October 20, 2025 at 9:12 PM, "David Heidelberg via B4 Relay" <[email protected] mailto:[email protected]?to=%22David%20Heidelberg%20via%20B4%20Relay%22%20%3Cdevnull%2Bdavid.ixit.cz%40kernel.org%3E > wrote:
> > From: David Heidelberg <[email protected]> > > Use qcom,use-guard-pages property instead of polluting device-tree with > lower and upper rmtfs guard nodes. > > No functional change intended. > > cosmetic: set name the node rmtfs-region. > > Signed-off-by: David Heidelberg <[email protected]> > --- > Tested on OnePlus 6T. > --- > arch/arm64/boot/dts/qcom/sdm845-lg-common.dtsi | 17 +++-------------- > arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi | 18 +++--------------- > 2 files changed, 6 insertions(+), 29 deletions(-) > > diff --git a/arch/arm64/boot/dts/qcom/sdm845-lg-common.dtsi > b/arch/arm64/boot/dts/qcom/sdm845-lg-common.dtsi > index 99dafc6716e76..83b98bad19dd2 100644 > --- a/arch/arm64/boot/dts/qcom/sdm845-lg-common.dtsi > +++ b/arch/arm64/boot/dts/qcom/sdm845-lg-common.dtsi > @@ -99,26 +99,15 @@ memory@9d400000 { > no-map; > }; > > - /* rmtfs lower guard */ > - memory@f0800000 { > - reg = <0 0xf0800000 0 0x1000>; > - no-map; > - }; > - > - rmtfs_mem: memory@f0801000 { > + rmtfs_mem: rmtfs-region@f0800000 { > compatible = "qcom,rmtfs-mem"; > - reg = <0 0xf0801000 0 0x200000>; > + reg = <0 0xf0800000 0 0x202000>; > + qcom,use-guard-pages; > no-map; > > qcom,client-id = <1>; > qcom,vmid = <QCOM_SCM_VMID_MSS_MSA>; > }; > - > - /* rmtfs upper guard */ > - memory@f0a01000 { > - reg = <0 0xf0a01000 0 0x1000>; > - no-map; > - }; > }; > > gpio-keys { > diff --git a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi > b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi > index dcfffb271fcf3..61d63003fa371 100644 > --- a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi > +++ b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi > @@ -75,32 +75,20 @@ key-vol-up { > }; > > 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: rmtfs-lower-guard@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 > * where the modem firmware expects it to be. > */ > - rmtfs_mem: rmtfs-mem@f5b01000 { > + rmtfs_mem: rmtfs-region@f5b00000 { > compatible = "qcom,rmtfs-mem"; > - reg = <0 0xf5b01000 0 0x200000>; > + reg = <0 0xf5b00000 0 0x202000>; > + qcom,use-guard-pages; > no-map; > > qcom,client-id = <1>; > qcom,vmid = <QCOM_SCM_VMID_MSS_MSA>; > }; > - rmtfs_upper_guard: rmtfs-upper-guard@f5d01000 { > - no-map; > - reg = <0 0xf5d01000 0 0x1000>; > - }; > > /* > * It seems like reserving the old rmtfs_mem region is also needed to prevent > > --- > base-commit: 606da5bb165594c052ee11de79bf05bc38bc1aa6 > change-id: 20251020-sdm845-use-guard-pages-9c2b2fa0b71e > > Best regards, > -- > David Heidelberg <[email protected]> > I tried something similar before and didn't have much luck with it. I'll test your patch when I have time.
