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authorYong Wu <yong.wu@mediatek.com>2018-01-26 10:11:28 +0300
committerJoerg Roedel <jroedel@suse.de>2018-02-13 16:40:31 +0300
commitf3e827d73ed454053d2ce6a4bf021b5adde3ac54 (patch)
tree40b451520ff45f7bb4d3da8a125d327602b816d2
parent7928b2cbe55b2a410a0f5c1f154610059c57b1b2 (diff)
downloadlinux-f3e827d73ed454053d2ce6a4bf021b5adde3ac54.tar.xz
iommu/mediatek: Move attach_device after iommu-group is ready for M4Uv1
In the commit 05f80300dc8b ("iommu: Finish making iommu_group support mandatory"), the iommu framework has supposed all the iommu drivers have their owner iommu-group, it get rid of the FIXME workarounds while the group is NULL. But the flow of Mediatek M4U gen1 looks a bit trick that it will hang at this case: ========================================== Unable to handle kernel NULL pointer dereference at virtual address 00000030 pgd = c0004000 [00000030] *pgd=00000000 PC is at mutex_lock+0x28/0x54 LR is at iommu_attach_device+0xa4/0xd4 pc : [<c07632e8>] lr : [<c04736fc>] psr: 60000013 sp : df0edbb8 ip : df0edbc8 fp : df0edbc4 r10: c114da14 r9 : df2a3e40 r8 : 00000003 r7 : df27a210 r6 : df2a90c4 r5 : 00000030 r4 : 00000000 r3 : df0f8000 r2 : fffff000 r1 : df29c610 r0 : 00000030 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none xxx (mutex_lock) from [<c04736fc>] (iommu_attach_device+0xa4/0xd4) (iommu_attach_device) from [<c011b9dc>] (__arm_iommu_attach_device+0x28/0x90) (__arm_iommu_attach_device) from [<c011ba60>] (arm_iommu_attach_device+0x1c/0x30) (arm_iommu_attach_device) from [<c04759ac>] (mtk_iommu_add_device+0xfc/0x214) (mtk_iommu_add_device) from [<c0472aa4>] (add_iommu_group+0x3c/0x68) (add_iommu_group) from [<c047d044>] (bus_for_each_dev+0x78/0xac) (bus_for_each_dev) from [<c04734a4>] (bus_set_iommu+0xb0/0xec) (bus_set_iommu) from [<c0476310>] (mtk_iommu_probe+0x328/0x368) (mtk_iommu_probe) from [<c048189c>] (platform_drv_probe+0x5c/0xc0) (platform_drv_probe) from [<c047f510>] (driver_probe_device+0x2f4/0x4d8) (driver_probe_device) from [<c047f800>] (__driver_attach+0x10c/0x128) (__driver_attach) from [<c047d044>] (bus_for_each_dev+0x78/0xac) (bus_for_each_dev) from [<c047ec78>] (driver_attach+0x2c/0x30) (driver_attach) from [<c047e640>] (bus_add_driver+0x1e0/0x278) (bus_add_driver) from [<c048052c>] (driver_register+0x88/0x108) (driver_register) from [<c04817ec>] (__platform_driver_register+0x50/0x58) (__platform_driver_register) from [<c0b31380>] (m4u_init+0x24/0x28) (m4u_init) from [<c0101c38>] (do_one_initcall+0xf0/0x17c) ========================= The root cause is that the device's iommu-group is NULL while arm_iommu_attach_device is called. This patch prepare a new iommu-group for the iommu consumer devices to fix this issue. CC: Robin Murphy <robin.murphy@arm.com> CC: Honghui Zhang <honghui.zhang@mediatek.com> Fixes: 05f80300dc8b ("iommu: Finish making iommu_group support mandatory") Reported-by: Ryder Lee <ryder.lee@mediatek.com> Signed-off-by: Yong Wu <yong.wu@mediatek.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
-rw-r--r--drivers/iommu/mtk_iommu_v1.c54
1 files changed, 21 insertions, 33 deletions
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 542930cd183d..1b1b77594897 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -418,20 +418,12 @@ static int mtk_iommu_create_mapping(struct device *dev,
m4udev->archdata.iommu = mtk_mapping;
}
- ret = arm_iommu_attach_device(dev, mtk_mapping);
- if (ret)
- goto err_release_mapping;
-
return 0;
-
-err_release_mapping:
- arm_iommu_release_mapping(mtk_mapping);
- m4udev->archdata.iommu = NULL;
- return ret;
}
static int mtk_iommu_add_device(struct device *dev)
{
+ struct dma_iommu_mapping *mtk_mapping;
struct of_phandle_args iommu_spec;
struct of_phandle_iterator it;
struct mtk_iommu_data *data;
@@ -452,15 +444,30 @@ static int mtk_iommu_add_device(struct device *dev)
if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
return -ENODEV; /* Not a iommu client device */
- data = dev->iommu_fwspec->iommu_priv;
- iommu_device_link(&data->iommu, dev);
-
- group = iommu_group_get_for_dev(dev);
+ /*
+ * This is a short-term bodge because the ARM DMA code doesn't
+ * understand multi-device groups, but we have to call into it
+ * successfully (and not just rely on a normal IOMMU API attach
+ * here) in order to set the correct DMA API ops on @dev.
+ */
+ group = iommu_group_alloc();
if (IS_ERR(group))
return PTR_ERR(group);
+ err = iommu_group_add_device(group, dev);
iommu_group_put(group);
- return 0;
+ if (err)
+ return err;
+
+ data = dev->iommu_fwspec->iommu_priv;
+ mtk_mapping = data->dev->archdata.iommu;
+ err = arm_iommu_attach_device(dev, mtk_mapping);
+ if (err) {
+ iommu_group_remove_device(dev);
+ return err;
+ }
+
+ return iommu_device_link(&data->iommu, dev);;
}
static void mtk_iommu_remove_device(struct device *dev)
@@ -477,24 +484,6 @@ static void mtk_iommu_remove_device(struct device *dev)
iommu_fwspec_free(dev);
}
-static struct iommu_group *mtk_iommu_device_group(struct device *dev)
-{
- struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
-
- if (!data)
- return ERR_PTR(-ENODEV);
-
- /* All the client devices are in the same m4u iommu-group */
- if (!data->m4u_group) {
- data->m4u_group = iommu_group_alloc();
- if (IS_ERR(data->m4u_group))
- dev_err(dev, "Failed to allocate M4U IOMMU group\n");
- } else {
- iommu_group_ref_get(data->m4u_group);
- }
- return data->m4u_group;
-}
-
static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
{
u32 regval;
@@ -547,7 +536,6 @@ static struct iommu_ops mtk_iommu_ops = {
.iova_to_phys = mtk_iommu_iova_to_phys,
.add_device = mtk_iommu_add_device,
.remove_device = mtk_iommu_remove_device,
- .device_group = mtk_iommu_device_group,
.pgsize_bitmap = ~0UL << MT2701_IOMMU_PAGE_SHIFT,
};