[PATCH 3/3] powerpc/64s: make linear_map_hash_lock a raw spinlock

[Guenter Roeck]

On Fri, Oct 14, 2022 at 09:07:10AM +1000, Nicholas Piggin wrote:
> This lock is taken while the raw kfence_freelist_lock is held, so it
> must also be a raw spinlock, as reported by lockdep when raw lock
> nesting checking is enabled.
> 
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>

Tested-by: Guenter Roeck <linux at roeck-us.net>

> ---
>  arch/powerpc/mm/book3s64/hash_utils.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
> index df008edf7be0..6df4c6d38b66 100644
> --- a/arch/powerpc/mm/book3s64/hash_utils.c
> +++ b/arch/powerpc/mm/book3s64/hash_utils.c
> @@ -1981,7 +1981,7 @@ long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
>  }
>  
>  #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
> -static DEFINE_SPINLOCK(linear_map_hash_lock);
> +static DEFINE_RAW_SPINLOCK(linear_map_hash_lock);
>  
>  static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
>  {
> @@ -2005,10 +2005,10 @@ static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
>  				    mmu_linear_psize, mmu_kernel_ssize);
>  
>  	BUG_ON (ret < 0);
> -	spin_lock(&linear_map_hash_lock);
> +	raw_spin_lock(&linear_map_hash_lock);
>  	BUG_ON(linear_map_hash_slots[lmi] & 0x80);
>  	linear_map_hash_slots[lmi] = ret | 0x80;
> -	spin_unlock(&linear_map_hash_lock);
> +	raw_spin_unlock(&linear_map_hash_lock);
>  }
>  
>  static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
> @@ -2018,14 +2018,14 @@ static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
>  	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
>  
>  	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
> -	spin_lock(&linear_map_hash_lock);
> +	raw_spin_lock(&linear_map_hash_lock);
>  	if (!(linear_map_hash_slots[lmi] & 0x80)) {
> -		spin_unlock(&linear_map_hash_lock);
> +		raw_spin_unlock(&linear_map_hash_lock);
>  		return;
>  	}
>  	hidx = linear_map_hash_slots[lmi] & 0x7f;
>  	linear_map_hash_slots[lmi] = 0;
> -	spin_unlock(&linear_map_hash_lock);
> +	raw_spin_unlock(&linear_map_hash_lock);
>  	if (hidx & _PTEIDX_SECONDARY)
>  		hash = ~hash;
>  	slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
> -- 
> 2.37.2
>