powerpc: Fix reverse map real-mode address lookup with huge vmalloc

real_vmalloc_addr() does not currently work for huge vmalloc, which is
what the reverse map can be allocated with for radix host, hash guest.

Extract the hugepage aware equivalent from eeh code into a helper, and
convert existing sites including this one to use it.

Fixes: 8abddd968a30 ("powerpc/64s/radix: Enable huge vmalloc mappings")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210526120005.3432222-1-npiggin@gmail.com

2 files changed, 4 insertions, 35 deletions

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index f24cd53ff26e..3bbdcc86d01b 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -346,28 +346,7 @@ void eeh_slot_error_detail(struct eeh_pe *pe, int severity)
  */
 static inline unsigned long eeh_token_to_phys(unsigned long token)
 {
-	pte_t *ptep;
-	unsigned long pa;
-	int hugepage_shift;
-
-	/*
-	 * We won't find hugepages here(this is iomem). Hence we are not
-	 * worried about _PAGE_SPLITTING/collapse. Also we will not hit
-	 * page table free, because of init_mm.
-	 */
-	ptep = find_init_mm_pte(token, &hugepage_shift);
-	if (!ptep)
-		return token;
-
-	pa = pte_pfn(*ptep);
-
-	/* On radix we can do hugepage mappings for io, so handle that */
-	if (!hugepage_shift)
-		hugepage_shift = PAGE_SHIFT;
-
-	pa <<= PAGE_SHIFT;
-	pa |= token & ((1ul << hugepage_shift) - 1);
-	return pa;
+	return ppc_find_vmap_phys(token);
 }
 
 /*
diff --git a/arch/powerpc/kernel/io-workarounds.c b/arch/powerpc/kernel/io-workarounds.c
index 51bbaae94ccc..c877f074d174 100644
--- a/arch/powerpc/kernel/io-workarounds.c
+++ b/arch/powerpc/kernel/io-workarounds.c
@@ -55,7 +55,6 @@ static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
 #ifdef CONFIG_PPC_INDIRECT_MMIO
 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
 {
-	unsigned hugepage_shift;
 	struct iowa_bus *bus;
 	int token;
 
@@ -65,22 +64,13 @@ struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
 		bus = &iowa_busses[token - 1];
 	else {
 		unsigned long vaddr, paddr;
-		pte_t *ptep;
 
 		vaddr = (unsigned long)PCI_FIX_ADDR(addr);
 		if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
 			return NULL;
-		/*
-		 * We won't find huge pages here (iomem). Also can't hit
-		 * a page table free due to init_mm
-		 */
-		ptep = find_init_mm_pte(vaddr, &hugepage_shift);
-		if (ptep == NULL)
-			paddr = 0;
-		else {
-			WARN_ON(hugepage_shift);
-			paddr = pte_pfn(*ptep) << PAGE_SHIFT;
-		}
+
+		paddr = ppc_find_vmap_phys(vaddr);
+
 		bus = iowa_pci_find(vaddr, paddr);
 
 		if (bus == NULL)