@@ -21,6 +21,8 @@ cxled_to_mds(struct cxl_endpoint_decoder *cxled)
return container_of(cxlds, struct cxl_memdev_state, cxlds);
}
+void cxl_process_extent_list(struct cxl_endpoint_decoder *cxled);
+
#ifdef CONFIG_CXL_REGION
extern struct device_attribute dev_attr_create_pmem_region;
extern struct device_attribute dev_attr_create_ram_region;
@@ -1697,6 +1697,111 @@ int cxl_dev_dynamic_capacity_identify(struct cxl_memdev_state *mds)
}
EXPORT_SYMBOL_NS_GPL(cxl_dev_dynamic_capacity_identify, CXL);
+/* Return -EAGAIN if the extent list changes while reading */
+static int __cxl_process_extent_list(struct cxl_endpoint_decoder *cxled)
+{
+ u32 current_index, total_read, total_expected, initial_gen_num;
+ struct cxl_memdev_state *mds = cxled_to_mds(cxled);
+ struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
+ struct device *dev = mds->cxlds.dev;
+ struct cxl_mbox_cmd mbox_cmd;
+ u32 max_extent_count;
+ bool first = true;
+
+ struct cxl_mbox_get_extent_out *extents __free(kfree) =
+ kvmalloc(cxl_mbox->payload_size, GFP_KERNEL);
+ if (!extents)
+ return -ENOMEM;
+
+ total_read = 0;
+ current_index = 0;
+ total_expected = 0;
+ max_extent_count = (cxl_mbox->payload_size - sizeof(*extents)) /
+ sizeof(struct cxl_extent);
+ do {
+ struct cxl_mbox_get_extent_in get_extent;
+ u32 nr_returned, current_total, current_gen_num;
+ int rc;
+
+ get_extent = (struct cxl_mbox_get_extent_in) {
+ .extent_cnt = max(max_extent_count,
+ total_expected - current_index),
+ .start_extent_index = cpu_to_le32(current_index),
+ };
+
+ mbox_cmd = (struct cxl_mbox_cmd) {
+ .opcode = CXL_MBOX_OP_GET_DC_EXTENT_LIST,
+ .payload_in = &get_extent,
+ .size_in = sizeof(get_extent),
+ .size_out = cxl_mbox->payload_size,
+ .payload_out = extents,
+ .min_out = 1,
+ };
+
+ rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+ if (rc < 0)
+ return rc;
+
+ /* Save initial data */
+ if (first) {
+ total_expected = le32_to_cpu(extents->total_extent_count);
+ initial_gen_num = le32_to_cpu(extents->generation_num);
+ first = false;
+ }
+
+ nr_returned = le32_to_cpu(extents->returned_extent_count);
+ total_read += nr_returned;
+ current_total = le32_to_cpu(extents->total_extent_count);
+ current_gen_num = le32_to_cpu(extents->generation_num);
+
+ dev_dbg(dev, "Got extent list %d-%d of %d generation Num:%d\n",
+ current_index, total_read - 1, current_total, current_gen_num);
+
+ if (current_gen_num != initial_gen_num || total_expected != current_total) {
+ dev_dbg(dev, "Extent list change detected; gen %u != %u : cnt %u != %u\n",
+ current_gen_num, initial_gen_num,
+ total_expected, current_total);
+ return -EAGAIN;
+ }
+
+ for (int i = 0; i < nr_returned ; i++) {
+ struct cxl_extent *extent = &extents->extent[i];
+
+ dev_dbg(dev, "Processing extent %d/%d\n",
+ current_index + i, total_expected);
+
+ rc = validate_add_extent(mds, extent);
+ if (rc)
+ continue;
+ }
+
+ current_index += nr_returned;
+ } while (total_expected > total_read);
+
+ return 0;
+}
+
+/**
+ * cxl_process_extent_list() - Read existing extents
+ * @cxled: Endpoint decoder which is part of a region
+ *
+ * Issue the Get Dynamic Capacity Extent List command to the device
+ * and add existing extents if found.
+ *
+ * A retry of 10 is somewhat arbitrary, however, extent changes should be
+ * relatively rare while bringing up a region. So 10 should be plenty.
+ */
+#define CXL_READ_EXTENT_LIST_RETRY 10
+void cxl_process_extent_list(struct cxl_endpoint_decoder *cxled)
+{
+ int retry = CXL_READ_EXTENT_LIST_RETRY;
+ int rc;
+
+ do {
+ rc = __cxl_process_extent_list(cxled);
+ } while (rc == -EAGAIN && retry--);
+}
+
static int add_dpa_res(struct device *dev, struct resource *parent,
struct resource *res, resource_size_t start,
resource_size_t size, const char *type)
@@ -3190,6 +3190,15 @@ static int devm_cxl_add_pmem_region(struct cxl_region *cxlr)
return rc;
}
+static void cxlr_add_existing_extents(struct cxl_region *cxlr)
+{
+ struct cxl_region_params *p = &cxlr->params;
+ int i;
+
+ for (i = 0; i < p->nr_targets; i++)
+ cxl_process_extent_list(p->targets[i]);
+}
+
static void cxlr_dax_unregister(void *_cxlr_dax)
{
struct cxl_dax_region *cxlr_dax = _cxlr_dax;
@@ -3224,6 +3233,9 @@ static int devm_cxl_add_dax_region(struct cxl_region *cxlr)
dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent),
dev_name(dev));
+ if (cxlr->mode == CXL_REGION_DC)
+ cxlr_add_existing_extents(cxlr);
+
return devm_add_action_or_reset(&cxlr->dev, cxlr_dax_unregister,
cxlr_dax);
err:
@@ -626,6 +626,27 @@ struct cxl_mbox_dc_response {
} __packed extent_list[];
} __packed;
+/*
+ * Get Dynamic Capacity Extent List; Input Payload
+ * CXL rev 3.1 section 8.2.9.9.9.2; Table 8-166
+ */
+struct cxl_mbox_get_extent_in {
+ __le32 extent_cnt;
+ __le32 start_extent_index;
+} __packed;
+
+/*
+ * Get Dynamic Capacity Extent List; Output Payload
+ * CXL rev 3.1 section 8.2.9.9.9.2; Table 8-167
+ */
+struct cxl_mbox_get_extent_out {
+ __le32 returned_extent_count;
+ __le32 total_extent_count;
+ __le32 generation_num;
+ u8 rsvd[4];
+ struct cxl_extent extent[];
+} __packed;
+
struct cxl_mbox_get_supported_logs {
__le16 entries;
u8 rsvd[6];