From 12997d1a999cd1b22e21a238c96780f2a55e4e13 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Mon, 18 Nov 2013 11:00:29 -0700 Subject: Revert "workqueue: allow work_on_cpu() to be called recursively" This reverts commit c2fda509667b0fda4372a237f5a59ea4570b1627. c2fda509667b removed lockdep annotation from work_on_cpu() to work around the PCI path that calls work_on_cpu() from within a work_on_cpu() work item (PF driver .probe() method -> pci_enable_sriov() -> add VFs -> VF driver .probe method). 961da7fb6b22 ("PCI: Avoid unnecessary CPU switch when calling driver .probe() method) avoids that recursive work_on_cpu() use in a different way, so this revert restores the work_on_cpu() lockdep annotation. Signed-off-by: Bjorn Helgaas Acked-by: Tejun Heo --- kernel/workqueue.c | 32 ++++++++++---------------------- 1 file changed, 10 insertions(+), 22 deletions(-) (limited to 'kernel') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 987293d03eb..5690b8eabfb 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2840,19 +2840,6 @@ already_gone: return false; } -static bool __flush_work(struct work_struct *work) -{ - struct wq_barrier barr; - - if (start_flush_work(work, &barr)) { - wait_for_completion(&barr.done); - destroy_work_on_stack(&barr.work); - return true; - } else { - return false; - } -} - /** * flush_work - wait for a work to finish executing the last queueing instance * @work: the work to flush @@ -2866,10 +2853,18 @@ static bool __flush_work(struct work_struct *work) */ bool flush_work(struct work_struct *work) { + struct wq_barrier barr; + lock_map_acquire(&work->lockdep_map); lock_map_release(&work->lockdep_map); - return __flush_work(work); + if (start_flush_work(work, &barr)) { + wait_for_completion(&barr.done); + destroy_work_on_stack(&barr.work); + return true; + } else { + return false; + } } EXPORT_SYMBOL_GPL(flush_work); @@ -4814,14 +4809,7 @@ long work_on_cpu(int cpu, long (*fn)(void *), void *arg) INIT_WORK_ONSTACK(&wfc.work, work_for_cpu_fn); schedule_work_on(cpu, &wfc.work); - - /* - * The work item is on-stack and can't lead to deadlock through - * flushing. Use __flush_work() to avoid spurious lockdep warnings - * when work_on_cpu()s are nested. - */ - __flush_work(&wfc.work); - + flush_work(&wfc.work); return wfc.ret; } EXPORT_SYMBOL_GPL(work_on_cpu); -- cgit v1.2.3-70-g09d2 From 4fc9bbf98fd66f879e628d8537ba7c240be2b58e Mon Sep 17 00:00:00 2001 From: Khalid Aziz Date: Wed, 27 Nov 2013 15:19:25 -0700 Subject: PCI: Disable Bus Master only on kexec reboot Add a flag to tell the PCI subsystem that kernel is shutting down in preparation to kexec a kernel. Add code in PCI subsystem to use this flag to clear Bus Master bit on PCI devices only in case of kexec reboot. This fixes a power-off problem on Acer Aspire V5-573G and likely other machines and avoids any other issues caused by clearing Bus Master bit on PCI devices in normal shutdown path. The problem was introduced by b566a22c2332 ("PCI: disable Bus Master on PCI device shutdown"). This patch is based on discussion at http://marc.info/?l=linux-pci&m=138425645204355&w=2 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63861 Reported-by: Chang Liu Signed-off-by: Khalid Aziz Signed-off-by: Bjorn Helgaas Acked-by: Konstantin Khlebnikov Cc: stable@vger.kernel.org # v3.5+ --- drivers/pci/pci-driver.c | 12 +++++++++--- include/linux/kexec.h | 3 +++ kernel/kexec.c | 4 ++++ 3 files changed, 16 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 7edd5c30744..25f0bc65916 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -19,6 +19,7 @@ #include #include #include +#include #include "pci.h" struct pci_dynid { @@ -415,12 +416,17 @@ static void pci_device_shutdown(struct device *dev) pci_msi_shutdown(pci_dev); pci_msix_shutdown(pci_dev); +#ifdef CONFIG_KEXEC /* - * Turn off Bus Master bit on the device to tell it to not - * continue to do DMA. Don't touch devices in D3cold or unknown states. + * If this is a kexec reboot, turn off Bus Master bit on the + * device to tell it to not continue to do DMA. Don't touch + * devices in D3cold or unknown states. + * If it is not a kexec reboot, firmware will hit the PCI + * devices with big hammer and stop their DMA any way. */ - if (pci_dev->current_state <= PCI_D3hot) + if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot)) pci_clear_master(pci_dev); +#endif } #ifdef CONFIG_PM diff --git a/include/linux/kexec.h b/include/linux/kexec.h index d78d28a733b..5fd33dc1fe3 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -198,6 +198,9 @@ extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; extern size_t vmcoreinfo_size; extern size_t vmcoreinfo_max_size; +/* flag to track if kexec reboot is in progress */ +extern bool kexec_in_progress; + int __init parse_crashkernel(char *cmdline, unsigned long long system_ram, unsigned long long *crash_size, unsigned long long *crash_base); int parse_crashkernel_high(char *cmdline, unsigned long long system_ram, diff --git a/kernel/kexec.c b/kernel/kexec.c index 490afc03627..d0d8fca5406 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -47,6 +47,9 @@ u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; size_t vmcoreinfo_size; size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data); +/* Flag to indicate we are going to kexec a new kernel */ +bool kexec_in_progress = false; + /* Location of the reserved area for the crash kernel */ struct resource crashk_res = { .name = "Crash kernel", @@ -1675,6 +1678,7 @@ int kernel_kexec(void) } else #endif { + kexec_in_progress = true; kernel_restart_prepare(NULL); printk(KERN_EMERG "Starting new kernel\n"); machine_shutdown(); -- cgit v1.2.3-70-g09d2