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authorWill Deacon <will.deacon@arm.com>2014-08-27 17:40:58 +0400
committerWill Deacon <will.deacon@arm.com>2014-12-01 19:47:46 +0300
commit1cd076bf67793942ed921b766f7d461de2ebc0a2 (patch)
tree9be0b9940e90c029fa6e70c773b43d2baef5a8b6 /drivers
parent5d01410fe4d92081f349b013a2e7a95429e4f2c9 (diff)
downloadlinux-1cd076bf67793942ed921b766f7d461de2ebc0a2.tar.xz
iommu: provide early initialisation hook for IOMMU drivers
IOMMU drivers must be initialised before any of their upstream devices, otherwise the relevant iommu_ops won't be configured for the bus in question. To solve this, a number of IOMMU drivers use initcalls to initialise the driver before anything has a chance to be probed. Whilst this solves the immediate problem, it leaves the job of probing the IOMMU completely separate from the iommu_ops to configure the IOMMU, which are called on a per-bus basis and require the driver to figure out exactly which instance of the IOMMU is being requested. In particular, the add_device callback simply passes a struct device to the driver, which then has to parse firmware tables or probe buses to identify the relevant IOMMU instance. This patch takes the first step in addressing this problem by adding an early initialisation pass for IOMMU drivers, giving them the ability to store some per-instance data in their iommu_ops structure and store that in their of_node. This can later be used when parsing OF masters to identify the IOMMU instance in question. Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Joerg Roedel <jroedel@suse.de> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iommu/of_iommu.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index e550ccb7634e..89b903406968 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -22,6 +22,9 @@
#include <linux/of.h>
#include <linux/of_iommu.h>
+static const struct of_device_id __iommu_of_table_sentinel
+ __used __section(__iommu_of_table_end);
+
/**
* of_get_dma_window - Parse *dma-window property and returns 0 if found.
*
@@ -89,3 +92,17 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
return 0;
}
EXPORT_SYMBOL_GPL(of_get_dma_window);
+
+void __init of_iommu_init(void)
+{
+ struct device_node *np;
+ const struct of_device_id *match, *matches = &__iommu_of_table;
+
+ for_each_matching_node_and_match(np, matches, &match) {
+ const of_iommu_init_fn init_fn = match->data;
+
+ if (init_fn(np))
+ pr_err("Failed to initialise IOMMU %s\n",
+ of_node_full_name(np));
+ }
+}