Arthur Heymans has uploaded this change for review.
arch/x86/timestamp.c: Don't depend on CONFIG_TSC_CONSTANT_RATE
timestamp_tick_freq_mhz() is used to populate the coreboot tables
which cbmem can use to determine timestamps without needing userspace
tools to get the TSC frequency rate. CONFIG_TSC_CONSTANT_RATE depends
on CONFIG_UDELAY_TSC which is not the case on all targets that could
still make use of this functionality.
Change-Id: I8c34eb811e27d2a91ccf1ca6f48a638da5f6cfd9
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
---
M src/arch/x86/timestamp.c
1 file changed, 13 insertions(+), 7 deletions(-)
git pull ssh://review.coreboot.org:29418/coreboot refs/changes/02/31202/1
diff --git a/src/arch/x86/timestamp.c b/src/arch/x86/timestamp.c
index b5257c4..f7b5541 100644
--- a/src/arch/x86/timestamp.c
+++ b/src/arch/x86/timestamp.c
@@ -21,14 +21,20 @@
return rdtscll();
}
+/* We want build to fail on targets with CONFIG_TSC_CONSTANT_RATE
+ if an implementation is lacking since it used to compute udelays.
+ FIXME: provide an implementation on every target to get rid of this.*/
+#if !IS_ENABLED(CONFIG_TSC_CONSTANT_RATE)
+unsigned long __weak tsc_freq_mhz(void)
+{
+ /* Default to not knowing TSC frequency. cbmem will have to fallback
+ * on trying to determine it in userspace. */
+ return 0;
+}
+#endif
+
int timestamp_tick_freq_mhz(void)
{
/* Chipsets that have a constant TSC provide this value correctly. */
- if (IS_ENABLED(CONFIG_TSC_CONSTANT_RATE))
- return tsc_freq_mhz();
-
- /* Filling tick_freq_mhz = 0 in timestamps-table will trigger
- * userspace utility to try deduce it from the running system.
- */
- return 0;
+ return tsc_freq_mhz();
}
To view, visit change 31202. To unsubscribe, or for help writing mail filters, visit settings.