The tegra_smmu_probe_device() handles only the first IOMMU device-tree
phandle, skipping the rest. Devices like 3D module on Tegra30 have
multiple IOMMU phandles, one for each h/w block, and thus, only one
IOMMU phandle is added to fwspec for the 3D module, breaking GPU.
Previously this problem was masked by tegra_smmu_attach_dev() which
didn't use the fwspec, but parsed the DT by itself. The previous commit
to tegra-smmu driver partially reverted changes that caused problems for
T124 and now we have tegra_smmu_attach_dev() that uses the fwspec and
the old-buggy variant of tegra_smmu_probe_device() which skips secondary
IOMMUs.
Make tegra_smmu_probe_device() not to skip the secondary IOMMUs. This
fixes a partially attached IOMMU of the 3D module on Tegra30 and now GPU
works properly once again.
Fixes: 765a9d1d02 ("iommu/tegra-smmu: Fix mc errors on tegra124-nyan")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Nicolin Chen <nicoleotsuka@gmail.com>
Link: https://lore.kernel.org/r/20210312155439.18477-1-digetx@gmail.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Pull iommu fixes from Joerg Roedel:
- Fix a sleeping-while-atomic issue in the AMD IOMMU code
- Disable lazy IOTLB flush for untrusted devices in the Intel VT-d
driver
- Fix status code definitions for Intel VT-d
- Fix IO Page Fault issue in Tegra IOMMU driver
* tag 'iommu-fixes-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
iommu/vt-d: Fix status code for Allocate/Free PASID command
iommu: Don't use lazy flush for untrusted device
iommu/tegra-smmu: Fix mc errors on tegra124-nyan
iommu/amd: Fix sleeping in atomic in increase_address_space()
As per Intel vt-d spec, Rev 3.0 (section 10.4.45 "Virtual Command Response
Register"), the status code of "No PASID available" error in response to
the Allocate PASID command is 2, not 1. The same for "Invalid PASID" error
in response to the Free PASID command.
We will otherwise see confusing kernel log under the command failure from
guest side. Fix it.
Fixes: 24f27d32ab ("iommu/vt-d: Enlightened PASID allocation")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210227073909.432-1-yuzenghui@huawei.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
The lazy IOTLB flushing setup leaves a time window, in which the device
can still access some system memory, which has already been unmapped by
the device driver. It's not suitable for untrusted devices. A malicious
device might use this to attack the system by obtaining data that it
shouldn't obtain.
Fixes: c588072bba ("iommu/vt-d: Convert intel iommu driver to the iommu ops")
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210225061454.2864009-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Commit 25938c73cd ("iommu/tegra-smmu: Rework tegra_smmu_probe_device()")
removed certain hack in the tegra_smmu_probe() by relying on IOMMU core to
of_xlate SMMU's SID per device, so as to get rid of tegra_smmu_find() and
tegra_smmu_configure() that are typically done in the IOMMU core also.
This approach works for both existing devices that have DT nodes and other
devices (like PCI device) that don't exist in DT, on Tegra210 and Tegra3
upon testing. However, Page Fault errors are reported on tegra124-Nyan:
tegra-mc 70019000.memory-controller: display0a: read @0xfe056b40:
EMEM address decode error (SMMU translation error [--S])
tegra-mc 70019000.memory-controller: display0a: read @0xfe056b40:
Page fault (SMMU translation error [--S])
After debugging, I found that the mentioned commit changed some function
callback sequence of tegra-smmu's, resulting in enabling SMMU for display
client before display driver gets initialized. I couldn't reproduce exact
same issue on Tegra210 as Tegra124 (arm-32) differs at arch-level code.
Actually this Page Fault is a known issue, as on most of Tegra platforms,
display gets enabled by the bootloader for the splash screen feature, so
it keeps filling the framebuffer memory. A proper fix to this issue is to
1:1 linear map the framebuffer memory to IOVA space so the SMMU will have
the same address as the physical address in its page table. Yet, Thierry
has been working on the solution above for a year, and it hasn't merged.
Therefore, let's partially revert the mentioned commit to fix the errors.
The reason why we do a partial revert here is that we can still set priv
in ->of_xlate() callback for PCI devices. Meanwhile, devices existing in
DT, like display, will go through tegra_smmu_configure() at the stage of
bus_set_iommu() when SMMU gets probed(), as what it did before we merged
the mentioned commit.
Once we have the linear map solution for framebuffer memory, this change
can be cleaned away.
[Big thank to Guillaume who reported and helped debugging/verification]
Fixes: 25938c73cd ("iommu/tegra-smmu: Rework tegra_smmu_probe_device()")
Reported-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20210218220702.1962-1-nicoleotsuka@gmail.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
increase_address_space() calls get_zeroed_page(gfp) under spin_lock with
disabled interrupts. gfp flags passed to increase_address_space() may allow
sleeping, so it comes to this:
BUG: sleeping function called from invalid context at mm/page_alloc.c:4342
in_atomic(): 1, irqs_disabled(): 1, pid: 21555, name: epdcbbf1qnhbsd8
Call Trace:
dump_stack+0x66/0x8b
___might_sleep+0xec/0x110
__alloc_pages_nodemask+0x104/0x300
get_zeroed_page+0x15/0x40
iommu_map_page+0xdd/0x3e0
amd_iommu_map+0x50/0x70
iommu_map+0x106/0x220
vfio_iommu_type1_ioctl+0x76e/0x950 [vfio_iommu_type1]
do_vfs_ioctl+0xa3/0x6f0
ksys_ioctl+0x66/0x70
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x4e/0x100
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fix this by moving get_zeroed_page() out of spin_lock/unlock section.
Fixes: 754265bcab ("iommu/amd: Fix race in increase_address_space()")
Signed-off-by: Andrey Ryabinin <arbn@yandex-team.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210217143004.19165-1-arbn@yandex-team.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Pull dma-mapping updates from Christoph Hellwig:
- add support to emulate processing delays in the DMA API benchmark
selftest (Barry Song)
- remove support for non-contiguous noncoherent allocations, which
aren't used and will be replaced by a different API
* tag 'dma-mapping-5.12' of git://git.infradead.org/users/hch/dma-mapping:
dma-mapping: remove the {alloc,free}_noncoherent methods
dma-mapping: benchmark: pretend DMA is transmitting
Pull iommu updates from Joerg Roedel:
- ARM SMMU and Mediatek updates from Will Deacon:
- Support for MT8192 IOMMU from Mediatek
- Arm v7s io-pgtable extensions for MT8192
- Removal of TLBI_ON_MAP quirk
- New Qualcomm compatible strings
- Allow SVA without hardware broadcast TLB maintenance on SMMUv3
- Virtualization Host Extension support for SMMUv3 (SVA)
- Allow SMMUv3 PMU perf driver to be built independently from IOMMU
- Some tidy-up in IOVA and core code
- Conversion of the AMD IOMMU code to use the generic IO-page-table
framework
- Intel VT-d updates from Lu Baolu:
- Audit capability consistency among different IOMMUs
- Add SATC reporting structure support
- Add iotlb_sync_map callback support
- SDHI support for Renesas IOMMU driver
- Misc cleanups and other small improvments
* tag 'iommu-updates-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (94 commits)
iommu/amd: Fix performance counter initialization
MAINTAINERS: repair file pattern in MEDIATEK IOMMU DRIVER
iommu/mediatek: Fix error code in probe()
iommu/mediatek: Fix unsigned domid comparison with less than zero
iommu/vt-d: Parse SATC reporting structure
iommu/vt-d: Add new enum value and structure for SATC
iommu/vt-d: Add iotlb_sync_map callback
iommu/vt-d: Move capability check code to cap_audit files
iommu/vt-d: Audit IOMMU Capabilities and add helper functions
iommu/vt-d: Fix 'physical' typos
iommu: Properly pass gfp_t in _iommu_map() to avoid atomic sleeping
iommu/vt-d: Fix compile error [-Werror=implicit-function-declaration]
driver/perf: Remove ARM_SMMU_V3_PMU dependency on ARM_SMMU_V3
MAINTAINERS: Add entry for MediaTek IOMMU
iommu/mediatek: Add mt8192 support
iommu/mediatek: Remove unnecessary check in attach_device
iommu/mediatek: Support master use iova over 32bit
iommu/mediatek: Add iova reserved function
iommu/mediatek: Support for multi domains
iommu/mediatek: Add get_domain_id from dev->dma_range_map
...
Pull Hyper-V updates from Wei Liu:
- VMBus hardening patches from Andrea Parri and Andres Beltran.
- Patches to make Linux boot as the root partition on Microsoft
Hypervisor from Wei Liu.
- One patch to add a new sysfs interface to support hibernation on
Hyper-V from Dexuan Cui.
- Two miscellaneous clean-up patches from Colin and Gustavo.
* tag 'hyperv-next-signed-20210216' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (31 commits)
Revert "Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer"
iommu/hyperv: setup an IO-APIC IRQ remapping domain for root partition
x86/hyperv: implement an MSI domain for root partition
asm-generic/hyperv: import data structures for mapping device interrupts
asm-generic/hyperv: introduce hv_device_id and auxiliary structures
asm-generic/hyperv: update hv_interrupt_entry
asm-generic/hyperv: update hv_msi_entry
x86/hyperv: implement and use hv_smp_prepare_cpus
x86/hyperv: provide a bunch of helper functions
ACPI / NUMA: add a stub function for node_to_pxm()
x86/hyperv: handling hypercall page setup for root
x86/hyperv: extract partition ID from Microsoft Hypervisor if necessary
x86/hyperv: allocate output arg pages if required
clocksource/hyperv: use MSR-based access if running as root
Drivers: hv: vmbus: skip VMBus initialization if Linux is root
x86/hyperv: detect if Linux is the root partition
asm-generic/hyperv: change HV_CPU_POWER_MANAGEMENT to HV_CPU_MANAGEMENT
hv: hyperv.h: Replace one-element array with flexible-array in struct icmsg_negotiate
hv_netvsc: Restrict configurations on isolated guests
Drivers: hv: vmbus: Enforce 'VMBus version >= 5.2' on isolated guests
...
Certain AMD platforms enable power gating feature for IOMMU PMC,
which prevents the IOMMU driver from updating the counter while
trying to validate the PMC functionality in the init_iommu_perf_ctr().
This results in disabling PMC support and the following error message:
"AMD-Vi: Unable to read/write to IOMMU perf counter"
To workaround this issue, disable power gating temporarily by programming
the counter source to non-zero value while validating the counter,
and restore the prior state afterward.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Tested-by: Tj (Elloe Linux) <ml.linux@elloe.vision>
Link: https://lore.kernel.org/r/20210208122712.5048-1-suravee.suthikulpanit@amd.com
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201753
Signed-off-by: Joerg Roedel <jroedel@suse.de>
It turns out allowing non-contigous allocations here was a rather bad
idea, as we'll now need to define ways to get the pages for mmaping
or dma_buf sharing. Revert this change and stick to the original
concept. A different API for the use case of non-contigous allocations
will be added back later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Tested-by: Ricardo Ribalda <ribalda@chromium.org>:wq
Audit IOMMU Capability/Extended Capability and check if the IOMMUs have
the consistent value for features. Report out or scale to the lowest
supported when IOMMU features have incompatibility among IOMMUs.
Report out features when below features are mismatched:
- First Level 5 Level Paging Support (FL5LP)
- First Level 1 GByte Page Support (FL1GP)
- Read Draining (DRD)
- Write Draining (DWD)
- Page Selective Invalidation (PSI)
- Zero Length Read (ZLR)
- Caching Mode (CM)
- Protected High/Low-Memory Region (PHMR/PLMR)
- Required Write-Buffer Flushing (RWBF)
- Advanced Fault Logging (AFL)
- RID-PASID Support (RPS)
- Scalable Mode Page Walk Coherency (SMPWC)
- First Level Translation Support (FLTS)
- Second Level Translation Support (SLTS)
- No Write Flag Support (NWFS)
- Second Level Accessed/Dirty Support (SLADS)
- Virtual Command Support (VCS)
- Scalable Mode Translation Support (SMTS)
- Device TLB Invalidation Throttle (DIT)
- Page Drain Support (PDS)
- Process Address Space ID Support (PASID)
- Extended Accessed Flag Support (EAFS)
- Supervisor Request Support (SRS)
- Execute Request Support (ERS)
- Page Request Support (PRS)
- Nested Translation Support (NEST)
- Snoop Control (SC)
- Pass Through (PT)
- Device TLB Support (DT)
- Queued Invalidation (QI)
- Page walk Coherency (C)
Set capability to the lowest supported when below features are mismatched:
- Maximum Address Mask Value (MAMV)
- Number of Fault Recording Registers (NFR)
- Second Level Large Page Support (SLLPS)
- Fault Recording Offset (FRO)
- Maximum Guest Address Width (MGAW)
- Supported Adjusted Guest Address Width (SAGAW)
- Number of Domains supported (NDOMS)
- Pasid Size Supported (PSS)
- Maximum Handle Mask Value (MHMV)
- IOTLB Register Offset (IRO)
Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210130184452.31711-1-kyung.min.park@intel.com
Link: https://lore.kernel.org/r/20210204014401.2846425-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Sleeping while atomic = bad. Let's fix an obvious typo to try to avoid it.
The warning that was seen (on a downstream kernel with the problematic
patch backported):
BUG: sleeping function called from invalid context at mm/page_alloc.c:4726
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 9, name: ksoftirqd/0
CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.4.93-12508-gc10c93e28e39 #1
Call trace:
dump_backtrace+0x0/0x154
show_stack+0x20/0x2c
dump_stack+0xa0/0xfc
___might_sleep+0x11c/0x12c
__might_sleep+0x50/0x84
__alloc_pages_nodemask+0xf8/0x2bc
__arm_lpae_alloc_pages+0x48/0x1b4
__arm_lpae_map+0x124/0x274
__arm_lpae_map+0x1cc/0x274
arm_lpae_map+0x140/0x170
arm_smmu_map+0x78/0xbc
__iommu_map+0xd4/0x210
_iommu_map+0x4c/0x84
iommu_map_atomic+0x44/0x58
__iommu_dma_map+0x8c/0xc4
iommu_dma_map_page+0xac/0xf0
Fixes: d8c1df02ac ("iommu: Move iotlb_sync_map out from __iommu_map")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Yong Wu <yong.wu@mediatek.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210201170611.1.I64a7b62579287d668d7c89e105dcedf45d641063@changeid
Signed-off-by: Joerg Roedel <jroedel@suse.de>
trace_qi_submit() could be used when interrupt remapping is supported,
but DMA remapping is not. In this case, the following compile error
occurs.
../drivers/iommu/intel/dmar.c: In function 'qi_submit_sync':
../drivers/iommu/intel/dmar.c:1311:3: error: implicit declaration of function 'trace_qi_submit';
did you mean 'ftrace_nmi_exit'? [-Werror=implicit-function-declaration]
trace_qi_submit(iommu, desc[i].qw0, desc[i].qw1,
^~~~~~~~~~~~~~~
ftrace_nmi_exit
Fixes: f2dd871799 ("iommu/vt-d: Add qi_submit trace event")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210130151907.3929148-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Merge in Mediatek support from Yong Wu which introduces significant
changes to the TLB invalidation and Arm short-descriptor code in the
io-pgtable layer.
* for-joerg/mtk: (40 commits)
MAINTAINERS: Add entry for MediaTek IOMMU
iommu/mediatek: Add mt8192 support
iommu/mediatek: Remove unnecessary check in attach_device
iommu/mediatek: Support master use iova over 32bit
iommu/mediatek: Add iova reserved function
iommu/mediatek: Support for multi domains
iommu/mediatek: Add get_domain_id from dev->dma_range_map
iommu/mediatek: Add iova_region structure
iommu/mediatek: Move geometry.aperture updating into domain_finalise
iommu/mediatek: Move domain_finalise into attach_device
iommu/mediatek: Adjust the structure
iommu/mediatek: Support report iova 34bit translation fault in ISR
iommu/mediatek: Support up to 34bit iova in tlb flush
iommu/mediatek: Add power-domain operation
iommu/mediatek: Add pm runtime callback
iommu/mediatek: Add device link for smi-common and m4u
iommu/mediatek: Add error handle for mtk_iommu_probe
iommu/mediatek: Move hw_init into attach_device
iommu/mediatek: Update oas for v7s
iommu/mediatek: Add a flag for iova 34bits case
...
After extending v7s, our pagetable already support iova reach
16GB(34bit). the master got the iova via dma_alloc_attrs may reach
34bits, but its HW register still is 32bit. then how to set the
bit32/bit33 iova? this depend on a SMI larb setting(bank_sel).
we separate whole 16GB iova to four banks:
bank: 0: 0~4G; 1: 4~8G; 2: 8-12G; 3: 12-16G;
The bank number is (iova >> 32).
We will preassign which bank the larbs belong to. currently we don't
have a interface for master to adjust its bank number.
Each a bank is a iova_region which is a independent iommu-domain.
the iova range for each iommu-domain can't cross 4G.
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org> #for memory part
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20210111111914.22211-31-yong.wu@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>
Some HW IP(ex: CCU) require the special iova range. That means the iova
got from dma_alloc_attrs for that devices must locate in his special range.
In this patch, we prepare a iommu group(domain) for each a iova range
requirement.
Meanwhile we still use one pagetable which support 16GB iova.
After this patch, If the iova range of a master is over 4G, the master
should:
a) Declare its special dma-ranges in its dtsi node. For example, If we
preassign the iova 4G-8G for vcodec, then the vcodec dtsi node should
add this:
/*
* iova start at 0x1_0000_0000, pa still start at 0x4000_0000
* size is 0x1_0000_0000.
*/
dma-ranges = <0x1 0x0 0x0 0x40000000 0x1 0x0>; /* 4G ~ 8G */
Note: we don't have a actual bus concept here. the master doesn't have its
special parent node, thus this dma-ranges can only be put in the master's
node.
b) Update the dma_mask:
dma_set_mask_and_coherent(dev, DMA_BIT_MASK(33));
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20210111111914.22211-29-yong.wu@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>
Add a new interface _get_domain_id from dev->dma_range_map,
The iommu consumer device will use dma-ranges in dtsi node to indicate
its dma address region requirement. In this iommu driver, we will get
the requirement and decide which iova domain it should locate.
In the lastest SoC, there will be several iova-regions(domains), we will
compare and calculate which domain is right. If the start/end of device
requirement equal some region. it is best fit of course. If it is inside
some region, it is also ok. the iova requirement of a device should not
be inside two or more regions.
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20210111111914.22211-28-yong.wu@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently domain_alloc only has a parameter(type), We have no chance to
input some special data. This patch moves the domain_finalise into
attach_device which has the device information, then could update
the domain's geometry.aperture ranges for each a device.
Strictly, I should use the data from mtk_iommu_get_m4u_data as the
parameter of mtk_iommu_domain_finalise in this patch. but dom->data
only is used in tlb ops in which the data is get from the m4u_list, thus
it is ok here.
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20210111111914.22211-25-yong.wu@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>
In the previous SoC, the M4U HW is in the EMI power domain which is
always on. the latest M4U is in the display power domain which may be
turned on/off, thus we have to add pm_runtime interface for it.
When the engine work, the engine always enable the power and clocks for
smi-larb/smi-common, then the M4U's power will always be powered on
automatically via the device link with smi-common.
Note: we don't enable the M4U power in iommu_map/unmap for tlb flush.
If its power already is on, of course it is ok. if the power is off,
the main tlb will be reset while M4U power on, thus the tlb flush while
m4u power off is unnecessary, just skip it.
Therefore, we increase the ref_count for pm when pm status is ACTIVE,
otherwise, skip it. Meanwhile, the tlb_flush_range is called so often,
thus, update pm ref_count while the SoC has power-domain to avoid touch the
dev->power.lock. and the tlb_flush_all only is called when boot, so no
need check if the SoC has power-domain to keep code clean.
There will be one case that pm runctime status is not expected when tlb
flush. After boot, the display may call dma_alloc_attrs before it call
pm_runtime_get(disp-dev), then the m4u's pm status is not active inside
the dma_alloc_attrs. Since it only happens after boot, the tlb is clean
at that time, I also think this is ok.
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20210111111914.22211-21-yong.wu@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>
In pm runtime case, all the registers backup/restore and bclk are
controlled in the pm_runtime callback, Rename the original
suspend/resume to the runtime_suspend/resume.
Use pm_runtime_force_suspend/resume as the normal suspend/resume.
iommu should suspend after iommu consumer devices, thus use _LATE_.
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20210111111914.22211-20-yong.wu@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>
In the lastest SoC, M4U has its special power domain. thus, If the engine
begin to work, it should help enable the power for M4U firstly.
Currently if the engine work, it always enable the power/clocks for
smi-larbs/smi-common. This patch adds device_link for smi-common and M4U.
then, if smi-common power is enabled, the M4U power also is powered on
automatically.
Normally M4U connect with several smi-larbs and their smi-common always
are the same, In this patch it get smi-common dev from the last smi-larb
device, then add the device_link.
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20210111111914.22211-19-yong.wu@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>
