Commit d3badb15 authored by Fang Xiang's avatar Fang Xiang Committed by Thomas Gleixner
Browse files

irqchip/gic-v3-its: Flush ITS tables correctly in non-coherent GIC designs 



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: a8707f55 ("irqchip/gic-v3: Add Rockchip 3588001 erratum workaround")
Suggested-by: default avatarMarc Zyngier <maz@kernel.org>
Signed-off-by: default avatarFang Xiang <fangxiang3@xiaomi.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231030083256.4345-1-fangxiang3@xiaomi.com
parent 8999ad99

drivers/irqchip/irq-gic-v3-its.c

+10 −6
Original line number Diff line number Diff line
@@ -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);