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* Re: [RFC PATCH v3 0/5] powerpc: Support context tracking for Power pSeries
From: Benjamin Herrenschmidt @ 2013-05-13  5:51 UTC (permalink / raw)
  To: Li Zhong
  Cc: fweisbec, Anton Blanchard, linux-kernel, paulus, paulmck,
	linuxppc-dev
In-Reply-To: <1368422493-9831-1-git-send-email-zhong@linux.vnet.ibm.com>

On Mon, 2013-05-13 at 13:21 +0800, Li Zhong wrote:
> These patches try to support context tracking for Power arch, beginning with
> 64-bit pSeries. The codes are ported from that of the x86_64, and in each
> patch, I listed the corresponding patch for x86.

So that's yet another pile of bloat on all syscall entry/exit and
exception entry/exit. What is it used for ? (I haven't followed on
x86_64 side).

Cheers,
Ben.

> v3:
> 
> This version is mainly a rebasing, against 3.10-rc1, also as the common code 
> to handle the exception are pulled into 3.10, so there is no dependency on 
> tip tree. So patch #2 and #6 in previous version_2 is merged together. 
> 
> Li Zhong (5):
>   powerpc: Syscall hooks for context tracking subsystem
>   powerpc: Exception hooks for context tracking subsystem
>   powerpc: Exit user context on notify resume
>   powerpc: Use the new schedule_user API on userspace preemption
>   powerpc: select HAVE_CONTEXT_TRACKING for pSeries
> 
>  arch/powerpc/include/asm/context_tracking.h |   10 +++
>  arch/powerpc/include/asm/thread_info.h      |    7 ++-
>  arch/powerpc/kernel/entry_64.S              |    3 +-
>  arch/powerpc/kernel/ptrace.c                |    5 ++
>  arch/powerpc/kernel/signal.c                |    5 ++
>  arch/powerpc/kernel/traps.c                 |   91 ++++++++++++++++++++-------
>  arch/powerpc/mm/fault.c                     |   16 ++++-
>  arch/powerpc/mm/hash_utils_64.c             |   38 ++++++++---
>  arch/powerpc/platforms/pseries/Kconfig      |    1 +
>  9 files changed, 140 insertions(+), 36 deletions(-)
>  create mode 100644 arch/powerpc/include/asm/context_tracking.h
> 

^ permalink raw reply

* [RFC PATCH v3 5/5] powerpc: select HAVE_CONTEXT_TRACKING for pSeries
From: Li Zhong @ 2013-05-13  5:21 UTC (permalink / raw)
  To: linux-kernel; +Cc: Li Zhong, fweisbec, paulus, paulmck, linuxppc-dev
In-Reply-To: <1368422493-9831-1-git-send-email-zhong@linux.vnet.ibm.com>

Start context tracking support from pSeries.

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/pseries/Kconfig |    1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index 9a0941b..023b288 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -18,6 +18,7 @@ config PPC_PSERIES
 	select PPC_PCI_CHOICE if EXPERT
 	select ZLIB_DEFLATE
 	select PPC_DOORBELL
+	select HAVE_CONTEXT_TRACKING
 	default y
 
 config PPC_SPLPAR
-- 
1.7.9.5

^ permalink raw reply related

* [RFC PATCH v3 4/5] powerpc: Use the new schedule_user API on userspace preemption
From: Li Zhong @ 2013-05-13  5:21 UTC (permalink / raw)
  To: linux-kernel; +Cc: Li Zhong, fweisbec, paulus, paulmck, linuxppc-dev
In-Reply-To: <1368422493-9831-1-git-send-email-zhong@linux.vnet.ibm.com>

This patch corresponds to
[PATCH] x86: Use the new schedule_user API on userspace preemption
  commit 0430499ce9d78691f3985962021b16bf8f8a8048

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/context_tracking.h |   10 ++++++++++
 arch/powerpc/kernel/entry_64.S              |    3 ++-
 2 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/include/asm/context_tracking.h

diff --git a/arch/powerpc/include/asm/context_tracking.h b/arch/powerpc/include/asm/context_tracking.h
new file mode 100644
index 0000000..b6f5a33
--- /dev/null
+++ b/arch/powerpc/include/asm/context_tracking.h
@@ -0,0 +1,10 @@
+#ifndef _ASM_POWERPC_CONTEXT_TRACKING_H
+#define _ASM_POWERPC_CONTEXT_TRACKING_H
+
+#ifdef CONFIG_CONTEXT_TRACKING
+#define SCHEDULE_USER bl	.schedule_user
+#else
+#define SCHEDULE_USER bl	.schedule
+#endif
+
+#endif
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 915fbb4..d418977 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -33,6 +33,7 @@
 #include <asm/irqflags.h>
 #include <asm/ftrace.h>
 #include <asm/hw_irq.h>
+#include <asm/context_tracking.h>
 
 /*
  * System calls.
@@ -634,7 +635,7 @@ _GLOBAL(ret_from_except_lite)
 	andi.	r0,r4,_TIF_NEED_RESCHED
 	beq	1f
 	bl	.restore_interrupts
-	bl	.schedule
+	SCHEDULE_USER
 	b	.ret_from_except_lite
 
 1:	bl	.save_nvgprs
-- 
1.7.9.5

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* [RFC PATCH v3 3/5] powerpc: Exit user context on notify resume
From: Li Zhong @ 2013-05-13  5:21 UTC (permalink / raw)
  To: linux-kernel; +Cc: Li Zhong, fweisbec, paulus, paulmck, linuxppc-dev
In-Reply-To: <1368422493-9831-1-git-send-email-zhong@linux.vnet.ibm.com>

This patch allows RCU usage in do_notify_resume, e.g. signal handling.
It corresponds to
[PATCH] x86: Exit RCU extended QS on notify resume
  commit edf55fda35c7dc7f2d9241c3abaddaf759b457c6

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/signal.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index cf12eae..d63b502 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -13,6 +13,7 @@
 #include <linux/signal.h>
 #include <linux/uprobes.h>
 #include <linux/key.h>
+#include <linux/context_tracking.h>
 #include <asm/hw_breakpoint.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -159,6 +160,8 @@ static int do_signal(struct pt_regs *regs)
 
 void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 {
+	user_exit();
+
 	if (thread_info_flags & _TIF_UPROBE)
 		uprobe_notify_resume(regs);
 
@@ -169,4 +172,6 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
 	}
+
+	user_enter();
 }
-- 
1.7.9.5

^ permalink raw reply related

* [RFC PATCH v3 2/5] powerpc: Exception hooks for context tracking subsystem
From: Li Zhong @ 2013-05-13  5:21 UTC (permalink / raw)
  To: linux-kernel; +Cc: Li Zhong, fweisbec, paulus, paulmck, linuxppc-dev
In-Reply-To: <1368422493-9831-1-git-send-email-zhong@linux.vnet.ibm.com>

This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.

This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
  commit 6ba3c97a38803883c2eee489505796cb0a727122

But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
  context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
  context_tracking: Restore correct previous context state on exception exit

it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/traps.c     |   91 +++++++++++++++++++++++++++++----------
 arch/powerpc/mm/fault.c         |   16 ++++++-
 arch/powerpc/mm/hash_utils_64.c |   38 ++++++++++++----
 3 files changed, 112 insertions(+), 33 deletions(-)

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 83efa2f..9d3c000 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -35,6 +35,7 @@
 #include <linux/kdebug.h>
 #include <linux/debugfs.h>
 #include <linux/ratelimit.h>
+#include <linux/context_tracking.h>
 
 #include <asm/emulated_ops.h>
 #include <asm/pgtable.h>
@@ -668,6 +669,9 @@ int machine_check_generic(struct pt_regs *regs)
 void machine_check_exception(struct pt_regs *regs)
 {
 	int recover = 0;
+	enum ctx_state prev_state;
+
+	prev_state = exception_enter();
 
 	__get_cpu_var(irq_stat).mce_exceptions++;
 
@@ -683,7 +687,7 @@ void machine_check_exception(struct pt_regs *regs)
 		recover = cur_cpu_spec->machine_check(regs);
 
 	if (recover > 0)
-		return;
+		goto exit;
 
 #if defined(CONFIG_8xx) && defined(CONFIG_PCI)
 	/* the qspan pci read routines can cause machine checks -- Cort
@@ -693,20 +697,23 @@ void machine_check_exception(struct pt_regs *regs)
 	 * -- BenH
 	 */
 	bad_page_fault(regs, regs->dar, SIGBUS);
-	return;
+	goto exit;
 #endif
 
 	if (debugger_fault_handler(regs))
-		return;
+		goto exit;
 
 	if (check_io_access(regs))
-		return;
+		goto exit;
 
 	die("Machine check", regs, SIGBUS);
 
 	/* Must die if the interrupt is not recoverable */
 	if (!(regs->msr & MSR_RI))
 		panic("Unrecoverable Machine check");
+
+exit:
+	exception_exit(prev_state);
 }
 
 void SMIException(struct pt_regs *regs)
@@ -716,20 +723,31 @@ void SMIException(struct pt_regs *regs)
 
 void unknown_exception(struct pt_regs *regs)
 {
+	enum ctx_state prev_state;
+	prev_state = exception_enter();
+
 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 	       regs->nip, regs->msr, regs->trap);
 
 	_exception(SIGTRAP, regs, 0, 0);
+
+	exception_exit(prev_state);
 }
 
 void instruction_breakpoint_exception(struct pt_regs *regs)
 {
+	enum ctx_state prev_state;
+	prev_state = exception_enter();
+
 	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
 					5, SIGTRAP) == NOTIFY_STOP)
-		return;
+		goto exit;
 	if (debugger_iabr_match(regs))
-		return;
+		goto exit;
 	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
+
+exit:
+	exception_exit(prev_state);
 }
 
 void RunModeException(struct pt_regs *regs)
@@ -739,15 +757,21 @@ void RunModeException(struct pt_regs *regs)
 
 void __kprobes single_step_exception(struct pt_regs *regs)
 {
+	enum ctx_state prev_state;
+	prev_state = exception_enter();
+
 	clear_single_step(regs);
 
 	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
 					5, SIGTRAP) == NOTIFY_STOP)
-		return;
+		goto exit;
 	if (debugger_sstep(regs))
-		return;
+		goto exit;
 
 	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
+
+exit:
+	exception_exit(prev_state);
 }
 
 /*
@@ -1006,34 +1030,37 @@ int is_valid_bugaddr(unsigned long addr)
 void __kprobes program_check_exception(struct pt_regs *regs)
 {
 	unsigned int reason = get_reason(regs);
+	enum ctx_state prev_state;
 	extern int do_mathemu(struct pt_regs *regs);
 
+	prev_state = exception_enter();
+
 	/* We can now get here via a FP Unavailable exception if the core
 	 * has no FPU, in that case the reason flags will be 0 */
 
 	if (reason & REASON_FP) {
 		/* IEEE FP exception */
 		parse_fpe(regs);
-		return;
+		goto exit;
 	}
 	if (reason & REASON_TRAP) {
 		/* Debugger is first in line to stop recursive faults in
 		 * rcu_lock, notify_die, or atomic_notifier_call_chain */
 		if (debugger_bpt(regs))
-			return;
+			goto exit;
 
 		/* trap exception */
 		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
 				== NOTIFY_STOP)
-			return;
+			goto exit;
 
 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
 		    report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
 			regs->nip += 4;
-			return;
+			goto exit;
 		}
 		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
-		return;
+		goto exit;
 	}
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (reason & REASON_TM) {
@@ -1049,7 +1076,7 @@ void __kprobes program_check_exception(struct pt_regs *regs)
 		if (!user_mode(regs) &&
 		    report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
 			regs->nip += 4;
-			return;
+			goto exit;
 		}
 		/* If usermode caused this, it's done something illegal and
 		 * gets a SIGILL slap on the wrist.  We call it an illegal
@@ -1059,7 +1086,7 @@ void __kprobes program_check_exception(struct pt_regs *regs)
 		 */
 		if (user_mode(regs)) {
 			_exception(SIGILL, regs, ILL_ILLOPN, regs->nip);
-			return;
+			goto exit;
 		} else {
 			printk(KERN_EMERG "Unexpected TM Bad Thing exception "
 			       "at %lx (msr 0x%x)\n", regs->nip, reason);
@@ -1083,16 +1110,16 @@ void __kprobes program_check_exception(struct pt_regs *regs)
 	switch (do_mathemu(regs)) {
 	case 0:
 		emulate_single_step(regs);
-		return;
+		goto exit;
 	case 1: {
 			int code = 0;
 			code = __parse_fpscr(current->thread.fpscr.val);
 			_exception(SIGFPE, regs, code, regs->nip);
-			return;
+			goto exit;
 		}
 	case -EFAULT:
 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
-		return;
+		goto exit;
 	}
 	/* fall through on any other errors */
 #endif /* CONFIG_MATH_EMULATION */
@@ -1103,10 +1130,10 @@ void __kprobes program_check_exception(struct pt_regs *regs)
 		case 0:
 			regs->nip += 4;
 			emulate_single_step(regs);
-			return;
+			goto exit;
 		case -EFAULT:
 			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
-			return;
+			goto exit;
 		}
 	}
 
@@ -1114,11 +1141,17 @@ void __kprobes program_check_exception(struct pt_regs *regs)
 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
 	else
 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+
+exit:
+	exception_exit(prev_state);
 }
 
 void alignment_exception(struct pt_regs *regs)
 {
 	int sig, code, fixed = 0;
+	enum ctx_state prev_state;
+
+	prev_state = exception_enter();
 
 	/* We restore the interrupt state now */
 	if (!arch_irq_disabled_regs(regs))
@@ -1131,7 +1164,7 @@ void alignment_exception(struct pt_regs *regs)
 	if (fixed == 1) {
 		regs->nip += 4;	/* skip over emulated instruction */
 		emulate_single_step(regs);
-		return;
+		goto exit;
 	}
 
 	/* Operand address was bad */
@@ -1146,6 +1179,9 @@ void alignment_exception(struct pt_regs *regs)
 		_exception(sig, regs, code, regs->dar);
 	else
 		bad_page_fault(regs, regs->dar, sig);
+
+exit:
+	exception_exit(prev_state);
 }
 
 void StackOverflow(struct pt_regs *regs)
@@ -1174,23 +1210,34 @@ void trace_syscall(struct pt_regs *regs)
 
 void kernel_fp_unavailable_exception(struct pt_regs *regs)
 {
+	enum ctx_state prev_state;
+	prev_state = exception_enter();
+
 	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
 			  "%lx at %lx\n", regs->trap, regs->nip);
 	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
+
+	exception_exit(prev_state);
 }
 
 void altivec_unavailable_exception(struct pt_regs *regs)
 {
+	enum ctx_state prev_state;
+	prev_state = exception_enter();
+
 	if (user_mode(regs)) {
 		/* A user program has executed an altivec instruction,
 		   but this kernel doesn't support altivec. */
 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
-		return;
+		goto exit;
 	}
 
 	printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
 			"%lx at %lx\n", regs->trap, regs->nip);
 	die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
+
+exit:
+	exception_exit(prev_state);
 }
 
 void vsx_unavailable_exception(struct pt_regs *regs)
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 229951f..141835b 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -32,6 +32,7 @@
 #include <linux/perf_event.h>
 #include <linux/magic.h>
 #include <linux/ratelimit.h>
+#include <linux/context_tracking.h>
 
 #include <asm/firmware.h>
 #include <asm/page.h>
@@ -193,8 +194,8 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
  * The return value is 0 if the fault was handled, or the signal
  * number if this is a kernel fault that can't be handled here.
  */
-int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
-			    unsigned long error_code)
+static int __kprobes __do_page_fault(struct pt_regs *regs,
+				unsigned long address, unsigned long error_code)
 {
 	struct vm_area_struct * vma;
 	struct mm_struct *mm = current->mm;
@@ -475,6 +476,17 @@ bad_area_nosemaphore:
 
 }
 
+int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
+			    unsigned long error_code)
+{
+	int ret;
+	enum ctx_state prev_state;
+	prev_state = exception_enter();
+	ret = __do_page_fault(regs, address, error_code);
+	exception_exit(prev_state);
+	return ret;
+}
+
 /*
  * bad_page_fault is called when we have a bad access from the kernel.
  * It is called from the DSI and ISI handlers in head.S and from some
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 88ac0ee..d92fb26 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -33,6 +33,7 @@
 #include <linux/init.h>
 #include <linux/signal.h>
 #include <linux/memblock.h>
+#include <linux/context_tracking.h>
 
 #include <asm/processor.h>
 #include <asm/pgtable.h>
@@ -962,6 +963,9 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 	const struct cpumask *tmp;
 	int rc, user_region = 0, local = 0;
 	int psize, ssize;
+	enum ctx_state prev_state;
+
+	prev_state = exception_enter();
 
 	DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
 		ea, access, trap);
@@ -973,7 +977,8 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 		mm = current->mm;
 		if (! mm) {
 			DBG_LOW(" user region with no mm !\n");
-			return 1;
+			rc = 1;
+			goto exit;
 		}
 		psize = get_slice_psize(mm, ea);
 		ssize = user_segment_size(ea);
@@ -992,19 +997,23 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 		/* Not a valid range
 		 * Send the problem up to do_page_fault 
 		 */
-		return 1;
+		rc = 1;
+		goto exit;
 	}
 	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;
+		rc = 1;
+		goto exit;
 	}
 	/* Get pgdir */
 	pgdir = mm->pgd;
-	if (pgdir == NULL)
-		return 1;
+	if (pgdir == NULL) {
+		rc = 1;
+		goto exit;
+	}
 
 	/* Check CPU locality */
 	tmp = cpumask_of(smp_processor_id());
@@ -1027,7 +1036,8 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 	ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugeshift);
 	if (ptep == NULL || !pte_present(*ptep)) {
 		DBG_LOW(" no PTE !\n");
-		return 1;
+		rc = 1;
+		goto exit;
 	}
 
 	/* Add _PAGE_PRESENT to the required access perm */
@@ -1038,13 +1048,16 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 	 */
 	if (access & ~pte_val(*ptep)) {
 		DBG_LOW(" no access !\n");
-		return 1;
+		rc = 1;
+		goto exit;
 	}
 
 #ifdef CONFIG_HUGETLB_PAGE
-	if (hugeshift)
-		return __hash_page_huge(ea, access, vsid, ptep, trap, local,
+	if (hugeshift) {
+		rc = __hash_page_huge(ea, access, vsid, ptep, trap, local,
 					ssize, hugeshift, psize);
+		goto exit;
+	}
 #endif /* CONFIG_HUGETLB_PAGE */
 
 #ifndef CONFIG_PPC_64K_PAGES
@@ -1124,6 +1137,8 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 		pte_val(*(ptep + PTRS_PER_PTE)));
 #endif
 	DBG_LOW(" -> rc=%d\n", rc);
+exit:
+	exception_exit(prev_state);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(hash_page);
@@ -1259,6 +1274,9 @@ void flush_hash_range(unsigned long number, int local)
  */
 void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
 {
+	enum ctx_state prev_state;
+	prev_state = exception_enter();
+
 	if (user_mode(regs)) {
 #ifdef CONFIG_PPC_SUBPAGE_PROT
 		if (rc == -2)
@@ -1268,6 +1286,8 @@ void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
 			_exception(SIGBUS, regs, BUS_ADRERR, address);
 	} else
 		bad_page_fault(regs, address, SIGBUS);
+
+	exception_exit(prev_state);
 }
 
 long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
-- 
1.7.9.5

^ permalink raw reply related

* [RFC PATCH v3 1/5] powerpc: Syscall hooks for context tracking subsystem
From: Li Zhong @ 2013-05-13  5:21 UTC (permalink / raw)
  To: linux-kernel; +Cc: Li Zhong, fweisbec, paulus, paulmck, linuxppc-dev
In-Reply-To: <1368422493-9831-1-git-send-email-zhong@linux.vnet.ibm.com>

This is the syscall slow path hooks for context tracking subsystem,
corresponding to
[PATCH] x86: Syscall hooks for userspace RCU extended QS
  commit bf5a3c13b939813d28ce26c01425054c740d6731

TIF_MEMDIE is moved to the second 16-bits (with value 17), as it seems there
is no asm code using it. TIF_NOHZ is added to _TIF_SYCALL_T_OR_A, so it is
better for it to be in the same 16 bits with others in the group, so in the
asm code, andi. with this group could work.

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
---
 arch/powerpc/include/asm/thread_info.h |    7 +++++--
 arch/powerpc/kernel/ptrace.c           |    5 +++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 8ceea14..ba7b197 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -97,7 +97,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_PERFMON_CTXSW	6	/* perfmon needs ctxsw calls */
 #define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
 #define TIF_SINGLESTEP		8	/* singlestepping active */
-#define TIF_MEMDIE		9	/* is terminating due to OOM killer */
+#define TIF_NOHZ		9	/* in adaptive nohz mode */
 #define TIF_SECCOMP		10	/* secure computing */
 #define TIF_RESTOREALL		11	/* Restore all regs (implies NOERROR) */
 #define TIF_NOERROR		12	/* Force successful syscall return */
@@ -106,6 +106,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_TRACEPOINT	15	/* syscall tracepoint instrumentation */
 #define TIF_EMULATE_STACK_STORE	16	/* Is an instruction emulation
 						for stack store? */
+#define TIF_MEMDIE		17	/* is terminating due to OOM killer */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
@@ -124,8 +125,10 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_UPROBE		(1<<TIF_UPROBE)
 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
 #define _TIF_EMULATE_STACK_STORE	(1<<TIF_EMULATE_STACK_STORE)
+#define _TIF_NOHZ		(1<<TIF_NOHZ)
 #define _TIF_SYSCALL_T_OR_A	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
-				 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT)
+				 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
+				 _TIF_NOHZ)
 
 #define _TIF_USER_WORK_MASK	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
 				 _TIF_NOTIFY_RESUME | _TIF_UPROBE)
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 3b14d32..98c2fc1 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -32,6 +32,7 @@
 #include <trace/syscall.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/perf_event.h>
+#include <linux/context_tracking.h>
 
 #include <asm/uaccess.h>
 #include <asm/page.h>
@@ -1788,6 +1789,8 @@ long do_syscall_trace_enter(struct pt_regs *regs)
 {
 	long ret = 0;
 
+	user_exit();
+
 	secure_computing_strict(regs->gpr[0]);
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
@@ -1832,4 +1835,6 @@ void do_syscall_trace_leave(struct pt_regs *regs)
 	step = test_thread_flag(TIF_SINGLESTEP);
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
 		tracehook_report_syscall_exit(regs, step);
+
+	user_enter();
 }
-- 
1.7.9.5

^ permalink raw reply related

* [RFC PATCH v3 0/5] powerpc: Support context tracking for Power pSeries
From: Li Zhong @ 2013-05-13  5:21 UTC (permalink / raw)
  To: linux-kernel; +Cc: Li Zhong, fweisbec, paulus, paulmck, linuxppc-dev

These patches try to support context tracking for Power arch, beginning with
64-bit pSeries. The codes are ported from that of the x86_64, and in each
patch, I listed the corresponding patch for x86.

v3:

This version is mainly a rebasing, against 3.10-rc1, also as the common code 
to handle the exception are pulled into 3.10, so there is no dependency on 
tip tree. So patch #2 and #6 in previous version_2 is merged together. 

Li Zhong (5):
  powerpc: Syscall hooks for context tracking subsystem
  powerpc: Exception hooks for context tracking subsystem
  powerpc: Exit user context on notify resume
  powerpc: Use the new schedule_user API on userspace preemption
  powerpc: select HAVE_CONTEXT_TRACKING for pSeries

 arch/powerpc/include/asm/context_tracking.h |   10 +++
 arch/powerpc/include/asm/thread_info.h      |    7 ++-
 arch/powerpc/kernel/entry_64.S              |    3 +-
 arch/powerpc/kernel/ptrace.c                |    5 ++
 arch/powerpc/kernel/signal.c                |    5 ++
 arch/powerpc/kernel/traps.c                 |   91 ++++++++++++++++++++-------
 arch/powerpc/mm/fault.c                     |   16 ++++-
 arch/powerpc/mm/hash_utils_64.c             |   38 ++++++++---
 arch/powerpc/platforms/pseries/Kconfig      |    1 +
 9 files changed, 140 insertions(+), 36 deletions(-)
 create mode 100644 arch/powerpc/include/asm/context_tracking.h

-- 
1.7.9.5

^ permalink raw reply

* Re: [PATCH v3 1/4] powerpc/mpic: add irq_set_wake support
From: Benjamin Herrenschmidt @ 2013-05-13  5:00 UTC (permalink / raw)
  To: Wang Dongsheng-B40534; +Cc: Wood Scott-B07421, linuxppc-dev@lists.ozlabs.org
In-Reply-To: <ABB05CD9C9F68C46A5CEDC7F15439259F2581C@039-SN2MPN1-022.039d.mgd.msft.net>

On Mon, 2013-05-13 at 04:25 +0000, Wang Dongsheng-B40534 wrote:
> Hi Benjamin,
> 
> Could you apply these patches?

I'll have a look, I was assuming Kumar would take them but since
not I'll queue them up.

Cheers,
Ben.

> Scott already ACK.
> 
> [v3,1/4] powerpc/mpic: add irq_set_wake support
> http://patchwork.ozlabs.org/patch/234934/
> 
> [v3,2/4] powerpc/mpic: add global timer support
> http://patchwork.ozlabs.org/patch/234935/
> 
> [v3,3/4] powerpc/mpic: create mpic subsystem object
> http://patchwork.ozlabs.org/patch/234936/
> 
> [v3,4/4] powerpc/fsl: add MPIC timer wakeup support
> http://patchwork.ozlabs.org/patch/234937/
> 
> Thanks.
> 
> > -----Original Message-----
> > From: Wang Dongsheng-B40534
> > Sent: Friday, May 03, 2013 9:54 AM
> > To: 'galak@kernel.crashing.org'
> > Cc: 'linuxppc-dev@lists.ozlabs.org'; Wood Scott-B07421;
> > 'benh@kernel.crashing.org'
> > Subject: RE: [PATCH v3 1/4] powerpc/mpic: add irq_set_wake support
> > 
> > Hi Kumar,
> > 
> > Could you apply these patches?
> > 
> > Thanks.
> > 
> > > -----Original Message-----
> > > From: Wang Dongsheng-B40534
> > > Sent: Tuesday, April 23, 2013 6:10 PM
> > > To: galak@kernel.crashing.org
> > > Cc: linuxppc-dev@lists.ozlabs.org; Wood Scott-B07421
> > > Subject: RE: [PATCH v3 1/4] powerpc/mpic: add irq_set_wake support
> > >
> > > Hi Kumar,
> > >
> > > Could you apply these patches?
> > >
> > > Thanks.
> > >
> > > [v3,1/4] powerpc/mpic: add irq_set_wake support
> > > http://patchwork.ozlabs.org/patch/234934/
> > >
> > > [v3,2/4] powerpc/mpic: add global timer support
> > > http://patchwork.ozlabs.org/patch/234935/
> > >
> > > [v3,3/4] powerpc/mpic: create mpic subsystem object
> > > http://patchwork.ozlabs.org/patch/234936/
> > >
> > > [v3,4/4] powerpc/fsl: add MPIC timer wakeup support
> > > http://patchwork.ozlabs.org/patch/234937/
> > >
> > >
> > > > -----Original Message-----
> > > > From: Wood Scott-B07421
> > > > Sent: Wednesday, April 17, 2013 7:30 AM
> > > > To: Wang Dongsheng-B40534
> > > > Cc: Wood Scott-B07421; linuxppc-dev@lists.ozlabs.org;
> > > > galak@kernel.crashing.org
> > > > Subject: Re: [PATCH v3 1/4] powerpc/mpic: add irq_set_wake support
> > > >
> > > > ACK
> > > >
> > > > -Scott
> > > >
> > > > On 04/16/2013 05:58:52 AM, Wang Dongsheng-B40534 wrote:
> > > > > Hi scott,
> > > > >
> > > > > Could you ACK these patches?
> > > > >
> > > > > [PATCH v3 2/4] powerpc/mpic: add global timer support [PATCH v3
> > > > > 3/4]
> > > > > powerpc/mpic: create mpic subsystem object [PATCH v3 4/4]
> > > > > powerpc/fsl: add MPIC timer wakeup support
> > > > >
> > > > > Thanks.
> > > > >

^ permalink raw reply

* RE: [PATCH v3 1/4] powerpc/mpic: add irq_set_wake support
From: Wang Dongsheng-B40534 @ 2013-05-13  4:25 UTC (permalink / raw)
  To: benh@kernel.crashing.org; +Cc: Wood Scott-B07421, linuxppc-dev@lists.ozlabs.org
In-Reply-To: <1366155021.23030.24@snotra>

Hi Benjamin,

Could you apply these patches?

Scott already ACK.

[v3,1/4] powerpc/mpic: add irq_set_wake support
http://patchwork.ozlabs.org/patch/234934/

[v3,2/4] powerpc/mpic: add global timer support
http://patchwork.ozlabs.org/patch/234935/

[v3,3/4] powerpc/mpic: create mpic subsystem object
http://patchwork.ozlabs.org/patch/234936/

[v3,4/4] powerpc/fsl: add MPIC timer wakeup support
http://patchwork.ozlabs.org/patch/234937/

Thanks.

> -----Original Message-----
> From: Wang Dongsheng-B40534
> Sent: Friday, May 03, 2013 9:54 AM
> To: 'galak@kernel.crashing.org'
> Cc: 'linuxppc-dev@lists.ozlabs.org'; Wood Scott-B07421;
> 'benh@kernel.crashing.org'
> Subject: RE: [PATCH v3 1/4] powerpc/mpic: add irq_set_wake support
>=20
> Hi Kumar,
>=20
> Could you apply these patches?
>=20
> Thanks.
>=20
> > -----Original Message-----
> > From: Wang Dongsheng-B40534
> > Sent: Tuesday, April 23, 2013 6:10 PM
> > To: galak@kernel.crashing.org
> > Cc: linuxppc-dev@lists.ozlabs.org; Wood Scott-B07421
> > Subject: RE: [PATCH v3 1/4] powerpc/mpic: add irq_set_wake support
> >
> > Hi Kumar,
> >
> > Could you apply these patches?
> >
> > Thanks.
> >
> > [v3,1/4] powerpc/mpic: add irq_set_wake support
> > http://patchwork.ozlabs.org/patch/234934/
> >
> > [v3,2/4] powerpc/mpic: add global timer support
> > http://patchwork.ozlabs.org/patch/234935/
> >
> > [v3,3/4] powerpc/mpic: create mpic subsystem object
> > http://patchwork.ozlabs.org/patch/234936/
> >
> > [v3,4/4] powerpc/fsl: add MPIC timer wakeup support
> > http://patchwork.ozlabs.org/patch/234937/
> >
> >
> > > -----Original Message-----
> > > From: Wood Scott-B07421
> > > Sent: Wednesday, April 17, 2013 7:30 AM
> > > To: Wang Dongsheng-B40534
> > > Cc: Wood Scott-B07421; linuxppc-dev@lists.ozlabs.org;
> > > galak@kernel.crashing.org
> > > Subject: Re: [PATCH v3 1/4] powerpc/mpic: add irq_set_wake support
> > >
> > > ACK
> > >
> > > -Scott
> > >
> > > On 04/16/2013 05:58:52 AM, Wang Dongsheng-B40534 wrote:
> > > > Hi scott,
> > > >
> > > > Could you ACK these patches?
> > > >
> > > > [PATCH v3 2/4] powerpc/mpic: add global timer support [PATCH v3
> > > > 3/4]
> > > > powerpc/mpic: create mpic subsystem object [PATCH v3 4/4]
> > > > powerpc/fsl: add MPIC timer wakeup support
> > > >
> > > > Thanks.
> > > >

^ permalink raw reply

* Re: [v1][KVM][PATCH 1/1] kvm:ppc:booehv: direct ISI exception to Guest
From: tiejun.chen @ 2013-05-13  2:04 UTC (permalink / raw)
  To: Alexander Graf, Caraman Mihai Claudiu-B02008
  Cc: Scott Wood, Wood Scott-B07421, linuxppc-dev@lists.ozlabs.org,
	kvm@vger.kernel.org, kvm-ppc@vger.kernel.org
In-Reply-To: <F3847E9E-D4F6-4727-B3A6-42C68797F5CF@suse.de>

On 05/11/2013 03:39 AM, Alexander Graf wrote:
>
>
> Am 10.05.2013 um 21:22 schrieb Scott Wood <scottwood@freescale.com>:
>
>> On 05/10/2013 12:57:33 PM, Alexander Graf wrote:
>>> Could you guys please collect performance data during the next weeks on both guest-directed ISIs as well as VF MMIOs (preferably with in-kernel MMIO), so that we can decide on the direction that's worth going towards?
>>
>> Collecting data on VF MMIO would require implementing it (or at least salvaging and fixing some old code), which is not a high priority at the moment.  If we do implement VF in the future we could always undo the direct ISI change, but it would still be nice to know if there's any real benefit in the first place.
>
> Mike sounded like he had an almost working poc, which is good enough to collect rough numbers.

Which can the test case be adopted?

Mike,

If you already have a good case for your poc, please share that with me. Then 
I'd like to run that.

Tiejun

>
> And yes, changes like these should always get at least basic performance numbers along with them, regardless of drawbacks.
>
>
> Alex
>
>>
>> FWIW, I doubt that the "more stress on HW TLB" will be significant.
>>
>> -Scott
>

^ permalink raw reply

* [v3][KVM][PATCH 1/1] kvm:ppc: control doorbell exception with CONFIG_PPC_DOORBELL
From: Tiejun Chen @ 2013-05-13  2:00 UTC (permalink / raw)
  To: agraf, scottwood; +Cc: linuxppc-dev, kvm, kvm-ppc

We can only use CONFIG_PPC_DOORBELL to control whether
the doorbell exception should be enabled.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
---
v3:

Just imporve the patch head.

v2: 

Use CONFIG_PPC_DOORBELL to replace CONFIG_KVM_E500MC as that control condition.


 arch/powerpc/kvm/booke.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index ac7ab08..2d063c7 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -794,7 +794,7 @@ static void kvmppc_restart_interrupt(struct kvm_vcpu *vcpu,
 		kvmppc_fill_pt_regs(&regs);
 		timer_interrupt(&regs);
 		break;
-#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_BOOK3E_64)
+#if defined(CONFIG_PPC_DOORBELL)
 	case BOOKE_INTERRUPT_DOORBELL:
 		kvmppc_fill_pt_regs(&regs);
 		doorbell_exception(&regs);
-- 
1.7.9.5

^ permalink raw reply related

* [PATCH] powerpc/kexec: Fix kexec when using VMX optimised memcpy
From: Anton Blanchard @ 2013-05-13  1:04 UTC (permalink / raw)
  To: benh, paulus; +Cc: linuxppc-dev


commit b3f271e86e5a (powerpc: POWER7 optimised memcpy using VMX and
enhanced prefetch) uses VMX when it is safe to do so (ie not in
interrupt). It also looks at the task struct to decide if we have to
save the current tasks' VMX state.

kexec calls memcpy() at a point where the task struct may have been
overwritten by the new kexec segments. If it has been overwritten
then when memcpy -> enable_altivec looks up current->thread.regs->msr
we get a cryptic oops or lockup.

I also notice we aren't initialising thread_info->cpu, which means
smp_processor_id is broken. Fix that too.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@vger.kernel.org> # 3.6+
---

Index: b/arch/powerpc/kernel/machine_kexec_64.c
===================================================================
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -17,6 +17,7 @@
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/cpu.h>
+#include <linux/hardirq.h>
 
 #include <asm/page.h>
 #include <asm/current.h>
@@ -335,10 +338,13 @@ void default_machine_kexec(struct kimage
 	pr_debug("kexec: Starting switchover sequence.\n");
 
 	/* switch to a staticly allocated stack.  Based on irq stack code.
+	 * We setup preempt_count to avoid using VMX in memcpy.
 	 * XXX: the task struct will likely be invalid once we do the copy!
 	 */
 	kexec_stack.thread_info.task = current_thread_info()->task;
 	kexec_stack.thread_info.flags = 0;
+	kexec_stack.thread_info.preempt_count = HARDIRQ_OFFSET;
+	kexec_stack.thread_info.cpu = current_thread_info()->cpu;
 
 	/* We need a static PACA, too; copy this CPU's PACA over and switch to
 	 * it.  Also poison per_cpu_offset to catch anyone using non-static

^ permalink raw reply

* Re: Build regressions/improvements in v3.10-rc1 (powerpc)
From: Geert Uytterhoeven @ 2013-05-12 20:47 UTC (permalink / raw)
  To: Linux Kernel Development; +Cc: Linux/PPC Development
In-Reply-To: <alpine.DEB.2.00.1305122239040.5463@ayla.of.borg>

On Sun, 12 May 2013, Geert Uytterhoeven wrote:
> However, the full list of errors isn't that unmanageable, so I'm following
> up with a digested list...

arch/powerpc/kernel/fadump.c:408:2: error: 'crashing_cpu' undeclared (first use in this function): 1 errors in 1 logs
arch/powerpc/kernel/fadump.c:410:2: error: implicit declaration of function 'crash_save_vmcoreinfo' [-Werror=implicit-function-declaration]: 1 errors in 1 logs
arch/powerpc/kernel/fadump.c:513:22: error: storage size of 'prstatus' isn't known: 1 errors in 1 logs
arch/powerpc/kernel/fadump.c:520:2: error: implicit declaration of function 'elf_core_copy_kernel_regs' [-Werror=implicit-function-declaration]: 1 errors in 1 logs
arch/powerpc/kernel/fadump.c:521:36: error: 'KEXEC_CORE_NOTE_NAME' undeclared (first use in this function): 1 errors in 1 logs
arch/powerpc/kernel/fadump.c:624:49: error: 'note_buf_t' undeclared (first use in this function): 1 errors in 1 logs
arch/powerpc/kernel/fadump.c:872:2: error: implicit declaration of function 'paddr_vmcoreinfo_note' [-Werror=implicit-function-declaration]: 1 errors in 1 logs
arch/powerpc/kernel/fadump.c:874:18: error: 'vmcoreinfo_max_size' undeclared (first use in this function): 1 errors in 1 logs
arch/powerpc/platforms/cell/spufs/inode.c:623:16: error: incompatible types when assigning to type 'kuid_t' from type 'int': 1 errors in 1 logs
arch/powerpc/platforms/cell/spufs/inode.c:628:16: error: incompatible types when assigning to type 'kgid_t' from type 'int': 1 errors in 1 logs
	v3.10-rc1/powerpc/powerpc-randconfig

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

^ permalink raw reply

* [PATCH -V8 09/18] powerpc/THP: Implement transparent hugepages for ppc64
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

We now have pmd entries covering 16MB range and the PMD table double its original size.
We use the second half of the PMD table to deposit the pgtable (PTE page).
The depoisted PTE page is further used to track the HPTE information. The information
include [ secondary group | 3 bit hidx | valid ]. We use one byte per each HPTE entry.
With 16MB hugepage and 64K HPTE we need 256 entries and with 4K HPTE we need
4096 entries. Both will fit in a 4K PTE page. On hugepage invalidate we need to walk
the PTE page and invalidate all valid HPTEs.

This patch implements necessary arch specific functions for THP support and also
hugepage invalidate logic. These PMD related functions are intentionally kept
similar to their PTE counter-part.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/pgtable-ppc64.h | 200 ++++++++++++++++-
 arch/powerpc/include/asm/pgtable.h       |   4 +
 arch/powerpc/include/asm/tlbflush.h      |   3 +-
 arch/powerpc/mm/pgtable_64.c             | 364 +++++++++++++++++++++++++++++++
 arch/powerpc/mm/tlb_hash64.c             |  29 +++
 arch/powerpc/platforms/Kconfig.cputype   |   1 +
 6 files changed, 599 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index ab84332..d8642fb 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -154,7 +154,7 @@
 #define	pmd_present(pmd)	(pmd_val(pmd) != 0)
 #define	pmd_clear(pmdp)		(pmd_val(*(pmdp)) = 0)
 #define pmd_page_vaddr(pmd)	(pmd_val(pmd) & ~PMD_MASKED_BITS)
-#define pmd_page(pmd)		virt_to_page(pmd_page_vaddr(pmd))
+extern struct page *pmd_page(pmd_t pmd);
 
 #define pud_set(pudp, pudval)	(pud_val(*(pudp)) = (pudval))
 #define pud_none(pud)		(!pud_val(pud))
@@ -382,4 +382,202 @@ static inline pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
 
 #endif /* __ASSEMBLY__ */
 
+/*
+ * THP pages can't be special. So use the _PAGE_SPECIAL
+ */
+#define _PAGE_SPLITTING _PAGE_SPECIAL
+
+/*
+ * We need to differentiate between explicit huge page and THP huge
+ * page, since THP huge page also need to track real subpage details
+ */
+#define _PAGE_THP_HUGE  _PAGE_4K_PFN
+
+/*
+ * set of bits not changed in pmd_modify.
+ */
+#define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS |		\
+			 _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPLITTING | \
+			 _PAGE_THP_HUGE)
+
+#ifndef __ASSEMBLY__
+/*
+ * The linux hugepage PMD now include the pmd entries followed by the address
+ * to the stashed pgtable_t. The stashed pgtable_t contains the hpte bits.
+ * [ 1 bit secondary | 3 bit hidx | 1 bit valid | 000]. We use one byte per
+ * each HPTE entry. With 16MB hugepage and 64K HPTE we need 256 entries and
+ * with 4K HPTE we need 4096 entries. Both will fit in a 4K pgtable_t.
+ *
+ * The last three bits are intentionally left to zero. This memory location
+ * are also used as normal page PTE pointers. So if we have any pointers
+ * left around while we collapse a hugepage, we need to make sure
+ * _PAGE_PRESENT and _PAGE_FILE bits of that are zero when we look at them
+ */
+static inline unsigned int hpte_valid(unsigned char *hpte_slot_array, int index)
+{
+	return (hpte_slot_array[index] >> 3) & 0x1;
+}
+
+static inline unsigned int hpte_hash_index(unsigned char *hpte_slot_array,
+					   int index)
+{
+	return hpte_slot_array[index] >> 4;
+}
+
+static inline void mark_hpte_slot_valid(unsigned char *hpte_slot_array,
+					unsigned int index, unsigned int hidx)
+{
+	hpte_slot_array[index] = hidx << 4 | 0x1 << 3;
+}
+
+extern void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
+				   pmd_t *pmdp);
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+extern pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot);
+extern pmd_t mk_pmd(struct page *page, pgprot_t pgprot);
+extern pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot);
+extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+		       pmd_t *pmdp, pmd_t pmd);
+extern void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
+				 pmd_t *pmd);
+
+static inline int pmd_trans_huge(pmd_t pmd)
+{
+	/*
+	 * leaf pte for huge page, bottom two bits != 00
+	 */
+	return (pmd_val(pmd) & 0x3) && (pmd_val(pmd) & _PAGE_THP_HUGE);
+}
+
+static inline int pmd_large(pmd_t pmd)
+{
+	/*
+	 * leaf pte for huge page, bottom two bits != 00
+	 */
+	if (pmd_trans_huge(pmd))
+		return pmd_val(pmd) & _PAGE_PRESENT;
+	return 0;
+}
+
+static inline int pmd_trans_splitting(pmd_t pmd)
+{
+	if (pmd_trans_huge(pmd))
+		return pmd_val(pmd) & _PAGE_SPLITTING;
+	return 0;
+}
+
+/* We will enable it in the last patch */
+#define has_transparent_hugepage() 0
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+static inline pte_t pmd_pte(pmd_t pmd)
+{
+	return __pte(pmd_val(pmd));
+}
+
+static inline pmd_t pte_pmd(pte_t pte)
+{
+	return __pmd(pte_val(pte));
+}
+
+static inline pte_t *pmdp_ptep(pmd_t *pmd)
+{
+	return (pte_t *)pmd;
+}
+
+#define pmd_pfn(pmd)		pte_pfn(pmd_pte(pmd))
+#define pmd_young(pmd)		pte_young(pmd_pte(pmd))
+#define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
+#define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
+#define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
+#define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
+#define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
+
+#define __HAVE_ARCH_PMD_WRITE
+#define pmd_write(pmd)		pte_write(pmd_pte(pmd))
+
+static inline pmd_t pmd_mkhuge(pmd_t pmd)
+{
+	/* Do nothing, mk_pmd() does this part.  */
+	return pmd;
+}
+
+static inline pmd_t pmd_mknotpresent(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~_PAGE_PRESENT;
+	return pmd;
+}
+
+static inline pmd_t pmd_mksplitting(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_SPLITTING;
+	return pmd;
+}
+
+#define __HAVE_ARCH_PMD_SAME
+static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
+{
+	return (((pmd_val(pmd_a) ^ pmd_val(pmd_b)) & ~_PAGE_HPTEFLAGS) == 0);
+}
+
+#define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
+extern int pmdp_set_access_flags(struct vm_area_struct *vma,
+				 unsigned long address, pmd_t *pmdp,
+				 pmd_t entry, int dirty);
+
+extern unsigned long pmd_hugepage_update(struct mm_struct *mm,
+					 unsigned long addr,
+					 pmd_t *pmdp, unsigned long clr);
+
+static inline int __pmdp_test_and_clear_young(struct mm_struct *mm,
+					      unsigned long addr, pmd_t *pmdp)
+{
+	unsigned long old;
+
+	if ((pmd_val(*pmdp) & (_PAGE_ACCESSED | _PAGE_HASHPTE)) == 0)
+		return 0;
+	old = pmd_hugepage_update(mm, addr, pmdp, _PAGE_ACCESSED);
+	return ((old & _PAGE_ACCESSED) != 0);
+}
+
+#define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
+extern int pmdp_test_and_clear_young(struct vm_area_struct *vma,
+				     unsigned long address, pmd_t *pmdp);
+#define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
+extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
+				  unsigned long address, pmd_t *pmdp);
+
+#define __HAVE_ARCH_PMDP_GET_AND_CLEAR
+extern pmd_t pmdp_get_and_clear(struct mm_struct *mm,
+				unsigned long addr, pmd_t *pmdp);
+
+#define __HAVE_ARCH_PMDP_CLEAR_FLUSH
+extern pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
+			      pmd_t *pmdp);
+
+#define __HAVE_ARCH_PMDP_SET_WRPROTECT
+static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr,
+				      pmd_t *pmdp)
+{
+
+	if ((pmd_val(*pmdp) & _PAGE_RW) == 0)
+		return;
+
+	pmd_hugepage_update(mm, addr, pmdp, _PAGE_RW);
+}
+
+#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
+extern void pmdp_splitting_flush(struct vm_area_struct *vma,
+				 unsigned long address, pmd_t *pmdp);
+
+#define __HAVE_ARCH_PGTABLE_DEPOSIT
+extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				       pgtable_t pgtable);
+#define __HAVE_ARCH_PGTABLE_WITHDRAW
+extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
+
+#define __HAVE_ARCH_PMDP_INVALIDATE
+extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+			    pmd_t *pmdp);
+#endif /* __ASSEMBLY__ */
 #endif /* _ASM_POWERPC_PGTABLE_PPC64_H_ */
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 7aeb955..d53db93 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -220,6 +220,10 @@ extern int gup_hugepd(hugepd_t *hugepd, unsigned pdshift, unsigned long addr,
 
 extern int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
 		       unsigned long end, int write, struct page **pages, int *nr);
+#ifndef CONFIG_TRANSPARENT_HUGEPAGE
+#define pmd_large(pmd)		0
+#define has_transparent_hugepage() 0
+#endif
 #endif /* __ASSEMBLY__ */
 
 #endif /* __KERNEL__ */
diff --git a/arch/powerpc/include/asm/tlbflush.h b/arch/powerpc/include/asm/tlbflush.h
index 61a5927..2def01ed 100644
--- a/arch/powerpc/include/asm/tlbflush.h
+++ b/arch/powerpc/include/asm/tlbflush.h
@@ -165,7 +165,8 @@ static inline void flush_tlb_kernel_range(unsigned long start,
 /* Private function for use by PCI IO mapping code */
 extern void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
 				     unsigned long end);
-
+extern void flush_tlb_pmd_range(struct mm_struct *mm, pmd_t *pmd,
+				unsigned long addr);
 #else
 #error Unsupported MMU type
 #endif
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index a854096..2ff92aa 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -338,6 +338,19 @@ EXPORT_SYMBOL(iounmap);
 EXPORT_SYMBOL(__iounmap);
 EXPORT_SYMBOL(__iounmap_at);
 
+/*
+ * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
+ * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
+ */
+struct page *pmd_page(pmd_t pmd)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	if (pmd_trans_huge(pmd))
+		return pfn_to_page(pmd_pfn(pmd));
+#endif
+	return virt_to_page(pmd_page_vaddr(pmd));
+}
+
 #ifdef CONFIG_PPC_64K_PAGES
 static pte_t *get_from_cache(struct mm_struct *mm)
 {
@@ -455,3 +468,354 @@ void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
 }
 #endif
 #endif /* CONFIG_PPC_64K_PAGES */
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+/*
+ * This is called when relaxing access to a hugepage. It's also called in the page
+ * fault path when we don't hit any of the major fault cases, ie, a minor
+ * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
+ * handled those two for us, we additionally deal with missing execute
+ * permission here on some processors
+ */
+int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
+			  pmd_t *pmdp, pmd_t entry, int dirty)
+{
+	int changed;
+#ifdef CONFIG_DEBUG_VM
+	WARN_ON(!pmd_trans_huge(*pmdp));
+	assert_spin_locked(&vma->vm_mm->page_table_lock);
+#endif
+	changed = !pmd_same(*(pmdp), entry);
+	if (changed) {
+		__ptep_set_access_flags(pmdp_ptep(pmdp), pmd_pte(entry));
+		/*
+		 * Since we are not supporting SW TLB systems, we don't
+		 * have any thing similar to flush_tlb_page_nohash()
+		 */
+	}
+	return changed;
+}
+
+unsigned long pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
+				  pmd_t *pmdp, unsigned long clr)
+{
+
+	unsigned long old, tmp;
+
+#ifdef CONFIG_DEBUG_VM
+	WARN_ON(!pmd_trans_huge(*pmdp));
+	assert_spin_locked(&mm->page_table_lock);
+#endif
+
+#ifdef PTE_ATOMIC_UPDATES
+	__asm__ __volatile__(
+	"1:	ldarx	%0,0,%3\n\
+		andi.	%1,%0,%6\n\
+		bne-	1b \n\
+		andc	%1,%0,%4 \n\
+		stdcx.	%1,0,%3 \n\
+		bne-	1b"
+	: "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
+	: "r" (pmdp), "r" (clr), "m" (*pmdp), "i" (_PAGE_BUSY)
+	: "cc" );
+#else
+	old = pmd_val(*pmdp);
+	*pmdp = __pmd(old & ~clr);
+#endif
+	if (old & _PAGE_HASHPTE)
+		hpte_do_hugepage_flush(mm, addr, pmdp);
+	return old;
+}
+
+pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
+		       pmd_t *pmdp)
+{
+	pmd_t pmd;
+
+	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+	if (pmd_trans_huge(*pmdp)) {
+		pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
+	} else {
+		/*
+		 * khugepaged calls this for normal pmd
+		 */
+		pmd = *pmdp;
+		pmd_clear(pmdp);
+		/*
+		 * Now invalidate the hpte entries in the range
+		 * covered by pmd. This make sure we take a
+		 * fault and will find the pmd as none, which will
+		 * result in a major fault which takes mmap_sem and
+		 * hence wait for collapse to complete. Without this
+		 * the __collapse_huge_page_copy can result in copying
+		 * the old content.
+		 */
+		flush_tlb_pmd_range(vma->vm_mm, &pmd, address);
+	}
+	return pmd;
+}
+
+int pmdp_test_and_clear_young(struct vm_area_struct *vma,
+			      unsigned long address, pmd_t *pmdp)
+{
+	return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
+}
+
+/*
+ * We currently remove entries from the hashtable regardless of whether
+ * the entry was young or dirty. The generic routines only flush if the
+ * entry was young or dirty which is not good enough.
+ *
+ * We should be more intelligent about this but for the moment we override
+ * these functions and force a tlb flush unconditionally
+ */
+int pmdp_clear_flush_young(struct vm_area_struct *vma,
+				  unsigned long address, pmd_t *pmdp)
+{
+	return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
+}
+
+/*
+ * We mark the pmd splitting and invalidate all the hpte
+ * entries for this hugepage.
+ */
+void pmdp_splitting_flush(struct vm_area_struct *vma,
+			  unsigned long address, pmd_t *pmdp)
+{
+	unsigned long old, tmp;
+
+	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+
+#ifdef CONFIG_DEBUG_VM
+	WARN_ON(!pmd_trans_huge(*pmdp));
+	assert_spin_locked(&vma->vm_mm->page_table_lock);
+#endif
+
+#ifdef PTE_ATOMIC_UPDATES
+
+	__asm__ __volatile__(
+	"1:	ldarx	%0,0,%3\n\
+		andi.	%1,%0,%6\n\
+		bne-	1b \n\
+		ori	%1,%0,%4 \n\
+		stdcx.	%1,0,%3 \n\
+		bne-	1b"
+	: "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
+	: "r" (pmdp), "i" (_PAGE_SPLITTING), "m" (*pmdp), "i" (_PAGE_BUSY)
+	: "cc" );
+#else
+	old = pmd_val(*pmdp);
+	*pmdp = __pmd(old | _PAGE_SPLITTING);
+#endif
+	/*
+	 * If we didn't had the splitting flag set, go and flush the
+	 * HPTE entries.
+	 */
+	if (!(old & _PAGE_SPLITTING)) {
+		/* We need to flush the hpte */
+		if (old & _PAGE_HASHPTE)
+			hpte_do_hugepage_flush(vma->vm_mm, address, pmdp);
+	}
+}
+
+/*
+ * We want to put the pgtable in pmd and use pgtable for tracking
+ * the base page size hptes
+ */
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				pgtable_t pgtable)
+{
+	pgtable_t *pgtable_slot;
+	assert_spin_locked(&mm->page_table_lock);
+	/*
+	 * we store the pgtable in the second half of PMD
+	 */
+	pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
+	*pgtable_slot = pgtable;
+	/*
+	 * expose the deposited pgtable to other cpus.
+	 * before we set the hugepage PTE at pmd level
+	 * hash fault code looks at the deposted pgtable
+	 * to store hash index values.
+	 */
+	smp_wmb();
+}
+
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
+{
+	pgtable_t pgtable;
+	pgtable_t *pgtable_slot;
+
+	assert_spin_locked(&mm->page_table_lock);
+	pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
+	pgtable = *pgtable_slot;
+	/*
+	 * Once we withdraw, mark the entry NULL.
+	 */
+	*pgtable_slot = NULL;
+	/*
+	 * We store HPTE information in the deposited PTE fragment.
+	 * zero out the content on withdraw.
+	 */
+	memset(pgtable, 0, PTE_FRAG_SIZE);
+	return pgtable;
+}
+
+/*
+ * set a new huge pmd. We should not be called for updating
+ * an existing pmd entry. That should go via pmd_hugepage_update.
+ */
+void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+		pmd_t *pmdp, pmd_t pmd)
+{
+#ifdef CONFIG_DEBUG_VM
+	WARN_ON(!pmd_none(*pmdp));
+	assert_spin_locked(&mm->page_table_lock);
+	WARN_ON(!pmd_trans_huge(pmd));
+#endif
+	return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
+}
+
+void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+		     pmd_t *pmdp)
+{
+	pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT);
+}
+
+/*
+ * A linux hugepage PMD was changed and the corresponding hash table entries
+ * neesd to be flushed.
+ */
+void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
+			    pmd_t *pmdp)
+{
+	int ssize, i;
+	unsigned long s_addr;
+	unsigned int psize, valid;
+	unsigned char *hpte_slot_array;
+	unsigned long hidx, vpn, vsid, hash, shift, slot;
+
+	/*
+	 * Flush all the hptes mapping this hugepage
+	 */
+	s_addr = addr & HPAGE_PMD_MASK;
+	/*
+	 * The hpte hindex are stored in the pgtable whose address is in the
+	 * second half of the PMD
+	 */
+	hpte_slot_array = *(char **)(pmdp + PTRS_PER_PMD);
+	/*
+	 * IF we try to do a HUGE PTE update after a withdraw is done.
+	 * we will find the below NULL. This happens when we do
+	 * split_huge_page_pmd
+	 */
+	if (!hpte_slot_array)
+		return;
+
+	/* get the base page size */
+	psize = get_slice_psize(mm, s_addr);
+	shift = mmu_psize_defs[psize].shift;
+
+	for (i = 0; i < (HPAGE_PMD_SIZE >> shift); i++) {
+		/*
+		 * 8 bits per each hpte entries
+		 * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
+		 */
+		valid = hpte_valid(hpte_slot_array, i);
+		if (!valid)
+			continue;
+		hidx =  hpte_hash_index(hpte_slot_array, i);
+
+		/* get the vpn */
+		addr = s_addr + (i * (1ul << shift));
+		if (!is_kernel_addr(addr)) {
+			ssize = user_segment_size(addr);
+			vsid = get_vsid(mm->context.id, addr, ssize);
+			WARN_ON(vsid == 0);
+		} else {
+			vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
+			ssize = mmu_kernel_ssize;
+		}
+
+		vpn = hpt_vpn(addr, vsid, ssize);
+		hash = hpt_hash(vpn, shift, ssize);
+		if (hidx & _PTEIDX_SECONDARY)
+			hash = ~hash;
+
+		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+		slot += hidx & _PTEIDX_GROUP_IX;
+		ppc_md.hpte_invalidate(slot, vpn, psize, ssize, 0);
+	}
+}
+
+static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
+{
+	pmd_val(pmd) |= pgprot_val(pgprot);
+	return pmd;
+}
+
+pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
+{
+	pmd_t pmd;
+	/*
+	 * For a valid pte, we would have _PAGE_PRESENT or _PAGE_FILE always
+	 * set. We use this to check THP page at pmd level.
+	 * leaf pte for huge page, bottom two bits != 00
+	 */
+	pmd_val(pmd) = pfn << PTE_RPN_SHIFT;
+	pmd_val(pmd) |= _PAGE_THP_HUGE;
+	pmd = pmd_set_protbits(pmd, pgprot);
+	return pmd;
+}
+
+pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
+{
+	return pfn_pmd(page_to_pfn(page), pgprot);
+}
+
+pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+
+	pmd_val(pmd) &= _HPAGE_CHG_MASK;
+	pmd = pmd_set_protbits(pmd, newprot);
+	return pmd;
+}
+
+/*
+ * This is called at the end of handling a user page fault, when the
+ * fault has been handled by updating a HUGE PMD entry in the linux page tables.
+ * We use it to preload an HPTE into the hash table corresponding to
+ * the updated linux HUGE PMD entry.
+ */
+void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
+			  pmd_t *pmd)
+{
+	return;
+}
+
+pmd_t pmdp_get_and_clear(struct mm_struct *mm,
+			 unsigned long addr, pmd_t *pmdp)
+{
+	pmd_t old_pmd;
+	pgtable_t pgtable;
+	unsigned long old;
+	pgtable_t *pgtable_slot;
+
+	old = pmd_hugepage_update(mm, addr, pmdp, ~0UL);
+	old_pmd = __pmd(old);
+	/*
+	 * We have pmd == none and we are holding page_table_lock.
+	 * So we can safely go and clear the pgtable hash
+	 * index info.
+	 */
+	pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
+	pgtable = *pgtable_slot;
+	/*
+	 * Let's zero out old valid and hash index details
+	 * hash fault look at them.
+	 */
+	memset(pgtable, 0, PTE_FRAG_SIZE);
+	return old_pmd;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
diff --git a/arch/powerpc/mm/tlb_hash64.c b/arch/powerpc/mm/tlb_hash64.c
index 023ec8a..fe07f57 100644
--- a/arch/powerpc/mm/tlb_hash64.c
+++ b/arch/powerpc/mm/tlb_hash64.c
@@ -219,3 +219,32 @@ void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
 	arch_leave_lazy_mmu_mode();
 	local_irq_restore(flags);
 }
+
+void flush_tlb_pmd_range(struct mm_struct *mm, pmd_t *pmd, unsigned long addr)
+{
+	pte_t *pte;
+	pte_t *start_pte;
+	unsigned long flags;
+
+	addr = _ALIGN_DOWN(addr, PMD_SIZE);
+	/* Note: Normally, we should only ever use a batch within a
+	 * PTE locked section. This violates the rule, but will work
+	 * since we don't actually modify the PTEs, we just flush the
+	 * hash while leaving the PTEs intact (including their reference
+	 * to being hashed). This is not the most performance oriented
+	 * way to do things but is fine for our needs here.
+	 */
+	local_irq_save(flags);
+	arch_enter_lazy_mmu_mode();
+
+	start_pte = pte_offset_map(pmd, addr);
+	pte = start_pte;
+	for (pte = start_pte; pte < start_pte + PTRS_PER_PMD; pte++) {
+		unsigned long pteval = pte_val(*pte);
+		if (pteval & _PAGE_HASHPTE)
+			hpte_need_flush(mm, addr, pte, pteval, 0);
+		addr += PAGE_SIZE;
+	}
+	arch_leave_lazy_mmu_mode();
+	local_irq_restore(flags);
+}
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 54f3936..ae0aaea 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -71,6 +71,7 @@ config PPC_BOOK3S_64
 	select PPC_FPU
 	select PPC_HAVE_PMU_SUPPORT
 	select SYS_SUPPORTS_HUGETLBFS
+	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if PPC_64K_PAGES
 
 config PPC_BOOK3E_64
 	bool "Embedded processors"
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 10/18] powerpc: move find_linux_pte_or_hugepte and gup_hugepte to common code
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

We will use this in the later patch for handling THP pages

Reviewed-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/hugetlb.h       |   8 +-
 arch/powerpc/include/asm/pgtable-ppc64.h |  13 --
 arch/powerpc/include/asm/pgtable.h       |   2 +
 arch/powerpc/mm/Makefile                 |   2 +-
 arch/powerpc/mm/hugetlbpage.c            | 251 ++++++++++++++++---------------
 5 files changed, 138 insertions(+), 138 deletions(-)

diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index f2498c8..d750336 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -191,8 +191,14 @@ static inline void flush_hugetlb_page(struct vm_area_struct *vma,
 				      unsigned long vmaddr)
 {
 }
-#endif /* CONFIG_HUGETLB_PAGE */
 
+#define hugepd_shift(x) 0
+static inline pte_t *hugepte_offset(hugepd_t *hpdp, unsigned long addr,
+				    unsigned pdshift)
+{
+	return 0;
+}
+#endif /* CONFIG_HUGETLB_PAGE */
 
 /*
  * FSL Book3E platforms require special gpage handling - the gpages
diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index d8642fb..74ce13b 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -367,19 +367,6 @@ static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea)
 	return pt;
 }
 
-#ifdef CONFIG_HUGETLB_PAGE
-pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
-				 unsigned *shift);
-#else
-static inline pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
-					       unsigned *shift)
-{
-	if (shift)
-		*shift = 0;
-	return find_linux_pte(pgdir, ea);
-}
-#endif /* !CONFIG_HUGETLB_PAGE */
-
 #endif /* __ASSEMBLY__ */
 
 /*
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index d53db93..959d575 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -224,6 +224,8 @@ extern int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
 #define pmd_large(pmd)		0
 #define has_transparent_hugepage() 0
 #endif
+pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
+				 unsigned *shift);
 #endif /* __ASSEMBLY__ */
 
 #endif /* __KERNEL__ */
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index cf16b57..fde36e6 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -28,8 +28,8 @@ obj-$(CONFIG_44x)		+= 44x_mmu.o
 obj-$(CONFIG_PPC_FSL_BOOK3E)	+= fsl_booke_mmu.o
 obj-$(CONFIG_NEED_MULTIPLE_NODES) += numa.o
 obj-$(CONFIG_PPC_MM_SLICES)	+= slice.o
-ifeq ($(CONFIG_HUGETLB_PAGE),y)
 obj-y				+= hugetlbpage.o
+ifeq ($(CONFIG_HUGETLB_PAGE),y)
 obj-$(CONFIG_PPC_STD_MMU_64)	+= hugetlbpage-hash64.o
 obj-$(CONFIG_PPC_BOOK3E_MMU)	+= hugetlbpage-book3e.o
 endif
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 237c8e5..2865077 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -21,6 +21,9 @@
 #include <asm/pgalloc.h>
 #include <asm/tlb.h>
 #include <asm/setup.h>
+#include <asm/hugetlb.h>
+
+#ifdef CONFIG_HUGETLB_PAGE
 
 #define PAGE_SHIFT_64K	16
 #define PAGE_SHIFT_16M	24
@@ -100,66 +103,6 @@ int pgd_huge(pgd_t pgd)
 }
 #endif
 
-/*
- * We have 4 cases for pgds and pmds:
- * (1) invalid (all zeroes)
- * (2) pointer to next table, as normal; bottom 6 bits == 0
- * (3) leaf pte for huge page, bottom two bits != 00
- * (4) hugepd pointer, bottom two bits == 00, next 4 bits indicate size of table
- */
-pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift)
-{
-	pgd_t *pg;
-	pud_t *pu;
-	pmd_t *pm;
-	pte_t *ret_pte;
-	hugepd_t *hpdp = NULL;
-	unsigned pdshift = PGDIR_SHIFT;
-
-	if (shift)
-		*shift = 0;
-
-	pg = pgdir + pgd_index(ea);
-
-	if (pgd_huge(*pg)) {
-		ret_pte = (pte_t *) pg;
-		goto out;
-	} else if (is_hugepd(pg))
-		hpdp = (hugepd_t *)pg;
-	else if (!pgd_none(*pg)) {
-		pdshift = PUD_SHIFT;
-		pu = pud_offset(pg, ea);
-
-		if (pud_huge(*pu)) {
-			ret_pte = (pte_t *) pu;
-			goto out;
-		} else if (is_hugepd(pu))
-			hpdp = (hugepd_t *)pu;
-		else if (!pud_none(*pu)) {
-			pdshift = PMD_SHIFT;
-			pm = pmd_offset(pu, ea);
-
-			if (pmd_huge(*pm)) {
-				ret_pte = (pte_t *) pm;
-				goto out;
-			} else if (is_hugepd(pm))
-				hpdp = (hugepd_t *)pm;
-			else if (!pmd_none(*pm))
-				return pte_offset_kernel(pm, ea);
-		}
-	}
-	if (!hpdp)
-		return NULL;
-
-	ret_pte = hugepte_offset(hpdp, ea, pdshift);
-	pdshift = hugepd_shift(*hpdp);
-out:
-	if (shift)
-		*shift = pdshift;
-	return ret_pte;
-}
-EXPORT_SYMBOL_GPL(find_linux_pte_or_hugepte);
-
 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
 {
 	return find_linux_pte_or_hugepte(mm->pgd, addr, NULL);
@@ -753,69 +696,6 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 	return NULL;
 }
 
-int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
-		unsigned long end, int write, struct page **pages, int *nr)
-{
-	unsigned long mask;
-	unsigned long pte_end;
-	struct page *head, *page, *tail;
-	pte_t pte;
-	int refs;
-
-	pte_end = (addr + sz) & ~(sz-1);
-	if (pte_end < end)
-		end = pte_end;
-
-	pte = *ptep;
-	mask = _PAGE_PRESENT | _PAGE_USER;
-	if (write)
-		mask |= _PAGE_RW;
-
-	if ((pte_val(pte) & mask) != mask)
-		return 0;
-
-	/* hugepages are never "special" */
-	VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
-
-	refs = 0;
-	head = pte_page(pte);
-
-	page = head + ((addr & (sz-1)) >> PAGE_SHIFT);
-	tail = page;
-	do {
-		VM_BUG_ON(compound_head(page) != head);
-		pages[*nr] = page;
-		(*nr)++;
-		page++;
-		refs++;
-	} while (addr += PAGE_SIZE, addr != end);
-
-	if (!page_cache_add_speculative(head, refs)) {
-		*nr -= refs;
-		return 0;
-	}
-
-	if (unlikely(pte_val(pte) != pte_val(*ptep))) {
-		/* Could be optimized better */
-		*nr -= refs;
-		while (refs--)
-			put_page(head);
-		return 0;
-	}
-
-	/*
-	 * Any tail page need their mapcount reference taken before we
-	 * return.
-	 */
-	while (refs--) {
-		if (PageTail(tail))
-			get_huge_page_tail(tail);
-		tail++;
-	}
-
-	return 1;
-}
-
 static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
 				      unsigned long sz)
 {
@@ -1032,3 +912,128 @@ void flush_dcache_icache_hugepage(struct page *page)
 		}
 	}
 }
+
+#endif /* CONFIG_HUGETLB_PAGE */
+
+/*
+ * We have 4 cases for pgds and pmds:
+ * (1) invalid (all zeroes)
+ * (2) pointer to next table, as normal; bottom 6 bits == 0
+ * (3) leaf pte for huge page, bottom two bits != 00
+ * (4) hugepd pointer, bottom two bits == 00, next 4 bits indicate size of table
+ */
+pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift)
+{
+	pgd_t *pg;
+	pud_t *pu;
+	pmd_t *pm;
+	pte_t *ret_pte;
+	hugepd_t *hpdp = NULL;
+	unsigned pdshift = PGDIR_SHIFT;
+
+	if (shift)
+		*shift = 0;
+
+	pg = pgdir + pgd_index(ea);
+
+	if (pgd_huge(*pg)) {
+		ret_pte = (pte_t *) pg;
+		goto out;
+	} else if (is_hugepd(pg))
+		hpdp = (hugepd_t *)pg;
+	else if (!pgd_none(*pg)) {
+		pdshift = PUD_SHIFT;
+		pu = pud_offset(pg, ea);
+
+		if (pud_huge(*pu)) {
+			ret_pte = (pte_t *) pu;
+			goto out;
+		} else if (is_hugepd(pu))
+			hpdp = (hugepd_t *)pu;
+		else if (!pud_none(*pu)) {
+			pdshift = PMD_SHIFT;
+			pm = pmd_offset(pu, ea);
+
+			if (pmd_huge(*pm)) {
+				ret_pte = (pte_t *) pm;
+				goto out;
+			} else if (is_hugepd(pm))
+				hpdp = (hugepd_t *)pm;
+			else if (!pmd_none(*pm))
+				return pte_offset_kernel(pm, ea);
+		}
+	}
+	if (!hpdp)
+		return NULL;
+
+	ret_pte = hugepte_offset(hpdp, ea, pdshift);
+	pdshift = hugepd_shift(*hpdp);
+out:
+	if (shift)
+		*shift = pdshift;
+	return ret_pte;
+}
+EXPORT_SYMBOL_GPL(find_linux_pte_or_hugepte);
+
+int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
+		unsigned long end, int write, struct page **pages, int *nr)
+{
+	unsigned long mask;
+	unsigned long pte_end;
+	struct page *head, *page, *tail;
+	pte_t pte;
+	int refs;
+
+	pte_end = (addr + sz) & ~(sz-1);
+	if (pte_end < end)
+		end = pte_end;
+
+	pte = *ptep;
+	mask = _PAGE_PRESENT | _PAGE_USER;
+	if (write)
+		mask |= _PAGE_RW;
+
+	if ((pte_val(pte) & mask) != mask)
+		return 0;
+
+	/* hugepages are never "special" */
+	VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
+
+	refs = 0;
+	head = pte_page(pte);
+
+	page = head + ((addr & (sz-1)) >> PAGE_SHIFT);
+	tail = page;
+	do {
+		VM_BUG_ON(compound_head(page) != head);
+		pages[*nr] = page;
+		(*nr)++;
+		page++;
+		refs++;
+	} while (addr += PAGE_SIZE, addr != end);
+
+	if (!page_cache_add_speculative(head, refs)) {
+		*nr -= refs;
+		return 0;
+	}
+
+	if (unlikely(pte_val(pte) != pte_val(*ptep))) {
+		/* Could be optimized better */
+		*nr -= refs;
+		while (refs--)
+			put_page(head);
+		return 0;
+	}
+
+	/*
+	 * Any tail page need their mapcount reference taken before we
+	 * return.
+	 */
+	while (refs--) {
+		if (PageTail(tail))
+			get_huge_page_tail(tail);
+		tail++;
+	}
+
+	return 1;
+}
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 06/18] mm/THP: Don't use HPAGE_SHIFT in transparent hugepage code
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

For architectures like powerpc that support multiple explicit hugepage
sizes, HPAGE_SHIFT indicate the default explicit hugepage shift. For
THP to work the hugepage size should be same as PMD_SIZE. So use
PMD_SHIFT directly. So move the define outside CONFIG_TRANSPARENT_HUGEPAGE
#ifdef because we want to use these defines in generic code with
if (pmd_trans_huge()) conditional.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 include/linux/huge_mm.h | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 528454c..cc276d2 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -58,12 +58,11 @@ extern pmd_t *page_check_address_pmd(struct page *page,
 
 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
+#define HPAGE_PMD_SHIFT PMD_SHIFT
+#define HPAGE_PMD_SIZE	((1UL) << HPAGE_PMD_SHIFT)
+#define HPAGE_PMD_MASK	(~(HPAGE_PMD_SIZE - 1))
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-#define HPAGE_PMD_SHIFT HPAGE_SHIFT
-#define HPAGE_PMD_MASK HPAGE_MASK
-#define HPAGE_PMD_SIZE HPAGE_SIZE
-
 extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
 
 #define transparent_hugepage_enabled(__vma)				\
@@ -181,9 +180,6 @@ extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vm
 				unsigned long addr, pmd_t pmd, pmd_t *pmdp);
 
 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
-#define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
-#define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
-#define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 
 #define hpage_nr_pages(x) 1
 
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 13/18] powerpc: Update gup_pmd_range to handle transparent hugepages
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/mm/gup.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/gup.c b/arch/powerpc/mm/gup.c
index 4b921af..3d36fd7 100644
--- a/arch/powerpc/mm/gup.c
+++ b/arch/powerpc/mm/gup.c
@@ -66,9 +66,20 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
 		pmd_t pmd = *pmdp;
 
 		next = pmd_addr_end(addr, end);
-		if (pmd_none(pmd))
+		/*
+		 * The pmd_trans_splitting() check below explains why
+		 * pmdp_splitting_flush has to flush the tlb, to stop
+		 * this gup-fast code from running while we set the
+		 * splitting bit in the pmd. Returning zero will take
+		 * the slow path that will call wait_split_huge_page()
+		 * if the pmd is still in splitting state. gup-fast
+		 * can't because it has irq disabled and
+		 * wait_split_huge_page() would never return as the
+		 * tlb flush IPI wouldn't run.
+		 */
+		if (pmd_none(pmd) || pmd_trans_splitting(pmd))
 			return 0;
-		if (pmd_huge(pmd)) {
+		if (pmd_huge(pmd) || pmd_large(pmd)) {
 			if (!gup_hugepte((pte_t *)pmdp, PMD_SIZE, addr, next,
 					 write, pages, nr))
 				return 0;
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 15/18] powerpc: Make linux pagetable walk safe with THP enabled
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

We need to have irqs disabled to handle all the possible parallel update for
linux page table without holding locks.

Events that we are intersted in while walking page tables are
1) Page fault
2) umap
3) THP split
4) THP collapse

A) local_irq_disabled:
------------------------
1) page fault:
A none to valid transition via page fault is not an issue because we
would either see a none or valid. If it is none, we would error out
the page table walk. We may need to use on stack values when checking for
type of page table elements, because if we do

if (!is_hugepd()) {
    if (!pmd_none() {
       if (pmd_bad() {

We could take that bad condition because the pmd got converted to a hugepd
after the !is_hugepd check via a hugetlb fault.

The right way would be to check for pmd_none higher up or use on stack value.

2) A valid to none conversion via unmap:
We can safely walk the upper level table, because we don't remove the the
page table entries until rcu grace period. So even if we followed a
wrong pointer we still have the pointer valid till the grace period.

A PTE pointer returned need to be atomically checked for _PAGE_PRESENT and
 _PAGE_BUSY. A valid pointer returned could becoming none later. To prevent
pte_clear we take _PAGE_BUSY.

3) THP split:
A valid transparent hugepage is converted to nomal page. Before we split we
do pmd_splitting_flush, which sets the hugepage PTE to _PAGE_SPLITTING
So when walking page table we need to check for pmd_trans_splitting and
handle that. The pte returned should also need to be checked for
_PAGE_SPLITTING before setting _PAGE_BUSY similar to _PAGE_PRESENT. We save
the value of PTE on stack and check for the flag in the local pte value.
If we don't have the value set we can safely operate on the local pte value
and we atomicaly set _PAGE_BUSY.

4) THP collapse:
A normal page gets converted to hugepage. In the collapse path, we
mark the pmd none early (pmdp_clear_flush). With irq disabled, if we
are aleady walking page table we would see the pmd_none and won't continue.
If we see a valid PMD, we should still check for _PAGE_PRESENT before
setting _PAGE_BUSY, to make sure we didn't collapse the PTE to a Huge PTE.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/mm/hash_utils_64.c   | 27 ++++++++-------
 arch/powerpc/mm/hugepage-hash64.c |  3 ++
 arch/powerpc/mm/hugetlbpage.c     | 72 +++++++++++++++++++++++++--------------
 arch/powerpc/mm/mem.c             |  4 +++
 4 files changed, 68 insertions(+), 38 deletions(-)

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 693ff94..13d43ea 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1158,13 +1158,25 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
 	pgdir = mm->pgd;
 	if (pgdir == NULL)
 		return;
+
+	/* Get VSID */
+	ssize = user_segment_size(ea);
+	vsid = get_vsid(mm->context.id, ea, ssize);
+	if (!vsid)
+		return;
+	/*
+	 * Hash doesn't like irqs. Walking linux page table with irq disabled
+	 * saves us from holding multiple locks.
+	 */
+	local_irq_save(flags);
+
 	/*
 	 * THP pages use update_mmu_cache_pmd. We don't do
 	 * hash preload there. Hence can ignore THP here
 	 */
 	ptep = find_linux_pte_or_hugepte(pgdir, ea, &shift);
 	if (!ptep)
-		return;
+		goto out_exit;
 
 	BUG_ON(shift);
 #ifdef CONFIG_PPC_64K_PAGES
@@ -1175,18 +1187,9 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
 	 * page size demotion here
 	 */
 	if (pte_val(*ptep) & (_PAGE_4K_PFN | _PAGE_NO_CACHE))
-		return;
+		goto out_exit;
 #endif /* CONFIG_PPC_64K_PAGES */
 
-	/* 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);
-
 	/* Is that local to this CPU ? */
 	if (cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
 		local = 1;
@@ -1208,7 +1211,7 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
 				   mm->context.user_psize,
 				   mm->context.user_psize,
 				   pte_val(*ptep));
-
+out_exit:
 	local_irq_restore(flags);
 }
 
diff --git a/arch/powerpc/mm/hugepage-hash64.c b/arch/powerpc/mm/hugepage-hash64.c
index 3712e80..e430766 100644
--- a/arch/powerpc/mm/hugepage-hash64.c
+++ b/arch/powerpc/mm/hugepage-hash64.c
@@ -37,6 +37,9 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
 		/* If PMD busy, retry the access */
 		if (unlikely(old_pmd & _PAGE_BUSY))
 			return 0;
+		/* If PMD is trans splitting retry the access */
+		if (unlikely(old_pmd & _PAGE_SPLITTING))
+			return 0;
 		/* If PMD permissions don't match, take page fault */
 		if (unlikely(access & ~old_pmd))
 			return 1;
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 8add580..9d178d8 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -925,12 +925,16 @@ void flush_dcache_icache_hugepage(struct page *page)
  * (2) pointer to next table, as normal; bottom 6 bits == 0
  * (3) leaf pte for huge page, bottom two bits != 00
  * (4) hugepd pointer, bottom two bits == 00, next 4 bits indicate size of table
+ *
+ * So long as we atomically load page table pointers we are safe against teardown,
+ * we can follow the address down to the the page and take a ref on it.
  */
+
 pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift)
 {
-	pgd_t *pg;
-	pud_t *pu;
-	pmd_t *pm;
+	pgd_t pgd, *pgdp;
+	pud_t pud, *pudp;
+	pmd_t pmd, *pmdp;
 	pte_t *ret_pte;
 	hugepd_t *hpdp = NULL;
 	unsigned pdshift = PGDIR_SHIFT;
@@ -938,34 +942,42 @@ pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift
 	if (shift)
 		*shift = 0;
 
-	pg = pgdir + pgd_index(ea);
-
+	pgdp = pgdir + pgd_index(ea);
+	pgd  = *pgdp;
 	/*
-	 * we should first check for none. That takes care of a
-	 * a parallel hugetlb or THP pagefault moving none entries
-	 * to respective types.
+	 * Always operate on the local stack value. This make sure the
+	 * value don't get updated by a parallel THP split/collapse,
+	 * page fault or a page unmap. The return pte_t * is still not
+	 * stable. So should be checked there for above conditions.
 	 */
-	if (pgd_none(*pg))
+	if (pgd_none(pgd))
 		return NULL;
-	else if (pgd_huge(*pg)) {
-		ret_pte = (pte_t *) pg;
+	else if (pgd_huge(pgd)) {
+		ret_pte = (pte_t *) pgdp;
 		goto out;
-	} else if (is_hugepd(pg))
-		hpdp = (hugepd_t *)pg;
+	} else if (is_hugepd(&pgd))
+		hpdp = (hugepd_t *)&pgd;
 	else {
+		/*
+		 * Even if we end up with an unmap, the pgtable will not
+		 * be freed, because we do an rcu free and here we are
+		 * irq disabled
+		 */
 		pdshift = PUD_SHIFT;
-		pu = pud_offset(pg, ea);
+		pudp = pud_offset(&pgd, ea);
+		pud  = *pudp;
 
-		if (pud_none(*pu))
+		if (pud_none(pud))
 			return NULL;
-		else if (pud_huge(*pu)) {
-			ret_pte = (pte_t *) pu;
+		else if (pud_huge(pud)) {
+			ret_pte = (pte_t *) pudp;
 			goto out;
-		} else if (is_hugepd(pu))
-			hpdp = (hugepd_t *)pu;
+		} else if (is_hugepd(&pud))
+			hpdp = (hugepd_t *)&pud;
 		else {
 			pdshift = PMD_SHIFT;
-			pm = pmd_offset(pu, ea);
+			pmdp = pmd_offset(&pud, ea);
+			pmd  = *pmdp;
 			/*
 			 * A hugepage collapse is captured by pmd_none, because
 			 * it mark the pmd none and do a hpte invalidate.
@@ -975,16 +987,16 @@ pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift
 			 * hpte invalidate
 			 *
 			 */
-			if (pmd_none(*pm) || pmd_trans_splitting(*pm))
+			if (pmd_none(pmd) || pmd_trans_splitting(pmd))
 				return NULL;
 
-			if (pmd_huge(*pm) || pmd_large(*pm)) {
-				ret_pte = (pte_t *) pm;
+			if (pmd_huge(pmd) || pmd_large(pmd)) {
+				ret_pte = (pte_t *) pmdp;
 				goto out;
-			} else if (is_hugepd(pm))
-				hpdp = (hugepd_t *)pm;
+			} else if (is_hugepd(&pmd))
+				hpdp = (hugepd_t *)&pmd;
 			else
-				return pte_offset_kernel(pm, ea);
+				return pte_offset_kernel(&pmd, ea);
 		}
 	}
 	if (!hpdp)
@@ -1020,6 +1032,14 @@ int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
 	if ((pte_val(pte) & mask) != mask)
 		return 0;
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	/*
+	 * check for splitting here
+	 */
+	if (pmd_trans_splitting(pte_pmd(pte)))
+		return 0;
+#endif
+
 	/* hugepages are never "special" */
 	VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
 
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 0988a26..ccd49f9 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -508,6 +508,10 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 		      pte_t *ptep)
 {
 #ifdef CONFIG_PPC_STD_MMU
+	/*
+	 * We don't need to worry about _PAGE_PRESENT here because we are
+	 * called with either mm->page_table_lock held or ptl lock held
+	 */
 	unsigned long access = 0, trap;
 
 	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 18/18] powerpc: disable assert_pte_locked for collapse_huge_page
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

With THP we set pmd to none, before we do pte_clear. Hence we can't
walk page table to get the pte lock ptr and verify whether it is locked.
THP do take pte lock before calling pte_clear. So we don't change the locking
rules here. It is that we can't use page table walking to check whether
pte locks are held with THP.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/mm/pgtable.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 214130a..edda589 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -235,6 +235,14 @@ void assert_pte_locked(struct mm_struct *mm, unsigned long addr)
 	pud = pud_offset(pgd, addr);
 	BUG_ON(pud_none(*pud));
 	pmd = pmd_offset(pud, addr);
+	/*
+	 * khugepaged to collapse normal pages to hugepage, first set
+	 * pmd to none to force page fault/gup to take mmap_sem. After
+	 * pmd is set to none, we do a pte_clear which does this assertion
+	 * so if we find pmd none, return.
+	 */
+	if (pmd_none(*pmd))
+		return;
 	BUG_ON(!pmd_present(*pmd));
 	assert_spin_locked(pte_lockptr(mm, pmd));
 }
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 03/18] mm/THP: Use the right function when updating access flags
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

We should use pmdp_set_access_flags to update access flags. Archs like powerpc
use extra checks(_PAGE_BUSY) when updating a hugepage PTE. A set_pmd_at doesn't
do those checks. We should use set_pmd_at only when updating a none hugepage PTE.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 mm/huge_memory.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 49cb001..a43d736 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1265,7 +1265,9 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
 		 * young bit, instead of the current set_pmd_at.
 		 */
 		_pmd = pmd_mkyoung(pmd_mkdirty(*pmd));
-		set_pmd_at(mm, addr & HPAGE_PMD_MASK, pmd, _pmd);
+		if (pmdp_set_access_flags(vma, addr & HPAGE_PMD_MASK,
+					  pmd, _pmd,  1))
+			update_mmu_cache_pmd(vma, addr, pmd);
 	}
 	if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) {
 		if (page->mapping && trylock_page(page)) {
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 04/18] mm/THP: Add pmd args to pgtable deposit and withdraw APIs
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

This will be later used by powerpc THP support. In powerpc we want to use
pgtable for storing the hash index values. So instead of adding them to
mm_context list, we would like to store them in the second half of pmd

Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/s390/include/asm/pgtable.h     |  5 +++--
 arch/s390/mm/pgtable.c              |  5 +++--
 arch/sparc/include/asm/pgtable_64.h |  5 +++--
 arch/sparc/mm/tlb.c                 |  5 +++--
 include/asm-generic/pgtable.h       |  5 +++--
 mm/huge_memory.c                    | 18 +++++++++---------
 mm/pgtable-generic.c                |  5 +++--
 7 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 4105b82..9fba7a8 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1351,10 +1351,11 @@ static inline pmd_t pmd_mkwrite(pmd_t pmd)
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 
 #define __HAVE_ARCH_PGTABLE_DEPOSIT
-extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable);
+extern void pgtable_trans_huge_deposit(struct mm_struct *mm, , pmd_t *pmdp,
+				       pgtable_t pgtable);
 
 #define __HAVE_ARCH_PGTABLE_WITHDRAW
-extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm);
+extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
 
 static inline int pmd_trans_splitting(pmd_t pmd)
 {
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 7805ddc..555c11d 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -1118,7 +1118,8 @@ void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
 	}
 }
 
-void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				pgtable_t pgtable)
 {
 	struct list_head *lh = (struct list_head *) pgtable;
 
@@ -1132,7 +1133,7 @@ void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
 	mm->pmd_huge_pte = pgtable;
 }
 
-pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 {
 	struct list_head *lh;
 	pgtable_t pgtable;
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 7619f2f..d22b92d 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -853,10 +853,11 @@ extern void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
 				 pmd_t *pmd);
 
 #define __HAVE_ARCH_PGTABLE_DEPOSIT
-extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable);
+extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				       pgtable_t pgtable);
 
 #define __HAVE_ARCH_PGTABLE_WITHDRAW
-extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm);
+extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
 #endif
 
 /* Encode and de-code a swap entry */
diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
index 83d89bc..f828dd3 100644
--- a/arch/sparc/mm/tlb.c
+++ b/arch/sparc/mm/tlb.c
@@ -188,7 +188,8 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 	}
 }
 
-void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				pgtable_t pgtable)
 {
 	struct list_head *lh = (struct list_head *) pgtable;
 
@@ -202,7 +203,7 @@ void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
 	mm->pmd_huge_pte = pgtable;
 }
 
-pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 {
 	struct list_head *lh;
 	pgtable_t pgtable;
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index a59ff51..18e27c2 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -173,11 +173,12 @@ extern void pmdp_splitting_flush(struct vm_area_struct *vma,
 #endif
 
 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
-extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable);
+extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				       pgtable_t pgtable);
 #endif
 
 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
-extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm);
+extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
 #endif
 
 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index a43d736..69f4153 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -730,7 +730,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
 		entry = mk_huge_pmd(page, vma);
 		page_add_new_anon_rmap(page, vma, haddr);
 		set_pmd_at(mm, haddr, pmd, entry);
-		pgtable_trans_huge_deposit(mm, pgtable);
+		pgtable_trans_huge_deposit(mm, pmd, pgtable);
 		add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
 		mm->nr_ptes++;
 		spin_unlock(&mm->page_table_lock);
@@ -772,7 +772,7 @@ static bool set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
 	entry = pmd_wrprotect(entry);
 	entry = pmd_mkhuge(entry);
 	set_pmd_at(mm, haddr, pmd, entry);
-	pgtable_trans_huge_deposit(mm, pgtable);
+	pgtable_trans_huge_deposit(mm, pmd, pgtable);
 	mm->nr_ptes++;
 	return true;
 }
@@ -917,7 +917,7 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	pmdp_set_wrprotect(src_mm, addr, src_pmd);
 	pmd = pmd_mkold(pmd_wrprotect(pmd));
 	set_pmd_at(dst_mm, addr, dst_pmd, pmd);
-	pgtable_trans_huge_deposit(dst_mm, pgtable);
+	pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
 	dst_mm->nr_ptes++;
 
 	ret = 0;
@@ -987,7 +987,7 @@ static int do_huge_pmd_wp_zero_page_fallback(struct mm_struct *mm,
 	pmdp_clear_flush(vma, haddr, pmd);
 	/* leave pmd empty until pte is filled */
 
-	pgtable = pgtable_trans_huge_withdraw(mm);
+	pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 	pmd_populate(mm, &_pmd, pgtable);
 
 	for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
@@ -1085,7 +1085,7 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
 	pmdp_clear_flush(vma, haddr, pmd);
 	/* leave pmd empty until pte is filled */
 
-	pgtable = pgtable_trans_huge_withdraw(mm);
+	pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 	pmd_populate(mm, &_pmd, pgtable);
 
 	for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
@@ -1360,7 +1360,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		struct page *page;
 		pgtable_t pgtable;
 		pmd_t orig_pmd;
-		pgtable = pgtable_trans_huge_withdraw(tlb->mm);
+		pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
 		orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd);
 		tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
 		if (is_huge_zero_pmd(orig_pmd)) {
@@ -1693,7 +1693,7 @@ static int __split_huge_page_map(struct page *page,
 	pmd = page_check_address_pmd(page, mm, address,
 				     PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG);
 	if (pmd) {
-		pgtable = pgtable_trans_huge_withdraw(mm);
+		pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 		pmd_populate(mm, &_pmd, pgtable);
 
 		haddr = address;
@@ -2358,7 +2358,7 @@ static void collapse_huge_page(struct mm_struct *mm,
 	page_add_new_anon_rmap(new_page, vma, address);
 	set_pmd_at(mm, address, pmd, _pmd);
 	update_mmu_cache_pmd(vma, address, pmd);
-	pgtable_trans_huge_deposit(mm, pgtable);
+	pgtable_trans_huge_deposit(mm, pmd, pgtable);
 	spin_unlock(&mm->page_table_lock);
 
 	*hpage = NULL;
@@ -2664,7 +2664,7 @@ static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
 	pmdp_clear_flush(vma, haddr, pmd);
 	/* leave pmd empty until pte is filled */
 
-	pgtable = pgtable_trans_huge_withdraw(mm);
+	pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 	pmd_populate(mm, &_pmd, pgtable);
 
 	for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 0c8323f..e1a6e4f 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -124,7 +124,8 @@ void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
 
 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				pgtable_t pgtable)
 {
 	assert_spin_locked(&mm->page_table_lock);
 
@@ -141,7 +142,7 @@ void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 /* no "address" argument so destroys page coloring of some arch */
-pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 {
 	pgtable_t pgtable;
 
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 02/18] mm/THP: Use pmd_populate to update the pmd with pgtable_t pointer
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

We should not use set_pmd_at to update pmd_t with pgtable_t pointer. set_pmd_at
is used to set pmd with huge pte entries and architectures like ppc64, clear
few flags from the pte when saving a new entry. Without this change we observe
bad pte errors like below on ppc64 with THP enabled.

BUG: Bad page map in process ld mm=0xc000001ee39f4780 pte:7fc3f37848000001 pmd:c000001ec0000000
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 mm/huge_memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 03a89a2..49cb001 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2325,7 +2325,7 @@ static void collapse_huge_page(struct mm_struct *mm,
 		pte_unmap(pte);
 		spin_lock(&mm->page_table_lock);
 		BUG_ON(!pmd_none(*pmd));
-		set_pmd_at(mm, address, pmd, _pmd);
+		pmd_populate(mm, pmd, _pmd);
 		spin_unlock(&mm->page_table_lock);
 		anon_vma_unlock_write(vma->anon_vma);
 		goto out;
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 17/18] powerpc: Optimize hugepage invalidate
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

Hugepage invalidate involves invalidating multiple hpte entries.
Optimize the operation using H_BULK_REMOVE on lpar platforms.
On native, reduce the number of tlb flush.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/machdep.h    |   3 +
 arch/powerpc/mm/hash_native_64.c      |  74 +++++++++++++++++++++
 arch/powerpc/mm/pgtable_64.c          |  12 +++-
 arch/powerpc/platforms/pseries/lpar.c | 122 ++++++++++++++++++++++++++++++++--
 4 files changed, 202 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 92386fc..9c5a3ad 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -57,6 +57,9 @@ struct machdep_calls {
 	void            (*hpte_removebolted)(unsigned long ea,
 					     int psize, int ssize);
 	void		(*flush_hash_range)(unsigned long number, int local);
+	void		(*hugepage_invalidate)(struct mm_struct *mm,
+					       unsigned char *hpte_slot_array,
+					       unsigned long addr, int psize);
 
 	/* special for kexec, to be called in real mode, linear mapping is
 	 * destroyed as well */
diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c
index 6a2aead..4a92f14 100644
--- a/arch/powerpc/mm/hash_native_64.c
+++ b/arch/powerpc/mm/hash_native_64.c
@@ -455,6 +455,79 @@ static void native_hpte_invalidate(unsigned long slot, unsigned long vpn,
 	local_irq_restore(flags);
 }
 
+static void native_hugepage_invalidate(struct mm_struct *mm,
+				       unsigned char *hpte_slot_array,
+				       unsigned long addr, int psize)
+{
+	int ssize = 0, i;
+	int lock_tlbie;
+	struct hash_pte *hptep;
+	int actual_psize = MMU_PAGE_16M;
+	unsigned int max_hpte_count, valid;
+	unsigned long flags, s_addr = addr;
+	unsigned long hpte_v, want_v, shift;
+	unsigned long hidx, vpn = 0, vsid, hash, slot;
+
+	shift = mmu_psize_defs[psize].shift;
+	max_hpte_count = HPAGE_PMD_SIZE >> shift;
+
+	local_irq_save(flags);
+	for (i = 0; i < max_hpte_count; i++) {
+		valid = hpte_valid(hpte_slot_array, i);
+		if (!valid)
+			continue;
+		hidx =  hpte_hash_index(hpte_slot_array, i);
+
+		/* get the vpn */
+		addr = s_addr + (i * (1ul << shift));
+		if (!is_kernel_addr(addr)) {
+			ssize = user_segment_size(addr);
+			vsid = get_vsid(mm->context.id, addr, ssize);
+			WARN_ON(vsid == 0);
+		} else {
+			vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
+			ssize = mmu_kernel_ssize;
+		}
+
+		vpn = hpt_vpn(addr, vsid, ssize);
+		hash = hpt_hash(vpn, shift, ssize);
+		if (hidx & _PTEIDX_SECONDARY)
+			hash = ~hash;
+
+		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+		slot += hidx & _PTEIDX_GROUP_IX;
+
+		hptep = htab_address + slot;
+		want_v = hpte_encode_avpn(vpn, psize, ssize);
+		native_lock_hpte(hptep);
+		hpte_v = hptep->v;
+
+		/* Even if we miss, we need to invalidate the TLB */
+		if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID))
+			native_unlock_hpte(hptep);
+		else
+			/* Invalidate the hpte. NOTE: this also unlocks it */
+			hptep->v = 0;
+	}
+	/*
+	 * Since this is a hugepage, we just need a single tlbie.
+	 * use the last vpn.
+	 */
+	lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
+	if (lock_tlbie)
+		raw_spin_lock(&native_tlbie_lock);
+
+	asm volatile("ptesync":::"memory");
+	__tlbie(vpn, psize, actual_psize, ssize);
+	asm volatile("eieio; tlbsync; ptesync":::"memory");
+
+	if (lock_tlbie)
+		raw_spin_unlock(&native_tlbie_lock);
+
+	local_irq_restore(flags);
+}
+
+
 static void hpte_decode(struct hash_pte *hpte, unsigned long slot,
 			int *psize, int *apsize, int *ssize, unsigned long *vpn)
 {
@@ -658,4 +731,5 @@ void __init hpte_init_native(void)
 	ppc_md.hpte_remove	= native_hpte_remove;
 	ppc_md.hpte_clear_all	= native_hpte_clear;
 	ppc_md.flush_hash_range = native_flush_hash_range;
+	ppc_md.hugepage_invalidate   = native_hugepage_invalidate;
 }
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 1abf9cd..8dd7c83 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -692,6 +692,7 @@ void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
 {
 	int ssize, i;
 	unsigned long s_addr;
+	int max_hpte_count;
 	unsigned int psize, valid;
 	unsigned char *hpte_slot_array;
 	unsigned long hidx, vpn, vsid, hash, shift, slot;
@@ -715,9 +716,16 @@ void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
 
 	/* get the base page size */
 	psize = get_slice_psize(mm, s_addr);
-	shift = mmu_psize_defs[psize].shift;
 
-	for (i = 0; i < (HPAGE_PMD_SIZE >> shift); i++) {
+	if (ppc_md.hugepage_invalidate)
+		return ppc_md.hugepage_invalidate(mm, hpte_slot_array,
+						  s_addr, psize);
+	/*
+	 * No bluk hpte removal support, invalidate each entry
+	 */
+	shift = mmu_psize_defs[psize].shift;
+	max_hpte_count = HPAGE_PMD_SIZE >> shift;
+	for (i = 0; i < max_hpte_count; i++) {
 		/*
 		 * 8 bits per each hpte entries
 		 * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 6d62072..aa098c7 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -45,6 +45,13 @@
 #include "plpar_wrappers.h"
 #include "pseries.h"
 
+/* Flag bits for H_BULK_REMOVE */
+#define HBR_REQUEST	0x4000000000000000UL
+#define HBR_RESPONSE	0x8000000000000000UL
+#define HBR_END		0xc000000000000000UL
+#define HBR_AVPN	0x0200000000000000UL
+#define HBR_ANDCOND	0x0100000000000000UL
+
 
 /* in hvCall.S */
 EXPORT_SYMBOL(plpar_hcall);
@@ -345,6 +352,113 @@ static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long vpn,
 	BUG_ON(lpar_rc != H_SUCCESS);
 }
 
+/*
+ * Limit iterations holding pSeries_lpar_tlbie_lock to 3. We also need
+ * to make sure that we avoid bouncing the hypervisor tlbie lock.
+ */
+#define PPC64_HUGE_HPTE_BATCH 12
+
+static void __pSeries_lpar_hugepage_invalidate(unsigned long *slot,
+					     unsigned long *vpn, int count,
+					     int psize, int ssize)
+{
+	unsigned long param[8];
+	int i = 0, pix = 0, rc;
+	unsigned long flags = 0;
+	int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
+
+	if (lock_tlbie)
+		spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
+
+	for (i = 0; i < count; i++) {
+
+		if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
+			pSeries_lpar_hpte_invalidate(slot[i], vpn[i], psize,
+						     ssize, 0);
+		} else {
+			param[pix] = HBR_REQUEST | HBR_AVPN | slot[i];
+			param[pix+1] = hpte_encode_avpn(vpn[i], psize, ssize);
+			pix += 2;
+			if (pix == 8) {
+				rc = plpar_hcall9(H_BULK_REMOVE, param,
+						  param[0], param[1], param[2],
+						  param[3], param[4], param[5],
+						  param[6], param[7]);
+				BUG_ON(rc != H_SUCCESS);
+				pix = 0;
+			}
+		}
+	}
+	if (pix) {
+		param[pix] = HBR_END;
+		rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
+				  param[2], param[3], param[4], param[5],
+				  param[6], param[7]);
+		BUG_ON(rc != H_SUCCESS);
+	}
+
+	if (lock_tlbie)
+		spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
+}
+
+static void pSeries_lpar_hugepage_invalidate(struct mm_struct *mm,
+				       unsigned char *hpte_slot_array,
+				       unsigned long addr, int psize)
+{
+	int ssize = 0, i, index = 0;
+	unsigned long s_addr = addr;
+	unsigned int max_hpte_count, valid;
+	unsigned long vpn_array[PPC64_HUGE_HPTE_BATCH];
+	unsigned long slot_array[PPC64_HUGE_HPTE_BATCH];
+	unsigned long shift, hidx, vpn = 0, vsid, hash, slot;
+
+	shift = mmu_psize_defs[psize].shift;
+	max_hpte_count = HPAGE_PMD_SIZE >> shift;
+
+	for (i = 0; i < max_hpte_count; i++) {
+		valid = hpte_valid(hpte_slot_array, i);
+		if (!valid)
+			continue;
+		hidx =  hpte_hash_index(hpte_slot_array, i);
+
+		/* get the vpn */
+		addr = s_addr + (i * (1ul << shift));
+		if (!is_kernel_addr(addr)) {
+			ssize = user_segment_size(addr);
+			vsid = get_vsid(mm->context.id, addr, ssize);
+			WARN_ON(vsid == 0);
+		} else {
+			vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
+			ssize = mmu_kernel_ssize;
+		}
+
+		vpn = hpt_vpn(addr, vsid, ssize);
+		hash = hpt_hash(vpn, shift, ssize);
+		if (hidx & _PTEIDX_SECONDARY)
+			hash = ~hash;
+
+		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+		slot += hidx & _PTEIDX_GROUP_IX;
+
+		slot_array[index] = slot;
+		vpn_array[index] = vpn;
+		if (index == PPC64_HUGE_HPTE_BATCH - 1) {
+			/*
+			 * Now do a bluk invalidate
+			 */
+			__pSeries_lpar_hugepage_invalidate(slot_array,
+							   vpn_array,
+							   PPC64_HUGE_HPTE_BATCH,
+							   psize, ssize);
+			index = 0;
+		} else
+			index++;
+	}
+	if (index)
+		__pSeries_lpar_hugepage_invalidate(slot_array, vpn_array,
+						   index, psize, ssize);
+}
+
 static void pSeries_lpar_hpte_removebolted(unsigned long ea,
 					   int psize, int ssize)
 {
@@ -360,13 +474,6 @@ static void pSeries_lpar_hpte_removebolted(unsigned long ea,
 	pSeries_lpar_hpte_invalidate(slot, vpn, psize, ssize, 0);
 }
 
-/* Flag bits for H_BULK_REMOVE */
-#define HBR_REQUEST	0x4000000000000000UL
-#define HBR_RESPONSE	0x8000000000000000UL
-#define HBR_END		0xc000000000000000UL
-#define HBR_AVPN	0x0200000000000000UL
-#define HBR_ANDCOND	0x0100000000000000UL
-
 /*
  * Take a spinlock around flushes to avoid bouncing the hypervisor tlbie
  * lock.
@@ -452,6 +559,7 @@ void __init hpte_init_lpar(void)
 	ppc_md.hpte_removebolted = pSeries_lpar_hpte_removebolted;
 	ppc_md.flush_hash_range	= pSeries_lpar_flush_hash_range;
 	ppc_md.hpte_clear_all   = pSeries_lpar_hptab_clear;
+	ppc_md.hugepage_invalidate = pSeries_lpar_hugepage_invalidate;
 }
 
 #ifdef CONFIG_PPC_SMLPAR
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 01/18] powerpc/mm: Use the correct mask value when looking at pgtable address
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

Our pgtable are 2*sizeof(pte_t)*PTRS_PER_PTE which is PTE_FRAG_SIZE.
Instead of depending on frag size, mask with PMD_MASKED_BITS.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/pgalloc-64.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/pgalloc-64.h b/arch/powerpc/include/asm/pgalloc-64.h
index 91acb12..b66ae72 100644
--- a/arch/powerpc/include/asm/pgalloc-64.h
+++ b/arch/powerpc/include/asm/pgalloc-64.h
@@ -186,7 +186,7 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
 
 static inline pgtable_t pmd_pgtable(pmd_t pmd)
 {
-	return (pgtable_t)(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE);
+	return (pgtable_t)(pmd_val(pmd) & ~PMD_MASKED_BITS);
 }
 
 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
-- 
1.8.1.2

^ permalink raw reply related

* [PATCH -V8 08/18] powerpc/THP: Double the PMD table size for THP
From: Aneesh Kumar K.V @ 2013-05-12 16:14 UTC (permalink / raw)
  To: benh, paulus, dwg; +Cc: linuxppc-dev, Aneesh Kumar K.V
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

THP code does PTE page allocation along with large page request and deposit them
for later use. This is to ensure that we won't have any failures when we split
hugepages to regular pages.

On powerpc we want to use the deposited PTE page for storing hash pte slot and
secondary bit information for the HPTEs. We use the second half
of the pmd table to save the deposted PTE page.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/pgalloc-64.h        | 6 +++---
 arch/powerpc/include/asm/pgtable-ppc64-64k.h | 3 ++-
 arch/powerpc/include/asm/pgtable-ppc64.h     | 6 +++++-
 arch/powerpc/mm/init_64.c                    | 9 ++++++---
 4 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/include/asm/pgalloc-64.h b/arch/powerpc/include/asm/pgalloc-64.h
index b66ae72..f65e27b 100644
--- a/arch/powerpc/include/asm/pgalloc-64.h
+++ b/arch/powerpc/include/asm/pgalloc-64.h
@@ -221,17 +221,17 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
 
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	return kmem_cache_alloc(PGT_CACHE(PMD_INDEX_SIZE),
+	return kmem_cache_alloc(PGT_CACHE(PMD_CACHE_INDEX),
 				GFP_KERNEL|__GFP_REPEAT);
 }
 
 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 {
-	kmem_cache_free(PGT_CACHE(PMD_INDEX_SIZE), pmd);
+	kmem_cache_free(PGT_CACHE(PMD_CACHE_INDEX), pmd);
 }
 
 #define __pmd_free_tlb(tlb, pmd, addr)		      \
-	pgtable_free_tlb(tlb, pmd, PMD_INDEX_SIZE)
+	pgtable_free_tlb(tlb, pmd, PMD_CACHE_INDEX)
 #ifndef CONFIG_PPC_64K_PAGES
 #define __pud_free_tlb(tlb, pud, addr)		      \
 	pgtable_free_tlb(tlb, pud, PUD_INDEX_SIZE)
diff --git a/arch/powerpc/include/asm/pgtable-ppc64-64k.h b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
index 45142d6..a56b82f 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64-64k.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
@@ -33,7 +33,8 @@
 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
 
 /* Bits to mask out from a PMD to get to the PTE page */
-#define PMD_MASKED_BITS		0x1ff
+/* PMDs point to PTE table fragments which are 4K aligned.  */
+#define PMD_MASKED_BITS		0xfff
 /* Bits to mask out from a PGD/PUD to get to the PMD page */
 #define PUD_MASKED_BITS		0x1ff
 
diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index e3d55f6f..ab84332 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -20,7 +20,11 @@
                 	    PUD_INDEX_SIZE + PGD_INDEX_SIZE + PAGE_SHIFT)
 #define PGTABLE_RANGE (ASM_CONST(1) << PGTABLE_EADDR_SIZE)
 
-
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#define PMD_CACHE_INDEX	(PMD_INDEX_SIZE + 1)
+#else
+#define PMD_CACHE_INDEX	PMD_INDEX_SIZE
+#endif
 /*
  * Define the address range of the kernel non-linear virtual area
  */
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index a90b9c4..d0cd9e4 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -88,7 +88,11 @@ static void pgd_ctor(void *addr)
 
 static void pmd_ctor(void *addr)
 {
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	memset(addr, 0, PMD_TABLE_SIZE * 2);
+#else
 	memset(addr, 0, PMD_TABLE_SIZE);
+#endif
 }
 
 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE];
@@ -137,10 +141,9 @@ void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
 void pgtable_cache_init(void)
 {
 	pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor);
-	pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor);
-	if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE))
+	pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor);
+	if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_CACHE_INDEX))
 		panic("Couldn't allocate pgtable caches");
-
 	/* In all current configs, when the PUD index exists it's the
 	 * same size as either the pgd or pmd index.  Verify that the
 	 * initialization above has also created a PUD cache.  This
-- 
1.8.1.2

^ permalink raw reply related


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