Commit 8e936e98 authored by Anup Patel's avatar Anup Patel Committed by Anup Patel
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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: 74967aa2 ("RISC-V: KVM: Add in-kernel emulation of AIA APLIC")
Signed-off-by: default avatarAnup Patel <apatel@ventanamicro.com>
Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240321085041.1955293-3-apatel@ventanamicro.com
parent d8dd9f11

arch/riscv/kvm/aia_aplic.c

+18 −3
Original line number Diff line number Diff line
@@ -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;