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| author | Caleb Connolly <caleb@connolly.tech> | 2021-05-02 01:42:57 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-20 16:02:24 +0200 |
| commit | b6e42191c0abf82f78ce35e2b681aa3a563722bf (patch) | |
| tree | 65217646a9ec7b12fc52043b6c2e7b7e85650084 | |
| parent | c7da67a6e40d494e04f33c14474631c22d0be0d3 (diff) | |
| download | linux-stable-b6e42191c0abf82f78ce35e2b681aa3a563722bf.tar.gz linux-stable-b6e42191c0abf82f78ce35e2b681aa3a563722bf.tar.bz2 linux-stable-b6e42191c0abf82f78ce35e2b681aa3a563722bf.zip | |
arm64: dts: qcom: sdm845-oneplus-common: guard rmtfs-mem
[ Upstream commit e60fd5ac1f6851be5b2c042b39584bfcf8a66f57 ]
The rmtfs_mem region is a weird one, downstream allocates it
dynamically, and supports a "qcom,guard-memory" property which when set
will reserve 4k above and below the rmtfs memory.
A common from qcom 4.9 kernel msm_sharedmem driver:
/*
* If guard_memory is set, then the shared memory region
* will be guarded by SZ_4K at the start and at the end.
* This is needed to overcome the XPU limitation on few
* MSM HW, so as to make this memory not contiguous with
* other allocations that may possibly happen from other
* clients in the system.
*/
When the kernel tries to touch memory that is too close the
rmtfs region it may cause an XPU violation. Such is the case on the
OnePlus 6 where random crashes would occur usually after boot.
Reserve 4k above and below the rmtfs_mem to avoid hitting these XPU
Violations.
This doesn't entirely solve the random crashes on the OnePlus 6/6T but
it does seem to prevent the ones which happen shortly after modem
bringup.
Fixes: 288ef8a42612 ("arm64: dts: sdm845: add oneplus6/6t devices")
Signed-off-by: Caleb Connolly <caleb@connolly.tech>
Link: https://lore.kernel.org/r/20210502014146.85642-4-caleb@connolly.tech
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi index 8f617f7b6d34..f712771df0c7 100644 --- a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi +++ b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi @@ -46,6 +46,14 @@ }; reserved-memory { + /* The rmtfs_mem needs to be guarded due to "XPU limitations" + * it is otherwise possible for an allocation adjacent to the + * rmtfs_mem region to trigger an XPU violation, causing a crash. + */ + rmtfs_lower_guard: memory@f5b00000 { + no-map; + reg = <0 0xf5b00000 0 0x1000>; + }; /* * The rmtfs memory region in downstream is 'dynamically allocated' * but given the same address every time. Hard code it as this address is @@ -59,6 +67,10 @@ qcom,client-id = <1>; qcom,vmid = <15>; }; + rmtfs_upper_guard: memory@f5d01000 { + no-map; + reg = <0 0xf5d01000 0 0x2000>; + }; /* * It seems like reserving the old rmtfs_mem region is also needed to prevent |