From 7da89a2a3776442a57e918ca0b8678d1b16a7072 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sat, 1 Nov 2014 00:33:58 -0400 Subject: sparc64: Fix crashes in schizo_pcierr_intr_other(). Meelis Roos reports crashes during bootup on a V480 that look like this: ==================== [ 61.300577] PCI: Scanning PBM /pci@9,600000 [ 61.304867] schizo f009b070: PCI host bridge to bus 0003:00 [ 61.310385] pci_bus 0003:00: root bus resource [io 0x7ffe9000000-0x7ffe9ffffff] (bus address [0x0000-0xffffff]) [ 61.320515] pci_bus 0003:00: root bus resource [mem 0x7fb00000000-0x7fbffffffff] (bus address [0x00000000-0xffffffff]) [ 61.331173] pci_bus 0003:00: root bus resource [bus 00] [ 61.385344] Unable to handle kernel NULL pointer dereference [ 61.390970] tsk->{mm,active_mm}->context = 0000000000000000 [ 61.396515] tsk->{mm,active_mm}->pgd = fff000b000002000 [ 61.401716] \|/ ____ \|/ [ 61.401716] "@'/ .. \`@" [ 61.401716] /_| \__/ |_\ [ 61.401716] \__U_/ [ 61.416362] swapper/0(0): Oops [#1] [ 61.419837] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.18.0-rc1-00422-g2cc9188-dirty #24 [ 61.427975] task: fff000b0fd8e9c40 ti: fff000b0fd928000 task.ti: fff000b0fd928000 [ 61.435426] TSTATE: 0000004480e01602 TPC: 00000000004455e4 TNPC: 00000000004455e8 Y: 00000000 Not tainted [ 61.445230] TPC: [ 61.449897] g0: 0000000000000000 g1: 0000000000000000 g2: 0000000000a10f78 g3: 000000000000000a [ 61.458563] g4: fff000b0fd8e9c40 g5: fff000b0fdd82000 g6: fff000b0fd928000 g7: 000000000000000a [ 61.467229] o0: 000000000000003d o1: 0000000000000000 o2: 0000000000000006 o3: fff000b0ffa5fc7e [ 61.475894] o4: 0000000000060000 o5: c000000000000000 sp: fff000b0ffa5f3c1 ret_pc: 00000000004455cc [ 61.484909] RPC: [ 61.489500] l0: fff000b0fd8e9c40 l1: 0000000000a20800 l2: 0000000000000000 l3: 000000000119a430 [ 61.498164] l4: 0000000001742400 l5: 00000000011cfbe0 l6: 00000000011319c0 l7: fff000b0fd8ea348 [ 61.506830] i0: 0000000000000000 i1: fff000b0fdb34000 i2: 0000000320000000 i3: 0000000000000000 [ 61.515497] i4: 00060002010b003f i5: 0000040004e02000 i6: fff000b0ffa5f481 i7: 00000000004a9920 [ 61.524175] I7: [ 61.529099] Call Trace: [ 61.531531] [00000000004a9920] handle_irq_event_percpu+0x40/0x140 [ 61.537681] [00000000004a9a58] handle_irq_event+0x38/0x80 [ 61.543145] [00000000004ac77c] handle_fasteoi_irq+0xbc/0x200 [ 61.548860] [00000000004a9084] generic_handle_irq+0x24/0x40 [ 61.554500] [000000000042be0c] handler_irq+0xac/0x100 ==================== The problem is that pbm->pci_bus->self is NULL. This code is trying to go through the standard PCI config space interfaces to read the PCI controller's PCI_STATUS register. This doesn't work, because we more often than not do not enumerate the PCI controller as a bonafide PCI device during the OF device node scan. Therefore bus->self remains NULL. Existing common code for PSYCHO and PSYCHO-like PCI controllers handles this properly, by doing the config space access directly. Do the same here, pbm->pci_ops->{read,write}(). Reported-by: Meelis Roos Tested-by: Meelis Roos Signed-off-by: David S. Miller --- arch/sparc/kernel/pci_schizo.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/sparc/kernel/pci_schizo.c b/arch/sparc/kernel/pci_schizo.c index 8f76f23dac3..f9c6813c132 100644 --- a/arch/sparc/kernel/pci_schizo.c +++ b/arch/sparc/kernel/pci_schizo.c @@ -581,7 +581,7 @@ static irqreturn_t schizo_pcierr_intr_other(struct pci_pbm_info *pbm) { unsigned long csr_reg, csr, csr_error_bits; irqreturn_t ret = IRQ_NONE; - u16 stat; + u32 stat; csr_reg = pbm->pbm_regs + SCHIZO_PCI_CTRL; csr = upa_readq(csr_reg); @@ -617,7 +617,7 @@ static irqreturn_t schizo_pcierr_intr_other(struct pci_pbm_info *pbm) pbm->name); ret = IRQ_HANDLED; } - pci_read_config_word(pbm->pci_bus->self, PCI_STATUS, &stat); + pbm->pci_ops->read(pbm->pci_bus, 0, PCI_STATUS, 2, &stat); if (stat & (PCI_STATUS_PARITY | PCI_STATUS_SIG_TARGET_ABORT | PCI_STATUS_REC_TARGET_ABORT | @@ -625,7 +625,7 @@ static irqreturn_t schizo_pcierr_intr_other(struct pci_pbm_info *pbm) PCI_STATUS_SIG_SYSTEM_ERROR)) { printk("%s: PCI bus error, PCI_STATUS[%04x]\n", pbm->name, stat); - pci_write_config_word(pbm->pci_bus->self, PCI_STATUS, 0xffff); + pbm->pci_ops->write(pbm->pci_bus, 0, PCI_STATUS, 2, 0xffff); ret = IRQ_HANDLED; } return ret; -- cgit v1.2.3-70-g09d2 From ab5c780913bca0a5763ca05dd5c2cb5cb08ccb26 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Fri, 7 Nov 2014 09:50:48 -0800 Subject: sparc64: Do irq_{enter,exit}() around generic_smp_call_function*(). Otherwise rcu_irq_{enter,exit}() do not happen and we get dumps like: ==================== [ 188.275021] =============================== [ 188.309351] [ INFO: suspicious RCU usage. ] [ 188.343737] 3.18.0-rc3-00068-g20f3963-dirty #54 Not tainted [ 188.394786] ------------------------------- [ 188.429170] include/linux/rcupdate.h:883 rcu_read_lock() used illegally while idle! [ 188.505235] other info that might help us debug this: [ 188.554230] RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 [ 188.637587] RCU used illegally from extended quiescent state! [ 188.690684] 3 locks held by swapper/7/0: [ 188.721932] #0: (&x->wait#11){......}, at: [<0000000000495de8>] complete+0x8/0x60 [ 188.797994] #1: (&p->pi_lock){-.-.-.}, at: [<000000000048510c>] try_to_wake_up+0xc/0x400 [ 188.881343] #2: (rcu_read_lock){......}, at: [<000000000048a910>] select_task_rq_fair+0x90/0xb40 [ 188.973043]stack backtrace: [ 188.993879] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 3.18.0-rc3-00068-g20f3963-dirty #54 [ 189.076187] Call Trace: [ 189.089719] [0000000000499360] lockdep_rcu_suspicious+0xe0/0x100 [ 189.147035] [000000000048a99c] select_task_rq_fair+0x11c/0xb40 [ 189.202253] [00000000004852d8] try_to_wake_up+0x1d8/0x400 [ 189.252258] [000000000048554c] default_wake_function+0xc/0x20 [ 189.306435] [0000000000495554] __wake_up_common+0x34/0x80 [ 189.356448] [00000000004955b4] __wake_up_locked+0x14/0x40 [ 189.406456] [0000000000495e08] complete+0x28/0x60 [ 189.448142] [0000000000636e28] blk_end_sync_rq+0x8/0x20 [ 189.496057] [0000000000639898] __blk_mq_end_request+0x18/0x60 [ 189.550249] [00000000006ee014] scsi_end_request+0x94/0x180 [ 189.601286] [00000000006ee334] scsi_io_completion+0x1d4/0x600 [ 189.655463] [00000000006e51c4] scsi_finish_command+0xc4/0xe0 [ 189.708598] [00000000006ed958] scsi_softirq_done+0x118/0x140 [ 189.761735] [00000000006398ec] __blk_mq_complete_request_remote+0xc/0x20 [ 189.827383] [00000000004c75d0] generic_smp_call_function_single_interrupt+0x150/0x1c0 [ 189.906581] [000000000043e514] smp_call_function_single_client+0x14/0x40 ==================== Based almost entirely upon a patch by Paul E. McKenney. Reported-by: Meelis Roos Tested-by: Meelis Roos Signed-off-by: David S. Miller --- arch/sparc/kernel/smp_64.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch') diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c index 302c476413d..da6f1a7fc4d 100644 --- a/arch/sparc/kernel/smp_64.c +++ b/arch/sparc/kernel/smp_64.c @@ -816,13 +816,17 @@ void arch_send_call_function_single_ipi(int cpu) void __irq_entry smp_call_function_client(int irq, struct pt_regs *regs) { clear_softint(1 << irq); + irq_enter(); generic_smp_call_function_interrupt(); + irq_exit(); } void __irq_entry smp_call_function_single_client(int irq, struct pt_regs *regs) { clear_softint(1 << irq); + irq_enter(); generic_smp_call_function_single_interrupt(); + irq_exit(); } static void tsb_sync(void *info) -- cgit v1.2.3-70-g09d2 From 1a17fdc4f4ed06b63fac1937470378a5441a663a Mon Sep 17 00:00:00 2001 From: Andreas Larsson Date: Wed, 5 Nov 2014 15:52:08 +0100 Subject: sparc32: Implement xchg and atomic_xchg using ATOMIC_HASH locks Atomicity between xchg and cmpxchg cannot be guaranteed when xchg is implemented with a swap and cmpxchg is implemented with locks. Without this, e.g. mcs_spin_lock and mcs_spin_unlock are broken. Signed-off-by: Andreas Larsson Signed-off-by: David S. Miller --- arch/sparc/include/asm/atomic_32.h | 2 +- arch/sparc/include/asm/cmpxchg_32.h | 12 ++---------- arch/sparc/lib/atomic32.c | 27 +++++++++++++++++++++++++++ 3 files changed, 30 insertions(+), 11 deletions(-) (limited to 'arch') diff --git a/arch/sparc/include/asm/atomic_32.h b/arch/sparc/include/asm/atomic_32.h index 765c1776ec9..0e69b7e7a43 100644 --- a/arch/sparc/include/asm/atomic_32.h +++ b/arch/sparc/include/asm/atomic_32.h @@ -22,7 +22,7 @@ int atomic_add_return(int, atomic_t *); int atomic_cmpxchg(atomic_t *, int, int); -#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) +int atomic_xchg(atomic_t *, int); int __atomic_add_unless(atomic_t *, int, int); void atomic_set(atomic_t *, int); diff --git a/arch/sparc/include/asm/cmpxchg_32.h b/arch/sparc/include/asm/cmpxchg_32.h index 32c29a133f9..d38b52dca21 100644 --- a/arch/sparc/include/asm/cmpxchg_32.h +++ b/arch/sparc/include/asm/cmpxchg_32.h @@ -11,22 +11,14 @@ #ifndef __ARCH_SPARC_CMPXCHG__ #define __ARCH_SPARC_CMPXCHG__ -static inline unsigned long xchg_u32(__volatile__ unsigned long *m, unsigned long val) -{ - __asm__ __volatile__("swap [%2], %0" - : "=&r" (val) - : "0" (val), "r" (m) - : "memory"); - return val; -} - +unsigned long __xchg_u32(volatile u32 *m, u32 new); void __xchg_called_with_bad_pointer(void); static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, int size) { switch (size) { case 4: - return xchg_u32(ptr, x); + return __xchg_u32(ptr, x); } __xchg_called_with_bad_pointer(); return x; diff --git a/arch/sparc/lib/atomic32.c b/arch/sparc/lib/atomic32.c index a7c418ac26a..71cd65ab200 100644 --- a/arch/sparc/lib/atomic32.c +++ b/arch/sparc/lib/atomic32.c @@ -45,6 +45,19 @@ ATOMIC_OP(add, +=) #undef ATOMIC_OP +int atomic_xchg(atomic_t *v, int new) +{ + int ret; + unsigned long flags; + + spin_lock_irqsave(ATOMIC_HASH(v), flags); + ret = v->counter; + v->counter = new; + spin_unlock_irqrestore(ATOMIC_HASH(v), flags); + return ret; +} +EXPORT_SYMBOL(atomic_xchg); + int atomic_cmpxchg(atomic_t *v, int old, int new) { int ret; @@ -137,3 +150,17 @@ unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new) return (unsigned long)prev; } EXPORT_SYMBOL(__cmpxchg_u32); + +unsigned long __xchg_u32(volatile u32 *ptr, u32 new) +{ + unsigned long flags; + u32 prev; + + spin_lock_irqsave(ATOMIC_HASH(ptr), flags); + prev = *ptr; + *ptr = new; + spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags); + + return (unsigned long)prev; +} +EXPORT_SYMBOL(__xchg_u32); -- cgit v1.2.3-70-g09d2 From 5a2b59d3993e8ca4f7788a48a23e5cb303f26954 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sun, 16 Nov 2014 13:19:32 -0800 Subject: sparc64: Fix constraints on swab helpers. We are reading the memory location, so we have to have a memory constraint in there purely for the sake of showing the data flow to the compiler. Reported-by: Martin K. Petersen Signed-off-by: David S. Miller --- arch/sparc/include/uapi/asm/swab.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'arch') diff --git a/arch/sparc/include/uapi/asm/swab.h b/arch/sparc/include/uapi/asm/swab.h index a34ad079487..4c7c12d69be 100644 --- a/arch/sparc/include/uapi/asm/swab.h +++ b/arch/sparc/include/uapi/asm/swab.h @@ -9,9 +9,9 @@ static inline __u16 __arch_swab16p(const __u16 *addr) { __u16 ret; - __asm__ __volatile__ ("lduha [%1] %2, %0" + __asm__ __volatile__ ("lduha [%2] %3, %0" : "=r" (ret) - : "r" (addr), "i" (ASI_PL)); + : "m" (*addr), "r" (addr), "i" (ASI_PL)); return ret; } #define __arch_swab16p __arch_swab16p @@ -20,9 +20,9 @@ static inline __u32 __arch_swab32p(const __u32 *addr) { __u32 ret; - __asm__ __volatile__ ("lduwa [%1] %2, %0" + __asm__ __volatile__ ("lduwa [%2] %3, %0" : "=r" (ret) - : "r" (addr), "i" (ASI_PL)); + : "m" (*addr), "r" (addr), "i" (ASI_PL)); return ret; } #define __arch_swab32p __arch_swab32p @@ -31,9 +31,9 @@ static inline __u64 __arch_swab64p(const __u64 *addr) { __u64 ret; - __asm__ __volatile__ ("ldxa [%1] %2, %0" + __asm__ __volatile__ ("ldxa [%2] %3, %0" : "=r" (ret) - : "r" (addr), "i" (ASI_PL)); + : "m" (*addr), "r" (addr), "i" (ASI_PL)); return ret; } #define __arch_swab64p __arch_swab64p -- cgit v1.2.3-70-g09d2