1 files changed, 209 insertions, 104 deletions

diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 60e852f2f8e..0399a670295 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -2,7 +2,7 @@
  * PowerPC64 SLB support.
  *
  * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM
- * Based on earlier code writteh by:
+ * Based on earlier code written by:
  * 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
@@ -14,21 +14,17 @@
  *      2 of the License, or (at your option) any later version.
  */
 
-#undef DEBUG
-
-#include <linux/config.h>
 #include <asm/pgtable.h>
 #include <asm/mmu.h>
 #include <asm/mmu_context.h>
 #include <asm/paca.h>
 #include <asm/cputable.h>
 #include <asm/cacheflush.h>
+#include <asm/smp.h>
+#include <linux/compiler.h>
+#include <asm/udbg.h>
+#include <asm/code-patching.h>
 
-#ifdef DEBUG
-#define DBG(fmt...) udbg_printf(fmt)
-#else
-#define DBG(fmt...)
-#endif
 
 extern void slb_allocate_realmode(unsigned long ea);
 extern void slb_allocate_user(unsigned long ea);
@@ -41,42 +37,86 @@ static void slb_allocate(unsigned long ea)
 	slb_allocate_realmode(ea);
 }
 
-static inline unsigned long mk_esid_data(unsigned long ea, unsigned long slot)
+#define slb_esid_mask(ssize)	\
+	(((ssize) == MMU_SEGSIZE_256M)? ESID_MASK: ESID_MASK_1T)
+
+static inline unsigned long mk_esid_data(unsigned long ea, int ssize,
+					 unsigned long slot)
 {
-	return (ea & ESID_MASK) | SLB_ESID_V | slot;
+	return (ea & slb_esid_mask(ssize)) | SLB_ESID_V | slot;
 }
 
-static inline unsigned long mk_vsid_data(unsigned long ea, unsigned long flags)
+#define slb_vsid_shift(ssize)	\
+	((ssize) == MMU_SEGSIZE_256M? SLB_VSID_SHIFT: SLB_VSID_SHIFT_1T)
+
+static inline unsigned long mk_vsid_data(unsigned long ea, int ssize,
+					 unsigned long flags)
 {
-	return (get_kernel_vsid(ea) << SLB_VSID_SHIFT) | flags;
+	return (get_kernel_vsid(ea, ssize) << slb_vsid_shift(ssize)) | flags |
+		((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
+}
+
+static inline void slb_shadow_update(unsigned long ea, int ssize,
+				     unsigned long flags,
+				     unsigned long entry)
+{
+	/*
+	 * Clear the ESID first so the entry is not valid while we are
+	 * updating it.  No write barriers are needed here, provided
+	 * we only update the current CPU's SLB shadow buffer.
+	 */
+	get_slb_shadow()->save_area[entry].esid = 0;
+	get_slb_shadow()->save_area[entry].vsid =
+				cpu_to_be64(mk_vsid_data(ea, ssize, flags));
+	get_slb_shadow()->save_area[entry].esid =
+				cpu_to_be64(mk_esid_data(ea, ssize, entry));
 }
 
-static inline void create_slbe(unsigned long ea, unsigned long flags,
-			       unsigned long entry)
+static inline void slb_shadow_clear(unsigned long entry)
 {
+	get_slb_shadow()->save_area[entry].esid = 0;
+}
+
+static inline void create_shadowed_slbe(unsigned long ea, int ssize,
+					unsigned long flags,
+					unsigned long entry)
+{
+	/*
+	 * Updating the shadow buffer before writing the SLB ensures
+	 * we don't get a stale entry here if we get preempted by PHYP
+	 * between these two statements.
+	 */
+	slb_shadow_update(ea, ssize, flags, entry);
+
 	asm volatile("slbmte  %0,%1" :
-		     : "r" (mk_vsid_data(ea, flags)),
-		       "r" (mk_esid_data(ea, entry))
+		     : "r" (mk_vsid_data(ea, ssize, flags)),
+		       "r" (mk_esid_data(ea, ssize, entry))
 		     : "memory" );
 }
 
-static void slb_flush_and_rebolt(void)
+static void __slb_flush_and_rebolt(void)
 {
 	/* If you change this make sure you change SLB_NUM_BOLTED
-	 * appropriately too. */
-	unsigned long linear_llp, virtual_llp, lflags, vflags;
-	unsigned long ksp_esid_data;
-
-	WARN_ON(!irqs_disabled());
+	 * and PR KVM appropriately too. */
+	unsigned long linear_llp, vmalloc_llp, lflags, vflags;
+	unsigned long ksp_esid_data, ksp_vsid_data;
 
 	linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
-	virtual_llp = mmu_psize_defs[mmu_virtual_psize].sllp;
+	vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp;
 	lflags = SLB_VSID_KERNEL | linear_llp;
-	vflags = SLB_VSID_KERNEL | virtual_llp;
+	vflags = SLB_VSID_KERNEL | vmalloc_llp;
 
-	ksp_esid_data = mk_esid_data(get_paca()->kstack, 2);
-	if ((ksp_esid_data & ESID_MASK) == KERNELBASE)
+	ksp_esid_data = mk_esid_data(get_paca()->kstack, mmu_kernel_ssize, 2);
+	if ((ksp_esid_data & ~0xfffffffUL) <= PAGE_OFFSET) {
 		ksp_esid_data &= ~SLB_ESID_V;
+		ksp_vsid_data = 0;
+		slb_shadow_clear(2);
+	} else {
+		/* Update stack entry; others don't change */
+		slb_shadow_update(get_paca()->kstack, mmu_kernel_ssize, lflags, 2);
+		ksp_vsid_data =
+			be64_to_cpu(get_slb_shadow()->save_area[2].vsid);
+	}
 
 	/* We need to do this all in asm, so we're sure we don't touch
 	 * the stack between the slbia and rebolting it. */
@@ -87,144 +127,209 @@ static void slb_flush_and_rebolt(void)
 		     /* Slot 2 - kernel stack */
 		     "slbmte	%2,%3\n"
 		     "isync"
-		     :: "r"(mk_vsid_data(VMALLOCBASE, vflags)),
-		        "r"(mk_esid_data(VMALLOCBASE, 1)),
-		        "r"(mk_vsid_data(ksp_esid_data, lflags)),
+		     :: "r"(mk_vsid_data(VMALLOC_START, mmu_kernel_ssize, vflags)),
+		        "r"(mk_esid_data(VMALLOC_START, mmu_kernel_ssize, 1)),
+		        "r"(ksp_vsid_data),
 		        "r"(ksp_esid_data)
 		     : "memory");
 }
 
+void slb_flush_and_rebolt(void)
+{
+
+	WARN_ON(!irqs_disabled());
+
+	/*
+	 * We can't take a PMU exception in the following code, so hard
+	 * disable interrupts.
+	 */
+	hard_irq_disable();
+
+	__slb_flush_and_rebolt();
+	get_paca()->slb_cache_ptr = 0;
+}
+
+void slb_vmalloc_update(void)
+{
+	unsigned long vflags;
+
+	vflags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_vmalloc_psize].sllp;
+	slb_shadow_update(VMALLOC_START, mmu_kernel_ssize, vflags, 1);
+	slb_flush_and_rebolt();
+}
+
+/* Helper function to compare esids.  There are four cases to handle.
+ * 1. The system is not 1T segment size capable.  Use the GET_ESID compare.
+ * 2. The system is 1T capable, both addresses are < 1T, use the GET_ESID compare.
+ * 3. The system is 1T capable, only one of the two addresses is > 1T.  This is not a match.
+ * 4. The system is 1T capable, both addresses are > 1T, use the GET_ESID_1T macro to compare.
+ */
+static inline int esids_match(unsigned long addr1, unsigned long addr2)
+{
+	int esid_1t_count;
+
+	/* System is not 1T segment size capable. */
+	if (!mmu_has_feature(MMU_FTR_1T_SEGMENT))
+		return (GET_ESID(addr1) == GET_ESID(addr2));
+
+	esid_1t_count = (((addr1 >> SID_SHIFT_1T) != 0) +
+				((addr2 >> SID_SHIFT_1T) != 0));
+
+	/* both addresses are < 1T */
+	if (esid_1t_count == 0)
+		return (GET_ESID(addr1) == GET_ESID(addr2));
+
+	/* One address < 1T, the other > 1T.  Not a match */
+	if (esid_1t_count == 1)
+		return 0;
+
+	/* Both addresses are > 1T. */
+	return (GET_ESID_1T(addr1) == GET_ESID_1T(addr2));
+}
+
 /* Flush all user entries from the segment table of the current processor. */
 void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
 {
-	unsigned long offset = get_paca()->slb_cache_ptr;
-	unsigned long esid_data = 0;
+	unsigned long offset;
+	unsigned long slbie_data = 0;
 	unsigned long pc = KSTK_EIP(tsk);
 	unsigned long stack = KSTK_ESP(tsk);
-	unsigned long unmapped_base;
+	unsigned long exec_base;
 
-	if (offset <= SLB_CACHE_ENTRIES) {
+	/*
+	 * We need interrupts hard-disabled here, not just soft-disabled,
+	 * so that a PMU interrupt can't occur, which might try to access
+	 * user memory (to get a stack trace) and possible cause an SLB miss
+	 * which would update the slb_cache/slb_cache_ptr fields in the PACA.
+	 */
+	hard_irq_disable();
+	offset = get_paca()->slb_cache_ptr;
+	if (!mmu_has_feature(MMU_FTR_NO_SLBIE_B) &&
+	    offset <= SLB_CACHE_ENTRIES) {
 		int i;
 		asm volatile("isync" : : : "memory");
 		for (i = 0; i < offset; i++) {
-			esid_data = ((unsigned long)get_paca()->slb_cache[i]
-				<< SID_SHIFT) | SLBIE_C;
-			asm volatile("slbie %0" : : "r" (esid_data));
+			slbie_data = (unsigned long)get_paca()->slb_cache[i]
+				<< SID_SHIFT; /* EA */
+			slbie_data |= user_segment_size(slbie_data)
+				<< SLBIE_SSIZE_SHIFT;
+			slbie_data |= SLBIE_C; /* C set for user addresses */
+			asm volatile("slbie %0" : : "r" (slbie_data));
 		}
 		asm volatile("isync" : : : "memory");
 	} else {
-		slb_flush_and_rebolt();
+		__slb_flush_and_rebolt();
 	}
 
 	/* Workaround POWER5 < DD2.1 issue */
 	if (offset == 1 || offset > SLB_CACHE_ENTRIES)
-		asm volatile("slbie %0" : : "r" (esid_data));
+		asm volatile("slbie %0" : : "r" (slbie_data));
 
 	get_paca()->slb_cache_ptr = 0;
 	get_paca()->context = mm->context;
-#ifdef CONFIG_PPC_64K_PAGES
-	get_paca()->pgdir = mm->pgd;
-#endif /* CONFIG_PPC_64K_PAGES */
 
 	/*
 	 * preload some userspace segments into the SLB.
+	 * Almost all 32 and 64bit PowerPC executables are linked at
+	 * 0x10000000 so it makes sense to preload this segment.
 	 */
-	if (test_tsk_thread_flag(tsk, TIF_32BIT))
-		unmapped_base = TASK_UNMAPPED_BASE_USER32;
-	else
-		unmapped_base = TASK_UNMAPPED_BASE_USER64;
-
-	if (pc >= KERNELBASE)
-		return;
-	slb_allocate(pc);
+	exec_base = 0x10000000;
 
-	if (GET_ESID(pc) == GET_ESID(stack))
+	if (is_kernel_addr(pc) || is_kernel_addr(stack) ||
+	    is_kernel_addr(exec_base))
 		return;
 
-	if (stack >= KERNELBASE)
-		return;
-	slb_allocate(stack);
+	slb_allocate(pc);
 
-	if ((GET_ESID(pc) == GET_ESID(unmapped_base))
-	    || (GET_ESID(stack) == GET_ESID(unmapped_base)))
-		return;
+	if (!esids_match(pc, stack))
+		slb_allocate(stack);
 
-	if (unmapped_base >= KERNELBASE)
-		return;
-	slb_allocate(unmapped_base);
+	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)
 {
-	/* Assume the instruction had a "0" immediate value, just
-	 * "or" in the new value
-	 */
-	*insn_addr |= immed;
-	flush_icache_range((unsigned long)insn_addr, 4+
-			   (unsigned long)insn_addr);
+	int insn = (*insn_addr & 0xffff0000) | immed;
+	patch_instruction(insn_addr, insn);
+}
+
+extern u32 slb_compare_rr_to_size[];
+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)
 {
-	unsigned long linear_llp, virtual_llp;
+	unsigned long linear_llp, vmalloc_llp, io_llp;
+	unsigned long lflags, vflags;
 	static int slb_encoding_inited;
-	extern unsigned int *slb_miss_kernel_load_linear;
-	extern unsigned int *slb_miss_kernel_load_virtual;
-	extern unsigned int *slb_miss_user_load_normal;
-#ifdef CONFIG_HUGETLB_PAGE
-	extern unsigned int *slb_miss_user_load_huge;
-	unsigned long huge_llp;
-
-	huge_llp = mmu_psize_defs[mmu_huge_psize].sllp;
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	unsigned long vmemmap_llp;
 #endif
 
 	/* Prepare our SLB miss handler based on our page size */
 	linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
-	virtual_llp = mmu_psize_defs[mmu_virtual_psize].sllp;
+	io_llp = mmu_psize_defs[mmu_io_psize].sllp;
+	vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp;
+	get_paca()->vmalloc_sllp = SLB_VSID_KERNEL | vmalloc_llp;
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	vmemmap_llp = mmu_psize_defs[mmu_vmemmap_psize].sllp;
+#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_virtual,
-				   SLB_VSID_KERNEL | virtual_llp);
-		patch_slb_encoding(slb_miss_user_load_normal,
-				   SLB_VSID_USER | virtual_llp);
-
-		DBG("SLB: linear  LLP = %04x\n", linear_llp);
-		DBG("SLB: virtual LLP = %04x\n", virtual_llp);
-#ifdef CONFIG_HUGETLB_PAGE
-		patch_slb_encoding(slb_miss_user_load_huge,
-				   SLB_VSID_USER | huge_llp);
-		DBG("SLB: huge    LLP = %04x\n", huge_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
 	}
 
-	/* On iSeries the bolted entries have already been set up by
-	 * the hypervisor from the lparMap data in head.S */
-#ifndef CONFIG_PPC_ISERIES
- {
-	unsigned long lflags, vflags;
+	get_paca()->stab_rr = SLB_NUM_BOLTED;
 
 	lflags = SLB_VSID_KERNEL | linear_llp;
-	vflags = SLB_VSID_KERNEL | virtual_llp;
+	vflags = SLB_VSID_KERNEL | vmalloc_llp;
 
 	/* Invalidate the entire SLB (even slot 0) & all the ERATS */
 	asm volatile("isync":::"memory");
 	asm volatile("slbmte  %0,%0"::"r" (0) : "memory");
 	asm volatile("isync; slbia; isync":::"memory");
-	create_slbe(KERNELBASE, lflags, 0);
+	create_shadowed_slbe(PAGE_OFFSET, mmu_kernel_ssize, lflags, 0);
 
-	/* VMALLOC space has 4K pages always for now */
-	create_slbe(VMALLOCBASE, vflags, 1);
+	create_shadowed_slbe(VMALLOC_START, mmu_kernel_ssize, vflags, 1);
 
-	/* We don't bolt the stack for the time being - we're in boot,
-	 * so the stack is in the bolted segment.  By the time it goes
-	 * elsewhere, we'll call _switch() which will bolt in the new
-	 * one. */
-	asm volatile("isync":::"memory");
- }
-#endif /* CONFIG_PPC_ISERIES */
+	/* For the boot cpu, we're running on the stack in init_thread_union,
+	 * which is in the first segment of the linear mapping, and also
+	 * get_paca()->kstack hasn't been initialized yet.
+	 * For secondary cpus, we need to bolt the kernel stack entry now.
+	 */
+	slb_shadow_clear(2);
+	if (raw_smp_processor_id() != boot_cpuid &&
+	    (get_paca()->kstack & slb_esid_mask(mmu_kernel_ssize)) > PAGE_OFFSET)
+		create_shadowed_slbe(get_paca()->kstack,
+				     mmu_kernel_ssize, lflags, 2);
 
-	get_paca()->stab_rr = SLB_NUM_BOLTED;
+	asm volatile("isync":::"memory");
 }