The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f34ee9cb2c5ac5af426fee6fa4591a34d187e696 Mon Sep 17 00:00:00 2001
From: "Pratik R. Sampat" psampat@linux.ibm.com Date: Wed, 28 Jul 2021 17:35:00 +0530 Subject: [PATCH] cpufreq: powernv: Fix init_chip_info initialization in numa=off
In the numa=off kernel command-line configuration init_chip_info() loops around the number of chips and attempts to copy the cpumask of that node which is NULL for all iterations after the first chip.
Hence, store the cpu mask for each chip instead of derving cpumask from node while populating the "chips" struct array and copy that to the chips[i].mask
Fixes: 053819e0bf84 ("cpufreq: powernv: Handle throttling due to Pmax capping at chip level") Cc: stable@vger.kernel.org # v4.3+ Reported-by: Shirisha Ganta shirisha.ganta1@ibm.com Signed-off-by: Pratik R. Sampat psampat@linux.ibm.com Reviewed-by: Gautham R. Shenoy ego@linux.vnet.ibm.com [mpe: Rename goto label to out_free_chip_cpu_mask] Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20210728120500.87549-2-psampat@linux.ibm.com
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index 005600cef273..6fbb46b2f6da 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -36,6 +36,7 @@ #define MAX_PSTATE_SHIFT 32 #define LPSTATE_SHIFT 48 #define GPSTATE_SHIFT 56 +#define MAX_NR_CHIPS 32
#define MAX_RAMP_DOWN_TIME 5120 /* @@ -1046,12 +1047,20 @@ static int init_chip_info(void) unsigned int *chip; unsigned int cpu, i; unsigned int prev_chip_id = UINT_MAX; + cpumask_t *chip_cpu_mask; int ret = 0;
chip = kcalloc(num_possible_cpus(), sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM;
+ /* Allocate a chip cpu mask large enough to fit mask for all chips */ + chip_cpu_mask = kcalloc(MAX_NR_CHIPS, sizeof(cpumask_t), GFP_KERNEL); + if (!chip_cpu_mask) { + ret = -ENOMEM; + goto free_and_return; + } + for_each_possible_cpu(cpu) { unsigned int id = cpu_to_chip_id(cpu);
@@ -1059,22 +1068,25 @@ static int init_chip_info(void) prev_chip_id = id; chip[nr_chips++] = id; } + cpumask_set_cpu(cpu, &chip_cpu_mask[nr_chips-1]); }
chips = kcalloc(nr_chips, sizeof(struct chip), GFP_KERNEL); if (!chips) { ret = -ENOMEM; - goto free_and_return; + goto out_free_chip_cpu_mask; }
for (i = 0; i < nr_chips; i++) { chips[i].id = chip[i]; - cpumask_copy(&chips[i].mask, cpumask_of_node(chip[i])); + cpumask_copy(&chips[i].mask, &chip_cpu_mask[i]); INIT_WORK(&chips[i].throttle, powernv_cpufreq_work_fn); for_each_cpu(cpu, &chips[i].mask) per_cpu(chip_info, cpu) = &chips[i]; }
+out_free_chip_cpu_mask: + kfree(chip_cpu_mask); free_and_return: kfree(chip); return ret;