powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU

Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves
128kB kernel image size (90kB text) on powernv_defconfig minus KVM,
350kB on pseries_defconfig minus KVM, 40kB on a tiny config.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup defined(ARCH_HAS_MEMREMAP_COMPAT_ALIGN), which needs CONFIG.
      Fix radix_enabled() use in setup_initial_memory_limit(). Add some
      stubs to reduce number of ifdefs.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211201144153.2456614-18-npiggin@gmail.com

7 files changed, 44 insertions, 15 deletions

diff --git a/arch/powerpc/mm/book3s64/Makefile b/arch/powerpc/mm/book3s64/Makefile
index 501efadb287f..2d50cac499c5 100644
--- a/arch/powerpc/mm/book3s64/Makefile
+++ b/arch/powerpc/mm/book3s64/Makefile
@@ -2,20 +2,23 @@
 
 ccflags-y	:= $(NO_MINIMAL_TOC)
 
+obj-y				+= mmu_context.o pgtable.o trace.o
+ifdef CONFIG_PPC_64S_HASH_MMU
 CFLAGS_REMOVE_slb.o = $(CC_FLAGS_FTRACE)
-
-obj-y				+= hash_pgtable.o hash_utils.o slb.o \
-				   mmu_context.o pgtable.o hash_tlb.o trace.o
+obj-y				+= hash_pgtable.o hash_utils.o hash_tlb.o slb.o
 obj-$(CONFIG_PPC_HASH_MMU_NATIVE)	+= hash_native.o
-obj-$(CONFIG_PPC_RADIX_MMU)	+= radix_pgtable.o radix_tlb.o
 obj-$(CONFIG_PPC_4K_PAGES)	+= hash_4k.o
 obj-$(CONFIG_PPC_64K_PAGES)	+= hash_64k.o
+obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += hash_hugepage.o
+obj-$(CONFIG_PPC_SUBPAGE_PROT)	+= subpage_prot.o
+endif
+
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
+
+obj-$(CONFIG_PPC_RADIX_MMU)	+= radix_pgtable.o radix_tlb.o
 ifdef CONFIG_HUGETLB_PAGE
 obj-$(CONFIG_PPC_RADIX_MMU)	+= radix_hugetlbpage.o
 endif
-obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += hash_hugepage.o
-obj-$(CONFIG_PPC_SUBPAGE_PROT)	+= subpage_prot.o
 obj-$(CONFIG_SPAPR_TCE_IOMMU)	+= iommu_api.o
 obj-$(CONFIG_PPC_PKEY)	+= pkeys.o
 
diff --git a/arch/powerpc/mm/book3s64/hugetlbpage.c b/arch/powerpc/mm/book3s64/hugetlbpage.c
index a688e1324ae5..95b2a283fd6e 100644
--- a/arch/powerpc/mm/book3s64/hugetlbpage.c
+++ b/arch/powerpc/mm/book3s64/hugetlbpage.c
@@ -16,6 +16,7 @@
 unsigned int hpage_shift;
 EXPORT_SYMBOL(hpage_shift);
 
+#ifdef CONFIG_PPC_64S_HASH_MMU
 int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
 		     pte_t *ptep, unsigned long trap, unsigned long flags,
 		     int ssize, unsigned int shift, unsigned int mmu_psize)
@@ -122,6 +123,7 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
 	*ptep = __pte(new_pte & ~H_PAGE_BUSY);
 	return 0;
 }
+#endif
 
 pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
 				  unsigned long addr, pte_t *ptep)
diff --git a/arch/powerpc/mm/book3s64/mmu_context.c b/arch/powerpc/mm/book3s64/mmu_context.c
index c10fc8a72fb3..24aa953c9311 100644
--- a/arch/powerpc/mm/book3s64/mmu_context.c
+++ b/arch/powerpc/mm/book3s64/mmu_context.c
@@ -31,6 +31,7 @@ static int alloc_context_id(int min_id, int max_id)
 	return ida_alloc_range(&mmu_context_ida, min_id, max_id, GFP_KERNEL);
 }
 
+#ifdef CONFIG_PPC_64S_HASH_MMU
 void hash__reserve_context_id(int id)
 {
 	int result = ida_alloc_range(&mmu_context_ida, id, id, GFP_KERNEL);
@@ -50,7 +51,9 @@ int hash__alloc_context_id(void)
 	return alloc_context_id(MIN_USER_CONTEXT, max);
 }
 EXPORT_SYMBOL_GPL(hash__alloc_context_id);
+#endif
 
+#ifdef CONFIG_PPC_64S_HASH_MMU
 static int realloc_context_ids(mm_context_t *ctx)
 {
 	int i, id;
@@ -150,6 +153,13 @@ void hash__setup_new_exec(void)
 
 	slb_setup_new_exec();
 }
+#else
+static inline int hash__init_new_context(struct mm_struct *mm)
+{
+	BUILD_BUG();
+	return 0;
+}
+#endif
 
 static int radix__init_new_context(struct mm_struct *mm)
 {
@@ -175,7 +185,9 @@ static int radix__init_new_context(struct mm_struct *mm)
 	 */
 	asm volatile("ptesync;isync" : : : "memory");
 
+#ifdef CONFIG_PPC_64S_HASH_MMU
 	mm->context.hash_context = NULL;
+#endif
 
 	return index;
 }
@@ -213,14 +225,22 @@ EXPORT_SYMBOL_GPL(__destroy_context);
 
 static void destroy_contexts(mm_context_t *ctx)
 {
-	int index, context_id;
+	if (radix_enabled()) {
+		ida_free(&mmu_context_ida, ctx->id);
+	} else {
+#ifdef CONFIG_PPC_64S_HASH_MMU
+		int index, context_id;
 
-	for (index = 0; index < ARRAY_SIZE(ctx->extended_id); index++) {
-		context_id = ctx->extended_id[index];
-		if (context_id)
-			ida_free(&mmu_context_ida, context_id);
+		for (index = 0; index < ARRAY_SIZE(ctx->extended_id); index++) {
+			context_id = ctx->extended_id[index];
+			if (context_id)
+				ida_free(&mmu_context_ida, context_id);
+		}
+		kfree(ctx->hash_context);
+#else
+		BUILD_BUG(); // radix_enabled() should be constant true
+#endif
 	}
-	kfree(ctx->hash_context);
 }
 
 static void pmd_frag_destroy(void *pmd_frag)
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index d3b01f6ba530..79ce3c22a29d 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -529,7 +529,7 @@ static int __init pgtable_debugfs_setup(void)
 }
 arch_initcall(pgtable_debugfs_setup);
 
-#ifdef CONFIG_ZONE_DEVICE
+#if defined(CONFIG_ZONE_DEVICE) && defined(CONFIG_ARCH_HAS_MEMREMAP_COMPAT_ALIGN)
 /*
  * Override the generic version in mm/memremap.c.
  *
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 1f4afc37843d..3c4f0ebe5df8 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -334,7 +334,7 @@ static void __init radix_init_pgtable(void)
 	u64 i;
 
 	/* We don't support slb for radix */
-	mmu_slb_size = 0;
+	slb_set_size(0);
 
 	/*
 	 * Create the linear mapping
@@ -565,6 +565,7 @@ void __init radix__early_init_mmu(void)
 {
 	unsigned long lpcr;
 
+#ifdef CONFIG_PPC_64S_HASH_MMU
 #ifdef CONFIG_PPC_64K_PAGES
 	/* PAGE_SIZE mappings */
 	mmu_virtual_psize = MMU_PAGE_64K;
@@ -582,6 +583,7 @@ void __init radix__early_init_mmu(void)
 	} else
 		mmu_vmemmap_psize = mmu_virtual_psize;
 #endif
+#endif
 	/*
 	 * initialize page table size
 	 */
diff --git a/arch/powerpc/mm/copro_fault.c b/arch/powerpc/mm/copro_fault.c
index 8acd00178956..c1cb21a00884 100644
--- a/arch/powerpc/mm/copro_fault.c
+++ b/arch/powerpc/mm/copro_fault.c
@@ -82,6 +82,7 @@ out_unlock:
 }
 EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
 
+#ifdef CONFIG_PPC_64S_HASH_MMU
 int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
 {
 	u64 vsid, vsidkey;
@@ -146,3 +147,4 @@ void copro_flush_all_slbs(struct mm_struct *mm)
 	cxl_slbia(mm);
 }
 EXPORT_SYMBOL_GPL(copro_flush_all_slbs);
+#endif
diff --git a/arch/powerpc/mm/ptdump/Makefile b/arch/powerpc/mm/ptdump/Makefile
index 4050cbb55acf..b533caaf0910 100644
--- a/arch/powerpc/mm/ptdump/Makefile
+++ b/arch/powerpc/mm/ptdump/Makefile
@@ -10,5 +10,5 @@ obj-$(CONFIG_PPC_BOOK3S_64)	+= book3s64.o
 
 ifdef CONFIG_PTDUMP_DEBUGFS
 obj-$(CONFIG_PPC_BOOK3S_32)	+= bats.o segment_regs.o
-obj-$(CONFIG_PPC_BOOK3S_64)	+= hashpagetable.o
+obj-$(CONFIG_PPC_64S_HASH_MMU)	+= hashpagetable.o
 endif