| From 12f47073a40f6aa75119d8f5df4077b7f334cced Mon Sep 17 00:00:00 2001 |
| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Mon, 4 Jun 2018 17:33:59 +0200 |
| Subject: genirq/affinity: Defer affinity setting if irq chip is busy |
| |
| From: Thomas Gleixner <tglx@linutronix.de> |
| |
| commit 12f47073a40f6aa75119d8f5df4077b7f334cced upstream. |
| |
| The case that interrupt affinity setting fails with -EBUSY can be handled |
| in the kernel completely by using the already available generic pending |
| infrastructure. |
| |
| If a irq_chip::set_affinity() fails with -EBUSY, handle it like the |
| interrupts for which irq_chip::set_affinity() can only be invoked from |
| interrupt context. Copy the new affinity mask to irq_desc::pending_mask and |
| set the affinity pending bit. The next raised interrupt for the affected |
| irq will check the pending bit and try to set the new affinity from the |
| handler. This avoids that -EBUSY is returned when an affinity change is |
| requested from user space and the previous change has not been cleaned |
| up. The new affinity will take effect when the next interrupt is raised |
| from the device. |
| |
| Fixes: dccfe3147b42 ("x86/vector: Simplify vector move cleanup") |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Tested-by: Song Liu <songliubraving@fb.com> |
| Cc: Joerg Roedel <jroedel@suse.de> |
| Cc: Peter Zijlstra <peterz@infradead.org> |
| Cc: Song Liu <liu.song.a23@gmail.com> |
| Cc: Dmitry Safonov <0x7f454c46@gmail.com> |
| Cc: stable@vger.kernel.org |
| Cc: Mike Travis <mike.travis@hpe.com> |
| Cc: Borislav Petkov <bp@alien8.de> |
| Cc: Tariq Toukan <tariqt@mellanox.com> |
| Link: https://lkml.kernel.org/r/20180604162224.819273597@linutronix.de |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| kernel/irq/manage.c | 37 +++++++++++++++++++++++++++++++++++-- |
| 1 file changed, 35 insertions(+), 2 deletions(-) |
| |
| --- a/kernel/irq/manage.c |
| +++ b/kernel/irq/manage.c |
| @@ -205,6 +205,39 @@ int irq_do_set_affinity(struct irq_data |
| return ret; |
| } |
| |
| +#ifdef CONFIG_GENERIC_PENDING_IRQ |
| +static inline int irq_set_affinity_pending(struct irq_data *data, |
| + const struct cpumask *dest) |
| +{ |
| + struct irq_desc *desc = irq_data_to_desc(data); |
| + |
| + irqd_set_move_pending(data); |
| + irq_copy_pending(desc, dest); |
| + return 0; |
| +} |
| +#else |
| +static inline int irq_set_affinity_pending(struct irq_data *data, |
| + const struct cpumask *dest) |
| +{ |
| + return -EBUSY; |
| +} |
| +#endif |
| + |
| +static int irq_try_set_affinity(struct irq_data *data, |
| + const struct cpumask *dest, bool force) |
| +{ |
| + int ret = irq_do_set_affinity(data, dest, force); |
| + |
| + /* |
| + * In case that the underlying vector management is busy and the |
| + * architecture supports the generic pending mechanism then utilize |
| + * this to avoid returning an error to user space. |
| + */ |
| + if (ret == -EBUSY && !force) |
| + ret = irq_set_affinity_pending(data, dest); |
| + return ret; |
| +} |
| + |
| int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask, |
| bool force) |
| { |
| @@ -215,8 +248,8 @@ int irq_set_affinity_locked(struct irq_d |
| if (!chip || !chip->irq_set_affinity) |
| return -EINVAL; |
| |
| - if (irq_can_move_pcntxt(data)) { |
| - ret = irq_do_set_affinity(data, mask, force); |
| + if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) { |
| + ret = irq_try_set_affinity(data, mask, force); |
| } else { |
| irqd_set_move_pending(data); |
| irq_copy_pending(desc, mask); |