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

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);