From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f46.google.com ([209.85.160.46]:60421 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755102Ab2EEDBQ (ORCPT ); Fri, 4 May 2012 23:01:16 -0400 Received: by mail-pb0-f46.google.com with SMTP id rp8so4527911pbb.19 for ; Fri, 04 May 2012 20:01:16 -0700 (PDT) From: Jiang Liu To: Bjorn Helgaas , Taku Izumi , Yinghai Lu Cc: Jiang Liu , Kenji Kaneshige , Don Dutile , Keping Chen , linux-pci@vger.kernel.org, Jiang Liu Subject: [PATCH v5 3/6] PCI, x86: use RCU list to protect mmconfig list Date: Sat, 5 May 2012 11:00:27 +0800 Message-Id: <1336186830-10765-4-git-send-email-jiang.liu@huawei.com> In-Reply-To: <1336186830-10765-1-git-send-email-jiang.liu@huawei.com> References: <1336186830-10765-1-git-send-email-jiang.liu@huawei.com> Sender: linux-pci-owner@vger.kernel.org List-ID: From: Jiang Liu Use RCU list to protect mmconfig list from dynamic change when supporting PCI host bridge hotplug. Signed-off-by: Jiang Liu --- arch/x86/pci/mmconfig-shared.c | 18 ++++++++++++------ arch/x86/pci/mmconfig_32.c | 13 +++++++++++-- arch/x86/pci/mmconfig_64.c | 13 +++++++++++-- 3 files changed, 34 insertions(+), 10 deletions(-) diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c index 5e2cd2a..0ac97d5 100644 --- a/arch/x86/pci/mmconfig-shared.c +++ b/arch/x86/pci/mmconfig-shared.c @@ -17,6 +17,8 @@ #include #include #include +#include +#include #include #include #include @@ -25,6 +27,7 @@ /* Indicate if the mmcfg resources have been placed into the resource table. */ static int __initdata pci_mmcfg_resources_inserted; +static DEFINE_MUTEX(pci_mmcfg_lock); LIST_HEAD(pci_mmcfg_list); @@ -45,20 +48,20 @@ static __init void free_all_mmcfg(void) pci_mmconfig_remove(cfg); } -static __init void list_add_sorted(struct pci_mmcfg_region *new) +static __devinit void list_add_sorted(struct pci_mmcfg_region *new) { struct pci_mmcfg_region *cfg; /* keep list sorted by segment and starting bus number */ - list_for_each_entry(cfg, &pci_mmcfg_list, list) { + list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) { if (cfg->segment > new->segment || (cfg->segment == new->segment && cfg->start_bus >= new->start_bus)) { - list_add_tail(&new->list, &cfg->list); + list_add_tail_rcu(&new->list, &cfg->list); return; } } - list_add_tail(&new->list, &pci_mmcfg_list); + list_add_tail_rcu(&new->list, &pci_mmcfg_list); } static __devinit struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, @@ -101,8 +104,11 @@ static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start, struct pci_mmcfg_region *new; new = pci_mmconfig_alloc(segment, start, end, addr); - if (new) + if (new) { + mutex_lock(&pci_mmcfg_lock); list_add_sorted(new); + mutex_unlock(&pci_mmcfg_lock); + } return new; } @@ -111,7 +117,7 @@ struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus) { struct pci_mmcfg_region *cfg; - list_for_each_entry(cfg, &pci_mmcfg_list, list) + list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) if (cfg->segment == segment && cfg->start_bus <= bus && bus <= cfg->end_bus) return cfg; diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c index 5372e86..5dad04a 100644 --- a/arch/x86/pci/mmconfig_32.c +++ b/arch/x86/pci/mmconfig_32.c @@ -11,6 +11,7 @@ #include #include +#include #include #include #include @@ -60,9 +61,12 @@ err: *value = -1; return -EINVAL; } + rcu_read_lock(); base = get_base_addr(seg, bus, devfn); - if (!base) + if (!base) { + rcu_read_unlock(); goto err; + } raw_spin_lock_irqsave(&pci_config_lock, flags); @@ -80,6 +84,7 @@ err: *value = -1; break; } raw_spin_unlock_irqrestore(&pci_config_lock, flags); + rcu_read_unlock(); return 0; } @@ -93,9 +98,12 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, if ((bus > 255) || (devfn > 255) || (reg > 4095)) return -EINVAL; + rcu_read_lock(); base = get_base_addr(seg, bus, devfn); - if (!base) + if (!base) { + rcu_read_unlock(); return -EINVAL; + } raw_spin_lock_irqsave(&pci_config_lock, flags); @@ -113,6 +121,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, break; } raw_spin_unlock_irqrestore(&pci_config_lock, flags); + rcu_read_unlock(); return 0; } diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c index 915a493..acc48c5 100644 --- a/arch/x86/pci/mmconfig_64.c +++ b/arch/x86/pci/mmconfig_64.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include @@ -34,9 +35,12 @@ err: *value = -1; return -EINVAL; } + rcu_read_lock(); addr = pci_dev_base(seg, bus, devfn); - if (!addr) + if (!addr) { + rcu_read_unlock(); goto err; + } switch (len) { case 1: @@ -49,6 +53,7 @@ err: *value = -1; *value = mmio_config_readl(addr + reg); break; } + rcu_read_unlock(); return 0; } @@ -62,9 +67,12 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) return -EINVAL; + rcu_read_lock(); addr = pci_dev_base(seg, bus, devfn); - if (!addr) + if (!addr) { + rcu_read_unlock(); return -EINVAL; + } switch (len) { case 1: @@ -77,6 +85,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, mmio_config_writel(addr + reg, value); break; } + rcu_read_unlock(); return 0; } -- 1.7.9.5