Commit a33d16dc authored by Anup Patel's avatar Anup Patel Committed by Thomas Gleixner
Browse files

Revert "irqchip/riscv-imsic: Embed the vector array in lpriv" 



The __alloc_percpu() fails when the number of IDs are greater than 959
because size parameter of __alloc_percpu() must be less than 32768 (aka
PCPU_MIN_UNIT_SIZE). This failure is observed with KVMTOOL when AIA is
trap-n-emulated by in-kernel KVM because in this case KVM guest has 2047
interrupt IDs.

To address this issue, don't embed vector array in struct imsic_local_priv
until __alloc_percpu() support size parameter greater than 32768.

This reverts commit 79eaabc6 ("irqchip/riscv-imsic: Embed the vector
array in lpriv").

Signed-off-by: default avatarAnup Patel <anup.patel@oss.qualcomm.com>
Signed-off-by: default avatarThomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20251223143544.1504217-1-anup.patel@oss.qualcomm.com
parent 1690eeb0

drivers/irqchip/irq-riscv-imsic-state.c

+8 −2
Original line number Diff line number Diff line
@@ -477,6 +477,7 @@ static void __init imsic_local_cleanup(void) 
		lpriv = per_cpu_ptr(imsic->lpriv, cpu);



		bitmap_free(lpriv->dirty_bitmap);

		kfree(lpriv->vectors);

	}



	free_percpu(imsic->lpriv);
@@ -490,8 +491,7 @@ static int __init imsic_local_init(void) 
	int cpu, i;



	/* Allocate per-CPU private state */

	imsic->lpriv = __alloc_percpu(struct_size(imsic->lpriv, vectors, global->nr_ids + 1),

				      __alignof__(*imsic->lpriv));

	imsic->lpriv = alloc_percpu(typeof(*imsic->lpriv));

	if (!imsic->lpriv)

		return -ENOMEM;
@@ -511,6 +511,12 @@ static int __init imsic_local_init(void) 
		timer_setup(&lpriv->timer, imsic_local_timer_callback, TIMER_PINNED);

#endif



		/* Allocate vector array */

		lpriv->vectors = kcalloc(global->nr_ids + 1, sizeof(*lpriv->vectors),

					 GFP_KERNEL);

		if (!lpriv->vectors)

			goto fail_local_cleanup;



		/* Setup vector array */

		for (i = 0; i <= global->nr_ids; i++) {

			vec = &lpriv->vectors[i];

drivers/irqchip/irq-riscv-imsic-state.h

+1 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ struct imsic_local_priv { 
#endif



	/* Local vector table */

	struct imsic_vector			vectors[];

	struct imsic_vector			*vectors;

};



struct imsic_priv {