Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753284AbbDPQ3j (ORCPT ); Thu, 16 Apr 2015 12:29:39 -0400 Received: from mail-pd0-f174.google.com ([209.85.192.174]:33412 "EHLO mail-pd0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752472AbbDPQ3a (ORCPT ); Thu, 16 Apr 2015 12:29:30 -0400 Message-ID: <552FE363.2060604@ozlabs.ru> Date: Fri, 17 Apr 2015 02:29:23 +1000 From: Alexey Kardashevskiy User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: David Gibson CC: linuxppc-dev@lists.ozlabs.org, Benjamin Herrenschmidt , Paul Mackerras , Alex Williamson , linux-kernel@vger.kernel.org Subject: Re: [PATCH kernel v8 21/31] powerpc/iommu: Split iommu_free_table into 2 helpers References: <1428647473-11738-1-git-send-email-aik@ozlabs.ru> <1428647473-11738-22-git-send-email-aik@ozlabs.ru> <20150416064637.GL3632@voom.redhat.com> In-Reply-To: <20150416064637.GL3632@voom.redhat.com> Content-Type: text/plain; charset=koi8-r; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4238 Lines: 126 On 04/16/2015 04:46 PM, David Gibson wrote: > On Fri, Apr 10, 2015 at 04:31:03PM +1000, Alexey Kardashevskiy wrote: >> The iommu_free_table helper release memory it is using (the TCE table and >> @it_map) and release the iommu_table struct as well. We might not want >> the very last step as we store iommu_table in parent structures. > > Yeah, as I commented on the earlier patch, freeing the surrounding > group from a function taking just the individual table is wrong. This is iommu tables created by the old code which stores these iommu_table struct pointers in device nodes. I believe there is a plan to get rid of iommu tables there and when this is done, this workaround will be gone. > >> >> Signed-off-by: Alexey Kardashevskiy >> --- >> arch/powerpc/include/asm/iommu.h | 1 + >> arch/powerpc/kernel/iommu.c | 57 ++++++++++++++++++++++++---------------- >> 2 files changed, 35 insertions(+), 23 deletions(-) >> >> diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h >> index bde7ee7..8ed4648 100644 >> --- a/arch/powerpc/include/asm/iommu.h >> +++ b/arch/powerpc/include/asm/iommu.h >> @@ -127,6 +127,7 @@ static inline void *get_iommu_table_base(struct device *dev) >> >> extern struct iommu_table *iommu_table_alloc(int node); >> /* Frees table for an individual device node */ >> +extern void iommu_reset_table(struct iommu_table *tbl, const char *node_name); >> extern void iommu_free_table(struct iommu_table *tbl, const char *node_name); >> >> /* Initializes an iommu_table based in values set in the passed-in >> diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c >> index 501e8ee..0bcd988 100644 >> --- a/arch/powerpc/kernel/iommu.c >> +++ b/arch/powerpc/kernel/iommu.c >> @@ -721,24 +721,46 @@ struct iommu_table *iommu_table_alloc(int node) >> return &table_group->tables[0]; >> } >> >> +void iommu_reset_table(struct iommu_table *tbl, const char *node_name) >> +{ >> + if (!tbl) >> + return; >> + >> + if (tbl->it_map) { >> + unsigned long bitmap_sz; >> + unsigned int order; >> + >> + /* >> + * In case we have reserved the first bit, we should not emit >> + * the warning below. >> + */ >> + if (tbl->it_offset == 0) >> + clear_bit(0, tbl->it_map); >> + >> + /* verify that table contains no entries */ >> + if (!bitmap_empty(tbl->it_map, tbl->it_size)) >> + pr_warn("%s: Unexpected TCEs for %s\n", __func__, >> + node_name); >> + >> + /* calculate bitmap size in bytes */ >> + bitmap_sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long); >> + >> + /* free bitmap */ >> + order = get_order(bitmap_sz); >> + free_pages((unsigned long) tbl->it_map, order); >> + } >> + >> + memset(tbl, 0, sizeof(*tbl)); >> +} >> + >> void iommu_free_table(struct iommu_table *tbl, const char *node_name) >> { >> - unsigned long bitmap_sz; >> - unsigned int order; >> struct iommu_table_group *table_group = tbl->it_group; >> >> - if (!tbl || !tbl->it_map) { >> - printk(KERN_ERR "%s: expected TCE map for %s\n", __func__, >> - node_name); >> + if (!tbl) >> return; >> - } >> >> - /* >> - * In case we have reserved the first bit, we should not emit >> - * the warning below. >> - */ >> - if (tbl->it_offset == 0) >> - clear_bit(0, tbl->it_map); >> + iommu_reset_table(tbl, node_name); >> >> #ifdef CONFIG_IOMMU_API >> if (table_group->group) { >> @@ -747,17 +769,6 @@ void iommu_free_table(struct iommu_table *tbl, const char *node_name) >> } >> #endif >> >> - /* verify that table contains no entries */ >> - if (!bitmap_empty(tbl->it_map, tbl->it_size)) >> - pr_warn("%s: Unexpected TCEs for %s\n", __func__, node_name); >> - >> - /* calculate bitmap size in bytes */ >> - bitmap_sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long); >> - >> - /* free bitmap */ >> - order = get_order(bitmap_sz); >> - free_pages((unsigned long) tbl->it_map, order); >> - >> /* free table */ >> kfree(table_group); >> } > -- Alexey -- 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/