Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753463Ab2FMHeT (ORCPT ); Wed, 13 Jun 2012 03:34:19 -0400 Received: from linux-sh.org ([111.68.239.195]:41662 "EHLO linux-sh.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752252Ab2FMHeQ (ORCPT ); Wed, 13 Jun 2012 03:34:16 -0400 From: Paul Mundt To: Grant Likely Cc: linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org, Paul Mundt Subject: [PATCH 1/2] irqdomain: Fix up linear revmap for non-zero hwirq displacement. Date: Wed, 13 Jun 2012 16:34:00 +0900 Message-Id: <1339572841-26175-1-git-send-email-lethal@linux-sh.org> X-Mailer: git-send-email 1.7.10.207.g0bb2e Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3930 Lines: 99 Presently the linear revmap code assumes that all hwirqs start at 0, using the hwirq directly as an index value for the lookup. In the case of legacy revmaps this isn't necessarily the case, as the first_hwirq value passed in can be non-zero, causing those types of users to silently have their IRQs placed in the radix tree instead. With this change, hwirq displacement is factored in at association time directly. This also makes it possible for non-legacy users to use linear revmaps regardless of hwirq base position. This could potentially lead to a bug if there's an attempt to associate multiple times in to the linear map in a nonsensical and non-linear order, but at that point being silently punted to the radix tree is likely to be the least of your concerns (in such a case it's fairly trivial to simply extend irq_domain_add_linear() to take a hwirq base and move the linear base assignment there). Signed-off-by: Paul Mundt --- include/linux/irqdomain.h | 1 + kernel/irq/irqdomain.c | 18 +++++++++++++----- 2 files changed, 14 insertions(+), 5 deletions(-) diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index 775765d..58defd5 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -97,6 +97,7 @@ struct irq_domain { /* Reverse mapping data */ unsigned int nomap_max_irq; struct radix_tree_root radix_tree; + unsigned int linear_start; unsigned int linear_size; unsigned int linear_revmap[]; }; diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 906307b..8591cb6 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -55,6 +55,7 @@ static struct irq_domain *irq_domain_alloc(struct device_node *of_node, domain->ops = ops; domain->host_data = host_data; domain->of_node = of_node_get(of_node); + domain->linear_start = 0; domain->linear_size = size; return domain; @@ -268,8 +269,8 @@ static void irq_domain_disassociate_many(struct irq_domain *domain, irq_data->hwirq = 0; /* Clear reverse map */ - if (hwirq < domain->linear_size) - domain->linear_revmap[hwirq] = 0; + if (hwirq - domain->linear_start < domain->linear_size) + domain->linear_revmap[hwirq - domain->linear_start] = 0; else { mutex_lock(&revmap_trees_mutex); radix_tree_delete(&domain->radix_tree, hwirq); @@ -288,6 +289,13 @@ int irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base, pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__, of_node_full_name(domain->of_node), irq_base, (int)hwirq_base, count); + /* + * The linear revmap may not begin at 0, factor in the hwirq + * displacement here. + */ + if (domain->linear_size) + domain->linear_start = hwirq_base; + for (i = 0; i < count; i++) { struct irq_data *irq_data = irq_get_irq_data(virq + i); @@ -311,8 +319,8 @@ int irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base, goto err_unmap; } - if (hwirq < domain->linear_size) - domain->linear_revmap[hwirq] = virq; + if (hwirq - domain->linear_start < domain->linear_size) + domain->linear_revmap[hwirq - domain->linear_start] = virq; else { mutex_lock(&revmap_trees_mutex); radix_tree_insert(&domain->radix_tree, hwirq, irq_data); @@ -585,7 +593,7 @@ unsigned int irq_linear_revmap(struct irq_domain *domain, BUG_ON(domain->revmap_type != IRQ_DOMAIN_MAP_LINEAR); /* Check revmap bounds; complain if exceeded */ - if (hwirq >= domain->linear_size) { + if (hwirq - domain->linear_start >= domain->linear_size) { rcu_read_lock(); data = radix_tree_lookup(&domain->radix_tree, hwirq); rcu_read_unlock(); -- 1.7.9.rc0.28.g0e1cf -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/