Re: [PATCH V3 13/15] parisc/kmap: Remove duplicate kmap code

[Ira Weiny]

On Thu, May 07, 2020 at 01:52:58PM -0700, Andrew Morton wrote:
> On Thu,  7 May 2020 08:00:01 -0700 ira.weiny@xxxxxxxxx wrote:
> 
> > parisc reimplements the kmap calls except to flush it's dcache.  This is
> > arguably an abuse of kmap but regardless it is messy and confusing.
> > 
> > Remove the duplicate code and have parisc define
> > ARCH_HAS_FLUSH_ON_KUNMAP for a kunmap_flush_on_unmap() architecture
> > specific call to flush the cache.
> 
> checkpatch says:
> 
> ERROR: #define of 'ARCH_HAS_FLUSH_ON_KUNMAP' is wrong - use Kconfig variables or standard guards instead
> #69: FILE: arch/parisc/include/asm/cacheflush.h:103:
> +#define ARCH_HAS_FLUSH_ON_KUNMAP
> 
> which is fair enough, I guess.  More conventional would be
> 
> arch/parisc/include/asm/cacheflush.h:
> 
> static inline void kunmap_flush_on_unmap(void *addr)
> {
> 	...
> }
> #define kunmap_flush_on_unmap kunmap_flush_on_unmap
> 
> 
> include/linux/highmem.h:
> 
> #ifndef kunmap_flush_on_unmap
> static inline void kunmap_flush_on_unmap(void *addr)
> {
> }
> #define kunmap_flush_on_unmap kunmap_flush_on_unmap
> #endif
> 
> 
> static inline void kunmap_atomic_high(void *addr)
> {
> 	/* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
> 	 * handles re-enabling faults + preemption */
> 	kunmap_flush_on_unmap(addr);
> }
> 
> 
> but I don't really think it's worth bothering changing it.	
> 
> (Ditto patch 3/15)

Yes I was following the pattern already there.

I'll fix up the last patch now.
Ira