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author | Yong Wu <yong.wu@mediatek.com> | 2018-01-26 15:11:28 +0800 |
---|---|---|
committer | Joerg Roedel <jroedel@suse.de> | 2018-02-13 14:40:31 +0100 |
commit | f3e827d73ed454053d2ce6a4bf021b5adde3ac54 (patch) | |
tree | 40b451520ff45f7bb4d3da8a125d327602b816d2 /drivers/iommu | |
parent | 7928b2cbe55b2a410a0f5c1f154610059c57b1b2 (diff) | |
download | linux-next-f3e827d73ed454053d2ce6a4bf021b5adde3ac54.tar.gz |
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>
Diffstat (limited to 'drivers/iommu')
-rw-r--r-- | drivers/iommu/mtk_iommu_v1.c | 54 |
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, }; |