[U-Boot] [PATCH v4 5/8] x86: slimbootloader: Set TSC information for timer driver

[Park, Aiden]

Slim Bootloader provides TSC clock information in its performance
info hob. For now, TSC clock information is only used for timer driver
from the performance info hob.
- Get TSC frequency from performance info hob
- Set tsc_base and clock_rate for timer driver

Signed-off-by: Aiden Park <aiden.park at intel.com>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
---

Changes in v3:
  * Use HOB function from the common HOB library

 arch/x86/cpu/slimbootloader/slimbootloader.c  | 34 +++++++++++++++++++
 .../asm/arch-slimbootloader/slimbootloader.h  | 30 ++++++++++++++++
 2 files changed, 64 insertions(+)

diff --git a/arch/x86/cpu/slimbootloader/slimbootloader.c b/arch/x86/cpu/slimbootloader/slimbootloader.c
index 9f3a61ec61..2153d2ac66 100644
--- a/arch/x86/cpu/slimbootloader/slimbootloader.c
+++ b/arch/x86/cpu/slimbootloader/slimbootloader.c
@@ -4,9 +4,43 @@
  */

 #include <common.h>
+#include <asm/arch/slimbootloader.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * This sets tsc_base and clock_rate for early_timer and tsc_timer.
+ * The performance info guid hob has all performance timestamp data, but
+ * the only tsc frequency info is used for the timer driver for now.
+ */
+static void tsc_init(void)
+{
+       struct performance_info *data = NULL;
+       const struct efi_guid guid = LOADER_PERFORMANCE_INFO_GUID;
+
+       if (!gd->arch.hob_list)
+               panic("hob list not found!");
+
+       gd->arch.tsc_base = rdtsc();
+       debug("tsc_base=0x%llx\n", gd->arch.tsc_base);
+
+       data = (struct performance_info *)
+               hob_get_guid_hob_data(gd->arch.hob_list, NULL, &guid);
+
+       if (!data) {
+               debug("performance info hob not found\n");
+               return;
+       }
+
+       /* frequency is in KHz, so to Hz */
+       gd->arch.clock_rate = data->frequency * 1000;
+       debug("freq=0x%lx\n", gd->arch.clock_rate);
+}

 int arch_cpu_init(void)
 {
+       tsc_init();
+
        return x86_cpu_init_f();
 }

diff --git a/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h b/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h
index 5a0994544a..e0edbdddf5 100644
--- a/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h
+++ b/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h
@@ -27,6 +27,15 @@
        { 0xbb, 0x98, 0x95, 0x8d, 0x62, 0xde, 0x87, 0xf1 } \
        }

+/**
+ * A GUID to get boot performance info hob which is provided by Slim Bootloader
+ */
+#define LOADER_PERFORMANCE_INFO_GUID \
+       { \
+       0x868204be, 0x23d0, 0x4ff9, \
+       { 0xac, 0x34, 0xb9, 0x95, 0xac, 0x04, 0xb1, 0xb9 } \
+       }
+
 /**
  * A single entry of memory map information
  *
@@ -71,6 +80,27 @@ struct serial_port_info {
        u32     rsvd1;
 } __packed;

+/**
+ * This includes timestamp data which has been collected in Slim Bootloader
+ * stages from the reset vector. In addition, this has TSC frequency in KHz to
+ * calculate each timestamp.
+ *
+ * @rev   : revision of performance_info structure. currently 1.
+ * @rsvd  : padding for alignment
+ * @count : the number of collected timestamp data
+ * @flags : only used in Slim Bootloader
+ * @frequency: tsc frequency in KHz
+ * @timestamp: the array of timestamp data which has 64-bit tsc value
+ */
+struct performance_info {
+       u8      rev;
+       u8      rsvd[3];
+       u16     count;
+       u16     flags;
+       u32     frequency;
+       u64     timestamp[0];
+} __packed;
+
 /**
  * This includes all memory map entries which is sorted based on physical start
  * address, from low to high, and carved out reserved, acpi nvs, acpi reclaim
--
2.20.1