hw/cxl/device: Timestamp implementation (8.2.9.3)

Errata F4 to CXL 2.0 clarified the meaning of the timer as the
sum of the value set with the timestamp set command and the number
of nano seconds since it was last set.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220429144110.25167-10-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index fb1f53f48e0d59453b69644f7fe26f360ae9bb66..4584aa31f71429f323e0497ba3c1b05b8b3bae19 100644 (file)
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -44,6 +44,9 @@ enum {
         #define CLEAR_RECORDS   0x1
         #define GET_INTERRUPT_POLICY   0x2
         #define SET_INTERRUPT_POLICY   0x3
+    TIMESTAMP   = 0x03,
+        #define GET           0x0
+        #define SET           0x1
 };
 
 /* 8.2.8.4.5.1 Command Return Codes */
@@ -106,9 +109,46 @@ DEFINE_MAILBOX_HANDLER_NOP(events_clear_records);
 DEFINE_MAILBOX_HANDLER_ZEROED(events_get_interrupt_policy, 4);
 DEFINE_MAILBOX_HANDLER_NOP(events_set_interrupt_policy);
 
+/* 8.2.9.3.1 */
+static ret_code cmd_timestamp_get(struct cxl_cmd *cmd,
+                                  CXLDeviceState *cxl_dstate,
+                                  uint16_t *len)
+{
+    uint64_t time, delta;
+    uint64_t final_time = 0;
+
+    if (cxl_dstate->timestamp.set) {
+        /* First find the delta from the last time the host set the time. */
+        time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+        delta = time - cxl_dstate->timestamp.last_set;
+        final_time = cxl_dstate->timestamp.host_set + delta;
+    }
+
+    /* Then adjust the actual time */
+    stq_le_p(cmd->payload, final_time);
+    *len = 8;
+
+    return CXL_MBOX_SUCCESS;
+}
+
+/* 8.2.9.3.2 */
+static ret_code cmd_timestamp_set(struct cxl_cmd *cmd,
+                                  CXLDeviceState *cxl_dstate,
+                                  uint16_t *len)
+{
+    cxl_dstate->timestamp.set = true;
+    cxl_dstate->timestamp.last_set = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+
+    cxl_dstate->timestamp.host_set = le64_to_cpu(*(uint64_t *)cmd->payload);
+
+    *len = 0;
+    return CXL_MBOX_SUCCESS;
+}
+
 static QemuUUID cel_uuid;
 
 #define IMMEDIATE_CONFIG_CHANGE (1 << 1)
+#define IMMEDIATE_POLICY_CHANGE (1 << 3)
 #define IMMEDIATE_LOG_CHANGE (1 << 4)
 
 static struct cxl_cmd cxl_cmd_set[256][256] = {
@@ -120,6 +160,8 @@ static struct cxl_cmd cxl_cmd_set[256][256] = {
         cmd_events_get_interrupt_policy, 0, 0 },
     [EVENTS][SET_INTERRUPT_POLICY] = { "EVENTS_SET_INTERRUPT_POLICY",
         cmd_events_set_interrupt_policy, 4, IMMEDIATE_CONFIG_CHANGE },
+    [TIMESTAMP][GET] = { "TIMESTAMP_GET", cmd_timestamp_get, 0, 0 },
+    [TIMESTAMP][SET] = { "TIMESTAMP_SET", cmd_timestamp_set, 8, IMMEDIATE_POLICY_CHANGE },
 };
 
 void cxl_process_mailbox(CXLDeviceState *cxl_dstate)

diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
index 954205653e917c7bbdc71241332538f050ed1fc8..797a22ddb483b234c3184d957811f1741f226994 100644 (file)
--- a/include/hw/cxl/cxl_device.h
+++ b/include/hw/cxl/cxl_device.h
@@ -111,6 +111,12 @@ typedef struct cxl_device_state {
         size_t cel_size;
     };
 
+    struct {
+        bool set;
+        uint64_t last_set;
+        uint64_t host_set;
+    } timestamp;
+
     /* memory region for persistent memory, HDM */
     uint64_t pmem_size;
 } CXLDeviceState;