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: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/6d3cd726f9042a59902785b0a2cb3ddfb70e0219.1681838292.git.alison.schofield@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/cxl/core/trace.c b/drivers/cxl/core/trace.c
index 29ae7ce..d0403dc 100644 (file)
--- a/drivers/cxl/core/trace.c
+++ b/drivers/cxl/core/trace.c
@@ -1,5 +1,99 @@
 // 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);
+}

diff --git a/drivers/cxl/core/trace.h b/drivers/cxl/core/trace.h
index 17c24ba..220cc7e 100644 (file)
--- a/drivers/cxl/core/trace.h
+++ b/drivers/cxl/core/trace.h
@@ -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),