RISC-V: KVM: Fix APLIC in_clrip[x] read emulation

The reads to APLIC in_clrip[x] registers returns rectified input values
of the interrupt sources.

A rectified input value of an interrupt source is defined by the section
"4.5.2 Source configurations (sourcecfg[1]–sourcecfg[1023])" of the
RISC-V AIA specification as:

    rectified input value = (incoming wire value) XOR (source is inverted)

Update the riscv_aplic_input() implementation to match the above.

Cc: stable@vger.kernel.org
Fixes: 74967aa208 ("RISC-V: KVM: Add in-kernel emulation of AIA APLIC")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240321085041.1955293-3-apatel@ventanamicro.com
This commit is contained in:
Anup Patel 2024-03-21 14:20:41 +05:30 committed by Anup Patel
parent d8dd9f113e
commit 8e936e9871

View file

@ -197,16 +197,31 @@ static void aplic_write_enabled(struct aplic *aplic, u32 irq, bool enabled)
static bool aplic_read_input(struct aplic *aplic, u32 irq)
{
bool ret;
unsigned long flags;
u32 sourcecfg, sm, raw_input, irq_inverted;
struct aplic_irq *irqd;
unsigned long flags;
bool ret = false;
if (!irq || aplic->nr_irqs <= irq)
return false;
irqd = &aplic->irqs[irq];
raw_spin_lock_irqsave(&irqd->lock, flags);
ret = (irqd->state & APLIC_IRQ_STATE_INPUT) ? true : false;
sourcecfg = irqd->sourcecfg;
if (sourcecfg & APLIC_SOURCECFG_D)
goto skip;
sm = sourcecfg & APLIC_SOURCECFG_SM_MASK;
if (sm == APLIC_SOURCECFG_SM_INACTIVE)
goto skip;
raw_input = (irqd->state & APLIC_IRQ_STATE_INPUT) ? 1 : 0;
irq_inverted = (sm == APLIC_SOURCECFG_SM_LEVEL_LOW ||
sm == APLIC_SOURCECFG_SM_EDGE_FALL) ? 1 : 0;
ret = !!(raw_input ^ irq_inverted);
skip:
raw_spin_unlock_irqrestore(&irqd->lock, flags);
return ret;