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[23.128.96.18]) by mx.google.com with ESMTP id j66si14812091pgc.858.2022.01.24.11.18.40; Mon, 24 Jan 2022 11:18:54 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=qMlCTbq8; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243189AbiAXNiW (ORCPT + 99 others); Mon, 24 Jan 2022 08:38:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243179AbiAXNiR (ORCPT ); Mon, 24 Jan 2022 08:38:17 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64A4FC061401 for ; Mon, 24 Jan 2022 05:38:17 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0109061298 for ; Mon, 24 Jan 2022 13:38:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64DD6C340E1; Mon, 24 Jan 2022 13:38:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643031496; bh=6ULtvEmM53XpZVfgoAJQ9W/hCwEgO+guD2eYGiPzntw=; h=From:To:Cc:Subject:Date:From; b=qMlCTbq8gKKiIFbiZUj9e8mY67K+IcCYGh5bqxGVrjMT56Z9dT46e2CycMq5aPjeu 1WIR/EOoivFVsd8FfImvQZPcBhlwz604N92W01oTpTX6ynb+HP6CY5qK5e9OMP9TIE hevuUQhFpOe79jhDnog+55NCwzluZlyEAFUnrSWqcEDvDvVpIG2IBy9RlOQIOiY+2q QnoiHK5t41//lDht/j84gBD5WlbPXREjol8LhBE3Q+s2WATyPFTRF2zdGJs0b+/56z BdIGSvxy+k/nomG6TFMzR5TckCxjGaPSvZWzCmYosZMTMQna9gBaAT3sBqKwQataZS c7OakqBA9IzDQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=hot-poop.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nBzXy-002OVB-ED; Mon, 24 Jan 2022 13:38:14 +0000 From: Marc Zyngier To: linux-kernel@vger.kernel.org Cc: Thomas Gleixner , kernel-team@android.com, Lorenzo Pieralisi , Jay Chen Subject: [PATCH v3] irqchip/gic-v3-its: Reset each ITS's BASERn register before probe Date: Mon, 24 Jan 2022 13:38:09 +0000 Message-Id: <20220124133809.1291195-1-maz@kernel.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, tglx@linutronix.de, kernel-team@android.com, lorenzo.pieralisi@arm.com, jkchen@linux.alibaba.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A recent bug report outlined that the way GICv4.1 is handled across kexec is pretty bad. We can end-up in a situation where ITSs share memory (this is the case when SVPET==1) and reprogram the base registers, creating a situation where ITSs that are part of a given affinity group see different pointers. Which is illegal. Boo. In order to restore some sanity, reset the BASERn registers to 0 *before* probing any ITS. Although this isn't optimised at all, this is only a once-per-boot cost, which shouldn't show up on anyone's radar. Cc: Lorenzo Pieralisi Cc: Jay Chen Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20211216190315.GA14220@lpieralisi --- drivers/irqchip/irq-gic-v3-its.c | 114 +++++++++++++++++++++++++------ 1 file changed, 93 insertions(+), 21 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 7b8f1ec0ff78..c09d99d5b637 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -4856,6 +4856,38 @@ static struct syscore_ops its_syscore_ops = { .resume = its_restore_enable, }; +static void __init __iomem *its_map_one(struct resource *res, int *err) +{ + void __iomem *its_base; + u32 val; + + its_base = ioremap(res->start, SZ_64K); + if (!its_base) { + pr_warn("ITS@%pa: Unable to map ITS registers\n", &res->start); + *err = -ENOMEM; + return NULL; + } + + val = readl_relaxed(its_base + GITS_PIDR2) & GIC_PIDR2_ARCH_MASK; + if (val != 0x30 && val != 0x40) { + pr_warn("ITS@%pa: No ITS detected, giving up\n", &res->start); + *err = -ENODEV; + goto out_unmap; + } + + *err = its_force_quiescent(its_base); + if (*err) { + pr_warn("ITS@%pa: Failed to quiesce, giving up\n", &res->start); + goto out_unmap; + } + + return its_base; + +out_unmap: + iounmap(its_base); + return NULL; +} + static int its_init_domain(struct fwnode_handle *handle, struct its_node *its) { struct irq_domain *inner_domain; @@ -4963,29 +4995,14 @@ static int __init its_probe_one(struct resource *res, { struct its_node *its; void __iomem *its_base; - u32 val, ctlr; u64 baser, tmp, typer; struct page *page; + u32 ctlr; int err; - its_base = ioremap(res->start, SZ_64K); - if (!its_base) { - pr_warn("ITS@%pa: Unable to map ITS registers\n", &res->start); - return -ENOMEM; - } - - val = readl_relaxed(its_base + GITS_PIDR2) & GIC_PIDR2_ARCH_MASK; - if (val != 0x30 && val != 0x40) { - pr_warn("ITS@%pa: No ITS detected, giving up\n", &res->start); - err = -ENODEV; - goto out_unmap; - } - - err = its_force_quiescent(its_base); - if (err) { - pr_warn("ITS@%pa: Failed to quiesce, giving up\n", &res->start); - goto out_unmap; - } + its_base = its_map_one(res, &err); + if (!its_base) + return err; pr_info("ITS %pR\n", res); @@ -5249,6 +5266,23 @@ static int its_cpu_memreserve_lpi(unsigned int cpu) return ret; } +/* Mark all the BASER registers as invalid before they get reprogrammed */ +static int __init its_reset_one(struct resource *res) +{ + void __iomem *its_base; + int err, i; + + its_base = its_map_one(res, &err); + if (!its_base) + return err; + + for (i = 0; i < GITS_BASER_NR_REGS; i++) + gits_write_baser(0, its_base + GITS_BASER + (i << 3)); + + iounmap(its_base); + return 0; +} + static const struct of_device_id its_device_id[] = { { .compatible = "arm,gic-v3-its", }, {}, @@ -5259,6 +5293,26 @@ static int __init its_of_probe(struct device_node *node) struct device_node *np; struct resource res; + /* + * Make sure *all* the ITS are reset before we probe any, as + * they may be sharing memory. If any of the ITS fails to + * reset, don't even try to go any further, as this could + * result in something even worse. + */ + for (np = of_find_matching_node(node, its_device_id); np; + np = of_find_matching_node(np, its_device_id)) { + int err; + + if (!of_device_is_available(np) || + !of_property_read_bool(np, "msi-controller") || + of_address_to_resource(np, 0, &res)) + continue; + + err = its_reset_one(&res); + if (err) + return err; + } + for (np = of_find_matching_node(node, its_device_id); np; np = of_find_matching_node(np, its_device_id)) { if (!of_device_is_available(np)) @@ -5421,11 +5475,29 @@ static int __init gic_acpi_parse_madt_its(union acpi_subtable_headers *header, return err; } +static int __init its_acpi_reset(union acpi_subtable_headers *header, + const unsigned long end) +{ + struct acpi_madt_generic_translator *its_entry; + struct resource res; + + its_entry = (struct acpi_madt_generic_translator *)header; + res = (struct resource) { + .start = its_entry->base_address, + .end = its_entry->base_address + ACPI_GICV3_ITS_MEM_SIZE - 1, + .flags = IORESOURCE_MEM, + }; + + return its_reset_one(&res); +} + static void __init its_acpi_probe(void) { acpi_table_parse_srat_its(); - acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR, - gic_acpi_parse_madt_its, 0); + if (acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR, + its_acpi_reset, 0) > 0) + acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR, + gic_acpi_parse_madt_its, 0); acpi_its_srat_maps_free(); } #else -- 2.34.1