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authorLinus Torvalds <torvalds@linux-foundation.org>2020-09-18 11:48:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-09-18 11:48:25 -0700
commit5a55d36f715b01a00c1ad7127a73044c6f1c9668 (patch)
treef835c60c6e53090d83c6b9da62f7c0f0446fb769 /drivers/cpuidle
parent794a9965eef498f6e4c466167880acb4ab990b63 (diff)
parent0460534b532e5518c657c7d6492b9337d975eaa3 (diff)
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Merge tag 'powerpc-5.9-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman: "Some more powerpc fixes for 5.9: - Opt us out of the DEBUG_VM_PGTABLE support for now as it's causing crashes. - Fix a long standing bug in our DMA mask handling that was hidden until recently, and which caused problems with some drivers. - Fix a boot failure on systems with large amounts of RAM, and no hugepage support and using Radix MMU, only seen in the lab. - A few other minor fixes. Thanks to Alexey Kardashevskiy, Aneesh Kumar K.V, Gautham R. Shenoy, Hari Bathini, Ira Weiny, Nick Desaulniers, Shirisha Ganta, Vaibhav Jain, and Vaidyanathan Srinivasan" * tag 'powerpc-5.9-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/papr_scm: Limit the readability of 'perf_stats' sysfs attribute cpuidle: pseries: Fix CEDE latency conversion from tb to us powerpc/dma: Fix dma_map_ops::get_required_mask Revert "powerpc/build: vdso linker warning for orphan sections" powerpc/mm: Remove DEBUG_VM_PGTABLE support on powerpc selftests/powerpc: Skip PROT_SAO test in guests/LPARS powerpc/book3s64/radix: Fix boot failure with large amount of guest memory
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/cpuidle-pseries.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c
index ff6d99e923a4..a2b5c6f60cf0 100644
--- a/drivers/cpuidle/cpuidle-pseries.c
+++ b/drivers/cpuidle/cpuidle-pseries.c
@@ -361,7 +361,10 @@ static void __init fixup_cede0_latency(void)
for (i = 0; i < nr_xcede_records; i++) {
struct xcede_latency_record *record = &payload->records[i];
u64 latency_tb = be64_to_cpu(record->latency_ticks);
- u64 latency_us = tb_to_ns(latency_tb) / NSEC_PER_USEC;
+ u64 latency_us = DIV_ROUND_UP_ULL(tb_to_ns(latency_tb), NSEC_PER_USEC);
+
+ if (latency_us == 0)
+ pr_warn("cpuidle: xcede record %d has an unrealistic latency of 0us.\n", i);
if (latency_us < min_latency_us)
min_latency_us = latency_us;
@@ -378,10 +381,14 @@ static void __init fixup_cede0_latency(void)
* Perform the fix-up.
*/
if (min_latency_us < dedicated_states[1].exit_latency) {
- u64 cede0_latency = min_latency_us - 1;
+ /*
+ * We set a minimum of 1us wakeup latency for cede0 to
+ * distinguish it from snooze
+ */
+ u64 cede0_latency = 1;
- if (cede0_latency <= 0)
- cede0_latency = min_latency_us;
+ if (min_latency_us > cede0_latency)
+ cede0_latency = min_latency_us - 1;
dedicated_states[1].exit_latency = cede0_latency;
dedicated_states[1].target_residency = 10 * (cede0_latency);