From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00B82C433F4 for ; Mon, 24 Sep 2018 12:52:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9617520685 for ; Mon, 24 Sep 2018 12:52:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9617520685 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730097AbeIXSyv (ORCPT ); Mon, 24 Sep 2018 14:54:51 -0400 Received: from foss.arm.com ([217.140.101.70]:34972 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728448AbeIXSyv (ORCPT ); Mon, 24 Sep 2018 14:54:51 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 48B7C18A; Mon, 24 Sep 2018 05:52:50 -0700 (PDT) Received: from [10.4.13.92] (e112298-lin.emea.arm.com [10.4.13.92]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AE83E3F5BD; Mon, 24 Sep 2018 05:52:47 -0700 (PDT) Subject: Re: [PATCH 06/10] irqchip/gic-v3-its: Allow use of pre-programmed LPI tables To: Marc Zyngier , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Ard Biesheuvel , Jeremy Linton , Jeffrey Hugo , Thomas Gleixner , Jason Cooper References: <20180921195954.21574-1-marc.zyngier@arm.com> <20180921195954.21574-7-marc.zyngier@arm.com> From: Julien Thierry Message-ID: Date: Mon, 24 Sep 2018 13:52:46 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180921195954.21574-7-marc.zyngier@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21/09/18 20:59, Marc Zyngier wrote: > In order to cope with kexec and GICv3, let's try and spot when > we're booting with LPIs already enabled, and the tables already > programmed into the redistributors. > > This code is currently guarded by a predicate that is always false, > meaning this is not functionnal just yet. > Reviewed-by: Julien Thierry > Signed-off-by: Marc Zyngier > --- > drivers/irqchip/irq-gic-v3-its.c | 73 ++++++++++++++++++++++++++------ > 1 file changed, 61 insertions(+), 12 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c > index c2f1138034fd..e29ce9f2ac8a 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -52,6 +52,7 @@ > #define ITS_FLAGS_SAVE_SUSPEND_STATE (1ULL << 3) > > #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0) > +#define RDIST_FLAGS_RD_TABLES_PREALLOCATED (1 << 1) > > static u32 lpi_id_bits; > > @@ -1628,18 +1629,32 @@ static void its_free_prop_table(struct page *prop_page) > > static int __init its_alloc_lpi_prop_table(void) > { > - struct page *page; > + if (gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED) { > + u64 val; > > - lpi_id_bits = min_t(u32, GICD_TYPER_ID_BITS(gic_rdists->gicd_typer), > - ITS_MAX_LPI_NRBITS); > - page = its_allocate_prop_table(GFP_NOWAIT); > - if (!page) { > - pr_err("Failed to allocate PROPBASE\n"); > - return -ENOMEM; > - } > + val = gicr_read_propbaser(gic_data_rdist_rd_base() + GICR_PROPBASER); > + lpi_id_bits = (val & GICR_PROPBASER_IDBITS_MASK) + 1; > > - gic_rdists->prop_table_pa = page_to_phys(page); > - gic_rdists->prop_table_va = page_address(page); > + gic_rdists->prop_table_pa = val & GENMASK_ULL(51, 12); > + gic_rdists->prop_table_va = memremap(gic_rdists->prop_table_pa, > + LPI_PROPBASE_SZ, > + MEMREMAP_WB); > + gic_reset_prop_table(gic_rdists->prop_table_va); > + } else { > + struct page *page; > + > + lpi_id_bits = min_t(u32, > + GICD_TYPER_ID_BITS(gic_rdists->gicd_typer), > + ITS_MAX_LPI_NRBITS); > + page = its_allocate_prop_table(GFP_NOWAIT); > + if (!page) { > + pr_err("Failed to allocate PROPBASE\n"); > + return -ENOMEM; > + } > + > + gic_rdists->prop_table_pa = page_to_phys(page); > + gic_rdists->prop_table_va = page_address(page); > + } > > pr_info("GICv3: using LPI property table @%pa\n", > &gic_rdists->prop_table_pa); > @@ -1948,10 +1963,27 @@ static void its_free_pending_table(struct page *pt) > free_pages((unsigned long)page_address(pt), get_order(LPI_PENDBASE_SZ)); > } > > +static bool enabled_lpis_allowed(void) > +{ > + return false; > +} > + > static int __init allocate_lpi_tables(void) > { > + u64 val; > int err, cpu; > > + /* > + * If LPIs are enabled while we run this from the boot CPU, > + * flag the RD tables as pre-allocated if the stars do align. > + */ > + val = readl_relaxed(gic_data_rdist_rd_base() + GICR_CTLR); > + if ((val & GICR_CTLR_ENABLE_LPIS) && enabled_lpis_allowed()) { > + gic_rdists->flags |= (RDIST_FLAGS_RD_TABLES_PREALLOCATED | > + RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING); > + pr_info("GICv3: Using preallocated redistributor tables\n"); > + } > + > err = its_alloc_lpi_prop_table(); > if (err) > return err; > @@ -1986,6 +2018,18 @@ static void its_cpu_init_lpis(void) > if (gic_data_rdist()->lpi_enabled) > return; > > + val = readl_relaxed(rbase + GICR_CTLR); > + if ((gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED) && > + (val & GICR_CTLR_ENABLE_LPIS)) { > + paddr = gicr_read_pendbaser(rbase + GICR_PENDBASER); > + paddr &= GENMASK_ULL(51, 16); > + > + its_free_pending_table(gic_data_rdist()->pend_page); > + gic_data_rdist()->pend_page = NULL; > + > + goto out; > + } > + > pend_page = gic_data_rdist()->pend_page; > paddr = page_to_phys(pend_page); > > @@ -2040,9 +2084,11 @@ static void its_cpu_init_lpis(void) > > /* Make sure the GIC has seen the above */ > dsb(sy); > +out: > gic_data_rdist()->lpi_enabled = true; > - pr_info("GICv3: CPU%d: using LPI pending table @%pa\n", > + pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n", > smp_processor_id(), > + gic_data_rdist()->pend_page ? "allocated" : "reserved", > &paddr); > } > > @@ -3535,8 +3581,11 @@ static int redist_disable_lpis(void) > * If coming via a CPU hotplug event, we don't need to disable > * LPIs before trying to re-enable them. They are already > * configured and all is well in the world. > + * > + * If running with preallocated tables, there is nothing to do. > */ > - if (gic_data_rdist()->lpi_enabled) > + if (gic_data_rdist()->lpi_enabled || > + (gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED)) > return 0; > > /* > -- Julien Thierry