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 79eaabc61dfb ("irqchip/riscv-imsic: Embed the vector
array in lpriv").

Signed-off-by: Anup Patel <anup.patel@oss.qualcomm.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20251223143544.1504217-1-anup.patel@oss.qualcomm.com

diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index 385368052d5c0f45d42b7ee85f6196d1d4fadc56..b6cebfee9461191b833b077626ac8ac2fd7e5c78 100644 (file)
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -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];

diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 6332501dcbd8ef5d61587cafe7ae37cbe05ebeec..c42ee180b3050c239e2e4d07664fac5651378097 100644 (file)
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -40,7 +40,7 @@ struct imsic_local_priv {
 #endif
 
        /* Local vector table */
-       struct imsic_vector                     vectors[];
+       struct imsic_vector                     *vectors;
 };
 
 struct imsic_priv {