powerpc/mm: Add PG_dcache_clean to indicate dcache clean state

This just add a better name for PG_arch_1. No functional change in this patch.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210203045812.234439-2-aneesh.kumar@linux.ibm.com

arch/powerpc/include/asm/cacheflush.h

@@ -8,6 +8,12 @@
 #include <asm/cputable.h>
 #include <asm/cpu_has_feature.h>
 
+/*
+ * This flag is used to indicate that the page pointed to by a pte is clean
+ * and does not require cleaning before returning it to the user.
+ */
+#define PG_dcache_clean PG_arch_1
+
 #ifdef CONFIG_PPC_BOOK3S_64
 /*
  * Book3s has no ptesync after setting a pte, so without this ptesync it's

arch/powerpc/include/asm/kvm_ppc.h

@@ -881,9 +881,9 @@ static inline void kvmppc_mmu_flush_icache(kvm_pfn_t pfn)
 
 	/* Clear i-cache for new pages */
 	page = pfn_to_page(pfn);
-	if (!test_bit(PG_arch_1, &page->flags)) {
+	if (!test_bit(PG_dcache_clean, &page->flags)) {
 		flush_dcache_icache_page(page);
-		set_bit(PG_arch_1, &page->flags);
+		set_bit(PG_dcache_clean, &page->flags);
 	}
 }
 

arch/powerpc/mm/book3s64/hash_utils.c

@@ -1144,10 +1144,10 @@ unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
 	page = pte_page(pte);
 
 	/* page is dirty */
-	if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
+	if (!test_bit(PG_dcache_clean, &page->flags) && !PageReserved(page)) {
 		if (trap == 0x400) {
 			flush_dcache_icache_page(page);
-			set_bit(PG_arch_1, &page->flags);
+			set_bit(PG_dcache_clean, &page->flags);
 		} else
 			pp |= HPTE_R_N;
 	}

arch/powerpc/mm/mem.c

@@ -489,8 +489,8 @@ void flush_dcache_page(struct page *page)
 	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 		return;
 	/* avoid an atomic op if possible */
-	if (test_bit(PG_arch_1, &page->flags))
-		clear_bit(PG_arch_1, &page->flags);
+	if (test_bit(PG_dcache_clean, &page->flags))
+		clear_bit(PG_dcache_clean, &page->flags);
 }
 EXPORT_SYMBOL(flush_dcache_page);
 

arch/powerpc/mm/pgtable.c

@@ -82,9 +82,9 @@ static pte_t set_pte_filter_hash(pte_t pte)
 		struct page *pg = maybe_pte_to_page(pte);
 		if (!pg)
 			return pte;
-		if (!test_bit(PG_arch_1, &pg->flags)) {
+		if (!test_bit(PG_dcache_clean, &pg->flags)) {
 			flush_dcache_icache_page(pg);
-			set_bit(PG_arch_1, &pg->flags);
+			set_bit(PG_dcache_clean, &pg->flags);
 		}
 	}
 	return pte;
@@ -117,13 +117,13 @@ static inline pte_t set_pte_filter(pte_t pte)
 		return pte;
 
 	/* If the page clean, we move on */
-	if (test_bit(PG_arch_1, &pg->flags))
+	if (test_bit(PG_dcache_clean, &pg->flags))
 		return pte;
 
 	/* If it's an exec fault, we flush the cache and make it clean */
 	if (is_exec_fault()) {
 		flush_dcache_icache_page(pg);
-		set_bit(PG_arch_1, &pg->flags);
+		set_bit(PG_dcache_clean, &pg->flags);
 		return pte;
 	}
 
@@ -162,12 +162,12 @@ static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma,
 		goto bail;
 
 	/* If the page is already clean, we move on */
-	if (test_bit(PG_arch_1, &pg->flags))
+	if (test_bit(PG_dcache_clean, &pg->flags))
 		goto bail;
 
-	/* Clean the page and set PG_arch_1 */
+	/* Clean the page and set PG_dcache_clean */
 	flush_dcache_icache_page(pg);
-	set_bit(PG_arch_1, &pg->flags);
+	set_bit(PG_dcache_clean, &pg->flags);
 
  bail:
 	return pte_mkexec(pte);