From c9c98bc5cc2ab4e0d5c9ad58286fa7e1670dfded Mon Sep 17 00:00:00 2001 From: Oliver O'Halloran Date: Fri, 28 Jul 2017 01:35:53 +1000 Subject: [PATCH 1/9] powerpc/mm: Fix pmd/pte_devmap() on non-leaf entries The Radix MMU translation tree as defined in ISA v3.0 contains two different types of entry, directories and leaves. Leaves are identified by _PAGE_PTE being set. The formats of the two entries are different, with the directory entries containing no spare bits for use by software. In particular the bit we use for _PAGE_DEVMAP is not reserved for software, and is part of the NLB (Next Level Base) field, essentially the address of the next level in the tree. Note that the Linux pte_t is not == _PAGE_PTE. A huge page pmd entry (or devmap!) is also a leaf and so has _PAGE_PTE set, even though we use a pmd_t for it in Linux. The fix is to ensure that the pmd/pte_devmap() confirm they are looking at a leaf entry (_PAGE_PTE) as well as checking _PAGE_DEVMAP. Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64") Signed-off-by: Oliver O'Halloran Tested-by: Laurent Vivier Tested-by: Jose Ricardo Ziviani Reviewed-by: Suraj Jitindar Singh Reviewed-by: Aneesh Kumar K.V [mpe: Add a comment in the code and flesh out change log] Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/book3s/64/pgtable.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index d1da415e283c..818a58fc3f4f 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -608,9 +608,17 @@ static inline pte_t pte_mkdevmap(pte_t pte) return __pte(pte_val(pte) | _PAGE_SPECIAL|_PAGE_DEVMAP); } +/* + * This is potentially called with a pmd as the argument, in which case it's not + * safe to check _PAGE_DEVMAP unless we also confirm that _PAGE_PTE is set. + * That's because the bit we use for _PAGE_DEVMAP is not reserved for software + * use in page directory entries (ie. non-ptes). + */ static inline int pte_devmap(pte_t pte) { - return !!(pte_raw(pte) & cpu_to_be64(_PAGE_DEVMAP)); + u64 mask = cpu_to_be64(_PAGE_DEVMAP | _PAGE_PTE); + + return (pte_raw(pte) & mask) == mask; } static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) From cd63f3cf1d59b7ad8419eba1cac8f9126e79cc43 Mon Sep 17 00:00:00 2001 From: Gustavo Romero Date: Wed, 19 Jul 2017 01:44:13 -0400 Subject: [PATCH 2/9] powerpc/tm: Fix saving of TM SPRs in core dump Currently flush_tmregs_to_thread() does not save the TM SPRs (TFHAR, TFIAR, TEXASR) to the thread struct, unless the process is currently inside a suspended transaction. If the process is core dumping, and the TM SPRs have changed since the last time the process was context switched, then we will save stale values of the TM SPRs to the core dump. Fix it by saving the live register state to the thread struct in that case. Fixes: 08e1c01d6aed ("powerpc/ptrace: Enable support for TM SPR state") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Gustavo Romero Reviewed-by: Cyril Bur Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/ptrace.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 925a4ef90559..660ed39e9c9a 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -127,12 +127,19 @@ static void flush_tmregs_to_thread(struct task_struct *tsk) * If task is not current, it will have been flushed already to * it's thread_struct during __switch_to(). * - * A reclaim flushes ALL the state. + * A reclaim flushes ALL the state or if not in TM save TM SPRs + * in the appropriate thread structures from live. */ - if (tsk == current && MSR_TM_SUSPENDED(mfmsr())) - tm_reclaim_current(TM_CAUSE_SIGNAL); + if (tsk != current) + return; + if (MSR_TM_SUSPENDED(mfmsr())) { + tm_reclaim_current(TM_CAUSE_SIGNAL); + } else { + tm_enable(); + tm_save_sprs(&(tsk->thread)); + } } #else static inline void flush_tmregs_to_thread(struct task_struct *tsk) { } From 7b7622bb95eb587cbaa79608e47b832a82a262b1 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Thu, 27 Jul 2017 23:23:37 +1000 Subject: [PATCH 3/9] powerpc/smp: Call smp_ops->setup_cpu() directly on the boot CPU In smp_cpus_done() we need to call smp_ops->setup_cpu() for the boot CPU, which means it has to run *on* the boot CPU. In the past we ensured it ran on the boot CPU by changing the CPU affinity mask of current directly. That was removed in commit 6d11b87d55eb ("powerpc/smp: Replace open coded task affinity logic"), and replaced with a work queue call. Unfortunately using a work queue leads to a lockdep warning, now that the CPU hotplug lock is a regular semaphore: ====================================================== WARNING: possible circular locking dependency detected ... kworker/0:1/971 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++++}, at: [] apply_workqueue_attrs+0x34/0xa0 but task is already holding lock: ((&wfc.work)){+.+.+.}, at: [] process_one_work+0x25c/0x800 ... CPU0 CPU1 ---- ---- lock((&wfc.work)); lock(cpu_hotplug_lock.rw_sem); lock((&wfc.work)); lock(cpu_hotplug_lock.rw_sem); Although the deadlock can't happen in practice, because smp_cpus_done() only runs in early boot before CPU hotplug is allowed, lockdep can't tell that. Luckily in commit 8fb12156b8db ("init: Pin init task to the boot CPU, initially") tglx changed the generic code to pin init to the boot CPU to begin with. The unpinning of init from the boot CPU happens in sched_init_smp(), which is called after smp_cpus_done(). So smp_cpus_done() is always called on the boot CPU, which means we don't need the work queue call at all - and the lockdep warning goes away. Signed-off-by: Michael Ellerman Reviewed-by: Thomas Gleixner --- arch/powerpc/kernel/smp.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index c6b8bace1766..b0ea6d4d4853 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -985,21 +985,13 @@ static struct sched_domain_topology_level powerpc_topology[] = { { NULL, }, }; -static __init long smp_setup_cpu_workfn(void *data __always_unused) -{ - smp_ops->setup_cpu(boot_cpuid); - return 0; -} - void __init smp_cpus_done(unsigned int max_cpus) { /* - * We want the setup_cpu() here to be called on the boot CPU, but - * init might run on any CPU, so make sure it's invoked on the boot - * CPU. + * We are running pinned to the boot CPU, see rest_init(). */ if (smp_ops && smp_ops->setup_cpu) - work_on_cpu_safe(boot_cpuid, smp_setup_cpu_workfn, NULL); + smp_ops->setup_cpu(boot_cpuid); if (smp_ops && smp_ops->bringup_done) smp_ops->bringup_done(); From 65c5ec11c25eff6ba6e9b1cbfff014875fddd1e0 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Wed, 26 Jul 2017 23:19:04 +1000 Subject: [PATCH 4/9] powerpc/boot: Fix 64-bit boot wrapper build with non-biarch compiler MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Historically the boot wrapper was always built 32-bit big endian, even for 64-bit kernels. That was because old firmwares didn't necessarily support booting a 64-bit image. Because of that arch/powerpc/boot/Makefile uses CROSS32CC for compilation. However when we added 64-bit little endian support, we also added support for building the boot wrapper 64-bit. However we kept using CROSS32CC, because in most cases it is just CC and everything works. However if the user doesn't specify CROSS32_COMPILE (which no one ever does AFAIK), and CC is *not* biarch (32/64-bit capable), then CROSS32CC becomes just "gcc". On native systems that is probably OK, but if we're cross building it definitely isn't, leading to eg: gcc ... -m64 -mlittle-endian -mabi=elfv2 ... arch/powerpc/boot/cpm-serial.c gcc: error: unrecognized argument in option ‘-mabi=elfv2’ gcc: error: unrecognized command line option ‘-mlittle-endian’ make: *** [zImage] Error 2 To fix it, stop using CROSS32CC, because we may or may not be building 32-bit. Instead setup a BOOTCC, which defaults to CC, and only use CROSS32_COMPILE if it's set and we're building for 32-bit. Fixes: 147c05168fc8 ("powerpc/boot: Add support for 64bit little endian wrapper") Signed-off-by: Michael Ellerman Reviewed-by: Cyril Bur --- arch/powerpc/boot/Makefile | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile index a7814a7b1523..6f952fe1f084 100644 --- a/arch/powerpc/boot/Makefile +++ b/arch/powerpc/boot/Makefile @@ -25,12 +25,20 @@ compress-$(CONFIG_KERNEL_XZ) := CONFIG_KERNEL_XZ BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -Os -msoft-float -pipe \ -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \ - -isystem $(shell $(CROSS32CC) -print-file-name=include) \ -D$(compress-y) +BOOTCC := $(CC) ifdef CONFIG_PPC64_BOOT_WRAPPER BOOTCFLAGS += -m64 +else +BOOTCFLAGS += -m32 +ifdef CROSS32_COMPILE + BOOTCC := $(CROSS32_COMPILE)gcc endif +endif + +BOOTCFLAGS += -isystem $(shell $(BOOTCC) -print-file-name=include) + ifdef CONFIG_CPU_BIG_ENDIAN BOOTCFLAGS += -mbig-endian else @@ -183,10 +191,10 @@ clean-files := $(zlib-) $(zlibheader-) $(zliblinuxheader-) \ empty.c zImage.coff.lds zImage.ps3.lds zImage.lds quiet_cmd_bootcc = BOOTCC $@ - cmd_bootcc = $(CROSS32CC) -Wp,-MD,$(depfile) $(BOOTCFLAGS) -c -o $@ $< + cmd_bootcc = $(BOOTCC) -Wp,-MD,$(depfile) $(BOOTCFLAGS) -c -o $@ $< quiet_cmd_bootas = BOOTAS $@ - cmd_bootas = $(CROSS32CC) -Wp,-MD,$(depfile) $(BOOTAFLAGS) -c -o $@ $< + cmd_bootas = $(BOOTCC) -Wp,-MD,$(depfile) $(BOOTAFLAGS) -c -o $@ $< quiet_cmd_bootar = BOOTAR $@ cmd_bootar = $(CROSS32AR) -cr$(KBUILD_ARFLAGS) $@.$$$$ $(filter-out FORCE,$^); mv $@.$$$$ $@ From 253fd51e2f533552ae35a0c661705da6c4842c1b Mon Sep 17 00:00:00 2001 From: Alistair Popple Date: Wed, 26 Jul 2017 15:26:40 +1000 Subject: [PATCH 5/9] powerpc/powernv/pci: Return failure for some uses of dma_set_mask() Commit 8e3f1b1d8255 ("powerpc/powernv/pci: Enable 64-bit devices to access >4GB DMA space") introduced the ability for PCI device drivers to request a DMA mask between 64 and 32 bits and actually get a mask greater than 32-bits. However currently if certain machine configuration dependent conditions are not meet the code silently falls back to a 32-bit mask. This makes it hard for device drivers to detect which mask they actually got. Instead we should return an error when the request could not be fulfilled which allows drivers to either fallback or implement other workarounds as documented in DMA-API-HOWTO.txt. Signed-off-by: Alistair Popple Acked-by: Russell Currey Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/powernv/pci-ioda.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index 437613588df1..b900eb1d5e17 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -1852,6 +1852,14 @@ static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask) /* 4GB offset bypasses 32-bit space */ set_dma_offset(&pdev->dev, (1ULL << 32)); set_dma_ops(&pdev->dev, &dma_direct_ops); + } else if (dma_mask >> 32 && dma_mask != DMA_BIT_MASK(64)) { + /* + * Fail the request if a DMA mask between 32 and 64 bits + * was requested but couldn't be fulfilled. Ideally we + * would do this for 64-bits but historically we have + * always fallen back to 32-bits. + */ + return -ENOMEM; } else { dev_info(&pdev->dev, "Using 32-bit DMA via iommu\n"); set_dma_ops(&pdev->dev, &dma_iommu_ops); From cc491f1d3583146eaee635c86b9c9227fa835c6c Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Sat, 29 Jul 2017 22:50:27 +1000 Subject: [PATCH 6/9] powerpc/64s: Fix stack setup in watchdog soft_nmi_common() The watchdog soft-NMI exception stack setup loads a stack pointer twice, which is an obvious error. It ends up using the system reset interrupt (true-NMI) stack, which is also a bug because the watchdog could be preempted by a system reset interrupt that overwrites the NMI stack. Change the soft-NMI to use the "emergency stack". The current kernel stack is not used, because of the longer-term goal to prevent asynchronous stack access using soft-disable. Fixes: 2104180a5369 ("powerpc/64s: implement arch-specific hardlockup watchdog") Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/exceptions-64s.S | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 9029afd1fa2a..f14f3c04ec7e 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1325,10 +1325,18 @@ EXC_VIRT_NONE(0x5800, 0x100) std r10,PACA_EXGEN+EX_R13(r13); \ EXCEPTION_PROLOG_PSERIES_1(soft_nmi_common, _H) +/* + * Branch to soft_nmi_interrupt using the emergency stack. The emergency + * stack is one that is usable by maskable interrupts so long as MSR_EE + * remains off. It is used for recovery when something has corrupted the + * normal kernel stack, for example. The "soft NMI" must not use the process + * stack because we want irq disabled sections to avoid touching the stack + * at all (other than PMU interrupts), so use the emergency stack for this, + * and run it entirely with interrupts hard disabled. + */ EXC_COMMON_BEGIN(soft_nmi_common) mr r10,r1 ld r1,PACAEMERGSP(r13) - ld r1,PACA_NMI_EMERG_SP(r13) subi r1,r1,INT_FRAME_SIZE EXCEPTION_COMMON_NORET_STACK(PACA_EXGEN, 0x900, system_reset, soft_nmi_interrupt, From f29bb7861a5107cc1afbf5a565c3109aa88d5984 Mon Sep 17 00:00:00 2001 From: Sergei Shtylyov Date: Sat, 29 Jul 2017 22:52:09 +0300 Subject: [PATCH 7/9] powerpc/83xx/mpc832x_rdb: fix of_irq_to_resource() error check of_irq_to_resource() has recently been fixed to return negative error #'s along with 0 in case of failure, however the Freescale MPC832x RDB board code still only regards 0 as a failure indication -- fix it up. Fixes: 7a4228bbff76 ("of: irq: use of_irq_get() in of_irq_to_resource()") Signed-off-by: Sergei Shtylyov Acked-by: Scott Wood Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/83xx/mpc832x_rdb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/83xx/mpc832x_rdb.c b/arch/powerpc/platforms/83xx/mpc832x_rdb.c index d7c9b186954d..763ffca9628d 100644 --- a/arch/powerpc/platforms/83xx/mpc832x_rdb.c +++ b/arch/powerpc/platforms/83xx/mpc832x_rdb.c @@ -89,7 +89,7 @@ static int __init of_fsl_spi_probe(char *type, char *compatible, u32 sysclk, goto err; ret = of_irq_to_resource(np, 0, &res[1]); - if (!ret) + if (ret <= 0) goto err; pdev = platform_device_alloc("mpc83xx_spi", i); From 09539f9b123652e969894d6299ae0df2fe12cb5d Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Thu, 20 Jul 2017 11:53:22 +1000 Subject: [PATCH 8/9] powerpc/perf: POWER9 PMU stops after idle workaround POWER9 DD2 PMU can stop after a state-loss idle in some conditions. A solution is to set then clear MMCRA[60] after wake from state-loss idle. MMCRA[60] is a non-architected bit, see the user manual for details. Signed-off-by: Nicholas Piggin Acked-by: Madhavan Srinivasan Reviewed-by: Vaidyanathan Srinivasan Acked-by: Anton Blanchard Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/idle_book3s.S | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index 516ebef905c0..e6252c5a57a4 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -460,11 +460,17 @@ pnv_restore_hyp_resource_arch300: /* * Workaround for POWER9, if we lost resources, the ERAT * might have been mixed up and needs flushing. We also need - * to reload MMCR0 (see comment above). + * to reload MMCR0 (see comment above). We also need to set + * then clear bit 60 in MMCRA to ensure the PMU starts running. */ blt cr3,1f PPC_INVALIDATE_ERAT ld r1,PACAR1(r13) + mfspr r4,SPRN_MMCRA + ori r4,r4,(1 << (63-60)) + mtspr SPRN_MMCRA,r4 + xori r4,r4,(1 << (63-60)) + mtspr SPRN_MMCRA,r4 ld r4,_MMCR0(r1) mtspr SPRN_MMCR0,r4 1: From 3db40c312c2c1eb2187c5731102fa8ff380e6e40 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 1 Aug 2017 23:59:28 +1000 Subject: [PATCH 9/9] powerpc/64: Fix __check_irq_replay missing decrementer interrupt If the decrementer wraps again and de-asserts the decrementer exception while hard-disabled, __check_irq_replay() has a test to notice the wrap when interrupts are re-enabled. The decrementer check must be done when clearing the PACA_IRQ_HARD_DIS flag, not when the PACA_IRQ_DEC flag is tested. Previously this worked because the decrementer interrupt was always the first one checked after clearing the hard disable flag, but HMI check was moved ahead of that, which introduced this bug. This can cause a missed decrementer interrupt if we soft-disable interrupts then take an HMI which is recorded in irq_happened, then hard-disable interrupts for > 4s to wrap the decrementer. Fixes: e0e0d6b7390b ("powerpc/64: Replay hypervisor maintenance interrupt first") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/irq.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 0bcec745a672..f291f7826abc 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -145,6 +145,19 @@ notrace unsigned int __check_irq_replay(void) /* Clear bit 0 which we wouldn't clear otherwise */ local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; + if (happened & PACA_IRQ_HARD_DIS) { + /* + * We may have missed a decrementer interrupt if hard disabled. + * Check the decrementer register in case we had a rollover + * while hard disabled. + */ + if (!(happened & PACA_IRQ_DEC)) { + if (decrementer_check_overflow()) { + local_paca->irq_happened |= PACA_IRQ_DEC; + happened |= PACA_IRQ_DEC; + } + } + } /* * Force the delivery of pending soft-disabled interrupts on PS3. @@ -170,7 +183,7 @@ notrace unsigned int __check_irq_replay(void) * in case we also had a rollover while hard disabled */ local_paca->irq_happened &= ~PACA_IRQ_DEC; - if ((happened & PACA_IRQ_DEC) || decrementer_check_overflow()) + if (happened & PACA_IRQ_DEC) return 0x900; /* Finally check if an external interrupt happened */