Merge tag 'powerpc-4.19-3' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Michael writes:
  "powerpc fixes for 4.19 #3

   A reasonably big batch of fixes due to me being away for a few weeks.

   A fix for the TM emulation support on Power9, which could result in
   corrupting the guest r11 when running under KVM.

   Two fixes to the TM code which could lead to userspace GPR corruption
   if we take an SLB miss at exactly the wrong time.

   Our dynamic patching code had a bug that meant we could patch freed
   __init text, which could lead to corrupting userspace memory.

   csum_ipv6_magic() didn't work on little endian platforms since we
   optimised it recently.

   A fix for an endian bug when reading a device tree property telling
   us how many storage keys the machine has available.

   Fix a crash seen on some configurations of PowerVM when migrating the
   partition from one machine to another.

   A fix for a regression in the setup of our CPU to NUMA node mapping
   in KVM guests.

   A fix to our selftest Makefiles to make them work since a recent
   change to the shared Makefile logic."

* tag 'powerpc-4.19-3' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  selftests/powerpc: Fix Makefiles for headers_install change
  powerpc/numa: Use associativity if VPHN hcall is successful
  powerpc/tm: Avoid possible userspace r1 corruption on reclaim
  powerpc/tm: Fix userspace r13 corruption
  powerpc/pseries: Fix unitialized timer reset on migration
  powerpc/pkeys: Fix reading of ibm, processor-storage-keys property
  powerpc: fix csum_ipv6_magic() on little endian platforms
  powerpc/powernv/ioda2: Reduce upper limit for DMA window size (again)
  powerpc: Avoid code patching freed init sections
  KVM: PPC: Book3S HV: Fix guest r11 corruption with POWER9 TM workarounds

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

@@ -1314,9 +1314,7 @@ EXC_REAL_BEGIN(denorm_exception_hv, 0x1500, 0x100)
 
 #ifdef CONFIG_PPC_DENORMALISATION
 	mfspr	r10,SPRN_HSRR1
-	mfspr	r11,SPRN_HSRR0		/* save HSRR0 */
 	andis.	r10,r10,(HSRR1_DENORM)@h /* denorm? */
-	addi	r11,r11,-4		/* HSRR0 is next instruction */
 	bne+	denorm_assist
 #endif
 
@@ -1382,6 +1380,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
  */
 	XVCPSGNDP32(32)
 denorm_done:
+	mfspr	r11,SPRN_HSRR0
+	subi	r11,r11,4
 	mtspr	SPRN_HSRR0,r11
 	mtcrf	0x80,r9
 	ld	r9,PACA_EXGEN+EX_R9(r13)

arch/powerpc/kernel/tm.S

@@ -176,13 +176,27 @@ _GLOBAL(tm_reclaim)
 	std	r1, PACATMSCRATCH(r13)
 	ld	r1, PACAR1(r13)
 
-	/* Store the PPR in r11 and reset to decent value */
 	std	r11, GPR11(r1)			/* Temporary stash */
 
+	/*
+	 * Move the saved user r1 to the kernel stack in case PACATMSCRATCH is
+	 * clobbered by an exception once we turn on MSR_RI below.
+	 */
+	ld	r11, PACATMSCRATCH(r13)
+	std	r11, GPR1(r1)
+
+	/*
+	 * Store r13 away so we can free up the scratch SPR for the SLB fault
+	 * handler (needed once we start accessing the thread_struct).
+	 */
+	GET_SCRATCH0(r11)
+	std	r11, GPR13(r1)
+
 	/* Reset MSR RI so we can take SLB faults again */
 	li	r11, MSR_RI
 	mtmsrd	r11, 1
 
+	/* Store the PPR in r11 and reset to decent value */
 	mfspr	r11, SPRN_PPR
 	HMT_MEDIUM
 
@@ -207,11 +221,11 @@ _GLOBAL(tm_reclaim)
 	SAVE_GPR(8, r7)				/* user r8 */
 	SAVE_GPR(9, r7)				/* user r9 */
 	SAVE_GPR(10, r7)			/* user r10 */
-	ld	r3, PACATMSCRATCH(r13)		/* user r1 */
+	ld	r3, GPR1(r1)			/* user r1 */
 	ld	r4, GPR7(r1)			/* user r7 */
 	ld	r5, GPR11(r1)			/* user r11 */
 	ld	r6, GPR12(r1)			/* user r12 */
-	GET_SCRATCH0(8)				/* user r13 */
+	ld	r8, GPR13(r1)			/* user r13 */
 	std	r3, GPR1(r7)
 	std	r4, GPR7(r7)
 	std	r5, GPR11(r7)