Merge tag 'powerpc-4.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Fixes marked for stable:
   - Convert cmp to cmpd in idle enter sequence (Segher Boessenkool)
   - cxl: Fix leaking pid refs in some error paths (Vaibhav Jain)
   - Re-fix race condition between going idle and entering guest (Paul Mackerras)
   - Fix race condition in setting lock bit in idle/wakeup code (Paul Mackerras)
   - radix: Use tlbiel only if we ever ran on the current cpu (Aneesh Kumar K.V)
   - relocation, register save fixes for system reset interrupt (Nicholas Piggin)

  Fixes for code merged this cycle:
   - Fix CONFIG_ALIVEC typo in restore_tm_state() (Valentin Rothberg)
   - KVM: PPC: Book3S HV: Fix build error when SMP=n (Michael Ellerman)"

* tag 'powerpc-4.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: relocation, register save fixes for system reset interrupt
  powerpc/mm/radix: Use tlbiel only if we ever ran on the current cpu
  powerpc/process: Fix CONFIG_ALIVEC typo in restore_tm_state()
  powerpc/64: Fix race condition in setting lock bit in idle/wakeup code
  powerpc/64: Re-fix race condition between going idle and entering guest
  cxl: Fix leaking pid refs in some error paths
  powerpc: Convert cmp to cmpd in idle enter sequence
  KVM: PPC: Book3S HV: Fix build error when SMP=n

Author: torvalds

arch/powerpc/include/asm/cpuidle.h

@@ -26,7 +26,7 @@ extern u64 pnv_first_deep_stop_state;
 	std	r0,0(r1);					\
 	ptesync;						\
 	ld	r0,0(r1);					\
-1:	cmp	cr0,r0,r0;					\
+1:	cmpd	cr0,r0,r0;					\
 	bne	1b;						\
 	IDLE_INST;						\
 	b	.

arch/powerpc/include/asm/exception-64s.h

@@ -93,6 +93,10 @@
 	ld	reg,PACAKBASE(r13);	/* get high part of &label */	\
 	ori	reg,reg,(FIXED_SYMBOL_ABS_ADDR(label))@l;
 
+#define __LOAD_HANDLER(reg, label)					\
+	ld	reg,PACAKBASE(r13);					\
+	ori	reg,reg,(ABS_ADDR(label))@l;
+
 /* Exception register prefixes */
 #define EXC_HV	H
 #define EXC_STD
@@ -208,6 +212,18 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 #define kvmppc_interrupt kvmppc_interrupt_pr
 #endif
 
+#ifdef CONFIG_RELOCATABLE
+#define BRANCH_TO_COMMON(reg, label)					\
+	__LOAD_HANDLER(reg, label);					\
+	mtctr	reg;							\
+	bctr
+
+#else
+#define BRANCH_TO_COMMON(reg, label)					\
+	b	label
+
+#endif
+
 #define __KVM_HANDLER_PROLOG(area, n)					\
 	BEGIN_FTR_SECTION_NESTED(947)					\
 	ld	r10,area+EX_CFAR(r13);					\

arch/powerpc/include/asm/tlb.h

@@ -52,11 +52,23 @@ static inline int mm_is_core_local(struct mm_struct *mm)
 	return cpumask_subset(mm_cpumask(mm),
 			      topology_sibling_cpumask(smp_processor_id()));
 }
+
+static inline int mm_is_thread_local(struct mm_struct *mm)
+{
+	return cpumask_equal(mm_cpumask(mm),
+			      cpumask_of(smp_processor_id()));
+}
+
 #else
 static inline int mm_is_core_local(struct mm_struct *mm)
 {
 	return 1;
 }
+
+static inline int mm_is_thread_local(struct mm_struct *mm)
+{
+	return 1;
+}
 #endif
 
 #endif /* __KERNEL__ */

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

@@ -95,19 +95,35 @@ __start_interrupts:
 /* No virt vectors corresponding with 0x0..0x100 */
 EXC_VIRT_NONE(0x4000, 0x4100)
 
-EXC_REAL_BEGIN(system_reset, 0x100, 0x200)
-	SET_SCRATCH0(r13)
+
 #ifdef CONFIG_PPC_P7_NAP
-BEGIN_FTR_SECTION
-	/* Running native on arch 2.06 or later, check if we are
-	 * waking up from nap/sleep/winkle.
+	/*
+	 * If running native on arch 2.06 or later, check if we are waking up
+	 * from nap/sleep/winkle, and branch to idle handler.
 	 */
-	mfspr	r13,SPRN_SRR1
-	rlwinm.	r13,r13,47-31,30,31
-	beq	9f
+#define IDLETEST(n)							\
+	BEGIN_FTR_SECTION ;						\
+	mfspr	r10,SPRN_SRR1 ;						\
+	rlwinm.	r10,r10,47-31,30,31 ;					\
+	beq-	1f ;							\
+	cmpwi	cr3,r10,2 ;						\
+	BRANCH_TO_COMMON(r10, system_reset_idle_common) ;		\
+1:									\
+	END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
+#else
+#define IDLETEST NOTEST
+#endif
 
-	cmpwi	cr3,r13,2
-	GET_PACA(r13)
+EXC_REAL_BEGIN(system_reset, 0x100, 0x200)
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD,
+				 IDLETEST, 0x100)
+
+EXC_REAL_END(system_reset, 0x100, 0x200)
+EXC_VIRT_NONE(0x4100, 0x4200)
+
+#ifdef CONFIG_PPC_P7_NAP
+EXC_COMMON_BEGIN(system_reset_idle_common)
 	bl	pnv_restore_hyp_resource
 
 	li	r0,PNV_THREAD_RUNNING
@@ -130,14 +146,8 @@ BEGIN_FTR_SECTION
 	blt	cr3,2f
 	b	pnv_wakeup_loss
 2:	b	pnv_wakeup_noloss
+#endif
 
-9:
-END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
-#endif /* CONFIG_PPC_P7_NAP */
-	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD,
-				 NOTEST, 0x100)
-EXC_REAL_END(system_reset, 0x100, 0x200)
-EXC_VIRT_NONE(0x4100, 0x4200)
 EXC_COMMON(system_reset_common, 0x100, system_reset_exception)
 
 #ifdef CONFIG_PPC_PSERIES
@@ -817,10 +827,8 @@ EXC_VIRT(trap_0b, 0x4b00, 0x4c00, 0xb00)
 TRAMP_KVM(PACA_EXGEN, 0xb00)
 EXC_COMMON(trap_0b_common, 0xb00, unknown_exception)
 
-
-#define LOAD_SYSCALL_HANDLER(reg)				\
-	ld	reg,PACAKBASE(r13);				\
-	ori	reg,reg,(ABS_ADDR(system_call_common))@l;
+#define LOAD_SYSCALL_HANDLER(reg)					\
+	__LOAD_HANDLER(reg, system_call_common)
 
 /* Syscall routine is used twice, in reloc-off and reloc-on paths */
 #define SYSCALL_PSERIES_1 					\

arch/powerpc/kernel/idle_book3s.S

@@ -90,6 +90,7 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
  * Threads will spin in HMT_LOW until the lock bit is cleared.
  * r14 - pointer to core_idle_state
  * r15 - used to load contents of core_idle_state
+ * r9  - used as a temporary variable
  */
 
 core_idle_lock_held:
@@ -99,6 +100,8 @@ core_idle_lock_held:
 	bne	3b
 	HMT_MEDIUM
 	lwarx	r15,0,r14
+	andi.	r9,r15,PNV_CORE_IDLE_LOCK_BIT
+	bne	core_idle_lock_held
 	blr
 
 /*
@@ -163,12 +166,6 @@ _GLOBAL(pnv_powersave_common)
 	std	r9,_MSR(r1)
 	std	r1,PACAR1(r13)
 
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	/* Tell KVM we're entering idle */
-	li	r4,KVM_HWTHREAD_IN_IDLE
-	stb	r4,HSTATE_HWTHREAD_STATE(r13)
-#endif
-
 	/*
 	 * Go to real mode to do the nap, as required by the architecture.
 	 * Also, we need to be in real mode before setting hwthread_state,
@@ -185,6 +182,26 @@ _GLOBAL(pnv_powersave_common)
 
 	.globl pnv_enter_arch207_idle_mode
 pnv_enter_arch207_idle_mode:
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	/* Tell KVM we're entering idle */
+	li	r4,KVM_HWTHREAD_IN_IDLE
+	/******************************************************/
+	/*  N O T E   W E L L    ! ! !    N O T E   W E L L   */
+	/* The following store to HSTATE_HWTHREAD_STATE(r13)  */
+	/* MUST occur in real mode, i.e. with the MMU off,    */
+	/* and the MMU must stay off until we clear this flag */
+	/* and test HSTATE_HWTHREAD_REQ(r13) in the system    */
+	/* reset interrupt vector in exceptions-64s.S.        */
+	/* The reason is that another thread can switch the   */
+	/* MMU to a guest context whenever this flag is set   */
+	/* to KVM_HWTHREAD_IN_IDLE, and if the MMU was on,    */
+	/* that would potentially cause this thread to start  */
+	/* executing instructions from guest memory in        */
+	/* hypervisor mode, leading to a host crash or data   */
+	/* corruption, or worse.                              */
+	/******************************************************/
+	stb	r4,HSTATE_HWTHREAD_STATE(r13)
+#endif
 	stb	r3,PACA_THREAD_IDLE_STATE(r13)
 	cmpwi	cr3,r3,PNV_THREAD_SLEEP
 	bge	cr3,2f
@@ -250,6 +267,12 @@ enter_winkle:
  * r3 - requested stop state
  */
 power_enter_stop:
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	/* Tell KVM we're entering idle */
+	li	r4,KVM_HWTHREAD_IN_IDLE
+	/* DO THIS IN REAL MODE!  See comment above. */
+	stb	r4,HSTATE_HWTHREAD_STATE(r13)
+#endif
 /*
  * Check if the requested state is a deep idle state.
  */

arch/powerpc/kernel/process.c

@@ -1012,7 +1012,7 @@ void restore_tm_state(struct pt_regs *regs)
 	/* Ensure that restore_math() will restore */
 	if (msr_diff & MSR_FP)
 		current->thread.load_fp = 1;
-#ifdef CONFIG_ALIVEC
+#ifdef CONFIG_ALTIVEC
 	if (cpu_has_feature(CPU_FTR_ALTIVEC) && msr_diff & MSR_VEC)
 		current->thread.load_vec = 1;
 #endif

arch/powerpc/kvm/book3s_hv_rm_xics.c

@@ -23,6 +23,7 @@
 #include <asm/ppc-opcode.h>
 #include <asm/pnv-pci.h>
 #include <asm/opal.h>
+#include <asm/smp.h>
 
 #include "book3s_xics.h"
 

arch/powerpc/mm/tlb-radix.c

@@ -175,7 +175,7 @@ void radix__flush_tlb_mm(struct mm_struct *mm)
 	if (unlikely(pid == MMU_NO_CONTEXT))
 		goto no_context;
 
-	if (!mm_is_core_local(mm)) {
+	if (!mm_is_thread_local(mm)) {
 		int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 
 		if (lock_tlbie)
@@ -201,7 +201,7 @@ void radix__flush_tlb_pwc(struct mmu_gather *tlb, unsigned long addr)
 	if (unlikely(pid == MMU_NO_CONTEXT))
 		goto no_context;
 
-	if (!mm_is_core_local(mm)) {
+	if (!mm_is_thread_local(mm)) {
 		int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 
 		if (lock_tlbie)
@@ -226,7 +226,7 @@ void radix__flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr,
 	pid = mm ? mm->context.id : 0;
 	if (unlikely(pid == MMU_NO_CONTEXT))
 		goto bail;
-	if (!mm_is_core_local(mm)) {
+	if (!mm_is_thread_local(mm)) {
 		int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 
 		if (lock_tlbie)
@@ -321,7 +321,7 @@ void radix__flush_tlb_range_psize(struct mm_struct *mm, unsigned long start,
 {
 	unsigned long pid;
 	unsigned long addr;
-	int local = mm_is_core_local(mm);
+	int local = mm_is_thread_local(mm);
 	unsigned long ap = mmu_get_ap(psize);
 	int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 	unsigned long page_size = 1UL << mmu_psize_defs[psize].shift;

drivers/misc/cxl/api.c

@@ -247,7 +247,9 @@ int cxl_start_context(struct cxl_context *ctx, u64 wed,
 	cxl_ctx_get();
 
 	if ((rc = cxl_ops->attach_process(ctx, kernel, wed, 0))) {
+		put_pid(ctx->glpid);
 		put_pid(ctx->pid);
+		ctx->glpid = ctx->pid = NULL;
 		cxl_adapter_context_put(ctx->afu->adapter);
 		cxl_ctx_put();
 		goto out;

drivers/misc/cxl/file.c

@@ -193,6 +193,16 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
 
 	ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
 
+	/*
+	 * Increment the mapped context count for adapter. This also checks
+	 * if adapter_context_lock is taken.
+	 */
+	rc = cxl_adapter_context_get(ctx->afu->adapter);
+	if (rc) {
+		afu_release_irqs(ctx, ctx);
+		goto out;
+	}
+
 	/*
 	 * We grab the PID here and not in the file open to allow for the case
 	 * where a process (master, some daemon, etc) has opened the chardev on
@@ -205,22 +215,16 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
 	ctx->pid = get_task_pid(current, PIDTYPE_PID);
 	ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID);
 
-	/*
-	 * Increment the mapped context count for adapter. This also checks
-	 * if adapter_context_lock is taken.
-	 */
-	rc = cxl_adapter_context_get(ctx->afu->adapter);
-	if (rc) {
-		afu_release_irqs(ctx, ctx);
-		goto out;
-	}
 
 	trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
 
 	if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
 							amr))) {
 		afu_release_irqs(ctx, ctx);
 		cxl_adapter_context_put(ctx->afu->adapter);
+		put_pid(ctx->glpid);
+		put_pid(ctx->pid);
+		ctx->glpid = ctx->pid = NULL;
 		goto out;
 	}