Subject: Re: [PATCH kernel v10 04/34] powerpc/iommu: Put IOMMU group explicitly

From: Gavin Shan <[email-masked]>
Date: Wed, 13 May 2015 15:27:46 +1000

On Tue, May 12, 2015 at 01:38:53AM +1000, Alexey Kardashevskiy wrote:
>So far an iommu_table lifetime was the same as PE. Dynamic DMA windows
>will change this and iommu_free_table() will not always require
>the group to be released.
>
>This moves iommu_group_put() out of iommu_free_table().
>
>This adds a iommu_pseries_free_table() helper which does
>iommu_group_put() and iommu_free_table(). Later it will be
>changed to receive a table_group and we will have to change less
>lines then.
>
>This should cause no behavioural change.
>
>Signed-off-by: Alexey Kardashevskiy <[email-masked]>

Reviewed-by: Gavin Shan <[email-masked]>

Thanks,
Gavin

>---
> arch/powerpc/kernel/iommu.c               |  7 -------
> arch/powerpc/platforms/powernv/pci-ioda.c |  5 +++++
> arch/powerpc/platforms/pseries/iommu.c    | 14 +++++++++++++-
> 3 files changed, 18 insertions(+), 8 deletions(-)
>
>diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
>index b054f33..3d47eb3 100644
>--- a/arch/powerpc/kernel/iommu.c
>+++ b/arch/powerpc/kernel/iommu.c
>@@ -726,13 +726,6 @@ void iommu_free_table(struct iommu_table *tbl, const char *node_name)
> 	if (tbl->it_offset == 0)
> 		clear_bit(0, tbl->it_map);
>
>-#ifdef CONFIG_IOMMU_API
>-	if (tbl->it_group) {
>-		iommu_group_put(tbl->it_group);
>-		BUG_ON(tbl->it_group);
>-	}
>-#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);
>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>index 8ca7abd..8c3c4bf 100644
>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>@@ -23,6 +23,7 @@
> #include <linux/io.h>
> #include <linux/msi.h>
> #include <linux/memblock.h>
>+#include <linux/iommu.h>
>
> #include <asm/sections.h>
> #include <asm/io.h>
>@@ -1310,6 +1311,10 @@ static void pnv_pci_ioda2_release_dma_pe(struct pci_dev *dev, struct pnv_ioda_pe
> 	if (rc)
> 		pe_warn(pe, "OPAL error %ld release DMA window\n", rc);
>
>+	if (tbl->it_group) {
>+		iommu_group_put(tbl->it_group);
>+		BUG_ON(tbl->it_group);
>+	}
> 	iommu_free_table(tbl, of_node_full_name(dev->dev.of_node));
> 	free_pages(addr, get_order(TCE32_TABLE_SIZE));
> 	pe->tce32_table = NULL;
>diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
>index 05ab06d..89f557b 100644
>--- a/arch/powerpc/platforms/pseries/iommu.c
>+++ b/arch/powerpc/platforms/pseries/iommu.c
>@@ -36,6 +36,7 @@
> #include <linux/crash_dump.h>
> #include <linux/memory.h>
> #include <linux/of.h>
>+#include <linux/iommu.h>
> #include <asm/io.h>
> #include <asm/prom.h>
> #include <asm/rtas.h>
>@@ -51,6 +52,16 @@
>
> #include "pseries.h"
>
>+static void iommu_pseries_free_table(struct iommu_table *tbl,
>+		const char *node_name)
>+{
>+	if (tbl->it_group) {
>+		iommu_group_put(tbl->it_group);
>+		BUG_ON(tbl->it_group);
>+	}
>+	iommu_free_table(tbl, node_name);
>+}
>+
> static void tce_invalidate_pSeries_sw(struct iommu_table *tbl,
> 				      __be64 *startp, __be64 *endp)
> {
>@@ -1271,7 +1282,8 @@ static int iommu_reconfig_notifier(struct notifier_block *nb, unsigned long acti
> 		 */
> 		remove_ddw(np, false);
> 		if (pci && pci->iommu_table)
>-			iommu_free_table(pci->iommu_table, np->full_name);
>+			iommu_pseries_free_table(pci->iommu_table,
>+					np->full_name);
>
> 		spin_lock(&direct_window_list_lock);
> 		list_for_each_entry(window, &direct_window_list, list) {
>-- 
>2.4.0.rc3.8.gfb3e7d5
>