Subject: Re: [PATCH 8/9] acpi: Use built-in RCU list checking for acpi_ioremaps list (v1)

From: "Paul E. McKenney" <[email-masked]>
Date: Tue, 16 Jul 2019 11:43:31 -0700

On Mon, Jul 15, 2019 at 10:37:04AM -0400, Joel Fernandes (Google) wrote:
> list_for_each_entry_rcu has built-in RCU and lock checking. Make use of
> it for acpi_ioremaps list traversal.
> 
> Signed-off-by: Joel Fernandes (Google) <[email-masked]>

Given that Rafael acked it, this one looks ready.

							Thanx, Paul

> ---
>  drivers/acpi/osl.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
> index 9c0edf2fc0dd..2f9d0d20b836 100644
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -14,6 +14,7 @@
>  #include <linux/slab.h>
>  #include <linux/mm.h>
>  #include <linux/highmem.h>
> +#include <linux/lockdep.h>
>  #include <linux/pci.h>
>  #include <linux/interrupt.h>
>  #include <linux/kmod.h>
> @@ -80,6 +81,7 @@ struct acpi_ioremap {
>  
>  static LIST_HEAD(acpi_ioremaps);
>  static DEFINE_MUTEX(acpi_ioremap_lock);
> +#define acpi_ioremap_lock_held() lock_is_held(&acpi_ioremap_lock.dep_map)
>  
>  static void __init acpi_request_region (struct acpi_generic_address *gas,
>  	unsigned int length, char *desc)
> @@ -206,7 +208,7 @@ acpi_map_lookup(acpi_physical_address phys, acpi_size size)
>  {
>  	struct acpi_ioremap *map;
>  
> -	list_for_each_entry_rcu(map, &acpi_ioremaps, list)
> +	list_for_each_entry_rcu(map, &acpi_ioremaps, list, acpi_ioremap_lock_held())
>  		if (map->phys <= phys &&
>  		    phys + size <= map->phys + map->size)
>  			return map;
> @@ -249,7 +251,7 @@ acpi_map_lookup_virt(void __iomem *virt, acpi_size size)
>  {
>  	struct acpi_ioremap *map;
>  
> -	list_for_each_entry_rcu(map, &acpi_ioremaps, list)
> +	list_for_each_entry_rcu(map, &acpi_ioremaps, list, acpi_ioremap_lock_held())
>  		if (map->virt <= virt &&
>  		    virt + size <= map->virt + map->size)
>  			return map;
> -- 
> 2.22.0.510.g264f2c817a-goog
>