From: Pavel Tatashin <pasha.tatashin@soleen.com>
To: catalin.marinas@arm.com, will.deacon@arm.com,
akpm@linux-foundation.org, rppt@linux.vnet.ibm.com,
mhocko@suse.com, ard.biesheuvel@linaro.org,
andrew.murray@arm.com, james.morse@arm.com, marc.zyngier@arm.com,
sboyd@kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, pasha.tatashin@soleen.com
Subject: [PATCH v1 1/1] arm64: Early boot time stamps
Date: Mon, 19 Nov 2018 16:44:43 -0500 [thread overview]
Message-ID: <20181119214443.25175-2-pasha.tatashin@soleen.com> (raw)
In-Reply-To: <20181119214443.25175-1-pasha.tatashin@soleen.com>
Allow printk time stamps/sched_clock() to be available from the early
boot.
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
---
arch/arm64/kernel/setup.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index f4fc1e0544b7..4df41a66b403 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -40,6 +40,7 @@
#include <linux/efi.h>
#include <linux/psci.h>
#include <linux/sched/task.h>
+#include <linux/sched_clock.h>
#include <linux/mm.h>
#include <asm/acpi.h>
@@ -279,8 +280,26 @@ arch_initcall(reserve_memblock_reserved_regions);
u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
+/*
+ * Get time stamps available early in boot, useful to identify boot time issues
+ * from the early boot.
+ */
+static __init void sched_clock_early_init(void)
+{
+ u64 freq = arch_timer_get_cntfrq();
+ u64 (*read_time)(void) = arch_counter_get_cntvct;
+
+ /* Early clock is available only on platforms with known freqs */
+ if (!freq)
+ return;
+
+ sched_clock_register(read_time, BITS_PER_LONG, freq);
+}
+
void __init setup_arch(char **cmdline_p)
{
+ sched_clock_early_init();
+
init_mm.start_code = (unsigned long) _text;
init_mm.end_code = (unsigned long) _etext;
init_mm.end_data = (unsigned long) _edata;
--
2.19.1
next prev parent reply other threads:[~2018-11-19 21:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-19 21:44 [PATCH v1 0/1] Early boot time stamps for arm64 Pavel Tatashin
2018-11-19 21:44 ` Pavel Tatashin [this message]
2018-11-20 11:29 ` [PATCH v1 1/1] arm64: Early boot time stamps Marc Zyngier
2018-11-20 14:40 ` Pavel Tatashin
2018-11-20 14:53 ` Andrew Murray
2018-11-20 14:55 ` Marc Zyngier
2018-11-20 15:03 ` Pavel Tatashin
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