it
+ * @proc_num: how big proc is?
+ * @max_entries: how many entries can we process?
+ *
+ * For each proc_num find a subtable with proc->id and run proc->handler
+ * on it. Assumption is that there's only single handler for particular
+ * entry id.
+ *
+ * The table_size is not the size of the complete ACPI table (the length
+ * field in the header struct), but only the size of the root table; i.e.,
+ * the offset from the very first byte of the complete ACPI table, to the
+ * first byte of the very first subtable.
+ *
+ * On success returns sum of all matching entries for all proc handlers.
+ * Otherwise, -ENODEV or -EINVAL is returned.
+ */
+int __init_or_acpilib
+acpi_parse_entries_array(char *id, unsigned long table_size,
+			 struct acpi_table_header *table_header,
+			 struct acpi_subtable_proc *proc,
+			 int proc_num, unsigned int max_entries)
+{
+	unsigned long table_end, subtable_len, entry_len;
+	struct acpi_subtable_entry entry;
+	int count = 0;
+	int errs = 0;
+	int i;
+
+	table_end = (unsigned long)table_header + table_header->length;
+
+	/* Parse all entries looking for a match. */
+
+	entry.type = acpi_get_subtable_type(id);
+	entry.hdr = (union acpi_subtable_headers *)
+	    ((unsigned long)table_header + table_size);
+	subtable_len = acpi_get_subtable_header_length(&entry);
+
+	while (((unsigned long)entry.hdr) + subtable_len  < table_end) {
+		if (max_entries && count >= max_entries)
+			break;
+
+		for (i = 0; i < proc_num; i++) {
+			if (acpi_get_entry_type(&entry) != proc[i].id)
+				continue;
+			if (!has_handler(&proc[i]) ||
+			    (!errs &&
+			     call_handler(&proc[i], entry.hdr, table_end))) {
+				errs++;
+				continue;
+			}
+
+			proc[i].count++;
+			break;
+		}
+		if (i != proc_num)
+			count++;
+
+		/*
+		 * If entry->length is 0, break from this loop to avoid
+		 * infinite loop.
+		 */
+		entry_len = acpi_get_entry_length(&entry);
+		if (entry_len == 0) {
+			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
+			return -EINVAL;
+		}
+
+		entry.hdr = (union acpi_subtable_headers *)
+		    ((unsigned long)entry.hdr + entry_len);
+	}
+
+	if (max_entries && count > max_entries) {
+		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
+			id, proc->id, count);
+	}
+
+	return errs ? -EINVAL : count;
+}