Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

Pull powerpc updates from Ben Herrenschmidt:
 "This is the powerpc changes for the 3.11 merge window.  In addition to
  the usual bug fixes and small updates, the main highlights are:

   - Support for transparent huge pages by Aneesh Kumar for 64-bit
     server processors.  This allows the use of 16M pages as transparent
     huge pages on kernels compiled with a 64K base page size.

   - Base VFIO support for KVM on power by Alexey Kardashevskiy

   - Wiring up of our nvram to the pstore infrastructure, including
     putting compressed oopses in there by Aruna Balakrishnaiah

   - Move, rework and improve our "EEH" (basically PCI error handling
     and recovery) infrastructure.  It is no longer specific to pseries
     but is now usable by the new "powernv" platform as well (no
     hypervisor) by Gavin Shan.

   - I fixed some bugs in our math-emu instruction decoding and made it
     usable to emulate some optional FP instructions on processors with
     hard FP that lack them (such as fsqrt on Freescale embedded
     processors).

   - Support for Power8 "Event Based Branch" facility by Michael
     Ellerman.  This facility allows what is basically "userspace
     interrupts" for performance monitor events.

   - A bunch of Transactional Memory vs.  Signals bug fixes and HW
     breakpoint/watchpoint fixes by Michael Neuling.

  And more ...  I appologize in advance if I've failed to highlight
  something that somebody deemed worth it."

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits)
  pstore: Add hsize argument in write_buf call of pstore_ftrace_call
  powerpc/fsl: add MPIC timer wakeup support
  powerpc/mpic: create mpic subsystem object
  powerpc/mpic: add global timer support
  powerpc/mpic: add irq_set_wake support
  powerpc/85xx: enable coreint for all the 64bit boards
  powerpc/8xx: Erroneous double irq_eoi() on CPM IRQ in MPC8xx
  powerpc/fsl: Enable CONFIG_E1000E in mpc85xx_smp_defconfig
  powerpc/mpic: Add get_version API both for internal and external use
  powerpc: Handle both new style and old style reserve maps
  powerpc/hw_brk: Fix off by one error when validating DAWR region end
  powerpc/pseries: Support compression of oops text via pstore
  powerpc/pseries: Re-organise the oops compression code
  pstore: Pass header size in the pstore write callback
  powerpc/powernv: Fix iommu initialization again
  powerpc/pseries: Inform the hypervisor we are using EBB regs
  powerpc/perf: Add power8 EBB support
  powerpc/perf: Core EBB support for 64-bit book3s
  powerpc/perf: Drop MMCRA from thread_struct
  powerpc/perf: Don't enable if we have zero events
  ...

1 files changed, 34 insertions, 24 deletions

diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 9c1ff330c805..a1ecb14e4442 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -159,36 +159,46 @@ static inline int hpte_cache_flags_ok(unsigned long ptel, unsigned long io_type)
 }
 
 /*
- * Lock and read a linux PTE.  If it's present and writable, atomically
- * set dirty and referenced bits and return the PTE, otherwise return 0.
+ * If it's present and writable, atomically set dirty and referenced bits and
+ * return the PTE, otherwise return 0. If we find a transparent hugepage
+ * and if it is marked splitting we return 0;
  */
-static inline pte_t kvmppc_read_update_linux_pte(pte_t *p, int writing)
+static inline pte_t kvmppc_read_update_linux_pte(pte_t *ptep, int writing,
+						 unsigned int hugepage)
 {
-	pte_t pte, tmp;
-
-	/* wait until _PAGE_BUSY is clear then set it atomically */
-	__asm__ __volatile__ (
-		"1:	ldarx	%0,0,%3\n"
-		"	andi.	%1,%0,%4\n"
-		"	bne-	1b\n"
-		"	ori	%1,%0,%4\n"
-		"	stdcx.	%1,0,%3\n"
-		"	bne-	1b"
-		: "=&r" (pte), "=&r" (tmp), "=m" (*p)
-		: "r" (p), "i" (_PAGE_BUSY)
-		: "cc");
-
-	if (pte_present(pte)) {
-		pte = pte_mkyoung(pte);
-		if (writing && pte_write(pte))
-			pte = pte_mkdirty(pte);
-	}
+	pte_t old_pte, new_pte = __pte(0);
+
+	while (1) {
+		old_pte = pte_val(*ptep);
+		/*
+		 * wait until _PAGE_BUSY is clear then set it atomically
+		 */
+		if (unlikely(old_pte & _PAGE_BUSY)) {
+			cpu_relax();
+			continue;
+		}
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+		/* If hugepage and is trans splitting return None */
+		if (unlikely(hugepage &&
+			     pmd_trans_splitting(pte_pmd(old_pte))))
+			return __pte(0);
+#endif
+		/* If pte is not present return None */
+		if (unlikely(!(old_pte & _PAGE_PRESENT)))
+			return __pte(0);
 
-	*p = pte;	/* clears _PAGE_BUSY */
+		new_pte = pte_mkyoung(old_pte);
+		if (writing && pte_write(old_pte))
+			new_pte = pte_mkdirty(new_pte);
 
-	return pte;
+		if (old_pte == __cmpxchg_u64((unsigned long *)ptep, old_pte,
+					     new_pte))
+			break;
+	}
+	return new_pte;
 }
 
+
 /* Return HPTE cache control bits corresponding to Linux pte bits */
 static inline unsigned long hpte_cache_bits(unsigned long pte_val)
 {