Commit 28a3ae4f authored by Alison Schofield's avatar Alison Schofield Committed by Dan Williams
Browse files

cxl/trace: Add an HPA to cxl_poison trace events 



When a cxl_poison trace event is reported for a region, the poisoned
Device Physical Address (DPA) can be translated to a Host Physical
Address (HPA) for consumption by user space.

Translate and add the resulting HPA to the cxl_poison trace event.
Follow the device decode logic as defined in the CXL Spec 3.0 Section
8.2.4.19.13.

If no region currently maps the poison, assign ULLONG_MAX to the
cxl_poison event hpa field.

Signed-off-by: default avatarAlison Schofield <alison.schofield@intel.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: default avatarDave Jiang <dave.jiang@intel.com>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/6d3cd726f9042a59902785b0a2cb3ddfb70e0219.1681838292.git.alison.schofield@intel.com


Tested-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent f0832a58

drivers/cxl/core/trace.c

+94 −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 <cxl.h>

#include "core.h"



#define CREATE_TRACE_POINTS

#include "trace.h"



static bool cxl_is_hpa_in_range(u64 hpa, struct cxl_region *cxlr, int pos)

{

	struct cxl_region_params *p = &cxlr->params;

	int gran = p->interleave_granularity;

	int ways = p->interleave_ways;

	u64 offset;



	/* Is the hpa within this region at all */

	if (hpa < p->res->start || hpa > p->res->end) {

		dev_dbg(&cxlr->dev,

			"Addr trans fail: hpa 0x%llx not in region\n", hpa);

		return false;

	}



	/* Is the hpa in an expected chunk for its pos(-ition) */

	offset = hpa - p->res->start;

	offset = do_div(offset, gran * ways);

	if ((offset >= pos * gran) && (offset < (pos + 1) * gran))

		return true;



	dev_dbg(&cxlr->dev,

		"Addr trans fail: hpa 0x%llx not in expected chunk\n", hpa);



	return false;

}



static u64 cxl_dpa_to_hpa(u64 dpa,  struct cxl_region *cxlr,

			  struct cxl_endpoint_decoder *cxled)

{

	u64 dpa_offset, hpa_offset, bits_upper, mask_upper, hpa;

	struct cxl_region_params *p = &cxlr->params;

	int pos = cxled->pos;

	u16 eig = 0;

	u8 eiw = 0;



	ways_to_eiw(p->interleave_ways, &eiw);

	granularity_to_eig(p->interleave_granularity, &eig);



	/*

	 * The device position in the region interleave set was removed

	 * from the offset at HPA->DPA translation. To reconstruct the

	 * HPA, place the 'pos' in the offset.

	 *

	 * The placement of 'pos' in the HPA is determined by interleave

	 * ways and granularity and is defined in the CXL Spec 3.0 Section

	 * 8.2.4.19.13 Implementation Note: Device Decode Logic

	 */



	/* Remove the dpa base */

	dpa_offset = dpa - cxl_dpa_resource_start(cxled);



	mask_upper = GENMASK_ULL(51, eig + 8);



	if (eiw < 8) {

		hpa_offset = (dpa_offset & mask_upper) << eiw;

		hpa_offset |= pos << (eig + 8);

	} else {

		bits_upper = (dpa_offset & mask_upper) >> (eig + 8);

		bits_upper = bits_upper * 3;

		hpa_offset = ((bits_upper << (eiw - 8)) + pos) << (eig + 8);

	}



	/* The lower bits remain unchanged */

	hpa_offset |= dpa_offset & GENMASK_ULL(eig + 7, 0);



	/* Apply the hpa_offset to the region base address */

	hpa = hpa_offset + p->res->start;



	if (!cxl_is_hpa_in_range(hpa, cxlr, cxled->pos))

		return ULLONG_MAX;



	return hpa;

}



u64 cxl_trace_hpa(struct cxl_region *cxlr, struct cxl_memdev *cxlmd,

		  u64 dpa)

{

	struct cxl_region_params *p = &cxlr->params;

	struct cxl_endpoint_decoder *cxled = NULL;



	for (int i = 0; i <  p->nr_targets; i++) {

		cxled = p->targets[i];

		if (cxlmd == cxled_to_memdev(cxled))

			break;

	}

	if (!cxled || cxlmd != cxled_to_memdev(cxled))

		return ULLONG_MAX;



	return cxl_dpa_to_hpa(dpa, cxlr, cxled);

}

drivers/cxl/core/trace.h

+9 −2
Original line number Diff line number Diff line
@@ -636,6 +636,8 @@ TRACE_EVENT(cxl_memory_module, 
#define cxl_poison_overflow(flags, time)				\

	(flags & CXL_POISON_FLAG_OVERFLOW ? le64_to_cpu(time) : 0)



u64 cxl_trace_hpa(struct cxl_region *cxlr, struct cxl_memdev *memdev, u64 dpa);



TRACE_EVENT(cxl_poison,



	TP_PROTO(struct cxl_memdev *cxlmd, struct cxl_region *region,
@@ -651,6 +653,7 @@ TRACE_EVENT(cxl_poison, 
		__field(u8, trace_type)

		__string(region, region)

		__field(u64, overflow_ts)

		__field(u64, hpa)

		__field(u64, dpa)

		__field(u32, dpa_length)

		__array(char, uuid, 16)
@@ -671,21 +674,25 @@ TRACE_EVENT(cxl_poison, 
		if (region) {

			__assign_str(region, dev_name(&region->dev));

			memcpy(__entry->uuid, &region->params.uuid, 16);

			__entry->hpa = cxl_trace_hpa(region, cxlmd,

						     __entry->dpa);

		} else {

			__assign_str(region, "");

			memset(__entry->uuid, 0, 16);

			__entry->hpa = ULLONG_MAX;

		}

	    ),



	TP_printk("memdev=%s host=%s serial=%lld trace_type=%s region=%s "  \

		"region_uuid=%pU dpa=0x%llx dpa_length=0x%x source=%s "     \

		"flags=%s overflow_time=%llu",

		"region_uuid=%pU hpa=0x%llx dpa=0x%llx dpa_length=0x%x "    \

		"source=%s flags=%s overflow_time=%llu",

		__get_str(memdev),

		__get_str(host),

		__entry->serial,

		show_poison_trace_type(__entry->trace_type),

		__get_str(region),

		__entry->uuid,

		__entry->hpa,

		__entry->dpa,

		__entry->dpa_length,

		show_poison_source(__entry->source),