Rework iterating over DT CPU nodes to iterate over possible CPUs
instead. There's no need to walk the DT CPU nodes again. Possible CPUs
is equal to the number of CPUs defined in the DT. Using the "reg" value
for an array index is fragile as it assumes "reg" is 0-N which often is
not the case.

Signed-off-by: Rob Herring <robh@kernel.org>
---
 drivers/clk/mvebu/clk-cpu.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/clk/mvebu/clk-cpu.c b/drivers/clk/mvebu/clk-cpu.c
index c2af3395cf13..db2b38c21304 100644
--- a/drivers/clk/mvebu/clk-cpu.c
+++ b/drivers/clk/mvebu/clk-cpu.c
@@ -168,8 +168,8 @@ static void __init of_cpu_clk_setup(struct device_node *node)
 	struct cpu_clk *cpuclk;
 	void __iomem *clock_complex_base = of_iomap(node, 0);
 	void __iomem *pmu_dfs_base = of_iomap(node, 1);
-	int ncpus = 0;
-	struct device_node *dn;
+	int ncpus = num_possible_cpus();
+	int cpu;
 
 	if (clock_complex_base == NULL) {
 		pr_err("%s: clock-complex base register not set\n",
@@ -181,9 +181,6 @@ static void __init of_cpu_clk_setup(struct device_node *node)
 		pr_warn("%s: pmu-dfs base register not set, dynamic frequency scaling not available\n",
 			__func__);
 
-	for_each_of_cpu_node(dn)
-		ncpus++;
-
 	cpuclk = kcalloc(ncpus, sizeof(*cpuclk), GFP_KERNEL);
 	if (WARN_ON(!cpuclk))
 		goto cpuclk_out;
@@ -192,19 +189,14 @@ static void __init of_cpu_clk_setup(struct device_node *node)
 	if (WARN_ON(!clks))
 		goto clks_out;
 
-	for_each_of_cpu_node(dn) {
+	for_each_possible_cpu(cpu) {
 		struct clk_init_data init;
 		struct clk *clk;
 		char *clk_name = kzalloc(5, GFP_KERNEL);
-		int cpu, err;
 
 		if (WARN_ON(!clk_name))
 			goto bail_out;
 
-		err = of_property_read_u32(dn, "reg", &cpu);
-		if (WARN_ON(err))
-			goto bail_out;
-
 		sprintf(clk_name, "cpu%d", cpu);
 
 		cpuclk[cpu].parent_name = of_clk_get_parent_name(node, 0);

-- 
2.39.2

Le 09/06/2023 à 20:13, Rob Herring a écrit :
> Rework iterating over DT CPU nodes to iterate over possible CPUs
> instead. There's no need to walk the DT CPU nodes again. Possible CPUs
> is equal to the number of CPUs defined in the DT. Using the "reg" value
> for an array index is fragile as it assumes "reg" is 0-N which often is
> not the case.

Hi,

just for the records, this also fixes 2 bugs that were reported as patch 
1 and 2 at [1].

Nice :)


Part of patch 1 could still have some interest in order to remove the 
hard-coded 5 in the kzalloc().
Patch 3 and 4 are mostly useless.

Feel free to check/apply them if it makes sense to you.

Personaly, I won't bother resending them, unless explicitly requested.


CJ

[1]: 
https://lore.kernel.org/all/cover.1619157996.git.christophe.jaillet@wanadoo.fr/

> 
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
>   drivers/clk/mvebu/clk-cpu.c | 14 +++-----------
>   1 file changed, 3 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/clk/mvebu/clk-cpu.c b/drivers/clk/mvebu/clk-cpu.c
> index c2af3395cf13..db2b38c21304 100644
> --- a/drivers/clk/mvebu/clk-cpu.c
> +++ b/drivers/clk/mvebu/clk-cpu.c
> @@ -168,8 +168,8 @@ static void __init of_cpu_clk_setup(struct device_node *node)
>   	struct cpu_clk *cpuclk;
>   	void __iomem *clock_complex_base = of_iomap(node, 0);
>   	void __iomem *pmu_dfs_base = of_iomap(node, 1);
> -	int ncpus = 0;
> -	struct device_node *dn;
> +	int ncpus = num_possible_cpus();
> +	int cpu;
>   
>   	if (clock_complex_base == NULL) {
>   		pr_err("%s: clock-complex base register not set\n",
> @@ -181,9 +181,6 @@ static void __init of_cpu_clk_setup(struct device_node *node)
>   		pr_warn("%s: pmu-dfs base register not set, dynamic frequency scaling not available\n",
>   			__func__);
>   
> -	for_each_of_cpu_node(dn)
> -		ncpus++;
> -
>   	cpuclk = kcalloc(ncpus, sizeof(*cpuclk), GFP_KERNEL);
>   	if (WARN_ON(!cpuclk))
>   		goto cpuclk_out;
> @@ -192,19 +189,14 @@ static void __init of_cpu_clk_setup(struct device_node *node)
>   	if (WARN_ON(!clks))
>   		goto clks_out;
>   
> -	for_each_of_cpu_node(dn) {
> +	for_each_possible_cpu(cpu) {
>   		struct clk_init_data init;
>   		struct clk *clk;
>   		char *clk_name = kzalloc(5, GFP_KERNEL);
> -		int cpu, err;
>   
>   		if (WARN_ON(!clk_name))
>   			goto bail_out;
>   
> -		err = of_property_read_u32(dn, "reg", &cpu);
> -		if (WARN_ON(err))
> -			goto bail_out;
> -
>   		sprintf(clk_name, "cpu%d", cpu);
>   
>   		cpuclk[cpu].parent_name = of_clk_get_parent_name(node, 0);
> 

Quoting Rob Herring (2023-06-09 11:13:47)
> Rework iterating over DT CPU nodes to iterate over possible CPUs
> instead. There's no need to walk the DT CPU nodes again. Possible CPUs
> is equal to the number of CPUs defined in the DT. Using the "reg" value
> for an array index is fragile as it assumes "reg" is 0-N which often is
> not the case.
> 
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---

Applied to clk-next