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From: Shrikanth Hegde <sshegde@linux.ibm.com>
To: maddy@linux.ibm.com, linuxppc-dev@lists.ozlabs.org,
	yury.norov@gmail.com, linux@rasmusvillemoes.dk,
	linux-kernel@vger.kernel.org
Cc: sshegde@linux.ibm.com, chleroy@kernel.org
Subject: [PATCH 2/2] powerpc: Few misc cpumask code refactors
Date: Fri, 27 Mar 2026 12:01:29 +0530	[thread overview]
Message-ID: <20260327063129.127302-3-sshegde@linux.ibm.com> (raw)
In-Reply-To: <20260327063129.127302-1-sshegde@linux.ibm.com>

A few miscellanous changes in handling cpumask api's in the order
they appear:

- cpumask_next(cpu, mask) >= nr_cpu_ids is used to determine if
  cpu is the last CPU. 

- cpumask_next can take -1 as valid argument. So simplify cpuinfo
  iterator. /proc/cpuinfo shows same info with patch.

- cpumask_weight can't be more than nr_cpu_ids. So remove the pointless
  comparison.

Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
---
 arch/powerpc/kernel/setup-common.c | 7 ++-----
 arch/powerpc/sysdev/xive/common.c  | 7 +++----
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index b1761909c23f..47215eab296b 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -323,7 +323,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 	seq_putc(m, '\n');
 
 	/* If this is the last cpu, print the summary */
-	if (cpumask_next(cpu_id, cpu_online_mask) >= nr_cpu_ids)
+	if (cpu_id == cpumask_last(cpu_online_mask))
 		show_cpuinfo_summary(m);
 
 	return 0;
@@ -331,10 +331,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 
 static void *c_start(struct seq_file *m, loff_t *pos)
 {
-	if (*pos == 0)	/* just in case, cpu 0 is not the first */
-		*pos = cpumask_first(cpu_online_mask);
-	else
-		*pos = cpumask_next(*pos - 1, cpu_online_mask);
+	*pos = cpumask_next(*pos - 1, cpu_online_mask);
 	if ((*pos) < nr_cpu_ids)
 		return (void *)(unsigned long)(*pos + 1);
 	return NULL;
diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index b6446abe29a6..91dd3b364d7d 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -548,11 +548,10 @@ static void xive_dec_target_count(int cpu)
 static int xive_find_target_in_mask(const struct cpumask *mask,
 				    unsigned int fuzz)
 {
-	int cpu, first, num, i;
+	int cpu, first, i;
 
-	/* Pick up a starting point CPU in the mask based on  fuzz */
-	num = min_t(int, cpumask_weight(mask), nr_cpu_ids);
-	first = fuzz % num;
+	/* Pick up a starting point CPU in the mask based on fuzz */
+	first = fuzz % cpumask_weight(mask);
 
 	/* Locate it */
 	cpu = cpumask_first(mask);
-- 
2.47.3



  parent reply	other threads:[~2026-03-27  6:31 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-27  6:31 [PATCH 0/2] powerpc: A few misc cpumask refactors Shrikanth Hegde
2026-03-27  6:31 ` [PATCH 1/2] powerpc: Use cpumask_next_wrap instead Shrikanth Hegde
2026-03-28 20:44   ` Yury Norov
2026-03-29  9:18     ` Shrikanth Hegde
2026-03-27  6:31 ` Shrikanth Hegde [this message]
2026-03-28 20:27   ` [PATCH 2/2] powerpc: Few misc cpumask code refactors Yury Norov

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