diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 9bc98c239305e5e7a2cb4cce8df5a5b451565c33..2741831482f47b741fea6e34cd3fcc7c8e02714c 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -77,6 +77,8 @@ void kernel_bad_stack(struct pt_regs *regs);
 void system_reset_exception(struct pt_regs *regs);
 void machine_check_exception(struct pt_regs *regs);
 void emulation_assist_interrupt(struct pt_regs *regs);
+long do_slb_fault(struct pt_regs *regs, unsigned long ea);
+void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err);
 
 /* signals, syscalls and interrupts */
 long sys_swapcontext(struct ucontext __user *old_ctx,
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 403d73898a9a1f1830d9f31db204f9c95aa80754..3b4767ed3ec53f04528c1cd0d651d9a55f3f929b 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -60,14 +60,6 @@
  */
 #define MAX_MCE_DEPTH	4
 
-/*
- * EX_LR is only used in EXSLB and where it does not overlap with EX_DAR
- * EX_CCR similarly with DSISR, but being 4 byte registers there is a hole
- * in the save area so it's not necessary to overlap them. Could be used
- * for future savings though if another 4 byte register was to be saved.
- */
-#define EX_LR		EX_DAR
-
 /*
  * EX_R3 is only used by the bad_stack handler. bad_stack reloads and
  * saves DAR from SPRN_DAR, and EX_DAR is not used. So EX_R3 can overlap
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index b9239dbf6d59ab28a9bc45f5969f650a6f47c741..89d32bb79d5eeb91520e78364bca1590f7b265b1 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -596,28 +596,36 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 
 
 EXC_REAL_BEGIN(data_access_slb, 0x380, 0x80)
-	SET_SCRATCH0(r13)
-	EXCEPTION_PROLOG_0(PACA_EXSLB)
-	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x380)
-	mr	r12,r3	/* save r3 */
-	mfspr	r3,SPRN_DAR
-	mfspr	r11,SPRN_SRR1
-	crset	4*cr6+eq
-	BRANCH_TO_COMMON(r10, slb_miss_common)
+EXCEPTION_PROLOG(PACA_EXSLB, data_access_slb_common, EXC_STD, KVMTEST_PR, 0x380);
 EXC_REAL_END(data_access_slb, 0x380, 0x80)
 
 EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x80)
-	SET_SCRATCH0(r13)
-	EXCEPTION_PROLOG_0(PACA_EXSLB)
-	EXCEPTION_PROLOG_1(PACA_EXSLB, NOTEST, 0x380)
-	mr	r12,r3	/* save r3 */
-	mfspr	r3,SPRN_DAR
-	mfspr	r11,SPRN_SRR1
-	crset	4*cr6+eq
-	BRANCH_TO_COMMON(r10, slb_miss_common)
+EXCEPTION_RELON_PROLOG(PACA_EXSLB, data_access_slb_common, EXC_STD, NOTEST, 0x380);
 EXC_VIRT_END(data_access_slb, 0x4380, 0x80)
+
 TRAMP_KVM_SKIP(PACA_EXSLB, 0x380)
 
+EXC_COMMON_BEGIN(data_access_slb_common)
+	mfspr	r10,SPRN_DAR
+	std	r10,PACA_EXSLB+EX_DAR(r13)
+	EXCEPTION_PROLOG_COMMON(0x380, PACA_EXSLB)
+	ld	r4,PACA_EXSLB+EX_DAR(r13)
+	std	r4,_DAR(r1)
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	do_slb_fault
+	cmpdi	r3,0
+	bne-	1f
+	b	fast_exception_return
+1:	/* Error case */
+	std	r3,RESULT(r1)
+	bl	save_nvgprs
+	RECONCILE_IRQ_STATE(r10, r11)
+	ld	r4,_DAR(r1)
+	ld	r5,RESULT(r1)
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	do_bad_slb_fault
+	b	ret_from_except
+
 
 EXC_REAL(instruction_access, 0x400, 0x80)
 EXC_VIRT(instruction_access, 0x4400, 0x80, 0x400)
@@ -640,160 +648,34 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 
 
 EXC_REAL_BEGIN(instruction_access_slb, 0x480, 0x80)
-	SET_SCRATCH0(r13)
-	EXCEPTION_PROLOG_0(PACA_EXSLB)
-	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x480)
-	mr	r12,r3	/* save r3 */
-	mfspr	r3,SPRN_SRR0		/* SRR0 is faulting address */
-	mfspr	r11,SPRN_SRR1
-	crclr	4*cr6+eq
-	BRANCH_TO_COMMON(r10, slb_miss_common)
+EXCEPTION_PROLOG(PACA_EXSLB, instruction_access_slb_common, EXC_STD, KVMTEST_PR, 0x480);
 EXC_REAL_END(instruction_access_slb, 0x480, 0x80)
 
 EXC_VIRT_BEGIN(instruction_access_slb, 0x4480, 0x80)
-	SET_SCRATCH0(r13)
-	EXCEPTION_PROLOG_0(PACA_EXSLB)
-	EXCEPTION_PROLOG_1(PACA_EXSLB, NOTEST, 0x480)
-	mr	r12,r3	/* save r3 */
-	mfspr	r3,SPRN_SRR0		/* SRR0 is faulting address */
-	mfspr	r11,SPRN_SRR1
-	crclr	4*cr6+eq
-	BRANCH_TO_COMMON(r10, slb_miss_common)
+EXCEPTION_RELON_PROLOG(PACA_EXSLB, instruction_access_slb_common, EXC_STD, NOTEST, 0x480);
 EXC_VIRT_END(instruction_access_slb, 0x4480, 0x80)
-TRAMP_KVM(PACA_EXSLB, 0x480)
-
-
-/*
- * This handler is used by the 0x380 and 0x480 SLB miss interrupts, as well as
- * the virtual mode 0x4380 and 0x4480 interrupts if AIL is enabled.
- */
-EXC_COMMON_BEGIN(slb_miss_common)
-	/*
-	 * r13 points to the PACA, r9 contains the saved CR,
-	 * r12 contains the saved r3,
-	 * r11 contain the saved SRR1, SRR0 is still ready for return
-	 * r3 has the faulting address
-	 * r9 - r13 are saved in paca->exslb.
- 	 * cr6.eq is set for a D-SLB miss, clear for a I-SLB miss
-	 * We assume we aren't going to take any exceptions during this
-	 * procedure.
-	 */
-	mflr	r10
-	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
-	std	r10,PACA_EXSLB+EX_LR(r13)	/* save LR */
-
-	andi.	r9,r11,MSR_PR	// Check for exception from userspace
-	cmpdi	cr4,r9,MSR_PR	// And save the result in CR4 for later
-
-	/*
-	 * Test MSR_RI before calling slb_allocate_realmode, because the
-	 * MSR in r11 gets clobbered. However we still want to allocate
-	 * SLB in case MSR_RI=0, to minimise the risk of getting stuck in
-	 * recursive SLB faults. So use cr5 for this, which is preserved.
-	 */
-	andi.	r11,r11,MSR_RI	/* check for unrecoverable exception */
-	cmpdi	cr5,r11,MSR_RI
-
-	crset	4*cr0+eq
-#ifdef CONFIG_PPC_BOOK3S_64
-BEGIN_MMU_FTR_SECTION
-	bl	slb_allocate
-END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
-#endif
-
-	ld	r10,PACA_EXSLB+EX_LR(r13)
-	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */
-	mtlr	r10
-
-	/*
-	 * Large address, check whether we have to allocate new contexts.
-	 */
-	beq-	8f
 
-	bne-	cr5,2f		/* if unrecoverable exception, oops */
-
-	/* All done -- return from exception. */
-
-	bne	cr4,1f		/* returning to kernel */
-
-	mtcrf	0x80,r9
-	mtcrf	0x08,r9		/* MSR[PR] indication is in cr4 */
-	mtcrf	0x04,r9		/* MSR[RI] indication is in cr5 */
-	mtcrf	0x02,r9		/* I/D indication is in cr6 */
-	mtcrf	0x01,r9		/* slb_allocate uses cr0 and cr7 */
-
-	RESTORE_CTR(r9, PACA_EXSLB)
-	RESTORE_PPR_PACA(PACA_EXSLB, r9)
-	mr	r3,r12
-	ld	r9,PACA_EXSLB+EX_R9(r13)
-	ld	r10,PACA_EXSLB+EX_R10(r13)
-	ld	r11,PACA_EXSLB+EX_R11(r13)
-	ld	r12,PACA_EXSLB+EX_R12(r13)
-	ld	r13,PACA_EXSLB+EX_R13(r13)
-	RFI_TO_USER
-	b	.	/* prevent speculative execution */
-1:
-	mtcrf	0x80,r9
-	mtcrf	0x08,r9		/* MSR[PR] indication is in cr4 */
-	mtcrf	0x04,r9		/* MSR[RI] indication is in cr5 */
-	mtcrf	0x02,r9		/* I/D indication is in cr6 */
-	mtcrf	0x01,r9		/* slb_allocate uses cr0 and cr7 */
-
-	RESTORE_CTR(r9, PACA_EXSLB)
-	RESTORE_PPR_PACA(PACA_EXSLB, r9)
-	mr	r3,r12
-	ld	r9,PACA_EXSLB+EX_R9(r13)
-	ld	r10,PACA_EXSLB+EX_R10(r13)
-	ld	r11,PACA_EXSLB+EX_R11(r13)
-	ld	r12,PACA_EXSLB+EX_R12(r13)
-	ld	r13,PACA_EXSLB+EX_R13(r13)
-	RFI_TO_KERNEL
-	b	.	/* prevent speculative execution */
-
-
-2:	std     r3,PACA_EXSLB+EX_DAR(r13)
-	mr	r3,r12
-	mfspr	r11,SPRN_SRR0
-	mfspr	r12,SPRN_SRR1
-	LOAD_HANDLER(r10,unrecov_slb)
-	mtspr	SPRN_SRR0,r10
-	ld	r10,PACAKMSR(r13)
-	mtspr	SPRN_SRR1,r10
-	RFI_TO_KERNEL
-	b	.
-
-8:	std     r3,PACA_EXSLB+EX_DAR(r13)
-	mr	r3,r12
-	mfspr	r11,SPRN_SRR0
-	mfspr	r12,SPRN_SRR1
-	LOAD_HANDLER(r10, large_addr_slb)
-	mtspr	SPRN_SRR0,r10
-	ld	r10,PACAKMSR(r13)
-	mtspr	SPRN_SRR1,r10
-	RFI_TO_KERNEL
-	b	.
+TRAMP_KVM(PACA_EXSLB, 0x480)
 
-EXC_COMMON_BEGIN(unrecov_slb)
-	EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
-	RECONCILE_IRQ_STATE(r10, r11)
+EXC_COMMON_BEGIN(instruction_access_slb_common)
+	EXCEPTION_PROLOG_COMMON(0x480, PACA_EXSLB)
+	ld	r4,_NIP(r1)
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	do_slb_fault
+	cmpdi	r3,0
+	bne-	1f
+	b	fast_exception_return
+1:	/* Error case */
+	std	r3,RESULT(r1)
 	bl	save_nvgprs
-1:	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	unrecoverable_exception
-	b	1b
-
-EXC_COMMON_BEGIN(large_addr_slb)
-	EXCEPTION_PROLOG_COMMON(0x380, PACA_EXSLB)
 	RECONCILE_IRQ_STATE(r10, r11)
-	ld	r3, PACA_EXSLB+EX_DAR(r13)
-	std	r3, _DAR(r1)
-	beq	cr6, 2f
-	li	r10, 0x481		/* fix trap number for I-SLB miss */
-	std	r10, _TRAP(r1)
-2:	bl	save_nvgprs
-	addi	r3, r1, STACK_FRAME_OVERHEAD
-	bl	slb_miss_large_addr
+	ld	r4,_NIP(r1)
+	ld	r5,RESULT(r1)
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	do_bad_slb_fault
 	b	ret_from_except
 
+
 EXC_REAL_BEGIN(hardware_interrupt, 0x500, 0x100)
 	.globl hardware_interrupt_hv;
 hardware_interrupt_hv:
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index 3c844bdd16c4ee4e59656cf89f34364543fb9a82..ceb352ccbc76732caf3e31db927078a7df884bb4 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -7,6 +7,8 @@ subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
 
 ccflags-$(CONFIG_PPC64)	:= $(NO_MINIMAL_TOC)
 
+CFLAGS_REMOVE_slb.o = $(CC_FLAGS_FTRACE)
+
 obj-y				:= fault.o mem.o pgtable.o mmap.o \
 				   init_$(BITS).o pgtable_$(BITS).o \
 				   init-common.o mmu_context.o drmem.o
@@ -15,7 +17,7 @@ obj-$(CONFIG_PPC_MMU_NOHASH)	+= mmu_context_nohash.o tlb_nohash.o \
 obj-$(CONFIG_PPC_BOOK3E)	+= tlb_low_$(BITS)e.o
 hash64-$(CONFIG_PPC_NATIVE)	:= hash_native_64.o
 obj-$(CONFIG_PPC_BOOK3E_64)   += pgtable-book3e.o
-obj-$(CONFIG_PPC_BOOK3S_64)	+= pgtable-hash64.o hash_utils_64.o slb_low.o slb.o $(hash64-y) mmu_context_book3s64.o pgtable-book3s64.o
+obj-$(CONFIG_PPC_BOOK3S_64)	+= pgtable-hash64.o hash_utils_64.o slb.o $(hash64-y) mmu_context_book3s64.o pgtable-book3s64.o
 obj-$(CONFIG_PPC_RADIX_MMU)	+= pgtable-radix.o tlb-radix.o
 obj-$(CONFIG_PPC_STD_MMU_32)	+= ppc_mmu_32.o hash_low_32.o mmu_context_hash32.o
 obj-$(CONFIG_PPC_STD_MMU)	+= tlb_hash$(BITS).o
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 513c6596140ddbff4778fb5ad16deb02d541db80..76c1a9523049b44833e975a640eda95029311a60 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -14,6 +14,7 @@
  *      2 of the License, or (at your option) any later version.
  */
 
+#include <asm/asm-prototypes.h>
 #include <asm/pgtable.h>
 #include <asm/mmu.h>
 #include <asm/mmu_context.h>
@@ -33,7 +34,7 @@ enum slb_index {
 	KSTACK_INDEX	= 1, /* Kernel stack map */
 };
 
-extern void slb_allocate(unsigned long ea);
+static long slb_allocate_user(struct mm_struct *mm, unsigned long ea);
 
 #define slb_esid_mask(ssize)	\
 	(((ssize) == MMU_SEGSIZE_256M)? ESID_MASK: ESID_MASK_1T)
@@ -44,13 +45,19 @@ static inline unsigned long mk_esid_data(unsigned long ea, int ssize,
 	return (ea & slb_esid_mask(ssize)) | SLB_ESID_V | index;
 }
 
-static inline unsigned long mk_vsid_data(unsigned long ea, int ssize,
+static inline unsigned long __mk_vsid_data(unsigned long vsid, int ssize,
 					 unsigned long flags)
 {
-	return (get_kernel_vsid(ea, ssize) << slb_vsid_shift(ssize)) | flags |
+	return (vsid << slb_vsid_shift(ssize)) | flags |
 		((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
 }
 
+static inline unsigned long mk_vsid_data(unsigned long ea, int ssize,
+					 unsigned long flags)
+{
+	return __mk_vsid_data(get_kernel_vsid(ea, ssize), ssize, flags);
+}
+
 static inline void slb_shadow_update(unsigned long ea, int ssize,
 				     unsigned long flags,
 				     enum slb_index index)
@@ -353,49 +360,19 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
 	    is_kernel_addr(exec_base))
 		return;
 
-	slb_allocate(pc);
+	slb_allocate_user(mm, pc);
 
 	if (!esids_match(pc, stack))
-		slb_allocate(stack);
+		slb_allocate_user(mm, stack);
 
 	if (!esids_match(pc, exec_base) &&
 	    !esids_match(stack, exec_base))
-		slb_allocate(exec_base);
-}
-
-static inline void patch_slb_encoding(unsigned int *insn_addr,
-				      unsigned int immed)
-{
-
-	/*
-	 * This function patches either an li or a cmpldi instruction with
-	 * a new immediate value. This relies on the fact that both li
-	 * (which is actually addi) and cmpldi both take a 16-bit immediate
-	 * value, and it is situated in the same location in the instruction,
-	 * ie. bits 16-31 (Big endian bit order) or the lower 16 bits.
-	 * The signedness of the immediate operand differs between the two
-	 * instructions however this code is only ever patching a small value,
-	 * much less than 1 << 15, so we can get away with it.
-	 * To patch the value we read the existing instruction, clear the
-	 * immediate value, and or in our new value, then write the instruction
-	 * back.
-	 */
-	unsigned int insn = (*insn_addr & 0xffff0000) | immed;
-	patch_instruction(insn_addr, insn);
+		slb_allocate_user(mm, exec_base);
 }
 
-extern u32 slb_miss_kernel_load_linear[];
-extern u32 slb_miss_kernel_load_io[];
-extern u32 slb_compare_rr_to_size[];
-extern u32 slb_miss_kernel_load_vmemmap[];
-
 void slb_set_size(u16 size)
 {
-	if (mmu_slb_size == size)
-		return;
-
 	mmu_slb_size = size;
-	patch_slb_encoding(slb_compare_rr_to_size, mmu_slb_size);
 }
 
 void slb_initialize(void)
@@ -417,19 +394,9 @@ void slb_initialize(void)
 #endif
 	if (!slb_encoding_inited) {
 		slb_encoding_inited = 1;
-		patch_slb_encoding(slb_miss_kernel_load_linear,
-				   SLB_VSID_KERNEL | linear_llp);
-		patch_slb_encoding(slb_miss_kernel_load_io,
-				   SLB_VSID_KERNEL | io_llp);
-		patch_slb_encoding(slb_compare_rr_to_size,
-				   mmu_slb_size);
-
 		pr_devel("SLB: linear  LLP = %04lx\n", linear_llp);
 		pr_devel("SLB: io      LLP = %04lx\n", io_llp);
-
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
-		patch_slb_encoding(slb_miss_kernel_load_vmemmap,
-				   SLB_VSID_KERNEL | vmemmap_llp);
 		pr_devel("SLB: vmemmap LLP = %04lx\n", vmemmap_llp);
 #endif
 	}
@@ -458,125 +425,203 @@ void slb_initialize(void)
 	asm volatile("isync":::"memory");
 }
 
-static void insert_slb_entry(unsigned long vsid, unsigned long ea,
-			     int bpsize, int ssize)
+static void slb_cache_update(unsigned long esid_data)
 {
-	unsigned long flags, vsid_data, esid_data;
-	enum slb_index index;
 	int slb_cache_index;
 
 	if (cpu_has_feature(CPU_FTR_ARCH_300))
 		return; /* ISAv3.0B and later does not use slb_cache */
 
 	/*
-	 * We are irq disabled, hence should be safe to access PACA.
+	 * Now update slb cache entries
 	 */
-	VM_WARN_ON(!irqs_disabled());
+	slb_cache_index = local_paca->slb_cache_ptr;
+	if (slb_cache_index < SLB_CACHE_ENTRIES) {
+		/*
+		 * We have space in slb cache for optimized switch_slb().
+		 * Top 36 bits from esid_data as per ISA
+		 */
+		local_paca->slb_cache[slb_cache_index++] = esid_data >> 28;
+		local_paca->slb_cache_ptr++;
+	} else {
+		/*
+		 * Our cache is full and the current cache content strictly
+		 * doesn't indicate the active SLB conents. Bump the ptr
+		 * so that switch_slb() will ignore the cache.
+		 */
+		local_paca->slb_cache_ptr = SLB_CACHE_ENTRIES + 1;
+	}
+}
 
-	/*
-	 * We can't take a PMU exception in the following code, so hard
-	 * disable interrupts.
-	 */
-	hard_irq_disable();
+static enum slb_index alloc_slb_index(void)
+{
+	enum slb_index index;
 
+	/* round-robin replacement of slb starting at SLB_NUM_BOLTED. */
 	index = get_paca()->stab_rr;
-
-	/*
-	 * simple round-robin replacement of slb starting at SLB_NUM_BOLTED.
-	 */
 	if (index < (mmu_slb_size - 1))
 		index++;
 	else
 		index = SLB_NUM_BOLTED;
-
 	get_paca()->stab_rr = index;
 
-	flags = SLB_VSID_USER | mmu_psize_defs[bpsize].sllp;
-	vsid_data = (vsid << slb_vsid_shift(ssize)) | flags |
-		    ((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
+	return index;
+}
+
+static long slb_insert_entry(unsigned long ea, unsigned long context,
+				unsigned long flags, int ssize, bool kernel)
+{
+	unsigned long vsid;
+	unsigned long vsid_data, esid_data;
+	enum slb_index index;
+
+	vsid = get_vsid(context, ea, ssize);
+	if (!vsid)
+		return -EFAULT;
+
+	/*
+	 * There must not be a kernel SLB fault in alloc_slb_index or before
+	 * slbmte here or the allocation bitmaps could get out of whack with
+	 * the SLB.
+	 *
+	 * User SLB faults or preloads take this path which might get inlined
+	 * into the caller, so add compiler barriers here to ensure unsafe
+	 * memory accesses do not come between.
+	 */
+	barrier();
+
+	index = alloc_slb_index();
+
+	vsid_data = __mk_vsid_data(vsid, ssize, flags);
 	esid_data = mk_esid_data(ea, ssize, index);
 
 	/*
 	 * No need for an isync before or after this slbmte. The exception
 	 * we enter with and the rfid we exit with are context synchronizing.
-	 * Also we only handle user segments here.
+	 * User preloads should add isync afterwards in case the kernel
+	 * accesses user memory before it returns to userspace with rfid.
 	 */
-	asm volatile("slbmte %0, %1" : : "r" (vsid_data), "r" (esid_data)
-		     : "memory");
+	asm volatile("slbmte %0, %1" : : "r" (vsid_data), "r" (esid_data));
 
-	/*
-	 * Now update slb cache entries
-	 */
-	slb_cache_index = get_paca()->slb_cache_ptr;
-	if (slb_cache_index < SLB_CACHE_ENTRIES) {
-		/*
-		 * We have space in slb cache for optimized switch_slb().
-		 * Top 36 bits from esid_data as per ISA
-		 */
-		get_paca()->slb_cache[slb_cache_index++] = esid_data >> 28;
-		get_paca()->slb_cache_ptr++;
+	barrier();
+
+	if (!kernel)
+		slb_cache_update(esid_data);
+
+	return 0;
+}
+
+static long slb_allocate_kernel(unsigned long ea, unsigned long id)
+{
+	unsigned long context;
+	unsigned long flags;
+	int ssize;
+
+	if ((ea & ~REGION_MASK) >= (1ULL << MAX_EA_BITS_PER_CONTEXT))
+		return -EFAULT;
+
+	if (id == KERNEL_REGION_ID) {
+		flags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp;
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	} else if (id == VMEMMAP_REGION_ID) {
+		flags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_vmemmap_psize].sllp;
+#endif
+	} else if (id == VMALLOC_REGION_ID) {
+		if (ea < H_VMALLOC_END)
+			flags = get_paca()->vmalloc_sllp;
+		else
+			flags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_io_psize].sllp;
 	} else {
-		/*
-		 * Our cache is full and the current cache content strictly
-		 * doesn't indicate the active SLB conents. Bump the ptr
-		 * so that switch_slb() will ignore the cache.
-		 */
-		get_paca()->slb_cache_ptr = SLB_CACHE_ENTRIES + 1;
+		return -EFAULT;
 	}
+
+	ssize = MMU_SEGSIZE_1T;
+	if (!mmu_has_feature(MMU_FTR_1T_SEGMENT))
+		ssize = MMU_SEGSIZE_256M;
+
+	context = id - KERNEL_REGION_CONTEXT_OFFSET;
+
+	return slb_insert_entry(ea, context, flags, ssize, true);
 }
 
-static void handle_multi_context_slb_miss(int context_id, unsigned long ea)
+static long slb_allocate_user(struct mm_struct *mm, unsigned long ea)
 {
-	struct mm_struct *mm = current->mm;
-	unsigned long vsid;
+	unsigned long context;
+	unsigned long flags;
 	int bpsize;
+	int ssize;
 
 	/*
-	 * We are always above 1TB, hence use high user segment size.
+	 * consider this as bad access if we take a SLB miss
+	 * on an address above addr limit.
 	 */
-	vsid = get_vsid(context_id, ea, mmu_highuser_ssize);
+	if (ea >= mm->context.slb_addr_limit)
+		return -EFAULT;
+
+	context = get_ea_context(&mm->context, ea);
+	if (!context)
+		return -EFAULT;
+
+	if (unlikely(ea >= H_PGTABLE_RANGE)) {
+		WARN_ON(1);
+		return -EFAULT;
+	}
+
+	ssize = user_segment_size(ea);
+
 	bpsize = get_slice_psize(mm, ea);
-	insert_slb_entry(vsid, ea, bpsize, mmu_highuser_ssize);
+	flags = SLB_VSID_USER | mmu_psize_defs[bpsize].sllp;
+
+	return slb_insert_entry(ea, context, flags, ssize, false);
 }
 
-void slb_miss_large_addr(struct pt_regs *regs)
+long do_slb_fault(struct pt_regs *regs, unsigned long ea)
 {
-	enum ctx_state prev_state = exception_enter();
-	unsigned long ea = regs->dar;
-	int context;
+	unsigned long id = REGION_ID(ea);
 
-	if (REGION_ID(ea) != USER_REGION_ID)
-		goto slb_bad_addr;
+	/* IRQs are not reconciled here, so can't check irqs_disabled */
+	VM_WARN_ON(mfmsr() & MSR_EE);
 
-	/*
-	 * Are we beyound what the page table layout supports ?
-	 */
-	if ((ea & ~REGION_MASK) >= H_PGTABLE_RANGE)
-		goto slb_bad_addr;
-
-	/* Lower address should have been handled by asm code */
-	if (ea < (1UL << MAX_EA_BITS_PER_CONTEXT))
-		goto slb_bad_addr;
+	if (unlikely(!(regs->msr & MSR_RI)))
+		return -EINVAL;
 
 	/*
-	 * consider this as bad access if we take a SLB miss
-	 * on an address above addr limit.
+	 * SLB kernel faults must be very careful not to touch anything
+	 * that is not bolted. E.g., PACA and global variables are okay,
+	 * mm->context stuff is not.
+	 *
+	 * SLB user faults can access all of kernel memory, but must be
+	 * careful not to touch things like IRQ state because it is not
+	 * "reconciled" here. The difficulty is that we must use
+	 * fast_exception_return to return from kernel SLB faults without
+	 * looking at possible non-bolted memory. We could test user vs
+	 * kernel faults in the interrupt handler asm and do a full fault,
+	 * reconcile, ret_from_except for user faults which would make them
+	 * first class kernel code. But for performance it's probably nicer
+	 * if they go via fast_exception_return too.
 	 */
-	if (ea >= current->mm->context.slb_addr_limit)
-		goto slb_bad_addr;
+	if (id >= KERNEL_REGION_ID) {
+		return slb_allocate_kernel(ea, id);
+	} else {
+		struct mm_struct *mm = current->mm;
 
-	context = get_ea_context(&current->mm->context, ea);
-	if (!context)
-		goto slb_bad_addr;
+		if (unlikely(!mm))
+			return -EFAULT;
 
-	handle_multi_context_slb_miss(context, ea);
-	exception_exit(prev_state);
-	return;
+		return slb_allocate_user(mm, ea);
+	}
+}
 
-slb_bad_addr:
-	if (user_mode(regs))
-		_exception(SIGSEGV, regs, SEGV_BNDERR, ea);
-	else
-		bad_page_fault(regs, ea, SIGSEGV);
-	exception_exit(prev_state);
+void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err)
+{
+	if (err == -EFAULT) {
+		if (user_mode(regs))
+			_exception(SIGSEGV, regs, SEGV_BNDERR, ea);
+		else
+			bad_page_fault(regs, ea, SIGSEGV);
+	} else if (err == -EINVAL) {
+		unrecoverable_exception(regs);
+	} else {
+		BUG();
+	}
 }
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
deleted file mode 100644
index 4d2e921d696e8136f4e9ef07255ada7932ec79f7..0000000000000000000000000000000000000000
--- a/arch/powerpc/mm/slb_low.S
+++ /dev/null
@@ -1,335 +0,0 @@
-/*
- * Low-level SLB routines
- *
- * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM
- *
- * Based on earlier C version:
- * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com
- *    Copyright (c) 2001 Dave Engebretsen
- * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; either version
- *  2 of the License, or (at your option) any later version.
- */
-
-#include <asm/processor.h>
-#include <asm/ppc_asm.h>
-#include <asm/asm-offsets.h>
-#include <asm/cputable.h>
-#include <asm/page.h>
-#include <asm/mmu.h>
-#include <asm/pgtable.h>
-#include <asm/firmware.h>
-#include <asm/feature-fixups.h>
-
-/*
- * This macro generates asm code to compute the VSID scramble
- * function.  Used in slb_allocate() and do_stab_bolted.  The function
- * computed is: (protovsid*VSID_MULTIPLIER) % VSID_MODULUS
- *
- *	rt = register containing the proto-VSID and into which the
- *		VSID will be stored
- *	rx = scratch register (clobbered)
- *	rf = flags
- *
- *	- rt and rx must be different registers
- *	- The answer will end up in the low VSID_BITS bits of rt.  The higher
- *	  bits may contain other garbage, so you may need to mask the
- *	  result.
- */
-#define ASM_VSID_SCRAMBLE(rt, rx, rf, size)				\
-	lis	rx,VSID_MULTIPLIER_##size@h;				\
-	ori	rx,rx,VSID_MULTIPLIER_##size@l;				\
-	mulld	rt,rt,rx;		/* rt = rt * MULTIPLIER */	\
-/*									\
- * powermac get slb fault before feature fixup, so make 65 bit part     \
- * the default part of feature fixup					\
- */									\
-BEGIN_MMU_FTR_SECTION							\
-	srdi	rx,rt,VSID_BITS_65_##size;				\
-	clrldi	rt,rt,(64-VSID_BITS_65_##size);				\
-	add	rt,rt,rx;						\
-	addi	rx,rt,1;						\
-	srdi	rx,rx,VSID_BITS_65_##size;				\
-	add	rt,rt,rx;						\
-	rldimi	rf,rt,SLB_VSID_SHIFT_##size,(64 - (SLB_VSID_SHIFT_##size + VSID_BITS_65_##size)); \
-MMU_FTR_SECTION_ELSE							\
-	srdi	rx,rt,VSID_BITS_##size;					\
-	clrldi	rt,rt,(64-VSID_BITS_##size);				\
-	add	rt,rt,rx;		/* add high and low bits */	\
-	addi	rx,rt,1;						\
-	srdi	rx,rx,VSID_BITS_##size;	/* extract 2^VSID_BITS bit */	\
-	add	rt,rt,rx;						\
-	rldimi	rf,rt,SLB_VSID_SHIFT_##size,(64 - (SLB_VSID_SHIFT_##size + VSID_BITS_##size)); \
-ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_68_BIT_VA)
-
-
-/* void slb_allocate(unsigned long ea);
- *
- * Create an SLB entry for the given EA (user or kernel).
- * 	r3 = faulting address, r13 = PACA
- *	r9, r10, r11 are clobbered by this function
- *	r3 is preserved.
- * No other registers are examined or changed.
- */
-_GLOBAL(slb_allocate)
-	/*
-	 * Check if the address falls within the range of the first context, or
-	 * if we may need to handle multi context. For the first context we
-	 * allocate the slb entry via the fast path below. For large address we
-	 * branch out to C-code and see if additional contexts have been
-	 * allocated.
-	 * The test here is:
-	 *   (ea & ~REGION_MASK) >= (1ull << MAX_EA_BITS_PER_CONTEXT)
-	 */
-	rldicr. r9,r3,4,(63 - MAX_EA_BITS_PER_CONTEXT - 4)
-	bne-	8f
-
-	srdi	r9,r3,60		/* get region */
-	srdi	r10,r3,SID_SHIFT	/* get esid */
-	cmpldi	cr7,r9,0xc		/* cmp PAGE_OFFSET for later use */
-
-	/* r3 = address, r10 = esid, cr7 = <> PAGE_OFFSET */
-	blt	cr7,0f			/* user or kernel? */
-
-	/* Check if hitting the linear mapping or some other kernel space
-	*/
-	bne	cr7,1f
-
-	/* Linear mapping encoding bits, the "li" instruction below will
-	 * be patched by the kernel at boot
-	 */
-.globl slb_miss_kernel_load_linear
-slb_miss_kernel_load_linear:
-	li	r11,0
-	/*
-	 * context = (ea >> 60) - (0xc - 1)
-	 * r9 = region id.
-	 */
-	subi	r9,r9,KERNEL_REGION_CONTEXT_OFFSET
-
-BEGIN_FTR_SECTION
-	b	.Lslb_finish_load
-END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
-	b	.Lslb_finish_load_1T
-
-1:
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
-	cmpldi	cr0,r9,0xf
-	bne	1f
-/* Check virtual memmap region. To be patched at kernel boot */
-.globl slb_miss_kernel_load_vmemmap
-slb_miss_kernel_load_vmemmap:
-	li	r11,0
-	b	6f
-1:
-#endif /* CONFIG_SPARSEMEM_VMEMMAP */
-
-	/*
-	 * r10 contains the ESID, which is the original faulting EA shifted
-	 * right by 28 bits. We need to compare that with (H_VMALLOC_END >> 28)
-	 * which is 0xd00038000. That can't be used as an immediate, even if we
-	 * ignored the 0xd, so we have to load it into a register, and we only
-	 * have one register free. So we must load all of (H_VMALLOC_END >> 28)
-	 * into a register and compare ESID against that.
-	 */
-	lis	r11,(H_VMALLOC_END >> 32)@h	// r11 = 0xffffffffd0000000
-	ori	r11,r11,(H_VMALLOC_END >> 32)@l	// r11 = 0xffffffffd0003800
-	// Rotate left 4, then mask with 0xffffffff0
-	rldic	r11,r11,4,28			// r11 = 0xd00038000
-	cmpld	r10,r11				// if r10 >= r11
-	bge	5f				//   goto io_mapping
-
-	/*
-	 * vmalloc mapping gets the encoding from the PACA as the mapping
-	 * can be demoted from 64K -> 4K dynamically on some machines.
-	 */
-	lhz	r11,PACAVMALLOCSLLP(r13)
-	b	6f
-5:
-	/* IO mapping */
-.globl slb_miss_kernel_load_io
-slb_miss_kernel_load_io:
-	li	r11,0
-6:
-	/*
-	 * context = (ea >> 60) - (0xc - 1)
-	 * r9 = region id.
-	 */
-	subi	r9,r9,KERNEL_REGION_CONTEXT_OFFSET
-
-BEGIN_FTR_SECTION
-	b	.Lslb_finish_load
-END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
-	b	.Lslb_finish_load_1T
-
-0:	/*
-	 * For userspace addresses, make sure this is region 0.
-	 */
-	cmpdi	r9, 0
-	bne-	8f
-        /*
-         * user space make sure we are within the allowed limit
-	 */
-	ld	r11,PACA_SLB_ADDR_LIMIT(r13)
-	cmpld	r3,r11
-	bge-	8f
-
-	/* when using slices, we extract the psize off the slice bitmaps
-	 * and then we need to get the sllp encoding off the mmu_psize_defs
-	 * array.
-	 *
-	 * XXX This is a bit inefficient especially for the normal case,
-	 * so we should try to implement a fast path for the standard page
-	 * size using the old sllp value so we avoid the array. We cannot
-	 * really do dynamic patching unfortunately as processes might flip
-	 * between 4k and 64k standard page size
-	 */
-#ifdef CONFIG_PPC_MM_SLICES
-	/* r10 have esid */
-	cmpldi	r10,16
-	/* below SLICE_LOW_TOP */
-	blt	5f
-	/*
-	 * Handle hpsizes,
-	 * r9 is get_paca()->context.high_slices_psize[index], r11 is mask_index
-	 */
-	srdi    r11,r10,(SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT + 1) /* index */
-	addi	r9,r11,PACAHIGHSLICEPSIZE
-	lbzx	r9,r13,r9		/* r9 is hpsizes[r11] */
-	/* r11 = (r10 >> (SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT)) & 0x1 */
-	rldicl	r11,r10,(64 - (SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT)),63
-	b	6f
-
-5:
-	/*
-	 * Handle lpsizes
-	 * r9 is get_paca()->context.low_slices_psize[index], r11 is mask_index
-	 */
-	srdi    r11,r10,1 /* index */
-	addi	r9,r11,PACALOWSLICESPSIZE
-	lbzx	r9,r13,r9		/* r9 is lpsizes[r11] */
-	rldicl	r11,r10,0,63		/* r11 = r10 & 0x1 */
-6:
-	sldi	r11,r11,2  /* index * 4 */
-	/* Extract the psize and multiply to get an array offset */
-	srd	r9,r9,r11
-	andi.	r9,r9,0xf
-	mulli	r9,r9,MMUPSIZEDEFSIZE
-
-	/* Now get to the array and obtain the sllp
-	 */
-	ld	r11,PACATOC(r13)
-	ld	r11,mmu_psize_defs@got(r11)
-	add	r11,r11,r9
-	ld	r11,MMUPSIZESLLP(r11)
-	ori	r11,r11,SLB_VSID_USER
-#else
-	/* paca context sllp already contains the SLB_VSID_USER bits */
-	lhz	r11,PACACONTEXTSLLP(r13)
-#endif /* CONFIG_PPC_MM_SLICES */
-
-	ld	r9,PACACONTEXTID(r13)
-BEGIN_FTR_SECTION
-	cmpldi	r10,0x1000
-	bge	.Lslb_finish_load_1T
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
-	b	.Lslb_finish_load
-
-8:	/* invalid EA - return an error indication */
-	crset	4*cr0+eq		/* indicate failure */
-	blr
-
-/*
- * Finish loading of an SLB entry and return
- *
- * r3 = EA, r9 = context, r10 = ESID, r11 = flags, clobbers r9, cr7 = <> PAGE_OFFSET
- */
-.Lslb_finish_load:
-	rldimi  r10,r9,ESID_BITS,0
-	ASM_VSID_SCRAMBLE(r10,r9,r11,256M)
-	/* r3 = EA, r11 = VSID data */
-	/*
-	 * Find a slot, round robin. Previously we tried to find a
-	 * free slot first but that took too long. Unfortunately we
-	 * dont have any LRU information to help us choose a slot.
-	 */
-
-	mr	r9,r3
-
-	/* slb_finish_load_1T continues here. r9=EA with non-ESID bits clear */
-7:	ld	r10,PACASTABRR(r13)
-	addi	r10,r10,1
-	/* This gets soft patched on boot. */
-.globl slb_compare_rr_to_size
-slb_compare_rr_to_size:
-	cmpldi	r10,0
-
-	blt+	4f
-	li	r10,SLB_NUM_BOLTED
-
-4:
-	std	r10,PACASTABRR(r13)
-
-3:
-	rldimi	r9,r10,0,36		/* r9  = EA[0:35] | entry */
-	oris	r10,r9,SLB_ESID_V@h	/* r10 = r9 | SLB_ESID_V */
-
-	/* r9 = ESID data, r11 = VSID data */
-
-	/*
-	 * No need for an isync before or after this slbmte. The exception
-	 * we enter with and the rfid we exit with are context synchronizing.
-	 */
-	slbmte	r11,r10
-
-	/* we're done for kernel addresses */
-	crclr	4*cr0+eq		/* set result to "success" */
-	bgelr	cr7
-
-	/* Update the slb cache */
-	lhz	r9,PACASLBCACHEPTR(r13)	/* offset = paca->slb_cache_ptr */
-	cmpldi	r9,SLB_CACHE_ENTRIES
-	bge	1f
-
-	/* still room in the slb cache */
-	sldi	r11,r9,2		/* r11 = offset * sizeof(u32) */
-	srdi    r10,r10,28		/* get the 36 bits of the ESID */
-	add	r11,r11,r13		/* r11 = (u32 *)paca + offset */
-	stw	r10,PACASLBCACHE(r11)	/* paca->slb_cache[offset] = esid */
-	addi	r9,r9,1			/* offset++ */
-	b	2f
-1:					/* offset >= SLB_CACHE_ENTRIES */
-	li	r9,SLB_CACHE_ENTRIES+1
-2:
-	sth	r9,PACASLBCACHEPTR(r13)	/* paca->slb_cache_ptr = offset */
-	crclr	4*cr0+eq		/* set result to "success" */
-	blr
-
-/*
- * Finish loading of a 1T SLB entry (for the kernel linear mapping) and return.
- *
- * r3 = EA, r9 = context, r10 = ESID(256MB), r11 = flags, clobbers r9
- */
-.Lslb_finish_load_1T:
-	srdi	r10,r10,(SID_SHIFT_1T - SID_SHIFT)	/* get 1T ESID */
-	rldimi  r10,r9,ESID_BITS_1T,0
-	ASM_VSID_SCRAMBLE(r10,r9,r11,1T)
-
-	li	r10,MMU_SEGSIZE_1T
-	rldimi	r11,r10,SLB_VSID_SSIZE_SHIFT,0	/* insert segment size */
-
-	/* r3 = EA, r11 = VSID data */
-	clrrdi	r9,r3,SID_SHIFT_1T	/* clear out non-ESID bits */
-	b	7b
-
-
-_ASM_NOKPROBE_SYMBOL(slb_allocate)
-_ASM_NOKPROBE_SYMBOL(slb_miss_kernel_load_linear)
-_ASM_NOKPROBE_SYMBOL(slb_miss_kernel_load_io)
-_ASM_NOKPROBE_SYMBOL(slb_compare_rr_to_size)
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
-_ASM_NOKPROBE_SYMBOL(slb_miss_kernel_load_vmemmap)
-#endif