[Qemu-devel] [PATCH v4 10/17] spapr_drc: add spapr_drc_populate_dt()

[Michael Roth <mdroth@linux.vnet.ibm.com>]

This function handles generation of ibm,drc-* array device tree
properties to describe DRC topology to guests. This will by used
by the guest to direct RTAS calls to manage any dynamic resources
we associate with a particular DR Connector as part of
hotplug/unplug.

Since general management of boot-time device trees are handled
outside of sPAPRDRConnector, we insert these values blindly given
an FDT and offset. A mask of sPAPRDRConnector types is given to
instruct us on what types of connectors entries should be generated
for, since descriptions for different connectors may live in
different parts of the device tree.

Based on code originally written by Nathan Fontenot.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/ppc/spapr_drc.c         | 225 +++++++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/spapr_drc.h |   3 +-
 2 files changed, 227 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
index f81c6d1..b162184 100644
--- a/hw/ppc/spapr_drc.c
+++ b/hw/ppc/spapr_drc.c
@@ -501,3 +501,228 @@ sPAPRDRConnector *spapr_dr_connector_by_id(sPAPRDRConnectorType type,
             (get_type_shift(type) << DRC_INDEX_TYPE_SHIFT) |
             (id & DRC_INDEX_ID_MASK));
 }
+
+/* internal helper to gather up DRC info specific to populating DRC
+ * topology information in the device tree.
+ */
+typedef struct DRConnectorDTInfo {
+    char drc_type[64];
+    char drc_name[64];
+    uint32_t drc_index;
+    uint32_t drc_power_domain;
+} DRConnectorDTInfo;
+
+/* generate a string the describes the DRC to encode into the
+ * device tree.
+ *
+ * as documented by PAPR+ v2.7, 13.5.2.6 and C.6.1
+ */
+static void spapr_drc_get_type_str(char *buf, sPAPRDRConnectorType type)
+{
+    switch (type) {
+    case SPAPR_DR_CONNECTOR_TYPE_CPU:
+        sprintf(buf, "CPU");
+        break;
+    case SPAPR_DR_CONNECTOR_TYPE_PHB:
+        sprintf(buf, "PHB");
+        break;
+    case SPAPR_DR_CONNECTOR_TYPE_VIO:
+        sprintf(buf, "SLOT");
+        break;
+    case SPAPR_DR_CONNECTOR_TYPE_PCI:
+        sprintf(buf, "28");
+        break;
+    case SPAPR_DR_CONNECTOR_TYPE_LMB:
+        sprintf(buf, "MEM");
+        break;
+    default:
+        g_assert(false);
+    }
+}
+
+/* generate a human-readable name for a DRC to encode into the DT
+ * description. this is mainly only used within a guest in place
+ * of the unique DRC index.
+ *
+ * in the case of VIO/PCI devices, it corresponds to a
+ * "location code" that maps a logical device/function (DRC index)
+ * to a physical (or virtual in the case of VIO) location in the
+ * system by chaining together the "location label" for each
+ * encapsulating component.
+ *
+ * since this is more to do with diagnosing physical hardware
+ * issues than guest compatibility, we choose location codes/DRC
+ * names that adhere to the documented format, but avoid encoding
+ * the entire topology information into the label/code, instead
+ * just using the location codes based on the labels for the
+ * endpoints (VIO/PCI adaptor connectors), which is basically
+ * just "C" followed by an integer ID.
+ *
+ * DRC names as documented by PAPR+ v2.7, 13.5.2.4
+ * location codes as documented by PAPR+ v2.7, 12.3.1.5
+ */
+static void spapr_drc_get_name_str(char *buf,
+                                   sPAPRDRConnectorType type,
+                                   uint32_t drc_index)
+{
+    uint32_t id = drc_index & DRC_INDEX_ID_MASK;
+
+    switch (type) {
+    case SPAPR_DR_CONNECTOR_TYPE_CPU:
+        sprintf(buf, "CPU %d", id);
+        break;
+    case SPAPR_DR_CONNECTOR_TYPE_PHB:
+        sprintf(buf, "PHB %d", id);
+        break;
+    case SPAPR_DR_CONNECTOR_TYPE_VIO:
+    case SPAPR_DR_CONNECTOR_TYPE_PCI:
+        sprintf(buf, "C%d", id);
+        break;
+    case SPAPR_DR_CONNECTOR_TYPE_LMB:
+        sprintf(buf, "LMB %d", id);
+        break;
+    default:
+        g_assert(false);
+    }
+}
+
+static DRConnectorDTInfo *spapr_dr_connector_get_info(uint32_t drc_type_mask,
+                                                      unsigned int *count)
+{
+    Object *root_container;
+    ObjectProperty *prop;
+    GArray *drc_info_list = g_array_new(false, true,
+                                        sizeof(DRConnectorDTInfo));
+
+    /* aliases for all DRConnector objects will be rooted in QOM
+     * composition tree at /dr-connector
+     */
+    root_container = container_get(object_get_root(), "/dr-connector");
+
+    QTAILQ_FOREACH(prop, &root_container->properties, node) {
+        Object *obj;
+        sPAPRDRConnector *drc;
+        sPAPRDRConnectorClass *drck;
+        DRConnectorDTInfo drc_info;
+
+        if (!strstart(prop->type, "link<", NULL)) {
+            continue;
+        }
+
+        obj = object_property_get_link(root_container, prop->name, NULL);
+        drc = SPAPR_DR_CONNECTOR(obj);
+        drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+
+        if ((drc->type & drc_type_mask) == 0) {
+            continue;
+        }
+
+        drc_info.drc_index = drck->get_index(drc);
+        drc_info.drc_power_domain = -1;
+        spapr_drc_get_type_str(drc_info.drc_type, drc->type);
+        spapr_drc_get_name_str(drc_info.drc_name, drc->type,
+                               drck->get_index(drc));
+        g_array_append_val(drc_info_list, drc_info);
+    }
+
+    if (count) {
+        *count = drc_info_list->len;
+    }
+
+    /* if count is zero, free everything, including internal storage
+     * for array
+     */
+    return (DRConnectorDTInfo *)g_array_free(drc_info_list, count == 0);
+}
+
+/**
+ * spapr_drc_populate_dt
+ *
+ * @fdt: libfdt device tree
+ * @path: path in the DT to generate properties
+ * @drc_type_mask: mask of sPAPRDRConnectorType values corresponding
+ *   to the types of DRCs to generate entries for
+ *
+ * generate OF properties to describe DRC topology/indices to guests
+ *
+ * as documented in PAPR+ v2.1, 13.5.2
+ */
+int spapr_drc_populate_dt(void *fdt, int fdt_offset, uint32_t drc_type_mask)
+{
+    DRConnectorDTInfo *drc_info_list;
+    unsigned int i, count;
+    char *char_buf;
+    uint32_t *char_buf_count;
+    uint32_t *int_buf;
+    int char_buf_offset, ret;
+
+    drc_info_list =
+        spapr_dr_connector_get_info(drc_type_mask, &count);
+
+    if (!count) {
+        return 0;
+    }
+
+    int_buf = g_new0(uint32_t, count + 1);
+    int_buf[0] = cpu_to_be32(count);
+    char_buf = g_new0(char, count * 128 + sizeof(uint32_t));
+    char_buf_count = (uint32_t *)&char_buf[0];
+    *char_buf_count = cpu_to_be32(count);
+
+    /* ibm,drc-indexes */
+    for (i = 0; i < count; i++) {
+        int_buf[i + 1] = cpu_to_be32(drc_info_list[i].drc_index);
+    }
+    ret = fdt_setprop(fdt, fdt_offset, "ibm,drc-indexes", int_buf,
+                      (count + 1) * sizeof(uint32_t));
+    if (ret) {
+        fprintf(stderr, "Couldn't create ibm,drc-indexes property\n");
+        goto out;
+    }
+
+    /* ibm,drc-power-domains */
+    for (i = 0; i < count; i++) {
+        int_buf[i + 1] = cpu_to_be32(drc_info_list[i].drc_power_domain);
+    }
+    ret = fdt_setprop(fdt, fdt_offset, "ibm,drc-power-domains", int_buf,
+                      (count + 1) * sizeof(uint32_t));
+    if (ret) {
+        fprintf(stderr, "Couldn't finalize ibm,drc-power-domains property\n");
+        goto out;
+    }
+
+    /* ibm,drc-names */
+    char_buf_offset = sizeof(uint32_t);
+
+    for (i = 0; i < count; i++) {
+        strcpy(char_buf + char_buf_offset, drc_info_list[i].drc_name);
+        char_buf_offset += strlen(drc_info_list[i].drc_name) + 1;
+    }
+    ret = fdt_setprop(fdt, fdt_offset, "ibm,drc-names", char_buf,
+                      char_buf_offset);
+    if (ret) {
+        fprintf(stderr, "Couldn't finalize ibm,drc-names property\n");
+        goto out;
+    }
+
+    /* ibm,drc-types */
+    char_buf_offset = sizeof(uint32_t);
+
+    for (i = 0; i < count; i++) {
+        strcpy(char_buf + char_buf_offset, drc_info_list[i].drc_type);
+        char_buf_offset += strlen(drc_info_list[i].drc_type) + 1;
+    }
+
+    ret = fdt_setprop(fdt, fdt_offset, "ibm,drc-types", char_buf,
+                      char_buf_offset);
+    if (ret) {
+        fprintf(stderr, "Couldn't finalize ibm,drc-types property\n");
+        goto out;
+    }
+
+out:
+    g_free(int_buf);
+    g_free(char_buf);
+    g_free(drc_info_list);
+    return ret;
+}
diff --git a/include/hw/ppc/spapr_drc.h b/include/hw/ppc/spapr_drc.h
index 63ec687..5c70140 100644
--- a/include/hw/ppc/spapr_drc.h
+++ b/include/hw/ppc/spapr_drc.h
@@ -193,9 +193,10 @@ typedef struct sPAPRDRConnectorClass {
 
 sPAPRDRConnector *spapr_dr_connector_new(Object *owner,
                                          sPAPRDRConnectorType type,
-                                         uint32_t token);
+                                         uint32_t id);
 sPAPRDRConnector *spapr_dr_connector_by_index(uint32_t index);
 sPAPRDRConnector *spapr_dr_connector_by_id(sPAPRDRConnectorType type,
                                            uint32_t id);
+int spapr_drc_populate_dt(void *fdt, int fdt_offset, uint32_t drc_type_mask);
 
 #endif /* __HW_SPAPR_DRC_H__ */
-- 
1.9.1