Commit cc2a4878 authored by Dan Williams's avatar Dan Williams
Browse files

cxl/mem: Add a debugfs version of 'iomem' for DPA, 'dpamem' 



Dump the device-physical-address map for a CXL expander in /proc/iomem
style format. E.g.:

  cat /sys/kernel/debug/cxl/mem1/dpamem
  00000000-0fffffff : ram
  10000000-1fffffff : pmem

Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165603885318.551046.8308248564880066726.stgit@dwillia2-xfh


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 9b99ecf5

drivers/cxl/core/hdm.c

+25 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Copyright(c) 2022 Intel Corporation. All rights reserved. */

#include <linux/io-64-nonatomic-hi-lo.h>

#include <linux/seq_file.h>

#include <linux/device.h>

#include <linux/delay.h>
@@ -16,6 +17,8 @@ 
 * for enumerating these registers and capabilities.

 */



static DECLARE_RWSEM(cxl_dpa_rwsem);



static int add_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,

			   int *target_map)

{
@@ -128,6 +131,28 @@ struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port) 
}

EXPORT_SYMBOL_NS_GPL(devm_cxl_setup_hdm, CXL);



static void __cxl_dpa_debug(struct seq_file *file, struct resource *r, int depth)

{

	unsigned long long start = r->start, end = r->end;



	seq_printf(file, "%*s%08llx-%08llx : %s\n", depth * 2, "", start, end,

		   r->name);

}



void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds)

{

	struct resource *p1, *p2;



	down_read(&cxl_dpa_rwsem);

	for (p1 = cxlds->dpa_res.child; p1; p1 = p1->sibling) {

		__cxl_dpa_debug(file, p1, 0);

		for (p2 = p1->child; p2; p2 = p2->sibling)

			__cxl_dpa_debug(file, p2, 1);

	}

	up_read(&cxl_dpa_rwsem);

}

EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, CXL);



static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,

			    int *target_map, void __iomem *hdm, int which)

{

drivers/cxl/core/port.c

+1 −0
Original line number Diff line number Diff line
@@ -1506,6 +1506,7 @@ struct dentry *cxl_debugfs_create_dir(const char *dir) 
{

	return debugfs_create_dir(dir, cxl_debugfs);

}

EXPORT_SYMBOL_NS_GPL(cxl_debugfs_create_dir, CXL);



static __init int cxl_core_init(void)

{

drivers/cxl/cxlmem.h

+4 −0
Original line number Diff line number Diff line
@@ -372,4 +372,8 @@ struct cxl_hdm { 
	unsigned int interleave_mask;

	struct cxl_port *port;

};



struct seq_file;

struct dentry *cxl_debugfs_create_dir(const char *dir);

void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds);

#endif /* __CXL_MEM_H__ */

drivers/cxl/mem.c

+23 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Copyright(c) 2022 Intel Corporation. All rights reserved. */

#include <linux/debugfs.h>

#include <linux/device.h>

#include <linux/module.h>

#include <linux/pci.h>
@@ -56,10 +57,26 @@ static void enable_suspend(void *data) 
	cxl_mem_active_dec();

}



static void remove_debugfs(void *dentry)

{

	debugfs_remove_recursive(dentry);

}



static int cxl_mem_dpa_show(struct seq_file *file, void *data)

{

	struct device *dev = file->private;

	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);



	cxl_dpa_debug(file, cxlmd->cxlds);



	return 0;

}



static int cxl_mem_probe(struct device *dev)

{

	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);

	struct cxl_port *parent_port;

	struct dentry *dentry;

	int rc;



	/*
@@ -73,6 +90,12 @@ static int cxl_mem_probe(struct device *dev) 
	if (work_pending(&cxlmd->detach_work))

		return -EBUSY;



	dentry = cxl_debugfs_create_dir(dev_name(dev));

	debugfs_create_devm_seqfile(dev, "dpamem", dentry, cxl_mem_dpa_show);

	rc = devm_add_action_or_reset(dev, remove_debugfs, dentry);

	if (rc)

		return rc;



	rc = devm_cxl_enumerate_ports(cxlmd);

	if (rc)

		return rc;