Commit b1966a1f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'cxl-fixes-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl 

Pull cxl fixes from Ira Weiny:
 "The bulk of these fixes center around an initialization order bug
  reported by Gregory Price and some additional fall out from the
  debugging effort.

  In summary, cxl_acpi and cxl_mem race and previously worked because of
  a bus_rescan_devices() while testing without modules built in.

  Unfortunately with modules built in the rescan would fail due to the
  cxl_port driver being registered late via the build order. Furthermore
  it was found bus_rescan_devices() did not guarantee a probe barrier
  which CXL was expecting. Additional fixes to cxl-test and decoder
  allocation came along as they were found in this debugging effort.

  The other fixes are pretty minor but one affects trace point data seen
  by user space.

  Summary:

   - Fix crashes when running with cxl-test code

   - Fix Trace DRAM Event Record field decodes

   - Fix module/built in initialization order errors

   - Fix use after free on decoder shutdowns

   - Fix out of order decoder allocations

   - Improve cxl-test to better reflect real world systems"

* tag 'cxl-fixes-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
  cxl/test: Improve init-order fidelity relative to real-world systems
  cxl/port: Prevent out-of-order decoder allocation
  cxl/port: Fix use-after-free, permit out-of-order decoder shutdown
  cxl/acpi: Ensure ports ready at cxl_acpi_probe() return
  cxl/port: Fix cxl_bus_rescan() vs bus_rescan_devices()
  cxl/port: Fix CXL port initialization order when the subsystem is built-in
  cxl/events: Fix Trace DRAM Event Record
  cxl/core: Return error when cxl_endpoint_gather_bandwidth() handles a non-PCI device
parents f4a1e8e3 3a2b97b3

drivers/base/core.c

+35 −0
Original line number Diff line number Diff line
@@ -4037,6 +4037,41 @@ int device_for_each_child_reverse(struct device *parent, void *data, 
}

EXPORT_SYMBOL_GPL(device_for_each_child_reverse);



/**

 * device_for_each_child_reverse_from - device child iterator in reversed order.

 * @parent: parent struct device.

 * @from: optional starting point in child list

 * @fn: function to be called for each device.

 * @data: data for the callback.

 *

 * Iterate over @parent's child devices, starting at @from, and call @fn

 * for each, passing it @data. This helper is identical to

 * device_for_each_child_reverse() when @from is NULL.

 *

 * @fn is checked each iteration. If it returns anything other than 0,

 * iteration stop and that value is returned to the caller of

 * device_for_each_child_reverse_from();

 */

int device_for_each_child_reverse_from(struct device *parent,

				       struct device *from, const void *data,

				       int (*fn)(struct device *, const void *))

{

	struct klist_iter i;

	struct device *child;

	int error = 0;



	if (!parent->p)

		return 0;



	klist_iter_init_node(&parent->p->klist_children, &i,

			     (from ? &from->p->knode_parent : NULL));

	while ((child = prev_device(&i)) && !error)

		error = fn(child, data);

	klist_iter_exit(&i);

	return error;

}

EXPORT_SYMBOL_GPL(device_for_each_child_reverse_from);



/**

 * device_find_child - device iterator for locating a particular device.

 * @parent: parent struct device

drivers/cxl/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ config CXL_ACPI 
	default CXL_BUS

	select ACPI_TABLE_LIB

	select ACPI_HMAT

	select CXL_PORT

	help

	  Enable support for host managed device memory (HDM) resources

	  published by a platform's ACPI CXL memory layout description.  See

drivers/cxl/Makefile

+14 −6
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0



# Order is important here for the built-in case:

# - 'core' first for fundamental init

# - 'port' before platform root drivers like 'acpi' so that CXL-root ports

#   are immediately enabled

# - 'mem' and 'pmem' before endpoint drivers so that memdevs are

#   immediately enabled

# - 'pci' last, also mirrors the hardware enumeration hierarchy

obj-y += core/

obj-$(CONFIG_CXL_PCI) += cxl_pci.o

obj-$(CONFIG_CXL_MEM) += cxl_mem.o

obj-$(CONFIG_CXL_PORT) += cxl_port.o

obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o

obj-$(CONFIG_CXL_PMEM) += cxl_pmem.o

obj-$(CONFIG_CXL_PORT) += cxl_port.o

obj-$(CONFIG_CXL_MEM) += cxl_mem.o

obj-$(CONFIG_CXL_PCI) += cxl_pci.o



cxl_mem-y := mem.o

cxl_pci-y := pci.o

cxl_port-y := port.o

cxl_acpi-y := acpi.o

cxl_pmem-y := pmem.o security.o

cxl_port-y := port.o
 
cxl_mem-y := mem.o

cxl_pci-y := pci.o

drivers/cxl/acpi.c

+7 −0
Original line number Diff line number Diff line
@@ -924,6 +924,13 @@ static void __exit cxl_acpi_exit(void) 


/* load before dax_hmem sees 'Soft Reserved' CXL ranges */

subsys_initcall(cxl_acpi_init);



/*

 * Arrange for host-bridge ports to be active synchronous with

 * cxl_acpi_probe() exit.

 */

MODULE_SOFTDEP("pre: cxl_port");



module_exit(cxl_acpi_exit);

MODULE_DESCRIPTION("CXL ACPI: Platform Support");

MODULE_LICENSE("GPL v2");

drivers/cxl/core/cdat.c

+3 −0
Original line number Diff line number Diff line
@@ -641,6 +641,9 @@ static int cxl_endpoint_gather_bandwidth(struct cxl_region *cxlr, 
	void *ptr;

	int rc;



	if (!dev_is_pci(cxlds->dev))

		return -ENODEV;



	if (cxlds->rcd)

		return -ENODEV;