lib: utils/irqchip: plic: Fix the off-by-one error in context save/restore helpers

plic->num_src holds the number of interrupt sources without interrupt
source 0 but the interrupt enable register includes a bit for the
interrupt source 0 in the first word.

Fixes: 415ecf28f7ad ("lib: irqchip/plic: Add context save/restore helpers")
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Samuel Holland <samuel@sholland.org>

diff --git a/lib/utils/irqchip/plic.c b/lib/utils/irqchip/plic.c
index 5b87d3b..0a1596c 100644 (file)
--- a/lib/utils/irqchip/plic.c
+++ b/lib/utils/irqchip/plic.c
@@ -94,7 +94,7 @@ static void plic_set_ie(const struct plic_data *plic, u32 cntxid,
 void plic_context_save(const struct plic_data *plic, int context_id,
                       u32 *enable, u32 *threshold)
 {
-       u32 ie_words = (plic->num_src + 31) / 32;
+       u32 ie_words = plic->num_src / 32 + 1;
 
        for (u32 i = 0; i < ie_words; i++)
                enable[i] = plic_get_ie(plic, context_id, i);
@@ -105,7 +105,7 @@ void plic_context_save(const struct plic_data *plic, int context_id,
 void plic_context_restore(const struct plic_data *plic, int context_id,
                          const u32 *enable, u32 threshold)
 {
-       u32 ie_words = (plic->num_src + 31) / 32;
+       u32 ie_words = plic->num_src / 32 + 1;
 
        for (u32 i = 0; i < ie_words; i++)
                plic_set_ie(plic, context_id, i, enable[i]);