powerpc: Make virt_to_pfn() a static inline

Making virt_to_pfn() a static inline taking a strongly typed
(const void *) makes the contract of a passing a pointer of that
type to the function explicit and exposes any misuse of the
macro virt_to_pfn() acting polymorphic and accepting many types
such as (void *), (unitptr_t) or (unsigned long) as arguments
without warnings.

Move the virt_to_pfn() and related functions below the
declaration of __pa() so it compiles.

For symmetry do the same with pfn_to_kaddr().

As the file is included right into the linker file, we need
to surround the functions with ifndef __ASSEMBLY__ so we
don't cause compilation errors.

The conversion moreover exposes the fact that pmd_page_vaddr()
was returning an unsigned long rather than a const void * as
could be expected, so all the sites defining pmd_page_vaddr()
had to be augmented as well.

Finally the KVM code in book3s_64_mmu_hv.c was passing an
unsigned int to virt_to_phys() so fix that up with a cast so the
result compiles.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[mpe: Fixup kfence.h, simplify pfn_to_kaddr() & pmd_page_vaddr()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230809-virt-to-phys-powerpc-v1-1-12e912a7d439@linaro.org

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 6a88bfdaa69b..a92f1f65d0a7 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -60,9 +60,9 @@ static inline pgprot_t pte_pgprot(pte_t pte)
 }
 
 #ifndef pmd_page_vaddr
-static inline unsigned long pmd_page_vaddr(pmd_t pmd)
+static inline const void *pmd_page_vaddr(pmd_t pmd)
 {
-	return ((unsigned long)__va(pmd_val(pmd) & ~PMD_MASKED_BITS));
+	return __va(pmd_val(pmd) & ~PMD_MASKED_BITS);
 }
 #define pmd_page_vaddr pmd_page_vaddr
 #endif