Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754422AbbFEKvE (ORCPT ); Fri, 5 Jun 2015 06:51:04 -0400 Received: from mail-lb0-f176.google.com ([209.85.217.176]:35117 "EHLO mail-lb0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751597AbbFEKu6 (ORCPT ); Fri, 5 Jun 2015 06:50:58 -0400 From: Ricardo Ribalda Delgado To: Grant Likely , Rob Herring , Rob Herring , Andrew Morton , Bjorn Helgaas , Vivek Goyal , Jakub Sitnicki , Mike Travis , Jiang Liu , Thierry Reding , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, Tejun Heo , Cliff Wickman Cc: Ricardo Ribalda Delgado Subject: [PATCH 1/2] kernel/resource: Add new flag IORESOURCE_SHARED Date: Fri, 5 Jun 2015 12:51:17 +0200 Message-Id: <1433501478-15164-1-git-send-email-ricardo.ribalda@gmail.com> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2499 Lines: 67 Some device tree platforms have not defined correctly their memory resources (i.e. Overlapping or duplication of resources). To avoid this issue we have historically avoided to add their resources to the resource tree. This leads to code duplication and oops when trying to unload dynamically a device tree (feature introduced recently). This new flag tells the resource system that a resource can be shared by multiple owners, so we can support device trees with problems at the same time that we do not duplicate code or crash when unloading the device tree. Signed-off-by: Ricardo Ribalda Delgado --- include/linux/ioport.h | 1 + kernel/resource.c | 6 ++++-- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 388e3ae94f7a..f4d992381529 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -49,6 +49,7 @@ struct resource { #define IORESOURCE_WINDOW 0x00200000 /* forwarded by bridge */ #define IORESOURCE_MUXED 0x00400000 /* Resource is software muxed */ +#define IORESOURCE_SHARED 0x04000000 /* Resource can be shared */ #define IORESOURCE_EXCLUSIVE 0x08000000 /* Userland may not map this resource */ #define IORESOURCE_DISABLED 0x10000000 #define IORESOURCE_UNSET 0x20000000 /* No address assigned yet */ diff --git a/kernel/resource.c b/kernel/resource.c index 90552aab5f2d..4a3626489b62 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -210,6 +210,7 @@ static struct resource * __request_resource(struct resource *root, struct resour resource_size_t start = new->start; resource_size_t end = new->end; struct resource *tmp, **p; + bool root_shared = root && root->flags & IORESOURCE_SHARED; if (end < start) return root; @@ -220,14 +221,15 @@ static struct resource * __request_resource(struct resource *root, struct resour p = &root->child; for (;;) { tmp = *p; - if (!tmp || tmp->start > end) { + if (!tmp || tmp->start > end || + (root_shared && tmp->start > start)) { new->sibling = tmp; *p = new; new->parent = root; return NULL; } p = &tmp->sibling; - if (tmp->end < start) + if (tmp->end < start || root_shared) continue; return tmp; } -- 2.1.4 -- 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/