Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git…

…/benh/powerpc

Pull powerpc fixes from Ben Herrenschmidt:
 "Here's a few powerpc fixes for 3.9, mostly regressions (though not all
  from 3.9 merge window) that we've been hammering into shape over the
  last couple of weeks.  They fix booting on Cell and G5 among other
  things (yes, we've been a bit sloppy with older machines this time
  around)."

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Rename USER_ESID_BITS* to ESID_BITS*
  powerpc: Update kernel VSID range
  powerpc: Make VSID_BITS* dependency explicit
  powerpc: Make sure that we alays include CONFIG_BINFMT_ELF
  powerpc/ptrace: Fix brk.len used uninitialised
  powerpc: Fix -mcmodel=medium breakage in prom_init.c
  powerpc: Remove last traces of POWER4_ONLY
  powerpc: Fix cputable entry for 970MP rev 1.0
  powerpc: Fix STAB initialization

arch/powerpc/Kconfig

@@ -90,6 +90,7 @@ config GENERIC_GPIO
 config PPC
 	bool
 	default y
+	select BINFMT_ELF
 	select OF
 	select OF_EARLY_FLATTREE
 	select HAVE_FTRACE_MCOUNT_RECORD

arch/powerpc/include/asm/mmu-hash64.h

@@ -343,17 +343,16 @@ extern void slb_set_size(u16 size);
 /*
  * VSID allocation (256MB segment)
  *
- * We first generate a 38-bit "proto-VSID".  For kernel addresses this
- * is equal to the ESID | 1 << 37, for user addresses it is:
- *	(context << USER_ESID_BITS) | (esid & ((1U << USER_ESID_BITS) - 1)
+ * We first generate a 37-bit "proto-VSID". Proto-VSIDs are generated
+ * from mmu context id and effective segment id of the address.
  *
- * This splits the proto-VSID into the below range
- *  0 - (2^(CONTEXT_BITS + USER_ESID_BITS) - 1) : User proto-VSID range
- *  2^(CONTEXT_BITS + USER_ESID_BITS) - 2^(VSID_BITS) : Kernel proto-VSID range
- *
- * We also have CONTEXT_BITS + USER_ESID_BITS = VSID_BITS - 1
- * That is, we assign half of the space to user processes and half
- * to the kernel.
+ * For user processes max context id is limited to ((1ul << 19) - 5)
+ * for kernel space, we use the top 4 context ids to map address as below
+ * NOTE: each context only support 64TB now.
+ * 0x7fffc -  [ 0xc000000000000000 - 0xc0003fffffffffff ]
+ * 0x7fffd -  [ 0xd000000000000000 - 0xd0003fffffffffff ]
+ * 0x7fffe -  [ 0xe000000000000000 - 0xe0003fffffffffff ]
+ * 0x7ffff -  [ 0xf000000000000000 - 0xf0003fffffffffff ]
  *
  * The proto-VSIDs are then scrambled into real VSIDs with the
  * multiplicative hash:
@@ -363,41 +362,49 @@ extern void slb_set_size(u16 size);
  * VSID_MULTIPLIER is prime, so in particular it is
  * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
  * Because the modulus is 2^n-1 we can compute it efficiently without
- * a divide or extra multiply (see below).
- *
- * This scheme has several advantages over older methods:
- *
- *	- We have VSIDs allocated for every kernel address
- * (i.e. everything above 0xC000000000000000), except the very top
- * segment, which simplifies several things.
+ * a divide or extra multiply (see below). The scramble function gives
+ * robust scattering in the hash table (at least based on some initial
+ * results).
  *
- *	- We allow for USER_ESID_BITS significant bits of ESID and
- * CONTEXT_BITS  bits of context for user addresses.
- *  i.e. 64T (46 bits) of address space for up to half a million contexts.
+ * We also consider VSID 0 special. We use VSID 0 for slb entries mapping
+ * bad address. This enables us to consolidate bad address handling in
+ * hash_page.
  *
- *	- The scramble function gives robust scattering in the hash
- * table (at least based on some initial results).  The previous
- * method was more susceptible to pathological cases giving excessive
- * hash collisions.
+ * We also need to avoid the last segment of the last context, because that
+ * would give a protovsid of 0x1fffffffff. That will result in a VSID 0
+ * because of the modulo operation in vsid scramble. But the vmemmap
+ * (which is what uses region 0xf) will never be close to 64TB in size
+ * (it's 56 bytes per page of system memory).
  */
 
+#define CONTEXT_BITS		19
+#define ESID_BITS		18
+#define ESID_BITS_1T		6
+
+/*
+ * 256MB segment
+ * The proto-VSID space has 2^(CONTEX_BITS + ESID_BITS) - 1 segments
+ * available for user + kernel mapping. The top 4 contexts are used for
+ * kernel mapping. Each segment contains 2^28 bytes. Each
+ * context maps 2^46 bytes (64TB) so we can support 2^19-1 contexts
+ * (19 == 37 + 28 - 46).
+ */
+#define MAX_USER_CONTEXT	((ASM_CONST(1) << CONTEXT_BITS) - 5)
+
 /*
  * This should be computed such that protovosid * vsid_mulitplier
  * doesn't overflow 64 bits. It should also be co-prime to vsid_modulus
  */
 #define VSID_MULTIPLIER_256M	ASM_CONST(12538073)	/* 24-bit prime */
-#define VSID_BITS_256M		38
+#define VSID_BITS_256M		(CONTEXT_BITS + ESID_BITS)
 #define VSID_MODULUS_256M	((1UL<<VSID_BITS_256M)-1)
 
 #define VSID_MULTIPLIER_1T	ASM_CONST(12538073)	/* 24-bit prime */
-#define VSID_BITS_1T		26
+#define VSID_BITS_1T		(CONTEXT_BITS + ESID_BITS_1T)
 #define VSID_MODULUS_1T		((1UL<<VSID_BITS_1T)-1)
 
-#define CONTEXT_BITS		19
-#define USER_ESID_BITS		18
-#define USER_ESID_BITS_1T	6
 
-#define USER_VSID_RANGE	(1UL << (USER_ESID_BITS + SID_SHIFT))
+#define USER_VSID_RANGE	(1UL << (ESID_BITS + SID_SHIFT))
 
 /*
  * This macro generates asm code to compute the VSID scramble
@@ -421,7 +428,8 @@ extern void slb_set_size(u16 size);
 	srdi	rx,rt,VSID_BITS_##size;					\
 	clrldi	rt,rt,(64-VSID_BITS_##size);				\
 	add	rt,rt,rx;		/* add high and low bits */	\
-	/* Now, r3 == VSID (mod 2^36-1), and lies between 0 and		\
+	/* NOTE: explanation based on VSID_BITS_##size = 36		\
+	 * Now, r3 == VSID (mod 2^36-1), and lies between 0 and		\
 	 * 2^36-1+2^28-1.  That in particular means that if r3 >=	\
 	 * 2^36-1, then r3+1 has the 2^36 bit set.  So, if r3+1 has	\
 	 * the bit clear, r3 already has the answer we want, if it	\
@@ -513,34 +521,6 @@ typedef struct {
 	})
 #endif /* 1 */
 
-/*
- * This is only valid for addresses >= PAGE_OFFSET
- * The proto-VSID space is divided into two class
- * User:   0 to 2^(CONTEXT_BITS + USER_ESID_BITS) -1
- * kernel: 2^(CONTEXT_BITS + USER_ESID_BITS) to 2^(VSID_BITS) - 1
- *
- * With KERNEL_START at 0xc000000000000000, the proto vsid for
- * the kernel ends up with 0xc00000000 (36 bits). With 64TB
- * support we need to have kernel proto-VSID in the
- * [2^37 to 2^38 - 1] range due to the increased USER_ESID_BITS.
- */
-static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize)
-{
-	unsigned long proto_vsid;
-	/*
-	 * We need to make sure proto_vsid for the kernel is
-	 * >= 2^(CONTEXT_BITS + USER_ESID_BITS[_1T])
-	 */
-	if (ssize == MMU_SEGSIZE_256M) {
-		proto_vsid = ea >> SID_SHIFT;
-		proto_vsid |= (1UL << (CONTEXT_BITS + USER_ESID_BITS));
-		return vsid_scramble(proto_vsid, 256M);
-	}
-	proto_vsid = ea >> SID_SHIFT_1T;
-	proto_vsid |= (1UL << (CONTEXT_BITS + USER_ESID_BITS_1T));
-	return vsid_scramble(proto_vsid, 1T);
-}
-
 /* Returns the segment size indicator for a user address */
 static inline int user_segment_size(unsigned long addr)
 {
@@ -550,17 +530,41 @@ static inline int user_segment_size(unsigned long addr)
 	return MMU_SEGSIZE_256M;
 }
 
-/* This is only valid for user addresses (which are below 2^44) */
 static inline unsigned long get_vsid(unsigned long context, unsigned long ea,
 				     int ssize)
 {
+	/*
+	 * Bad address. We return VSID 0 for that
+	 */
+	if ((ea & ~REGION_MASK) >= PGTABLE_RANGE)
+		return 0;
+
 	if (ssize == MMU_SEGSIZE_256M)
-		return vsid_scramble((context << USER_ESID_BITS)
+		return vsid_scramble((context << ESID_BITS)
 				     | (ea >> SID_SHIFT), 256M);
-	return vsid_scramble((context << USER_ESID_BITS_1T)
+	return vsid_scramble((context << ESID_BITS_1T)
 			     | (ea >> SID_SHIFT_1T), 1T);
 }
 
+/*
+ * This is only valid for addresses >= PAGE_OFFSET
+ *
+ * For kernel space, we use the top 4 context ids to map address as below
+ * 0x7fffc -  [ 0xc000000000000000 - 0xc0003fffffffffff ]
+ * 0x7fffd -  [ 0xd000000000000000 - 0xd0003fffffffffff ]
+ * 0x7fffe -  [ 0xe000000000000000 - 0xe0003fffffffffff ]
+ * 0x7ffff -  [ 0xf000000000000000 - 0xf0003fffffffffff ]
+ */
+static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize)
+{
+	unsigned long context;
+
+	/*
+	 * kernel take the top 4 context from the available range
+	 */
+	context = (MAX_USER_CONTEXT) + ((ea >> 60) - 0xc) + 1;
+	return get_vsid(context, ea, ssize);
+}
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_MMU_HASH64_H_ */

arch/powerpc/kernel/cputable.c

@@ -275,7 +275,7 @@ static struct cpu_spec __initdata cpu_specs[] = {
 		.cpu_features		= CPU_FTRS_PPC970,
 		.cpu_user_features	= COMMON_USER_POWER4 |
 			PPC_FEATURE_HAS_ALTIVEC_COMP,
-		.mmu_features		= MMU_FTR_HPTE_TABLE,
+		.mmu_features		= MMU_FTRS_PPC970,
 		.icache_bsize		= 128,
 		.dcache_bsize		= 128,
 		.num_pmcs		= 8,

arch/powerpc/kernel/exceptions-64s.S

@@ -1452,20 +1452,36 @@ do_ste_alloc:
 _GLOBAL(do_stab_bolted)
 	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
 	std	r11,PACA_EXSLB+EX_SRR0(r13)	/* save SRR0 in exc. frame */
+	mfspr	r11,SPRN_DAR			/* ea */
 
+	/*
+	 * check for bad kernel/user address
+	 * (ea & ~REGION_MASK) >= PGTABLE_RANGE
+	 */
+	rldicr. r9,r11,4,(63 - 46 - 4)
+	li	r9,0	/* VSID = 0 for bad address */
+	bne-	0f
+
+	/*
+	 * Calculate VSID:
+	 * This is the kernel vsid, we take the top for context from
+	 * the range. context = (MAX_USER_CONTEXT) + ((ea >> 60) - 0xc) + 1
+	 * Here we know that (ea >> 60) == 0xc
+	 */
+	lis	r9,(MAX_USER_CONTEXT + 1)@ha
+	addi	r9,r9,(MAX_USER_CONTEXT + 1)@l
+
+	srdi	r10,r11,SID_SHIFT
+	rldimi  r10,r9,ESID_BITS,0 /* proto vsid */
+	ASM_VSID_SCRAMBLE(r10, r9, 256M)
+	rldic	r9,r10,12,16	/* r9 = vsid << 12 */
+
+0:
 	/* Hash to the primary group */
 	ld	r10,PACASTABVIRT(r13)
-	mfspr	r11,SPRN_DAR
-	srdi	r11,r11,28
+	srdi	r11,r11,SID_SHIFT
 	rldimi	r10,r11,7,52	/* r10 = first ste of the group */
 
-	/* Calculate VSID */
-	/* This is a kernel address, so protovsid = ESID | 1 << 37 */
-	li	r9,0x1
-	rldimi  r11,r9,(CONTEXT_BITS + USER_ESID_BITS),0
-	ASM_VSID_SCRAMBLE(r11, r9, 256M)
-	rldic	r9,r11,12,16	/* r9 = vsid << 12 */
-
 	/* Search the primary group for a free entry */
 1:	ld	r11,0(r10)	/* Test valid bit of the current ste	*/
 	andi.	r11,r11,0x80

arch/powerpc/kernel/prom_init.c

@@ -2832,11 +2832,13 @@ static void unreloc_toc(void)
 {
 }
 #else
-static void __reloc_toc(void *tocstart, unsigned long offset,
-			unsigned long nr_entries)
+static void __reloc_toc(unsigned long offset, unsigned long nr_entries)
 {
 	unsigned long i;
-	unsigned long *toc_entry = (unsigned long *)tocstart;
+	unsigned long *toc_entry;
+
+	/* Get the start of the TOC by using r2 directly. */
+	asm volatile("addi %0,2,-0x8000" : "=b" (toc_entry));
 
 	for (i = 0; i < nr_entries; i++) {
 		*toc_entry = *toc_entry + offset;
@@ -2850,8 +2852,7 @@ static void reloc_toc(void)
 	unsigned long nr_entries =
 		(__prom_init_toc_end - __prom_init_toc_start) / sizeof(long);
 
-	/* Need to add offset to get at __prom_init_toc_start */
-	__reloc_toc(__prom_init_toc_start + offset, offset, nr_entries);
+	__reloc_toc(offset, nr_entries);
 
 	mb();
 }
@@ -2864,8 +2865,7 @@ static void unreloc_toc(void)
 
 	mb();
 
-	/* __prom_init_toc_start has been relocated, no need to add offset */
-	__reloc_toc(__prom_init_toc_start, -offset, nr_entries);
+	__reloc_toc(-offset, nr_entries);
 }
 #endif
 #endif

arch/powerpc/kernel/ptrace.c

@@ -1428,6 +1428,7 @@ static long ppc_set_hwdebug(struct task_struct *child,
 
 	brk.address = bp_info->addr & ~7UL;
 	brk.type = HW_BRK_TYPE_TRANSLATE;
+	brk.len = 8;
 	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
 		brk.type |= HW_BRK_TYPE_READ;
 	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)

arch/powerpc/kvm/book3s_64_mmu_host.c

@@ -326,8 +326,8 @@ int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 	vcpu3s->context_id[0] = err;
 
 	vcpu3s->proto_vsid_max = ((vcpu3s->context_id[0] + 1)
-				  << USER_ESID_BITS) - 1;
-	vcpu3s->proto_vsid_first = vcpu3s->context_id[0] << USER_ESID_BITS;
+				  << ESID_BITS) - 1;
+	vcpu3s->proto_vsid_first = vcpu3s->context_id[0] << ESID_BITS;
 	vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
 
 	kvmppc_mmu_hpte_init(vcpu);

arch/powerpc/mm/hash_utils_64.c

@@ -195,6 +195,11 @@ int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
 		unsigned long vpn  = hpt_vpn(vaddr, vsid, ssize);
 		unsigned long tprot = prot;
 
+		/*
+		 * If we hit a bad address return error.
+		 */
+		if (!vsid)
+			return -1;
 		/* Make kernel text executable */
 		if (overlaps_kernel_text(vaddr, vaddr + step))
 			tprot &= ~HPTE_R_N;
@@ -759,6 +764,8 @@ void __init early_init_mmu(void)
 	/* Initialize stab / SLB management */
 	if (mmu_has_feature(MMU_FTR_SLB))
 		slb_initialize();
+	else
+		stab_initialize(get_paca()->stab_real);
 }
 
 #ifdef CONFIG_SMP
@@ -922,11 +929,6 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 	DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
 		ea, access, trap);
 
-	if ((ea & ~REGION_MASK) >= PGTABLE_RANGE) {
-		DBG_LOW(" out of pgtable range !\n");
- 		return 1;
-	}
-
 	/* Get region & vsid */
  	switch (REGION_ID(ea)) {
 	case USER_REGION_ID:
@@ -957,6 +959,11 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 	}
 	DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
 
+	/* Bad address. */
+	if (!vsid) {
+		DBG_LOW("Bad address!\n");
+		return 1;
+	}
 	/* Get pgdir */
 	pgdir = mm->pgd;
 	if (pgdir == NULL)
@@ -1126,6 +1133,8 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
 	/* Get VSID */
 	ssize = user_segment_size(ea);
 	vsid = get_vsid(mm->context.id, ea, ssize);
+	if (!vsid)
+		return;
 
 	/* Hash doesn't like irqs */
 	local_irq_save(flags);
@@ -1233,6 +1242,9 @@ static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
 	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
 	hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 
+	/* Don't create HPTE entries for bad address */
+	if (!vsid)
+		return;
 	ret = ppc_md.hpte_insert(hpteg, vpn, __pa(vaddr),
 				 mode, HPTE_V_BOLTED,
 				 mmu_linear_psize, mmu_kernel_ssize);

arch/powerpc/mm/mmu_context_hash64.c

@@ -29,15 +29,6 @@
 static DEFINE_SPINLOCK(mmu_context_lock);
 static DEFINE_IDA(mmu_context_ida);
 
-/*
- * 256MB segment
- * The proto-VSID space has 2^(CONTEX_BITS + USER_ESID_BITS) - 1 segments
- * available for user mappings. Each segment contains 2^28 bytes. Each
- * context maps 2^46 bytes (64TB) so we can support 2^19-1 contexts
- * (19 == 37 + 28 - 46).
- */
-#define MAX_CONTEXT	((1UL << CONTEXT_BITS) - 1)
-
 int __init_new_context(void)
 {
 	int index;
@@ -56,7 +47,7 @@ int __init_new_context(void)
 	else if (err)
 		return err;
 
-	if (index > MAX_CONTEXT) {
+	if (index > MAX_USER_CONTEXT) {
 		spin_lock(&mmu_context_lock);
 		ida_remove(&mmu_context_ida, index);
 		spin_unlock(&mmu_context_lock);