This is a note to let you know that I've just added the patch titled
irqchip/gic-v3-its: Flush ITS tables correctly in non-coherent GIC designs
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
irqchip-gic-v3-its-flush-its-tables-correctly-in-non.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c8382b4999d563033e4443e3d9407942837cde0e
Author: Fang Xiang <fangxiang3@xxxxxxxxxx>
Date: Mon Oct 30 16:32:56 2023 +0800
irqchip/gic-v3-its: Flush ITS tables correctly in non-coherent GIC designs
[ Upstream commit d3badb15613c14dd35d3495b1dde5c90fcd616dd ]
In non-coherent GIC designs, the ITS tables must be flushed before writing
to the GITS_BASER<n> registers, otherwise the ITS could read dirty tables,
which results in unpredictable behavior.
Flush the tables right at the begin of its_setup_baser() to prevent that.
[ tglx: Massage changelog ]
Fixes: a8707f553884 ("irqchip/gic-v3: Add Rockchip 3588001 erratum workaround")
Suggested-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Fang Xiang <fangxiang3@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231030083256.4345-1-fangxiang3@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index a8c89df1a9978..9a7a74239eabb 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2379,12 +2379,12 @@ static int its_setup_baser(struct its_node *its, struct its_baser *baser,
break;
}
+ if (!shr)
+ gic_flush_dcache_to_poc(base, PAGE_ORDER_TO_SIZE(order));
+
its_write_baser(its, baser, val);
tmp = baser->val;
- if (its->flags & ITS_FLAGS_FORCE_NON_SHAREABLE)
- tmp &= ~GITS_BASER_SHAREABILITY_MASK;
-
if ((val ^ tmp) & GITS_BASER_SHAREABILITY_MASK) {
/*
* Shareability didn't stick. Just use
@@ -2394,10 +2394,9 @@ static int its_setup_baser(struct its_node *its, struct its_baser *baser,
* non-cacheable as well.
*/
shr = tmp & GITS_BASER_SHAREABILITY_MASK;
- if (!shr) {
+ if (!shr)
cache = GITS_BASER_nC;
- gic_flush_dcache_to_poc(base, PAGE_ORDER_TO_SIZE(order));
- }
+
goto retry_baser;
}
@@ -2609,6 +2608,11 @@ static int its_alloc_tables(struct its_node *its)
/* erratum 24313: ignore memory access type */
cache = GITS_BASER_nCnB;
+ if (its->flags & ITS_FLAGS_FORCE_NON_SHAREABLE) {
+ cache = GITS_BASER_nC;
+ shr = 0;
+ }
+
for (i = 0; i < GITS_BASER_NR_REGS; i++) {
struct its_baser *baser = its->tables + i;
u64 val = its_read_baser(its, baser);
