powerpc/mem: flush_dcache_icache_phys() is for HIGHMEM pages only

__flush_dcache_icache() is usable for non HIGHMEM pages on
every platform.

It is only for HIGHMEM pages that BOOKE needs kmap() and
BOOK3S needs flush_dcache_icache_phys().

So make flush_dcache_icache_phys() dependent on CONFIG_HIGHMEM and
call it only when it is a HIGHMEM page.

We could make flush_dcache_icache_phys() available at all time,
but as it is declared NOKPROBE_SYMBOL(), GCC doesn't optimise
it out when it is not used.

So define a stub for !CONFIG_HIGHMEM in order to remove the #ifdef in
flush_dcache_icache_page() and use IS_ENABLED() instead.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/79ed5d7914f497cd5fcd681ca2f4d50a91719455.1617895813.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2021-04-08 15:30:30 +00:00 committed by Michael Ellerman
parent cd97d9e8b5
commit 52d490437f

View File

@ -76,7 +76,7 @@ void flush_icache_range(unsigned long start, unsigned long stop)
}
EXPORT_SYMBOL(flush_icache_range);
#if !defined(CONFIG_PPC_8xx) && !defined(CONFIG_PPC64)
#ifdef CONFIG_HIGHMEM
/**
* flush_dcache_icache_phys() - Flush a page by it's physical address
* @physaddr: the physical address of the page
@ -115,7 +115,11 @@ static void flush_dcache_icache_phys(unsigned long physaddr)
: "ctr", "memory");
}
NOKPROBE_SYMBOL(flush_dcache_icache_phys)
#endif // !defined(CONFIG_PPC_8xx) && !defined(CONFIG_PPC64)
#else
static void flush_dcache_icache_phys(unsigned long physaddr)
{
}
#endif
/*
* This is called when a page has been modified by the kernel.
@ -185,18 +189,15 @@ void flush_dcache_icache_page(struct page *page)
if (PageCompound(page))
return flush_dcache_icache_hugepage(page);
#if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64)
/* On 8xx there is no need to kmap since highmem is not supported */
__flush_dcache_icache(page_address(page));
#else
if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
if (!PageHighMem(page)) {
__flush_dcache_icache(lowmem_page_address(page));
} else if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
void *start = kmap_atomic(page);
__flush_dcache_icache(start);
kunmap_atomic(start);
} else {
flush_dcache_icache_phys(page_to_phys(page));
}
#endif
}
EXPORT_SYMBOL(flush_dcache_icache_page);