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

4 files changed, 35 insertions, 4 deletions

diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
index 3004f3323144..21f780942911 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
@@ -523,8 +523,14 @@ void slb_save_contents(struct slb_entry *slb_ptr);
 void slb_dump_contents(struct slb_entry *slb_ptr);
 
 extern void slb_vmalloc_update(void);
-extern void slb_set_size(u16 size);
 void preload_new_slb_context(unsigned long start, unsigned long sp);
+
+#ifdef CONFIG_PPC_64S_HASH_MMU
+void slb_set_size(u16 size);
+#else
+static inline void slb_set_size(u16 size) { }
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 /*
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index a265c5618ce8..7fee46e50377 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -105,7 +105,9 @@ typedef struct {
 		 * from EA and new context ids to build the new VAs.
 		 */
 		mm_context_id_t id;
+#ifdef CONFIG_PPC_64S_HASH_MMU
 		mm_context_id_t extended_id[TASK_SIZE_USER64/TASK_CONTEXT_SIZE];
+#endif
 	};
 
 	/* Number of bits in the mm_cpumask */
@@ -117,7 +119,9 @@ typedef struct {
 	/* Number of user space windows opened in process mm_context */
 	atomic_t vas_windows;
 
+#ifdef CONFIG_PPC_64S_HASH_MMU
 	struct hash_mm_context *hash_context;
+#endif
 
 	void __user *vdso;
 	/*
@@ -140,6 +144,7 @@ typedef struct {
 #endif
 } mm_context_t;
 
+#ifdef CONFIG_PPC_64S_HASH_MMU
 static inline u16 mm_ctx_user_psize(mm_context_t *ctx)
 {
 	return ctx->hash_context->user_psize;
@@ -200,8 +205,15 @@ static inline struct subpage_prot_table *mm_ctx_subpage_prot(mm_context_t *ctx)
 extern int mmu_linear_psize;
 extern int mmu_virtual_psize;
 extern int mmu_vmalloc_psize;
-extern int mmu_vmemmap_psize;
 extern int mmu_io_psize;
+#else /* CONFIG_PPC_64S_HASH_MMU */
+#ifdef CONFIG_PPC_64K_PAGES
+#define mmu_virtual_psize MMU_PAGE_64K
+#else
+#define mmu_virtual_psize MMU_PAGE_4K
+#endif
+#endif
+extern int mmu_vmemmap_psize;
 
 /* MMU initialization */
 void mmu_early_init_devtree(void);
@@ -240,8 +252,9 @@ static inline void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 	 * know which translations we will pick. Hence go with hash
 	 * restrictions.
 	 */
-	return hash__setup_initial_memory_limit(first_memblock_base,
-					   first_memblock_size);
+	if (!early_radix_enabled())
+		hash__setup_initial_memory_limit(first_memblock_base,
+						 first_memblock_size);
 }
 
 #ifdef CONFIG_PPC_PSERIES
@@ -262,6 +275,7 @@ static inline void radix_init_pseries(void) { }
 void cleanup_cpu_mmu_context(void);
 #endif
 
+#ifdef CONFIG_PPC_64S_HASH_MMU
 static inline int get_user_context(mm_context_t *ctx, unsigned long ea)
 {
 	int index = ea >> MAX_EA_BITS_PER_CONTEXT;
@@ -281,6 +295,7 @@ static inline unsigned long get_user_vsid(mm_context_t *ctx,
 
 	return get_vsid(context, ea, ssize);
 }
+#endif
 
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_POWERPC_BOOK3S_64_MMU_H_ */
diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
index 3b95769739c7..8b762f282190 100644
--- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
@@ -112,8 +112,14 @@ static inline void hash__flush_tlb_kernel_range(unsigned long start,
 
 struct mmu_gather;
 extern void hash__tlb_flush(struct mmu_gather *tlb);
+void flush_tlb_pmd_range(struct mm_struct *mm, pmd_t *pmd, unsigned long addr);
+
+#ifdef CONFIG_PPC_64S_HASH_MMU
 /* Private function for use by PCI IO mapping code */
 extern void __flush_hash_table_range(unsigned long start, unsigned long end);
 extern void flush_tlb_pmd_range(struct mm_struct *mm, pmd_t *pmd,
 				unsigned long addr);
+#else
+static inline void __flush_hash_table_range(unsigned long start, unsigned long end) { }
+#endif
 #endif /*  _ASM_POWERPC_BOOK3S_64_TLBFLUSH_HASH_H */
diff --git a/arch/powerpc/include/asm/book3s/pgtable.h b/arch/powerpc/include/asm/book3s/pgtable.h
index ad130e15a126..e8269434ecbe 100644
--- a/arch/powerpc/include/asm/book3s/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/pgtable.h
@@ -25,6 +25,7 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 				     unsigned long size, pgprot_t vma_prot);
 #define __HAVE_PHYS_MEM_ACCESS_PROT
 
+#if defined(CONFIG_PPC32) || defined(CONFIG_PPC_64S_HASH_MMU)
 /*
  * This gets called at the end of handling a page fault, when
  * the kernel has put a new PTE into the page table for the process.
@@ -35,6 +36,9 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  * waiting for the inevitable extra hash-table miss exception.
  */
 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep);
+#else
+static inline void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep) {}
+#endif
 
 #endif /* __ASSEMBLY__ */
 #endif