From d0cac39e4ec8097e4c7099d291b1fdcc0fe56b58 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 4 Mar 2009 14:43:47 -0800 Subject: sparc64: Fix lost interrupts on sun4u. Based upon a report by Meelis Roos. Sparc64 SBUS and PCI controllers use a combination of IMAP and ICLR registers to manage device interrupts. The IMAP register contains the "valid" enable bit as well as CPU targetting information. Whereas the ICLR register is written with zero at the end of handling an interrupt to reset the state machine for that interrupt to IDLE so it can be sent again. For PCI slot and SBUS slot devices we can have multiple interrupts sharing the same IMAP register. There are individual ICLR registers but only one IMAP register for managing those. We represent each shared case with individual virtual IRQs so the generic IRQ layer thinks there is only one user of the IRQ instance. In such shared IMAP cases this is wrong, so if there are multiple active users then a free_irq() call will prematurely turn off the interrupt by clearing the Valid bit in the IMAP register even though there are other active users. Fix this by simply doing nothing in sun4u_disable_irq() and checking IRQF_DISABLED during IRQ dispatch. This situation doesn't exist in the hypervisor sun4v cases, so I left those alone. Tested-by: Meelis Roos Signed-off-by: David S. Miller --- arch/sparc/kernel/irq_64.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) (limited to 'arch/sparc') diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c index e289376198e..1c378d8e90c 100644 --- a/arch/sparc/kernel/irq_64.c +++ b/arch/sparc/kernel/irq_64.c @@ -323,17 +323,25 @@ static void sun4u_set_affinity(unsigned int virt_irq, sun4u_irq_enable(virt_irq); } +/* Don't do anything. The desc->status check for IRQ_DISABLED in + * handler_irq() will skip the handler call and that will leave the + * interrupt in the sent state. The next ->enable() call will hit the + * ICLR register to reset the state machine. + * + * This scheme is necessary, instead of clearing the Valid bit in the + * IMAP register, to handle the case of IMAP registers being shared by + * multiple INOs (and thus ICLR registers). Since we use a different + * virtual IRQ for each shared IMAP instance, the generic code thinks + * there is only one user so it prematurely calls ->disable() on + * free_irq(). + * + * We have to provide an explicit ->disable() method instead of using + * NULL to get the default. The reason is that if the generic code + * sees that, it also hooks up a default ->shutdown method which + * invokes ->mask() which we do not want. See irq_chip_set_defaults(). + */ static void sun4u_irq_disable(unsigned int virt_irq) { - struct irq_handler_data *data = get_irq_chip_data(virt_irq); - - if (likely(data)) { - unsigned long imap = data->imap; - unsigned long tmp = upa_readq(imap); - - tmp &= ~IMAP_VALID; - upa_writeq(tmp, imap); - } } static void sun4u_irq_eoi(unsigned int virt_irq) @@ -746,7 +754,8 @@ void handler_irq(int irq, struct pt_regs *regs) desc = irq_desc + virt_irq; - desc->handle_irq(virt_irq, desc); + if (!(desc->status & IRQ_DISABLED)) + desc->handle_irq(virt_irq, desc); bucket_pa = next_pa; } -- cgit v1.2.3 From 42cc77c861e8e850e86252bb5b1e12e006261973 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 18 Mar 2009 23:51:57 -0700 Subject: sparc64: Reschedule KGDB capture to a software interrupt. Otherwise it might interrupt switch_to() midstream and use half-cooked register window state. Reported-by: Chris Torek Signed-off-by: David S. Miller --- arch/sparc/include/asm/pil.h | 1 + arch/sparc/kernel/kgdb_64.c | 2 +- arch/sparc/kernel/ttable.S | 7 ++++++- arch/sparc/mm/ultra.S | 24 ++---------------------- 4 files changed, 10 insertions(+), 24 deletions(-) (limited to 'arch/sparc') diff --git a/arch/sparc/include/asm/pil.h b/arch/sparc/include/asm/pil.h index 32a7efe76d0..26693703054 100644 --- a/arch/sparc/include/asm/pil.h +++ b/arch/sparc/include/asm/pil.h @@ -24,6 +24,7 @@ #define PIL_DEVICE_IRQ 5 #define PIL_SMP_CALL_FUNC_SNGL 6 #define PIL_DEFERRED_PCR_WORK 7 +#define PIL_KGDB_CAPTURE 8 #define PIL_NORMAL_MAX 14 #define PIL_NMI 15 diff --git a/arch/sparc/kernel/kgdb_64.c b/arch/sparc/kernel/kgdb_64.c index fefbe6dc51b..f5a0fd490b5 100644 --- a/arch/sparc/kernel/kgdb_64.c +++ b/arch/sparc/kernel/kgdb_64.c @@ -108,7 +108,7 @@ void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) } #ifdef CONFIG_SMP -void smp_kgdb_capture_client(struct pt_regs *regs) +void smp_kgdb_capture_client(int irq, struct pt_regs *regs) { unsigned long flags; diff --git a/arch/sparc/kernel/ttable.S b/arch/sparc/kernel/ttable.S index d9bdfb9d5c1..76d837fc47d 100644 --- a/arch/sparc/kernel/ttable.S +++ b/arch/sparc/kernel/ttable.S @@ -64,7 +64,12 @@ tl0_irq6: TRAP_IRQ(smp_call_function_single_client, 6) tl0_irq6: BTRAP(0x46) #endif tl0_irq7: TRAP_IRQ(deferred_pcr_work_irq, 7) -tl0_irq8: BTRAP(0x48) BTRAP(0x49) +#ifdef CONFIG_KGDB +tl0_irq8: TRAP_IRQ(smp_kgdb_capture_client, 8) +#else +tl0_irq8: BTRAP(0x48) +#endif +tl0_irq9: BTRAP(0x49) tl0_irq10: BTRAP(0x4a) BTRAP(0x4b) BTRAP(0x4c) BTRAP(0x4d) tl0_irq14: TRAP_IRQ(timer_interrupt, 14) tl0_irq15: TRAP_NMI_IRQ(perfctr_irq, 15) diff --git a/arch/sparc/mm/ultra.S b/arch/sparc/mm/ultra.S index 80c788ec7c3..b57a5942ba6 100644 --- a/arch/sparc/mm/ultra.S +++ b/arch/sparc/mm/ultra.S @@ -679,28 +679,8 @@ xcall_new_mmu_context_version: #ifdef CONFIG_KGDB .globl xcall_kgdb_capture xcall_kgdb_capture: -661: rdpr %pstate, %g2 - wrpr %g2, PSTATE_IG | PSTATE_AG, %pstate - .section .sun4v_2insn_patch, "ax" - .word 661b - nop - nop - .previous - - rdpr %pil, %g2 - wrpr %g0, PIL_NORMAL_MAX, %pil - sethi %hi(109f), %g7 - ba,pt %xcc, etrap_irq -109: or %g7, %lo(109b), %g7 -#ifdef CONFIG_TRACE_IRQFLAGS - call trace_hardirqs_off - nop -#endif - call smp_kgdb_capture_client - add %sp, PTREGS_OFF, %o0 - /* Has to be a non-v9 branch due to the large distance. */ - ba rtrap_xcall - ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1 + wr %g0, (1 << PIL_KGDB_CAPTURE), %set_softint + retry #endif #endif /* CONFIG_SMP */ -- cgit v1.2.3 From 192d7a4667c6d11d1a174ec4cad9a3c5d5f9043c Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 18 Mar 2009 23:53:16 -0700 Subject: sparc64: Fix crash with /proc/iomem When you compile kernel on Sparc64 with heap memory checking and type "cat /proc/iomem", you get a crash, because pointers in struct resource are uninitialized. Most code fills struct resource with zeros, so I assume that it is responsibility of the caller of request_resource to initialized it, not the responsibility of request_resource functuion. After 2.6.29 is out, there could be a check for uninitialized fields added to request_resource to avoid crashes like this. Signed-off-by: Mikulas Patocka Signed-off-by: David S. Miller --- arch/sparc/kernel/pci_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/sparc') diff --git a/arch/sparc/kernel/pci_common.c b/arch/sparc/kernel/pci_common.c index 64e6edf17b9..b775658a927 100644 --- a/arch/sparc/kernel/pci_common.c +++ b/arch/sparc/kernel/pci_common.c @@ -368,7 +368,7 @@ static void pci_register_iommu_region(struct pci_pbm_info *pbm) const u32 *vdma = of_get_property(pbm->op->node, "virtual-dma", NULL); if (vdma) { - struct resource *rp = kmalloc(sizeof(*rp), GFP_KERNEL); + struct resource *rp = kzalloc(sizeof(*rp), GFP_KERNEL); if (!rp) { prom_printf("Cannot allocate IOMMU resource.\n"); -- cgit v1.2.3