[RFC PATCH v2 2/6] cxl/core: introduce cxl_mem_report_poison()

[Shiyang Ruan]

If poison is detected(reported from cxl memdev), OS should be notified to
handle it. So, introduce this helper function for later use:
  1. translate DPA to HPA;
  2. enqueue records into memory_failure's work queue;

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
---

Currently poison injection from debugfs always create a 64-bytes-length
record, which is fine.  But the injection from qemu's QMP API:
qmp_cxl_inject_poison() could create a poison record contains big length,
which may cause many many times of calling memory_failure_queue().
Though the MEMORY_FAILURE_FIFO_SIZE is 1 << 4, it seems not enougth.

---
 drivers/cxl/core/mbox.c | 18 ++++++++++++++++++
 drivers/cxl/cxlmem.h    |  3 +++
 2 files changed, 21 insertions(+)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 9adda4795eb7..31b1b8711256 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -1290,6 +1290,24 @@ int cxl_set_timestamp(struct cxl_memdev_state *mds)
 }
 EXPORT_SYMBOL_NS_GPL(cxl_set_timestamp, CXL);
 
+void cxl_mem_report_poison(struct cxl_memdev *cxlmd,
+                          struct cxl_region *cxlr,
+                          struct cxl_poison_record *poison)
+{
+       u64 dpa = le64_to_cpu(poison->address) & CXL_POISON_START_MASK;
+       u64 len = PAGE_ALIGN(le32_to_cpu(poison->length) * CXL_POISON_LEN_MULT);
+       u64 hpa = cxl_trace_hpa(cxlr, cxlmd, dpa);
+       unsigned long pfn = PHYS_PFN(hpa);
+       unsigned long pfn_end = pfn + len / PAGE_SIZE - 1;
+
+       if (!IS_ENABLED(CONFIG_MEMORY_FAILURE))
+               return;
+
+       for (; pfn <= pfn_end; pfn++)
+               memory_failure_queue(pfn, MF_ACTION_REQUIRED);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_mem_report_poison, CXL);
+
 int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
                       struct cxl_region *cxlr)
 {
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 20fb3b35e89e..82f80eb381fb 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -828,6 +828,9 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
                            const uuid_t *uuid, union cxl_event *evt);
 int cxl_set_timestamp(struct cxl_memdev_state *mds);
 int cxl_poison_state_init(struct cxl_memdev_state *mds);
+void cxl_mem_report_poison(struct cxl_memdev *cxlmd,
+                          struct cxl_region *cxlr,
+                          struct cxl_poison_record *poison);
 int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
                       struct cxl_region *cxlr);
 int cxl_trigger_poison_list(struct cxl_memdev *cxlmd);
-- 
2.34.1