Add helper functions to parse the CDAT table and provide a callback to
parse the sub-table. Helpers are provided for DSMAS and DSLBIS sub-table
parsing. The code is patterned after the ACPI table parsing helpers.
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
v2:
- Use local headers to handle LE instead of ACPI header
- Reduce complexity of parser function. (Jonathan)
- Directly access header type. (Jonathan)
- Simplify header ptr math. (Jonathan)
- Move parsed counter to the correct location. (Jonathan)
- Add LE to host conversion for entry length
---
drivers/cxl/core/Makefile | 1
drivers/cxl/core/cdat.c | 100 +++++++++++++++++++++++++++++++++++++++++++++
drivers/cxl/cxlpci.h | 29 +++++++++++++
3 files changed, 130 insertions(+)
create mode 100644 drivers/cxl/core/cdat.c
diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
index ca4ae31d8f57..867a8014b462 100644
--- a/drivers/cxl/core/Makefile
+++ b/drivers/cxl/core/Makefile
@@ -12,5 +12,6 @@ cxl_core-y += memdev.o
cxl_core-y += mbox.o
cxl_core-y += pci.o
cxl_core-y += hdm.o
+cxl_core-y += cdat.o
cxl_core-$(CONFIG_TRACING) += trace.o
cxl_core-$(CONFIG_CXL_REGION) += region.o
diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
new file mode 100644
index 000000000000..210f4499bddb
--- /dev/null
+++ b/drivers/cxl/core/cdat.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2023 Intel Corporation. All rights reserved. */
+#include "cxlpci.h"
+#include "cxl.h"
+
+static bool has_handler(struct cdat_subtable_proc *proc)
+{
+ return proc->handler;
+}
+
+static int call_handler(struct cdat_subtable_proc *proc,
+ struct cdat_subtable_entry *ent)
+{
+ if (has_handler(proc))
+ return proc->handler(ent->hdr, proc->arg);
+ return -EINVAL;
+}
+
+static bool cdat_is_subtable_match(struct cdat_subtable_entry *ent)
+{
+ return ent->hdr->type == ent->type;
+}
+
+static int cdat_table_parse_entries(enum cdat_type type,
+ struct cdat_header *table_header,
+ struct cdat_subtable_proc *proc)
+{
+ unsigned long table_end, entry_len;
+ struct cdat_subtable_entry entry;
+ int count = 0;
+ int rc;
+
+ if (!has_handler(proc))
+ return -EINVAL;
+
+ table_end = (unsigned long)table_header + table_header->length;
+
+ if (type >= CDAT_TYPE_RESERVED)
+ return -EINVAL;
+
+ entry.type = type;
+ entry.hdr = (struct cdat_entry_header *)(table_header + 1);
+
+ while ((unsigned long)entry.hdr < table_end) {
+ entry_len = le16_to_cpu(entry.hdr->length);
+
+ if ((unsigned long)entry.hdr + entry_len > table_end)
+ return -EINVAL;
+
+ if (entry_len == 0)
+ return -EINVAL;
+
+ if (cdat_is_subtable_match(&entry)) {
+ rc = call_handler(proc, &entry);
+ if (rc)
+ return rc;
+ count++;
+ }
+
+ entry.hdr = (struct cdat_entry_header *)((unsigned long)entry.hdr + entry_len);
+ }
+
+ return count;
+}
+
+int cdat_table_parse_dsmas(struct cdat_header *table,
+ cdat_tbl_entry_handler handler, void *arg)
+{
+ struct cdat_subtable_proc proc = {
+ .handler = handler,
+ .arg = arg,
+ };
+
+ return cdat_table_parse_entries(CDAT_TYPE_DSMAS, table, &proc);
+}
+EXPORT_SYMBOL_NS_GPL(cdat_table_parse_dsmas, CXL);
+
+int cdat_table_parse_dslbis(struct cdat_header *table,
+ cdat_tbl_entry_handler handler, void *arg)
+{
+ struct cdat_subtable_proc proc = {
+ .handler = handler,
+ .arg = arg,
+ };
+
+ return cdat_table_parse_entries(CDAT_TYPE_DSLBIS, table, &proc);
+}
+EXPORT_SYMBOL_NS_GPL(cdat_table_parse_dslbis, CXL);
+
+int cdat_table_parse_sslbis(struct cdat_header *table,
+ cdat_tbl_entry_handler handler, void *arg)
+{
+ struct cdat_subtable_proc proc = {
+ .handler = handler,
+ .arg = arg,
+ };
+
+ return cdat_table_parse_entries(CDAT_TYPE_SSLBIS, table, &proc);
+}
+EXPORT_SYMBOL_NS_GPL(cdat_table_parse_sslbis, CXL);
diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
index 0465ef963cd6..45e2f2bf5ef8 100644
--- a/drivers/cxl/cxlpci.h
+++ b/drivers/cxl/cxlpci.h
@@ -76,12 +76,34 @@ struct cdat_header {
__le32 sequence;
} __packed;
+enum cdat_type {
+ CDAT_TYPE_DSMAS = 0,
+ CDAT_TYPE_DSLBIS,
+ CDAT_TYPE_DSMSCIS,
+ CDAT_TYPE_DSIS,
+ CDAT_TYPE_DSEMTS,
+ CDAT_TYPE_SSLBIS,
+ CDAT_TYPE_RESERVED
+};
+
struct cdat_entry_header {
u8 type;
u8 reserved;
__le16 length;
} __packed;
+typedef int (*cdat_tbl_entry_handler)(struct cdat_entry_header *header, void *arg);
+
+struct cdat_subtable_proc {
+ cdat_tbl_entry_handler handler;
+ void *arg;
+};
+
+struct cdat_subtable_entry {
+ struct cdat_entry_header *hdr;
+ enum cdat_type type;
+};
+
int devm_cxl_port_enumerate_dports(struct cxl_port *port);
struct cxl_dev_state;
int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
@@ -90,4 +112,11 @@ void read_cdat_data(struct cxl_port *port);
void cxl_cor_error_detected(struct pci_dev *pdev);
pci_ers_result_t cxl_error_detected(struct pci_dev *pdev,
pci_channel_state_t state);
+
+#define cdat_table_parse(x) \
+int cdat_table_parse_##x(struct cdat_header *table, \
+ cdat_tbl_entry_handler handler, void *arg)
+cdat_table_parse(dsmas);
+cdat_table_parse(dslbis);
+cdat_table_parse(sslbis);
#endif /* __CXL_PCI_H__ */
