From d3badb15613c14dd35d3495b1dde5c90fcd616dd Mon Sep 17 00:00:00 2001 From: Fang Xiang Date: Mon, 30 Oct 2023 16:32:56 +0800 Subject: 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 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 Signed-off-by: Fang Xiang Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20231030083256.4345-1-fangxiang3@xiaomi.com --- drivers/irqchip/irq-gic-v3-its.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'drivers/irqchip') diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index a8c89df1a997..9a7a74239eab 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -2379,12 +2379,12 @@ retry_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 @@ retry_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); -- cgit v1.2.3