Jonathan Cameron <jonathan.came...@huawei.com> writes:
> From: Ben Widawsky <ben.widaw...@intel.com>
>
> Per spec, timestamp appears to be a free-running counter from a value
> set by the host via the Set Timestamp command (0301h). There are
> references to the epoch, which seem like a red herring. Therefore, the
> implementation implements the timestamp as freerunning counter from the
> last value that was issued by the Set Timestamp command.
>
> Signed-off-by: Ben Widawsky <ben.widaw...@intel.com>
> Signed-off-by: Jonathan Cameron <jonathan.came...@huawei.com>
> ---
> hw/cxl/cxl-mailbox-utils.c | 53 +++++++++++++++++++++++++++++++++++++
> include/hw/cxl/cxl_device.h | 6 +++++
> 2 files changed, 59 insertions(+)
>
> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
> index 1a87846356..cea4b2a59c 100644
> --- a/hw/cxl/cxl-mailbox-utils.c
> +++ b/hw/cxl/cxl-mailbox-utils.c
> @@ -43,6 +43,9 @@ 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 */
> @@ -117,8 +120,11 @@ define_mailbox_handler_zeroed(EVENTS_GET_RECORDS, 0x20);
> define_mailbox_handler_nop(EVENTS_CLEAR_RECORDS);
> define_mailbox_handler_zeroed(EVENTS_GET_INTERRUPT_POLICY, 4);
> define_mailbox_handler_nop(EVENTS_SET_INTERRUPT_POLICY);
> +declare_mailbox_handler(TIMESTAMP_GET);
> +declare_mailbox_handler(TIMESTAMP_SET);
>
> #define IMMEDIATE_CONFIG_CHANGE (1 << 1)
> +#define IMMEDIATE_POLICY_CHANGE (1 << 3)
> #define IMMEDIATE_LOG_CHANGE (1 << 4)
>
> #define CXL_CMD(s, c, in, cel_effect) \
> @@ -129,10 +135,57 @@ static struct cxl_cmd cxl_cmd_set[256][256] = {
> CXL_CMD(EVENTS, CLEAR_RECORDS, ~0, IMMEDIATE_LOG_CHANGE),
> CXL_CMD(EVENTS, GET_INTERRUPT_POLICY, 0, 0),
> CXL_CMD(EVENTS, SET_INTERRUPT_POLICY, 4, IMMEDIATE_CONFIG_CHANGE),
> + CXL_CMD(TIMESTAMP, GET, 0, 0),
> + CXL_CMD(TIMESTAMP, SET, 8, IMMEDIATE_POLICY_CHANGE),
> };
>
> #undef CXL_CMD
>
> +/*
> + * 8.2.9.3.1
> + */
> +define_mailbox_handler(TIMESTAMP_GET)
> +{
> + struct timespec ts;
> + uint64_t delta;
> +
> + if (!cxl_dstate->timestamp.set) {
> + *(uint64_t *)cmd->payload = 0;
> + goto done;
> + }
> +
> + /* First find the delta from the last time the host set the time. */
> + clock_gettime(CLOCK_REALTIME, &ts);
Could you consider using qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)?
Otherwise by introducing a dependency on real time you'll loose the
ability to get deterministic execution via icount.
> + delta = (ts.tv_sec * NANOSECONDS_PER_SECOND + ts.tv_nsec) -
> + cxl_dstate->timestamp.last_set;
> +
> + /* Then adjust the actual time */
> + stq_le_p(cmd->payload, cxl_dstate->timestamp.host_set + delta);
> +
> +done:
> + *len = 8;
> + return CXL_MBOX_SUCCESS;
> +}
> +
> +/*
> + * 8.2.9.3.2
> + */
> +define_mailbox_handler(TIMESTAMP_SET)
> +{
> + struct timespec ts;
> +
> + clock_gettime(CLOCK_REALTIME, &ts);
> +
> + cxl_dstate->timestamp.set = true;
> + cxl_dstate->timestamp.last_set =
> + ts.tv_sec * NANOSECONDS_PER_SECOND + ts.tv_nsec;
> +
> + cxl_dstate->timestamp.host_set = le64_to_cpu(*(uint64_t *)cmd->payload);
> +
> + *len = 0;
> + return CXL_MBOX_SUCCESS;
> +}
> +
> QemuUUID cel_uuid;
>
> void cxl_process_mailbox(CXLDeviceState *cxl_dstate)
> diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
> index f88f844cb6..3dde7fb1fb 100644
> --- a/include/hw/cxl/cxl_device.h
> +++ b/include/hw/cxl/cxl_device.h
> @@ -114,6 +114,12 @@ 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;
--
Alex Bennée
