[PATCH v6 0/4] IRQ affinity support in PLIC driver

From: Anup Patel
Date: Tue Feb 12 2019 - 07:53:02 EST

This patchset primarily adds IRQ affinity support in PLIC driver and
other improvements.

It gives mechanism for explicitly route external interrupts to particular
CPUs using smp_affinity attribute of each Linux IRQs. Also, we can now
use IRQ balancer from kernel-space or user-space.

The patchset is tested on QEMU virt machine. It is based on Linux-5.0-rc6
and can be found at riscv_plic_irq_affinity_v6 branch of:

Changes since v5:
- Dropped PATCH2 based on discussion with Christoph

Changes since v4:
- Use "if (force)" instead of "if (!force)" in PATCH5

Changes since v3:
- Dropped PATCH2
- Added PATCH to not inline plic_toggle() and plic_irq_toggle()
- Moved PATCH3 changes to PATCH6
- Used WARN_ON_ONCE() instead of WARN_ON() in PATCH5

Changes since v2:
- Fixed incorrect address of enable registers using sizeof(u32) in PATCH1
- Retained comment about need for locking in PATCH1
- Split PATCH2 into two patches
- Split PATCH3 into two patches
- Minor fix in commit description of PATCH4

Changes since v1:
- Removed few whitspace changes from PATCH1
- Keep use of DEFINE_PER_CPU() as it is

Anup Patel (4):
irqchip: sifive-plic: Pre-compute context hart base and enable base
irqchip: sifive-plic: Add warning in plic_init() if handler already
irqchip: sifive-plic: Differentiate between PLIC handler and context
irqchip: sifive-plic: Implement irq_set_affinity() for SMP host

drivers/irqchip/irq-sifive-plic.c | 111 +++++++++++++++++++-----------
1 file changed, 72 insertions(+), 39 deletions(-)