powerpc/time: Expose boot_tb via accessor

JIRA: https://issues.redhat.com/browse/RHEL-53366

commit 2dc019ca39347f76891d34a992b67258078aa45d
Author: Aboorva Devarajan <aboorvad@linux.ibm.com>
Date:   Mon Sep 15 15:59:41 2025 +0530

    powerpc/time: Expose boot_tb via accessor

    - Define accessor function get_boot_tb() to safely return boot_tb value,
      this is only needed when running in SPLPAR environments, so the
      accessor is built conditionally under CONFIG_PPC_SPLPAR.

    - Tag boot_tb as __ro_after_init since it is written once at initialized
      and never updated afterwards.

    Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com>
    Tested-by: Tejas Manhas <tejas05@linux.ibm.com>
    Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
    Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
    Link: https://patch.msgid.link/20250915102947.26681-2-atrajeev@linux.ibm.com

Signed-off-by: Mamatha Inamdar <minamdar@redhat.com>
This commit is contained in:
Mamatha Inamdar
2026-07-07 01:05:50 -04:00
parent 90c304e113
commit fdae64acb5
2 changed files with 11 additions and 1 deletions
+4
View File
@@ -26,6 +26,10 @@ extern struct clock_event_device decrementer_clockevent;
extern void generic_calibrate_decr(void);
#ifdef CONFIG_PPC_SPLPAR
extern u64 get_boot_tb(void);
#endif
/* Some sane defaults: 125 MHz timebase, 1GHz processor */
extern unsigned long ppc_proc_freq;
#define DEFAULT_PROC_FREQ (DEFAULT_TB_FREQ * 8)
+7 -1
View File
@@ -130,7 +130,7 @@ EXPORT_SYMBOL_GPL(rtc_lock);
static u64 tb_to_ns_scale __read_mostly;
static unsigned tb_to_ns_shift __read_mostly;
static u64 boot_tb __read_mostly;
static u64 boot_tb __ro_after_init;
extern struct timezone sys_tz;
static long timezone_offset;
@@ -683,6 +683,12 @@ notrace unsigned long long sched_clock(void)
return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
}
#ifdef CONFIG_PPC_SPLPAR
u64 get_boot_tb(void)
{
return boot_tb;
}
#endif
#ifdef CONFIG_PPC_PSERIES