[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <c71e1543-6957-4aa6-98fa-160b3bd29c78@linaro.org>
Date: Thu, 20 Jun 2024 15:49:24 +0200
From: Caleb Connolly <caleb.connolly@...aro.org>
To: Tengfei Fan <quic_tengfan@...cinc.com>, andersson@...nel.org,
konrad.dybcio@...aro.org, robh@...nel.org, krzk+dt@...nel.org,
conor+dt@...nel.org, dmitry.baryshkov@...aro.org
Cc: linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, kernel@...cinc.com
Subject: Re: [PATCH v10 2/4] arm64: dts: qcom: qcs8550: introduce qcs8550 dtsi
On 20/06/2024 15:40, Tengfei Fan wrote:
>
>
> On 6/18/2024 6:06 PM, Caleb Connolly wrote:
>> HI Tengfei,
>>
>> On 18/06/2024 09:22, Tengfei Fan wrote:
>>> QCS8550 is derived from SM8550. The difference between SM8550 and
>>> QCS8550 is QCS8550 doesn't have modem RF system. QCS8550 is mainly used
>>> in IoT products.
>>> QCS8550 firmware has different memory map compared to SM8550.
>>> The memory map will be runtime added through bootloader.
>>> There are 3 types of reserved memory regions here:
>>> 1. Firmware related regions which aren't shared with kernel.
>>> The device tree source in kernel doesn't need to have node to
>>> indicate
>>> the firmware related reserved information. Bootloader converys the
>>> information by updating devicetree at runtime.
>>> This will be described as: UEFI saves the physical address of the
>>> UEFI System Table to dts file's chosen node. Kernel read this table and
>>> add reserved memory regions to efi config table. Current reserved memory
>>> region may have reserved region which was not yet used, release note of
>>> the firmware have such kind of information.
>>> 2. Firmware related memory regions which are shared with Kernel
>>> The device tree source in the kernel needs to include nodes that
>>> indicate fimware-related shared information. A label name is suggested
>>> because this type of shared information needs to be referenced by
>>> specific drivers for handling purposes.
>>> Unlike previous platforms, QCS8550 boots using EFI and describes
>>> most reserved regions in the ESRT memory map. As a result, reserved
>>> memory regions which aren't relevant to the kernel(like the hypervisor
>>> region) don't need to be described in DT.
>>> 3. Remoteproc regions.
>>> Remoteproc regions will be reserved and then assigned to subsystem
>>> firmware later.
>>> Here is a reserved memory map for this platform:
>>> 0x80000000 +-------------------+
>>> | |
>>> | Firmware Related |
>>> | |
>>> 0x8a800000 +-------------------+
>>> | |
>>> | Remoteproc Region |
>>> | |
>>> 0xa7000000 +-------------------+
>>> | |
>>> | Kernel Available |
>>> | |
>>> 0xd4d00000 +-------------------+
>>> | |
>>> | Firmware Related |
>>> | |
>>> 0x100000000 +-------------------+
>>>
>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
>>> Signed-off-by: Tengfei Fan <quic_tengfan@...cinc.com>
>>> ---
>>> arch/arm64/boot/dts/qcom/qcs8550.dtsi | 162 ++++++++++++++++++++++++++
>>> 1 file changed, 162 insertions(+)
>>> create mode 100644 arch/arm64/boot/dts/qcom/qcs8550.dtsi
>>>
>>> diff --git a/arch/arm64/boot/dts/qcom/qcs8550.dtsi
>>> b/arch/arm64/boot/dts/qcom/qcs8550.dtsi
>>> new file mode 100644
>>> index 000000000000..07b314834d88
>>> --- /dev/null
>>> +++ b/arch/arm64/boot/dts/qcom/qcs8550.dtsi
>>> @@ -0,0 +1,162 @@
>>> +// SPDX-License-Identifier: BSD-3-Clause
>>> +/*
>>> + * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All
>>> rights reserved.
>>> + */
>>> +
>>> +#include "sm8550.dtsi"
>>> +
>>> +/delete-node/ &reserved_memory;
>>> +
>>> +/ {
>>> + reserved_memory: reserved-memory {
>>> + #address-cells = <2>;
>>> + #size-cells = <2>;
>>> + ranges;
>>> +
>>> +
>>> + /* These are 3 types of reserved memory regions here:
>>> + * 1. Firmware related regions which aren't shared with kernel.
>>> + * The device tree source in kernel doesn't need to have
>>> node to
>>> + * indicate the firmware related reserved information.
>>> Bootloader
>>> + * conveys the information by updating devicetree at runtime.
>>> + * This will be described as: UEFI saves the physical
>>> address of
>>> + * the UEFI System Table to dts file's chosen node. Kernel
>>> read this
>>> + * table and add reserved memory regions to efi config
>>> table. Current
>>> + * reserved memory region may have reserved region which was
>>> not yet
>>> + * used, release note of the firmware have such kind of
>>> information.
>>
>> This is a lot of implementation detail about UEFI, I'd imagine that
>> anyone curious can go read the relevant docs instead. It's a lot of
>> words just to say "Firmware regions which the kernel doesn't need to
>> know about which are not included in the EFI provided memory map."
>
>
> The following update will be applied to this point:
>
> 1. Firmware related regions which aren't shared with kernel.
> Firmware regions which the kernel doesn't need to know about which
> are not included in the EFI provided memory map.
>
>
>>> + * 2. Firmware related memory regions which are shared with
>>> Kernel
>>> + * The device tree source in the kernel needs to include
>>> nodes
>>> + * that indicate fimware-related shared information. A label
>>> name
>>> + * is suggested because this type of shared information
>>> needs to
>>> + * be referenced by specific drivers for handling purposes.
>>
>> "Firmware regions the kernel DOES need to know about, which are
>> described in the reserved-memory node".
>
> The following update will be applied to this point:
>
> 2. Firmware related memory regions which are shared with Kernel
>
> Firmware regions the kernel does need to know about, which are described
> in the reserved-memory node.
>
>>> + * Unlike previous platforms, QCS8550 boots using EFI
>>> and describes
>>> + * most reserved regions in the ESRT memory map. As a
>>> result, reserved
>>> + * memory regions which aren't relevant to the kernel(like
>>> the hypervisor
>>> + ( region) don't need to be described in DT.
>>
>> These would fall under (1) "firmware the kernel doesn't need to know
>> about"
>
> This will be removed from its current position.
>
>>> + * 3. Remoteproc regions.
>>> + * Remoteproc regions will be reserved and then assigned to
>>> + * subsystem firmware later.
>>
>> How do these differ from those described in (2)?
>
> This point will do the following update:
>
> 3. Remoteproc regions
>
> Remoteproc regions will be reserved and then assigned to subsystem
> firmware later.
>
> Remoteproc regions can be loaded either in a fixed form or in a
> relocatable form, depending on the platform.
>
>>
>> I think this comment is trying to describe too much at once. You're
>> trying to describe what the different types of reserved memory are,
>> how the kernel learns about them, and how this differs from previous
>> platforms all at once. I think you should tackle these points separately:
>>
>> First describe the types of reserved memory and how the kernel learns
>> about them (my suggestions above). Then describe the differences with
>> previous platforms (like the hypervisor example)
>>
>> Thanks and regards,
>
> Your previous suggestion will be incorporated here as follows:
>
> Unlike previous platforms, QCS8550 boots using EFI and describes most
> reserved regions in the ESRT memory map. As a result, reserved memory
> regions which aren't relevant to the kernel(like the hypervisor region)
> don't need to be described in DT.
>
> Is it reasonable to place it here?
Thanks great, thanks a lot :)
>
> Thanks!
>
>>> + * Here is a reserved memory map for this platform:
>>> + * 0x80000000 +-------------------+
>>> + * | |
>>> + * | Firmware Related |
>>> + * | |
>>> + * 0x8a800000 +-------------------+
>>> + * | |
>>> + * | Remoteproc Region |
>>> + * | |
>>> + * 0xa7000000 +-------------------+
>>> + * | |
>>> + * | Kernel Available |
>>> + * | |
>>> + * 0xd4d00000 +-------------------+
>>> + * | |
>>> + * | Firmware Related |
>>> + * | |
>>> + * 0x100000000 +-------------------+
>>> + */
>>> +
>>> + aop_image_mem: aop-image-region@...00000 {
>>> + reg = <0x0 0x81c00000 0x0 0x60000>;
>>> + no-map;
>>> + };
>>> +
>>> + aop_cmd_db_mem: aop-cmd-db-region@...60000 {
>>> + compatible = "qcom,cmd-db";
>>> + reg = <0x0 0x81c60000 0x0 0x20000>;
>>> + no-map;
>>> + };
>>> +
>>> + aop_config_mem: aop-config-region@...80000 {
>>> + no-map;
>>> + reg = <0x0 0x81c80000 0x0 0x20000>;
>>> + };
>>> +
>>> + smem_mem: smem-region@...00000 {
>>> + compatible = "qcom,smem";
>>> + reg = <0x0 0x81d00000 0x0 0x200000>;
>>> + hwlocks = <&tcsr_mutex 3>;
>>> + no-map;
>>> + };
>>> +
>>> + adsp_mhi_mem: adsp-mhi-region@...00000 {
>>> + reg = <0x0 0x81f00000 0x0 0x20000>;
>>> + no-map;
>>> + };
>>> +
>>> + mpss_mem: mpss-region@...00000 {
>>> + reg = <0x0 0x8a800000 0x0 0x10800000>;
>>> + no-map;
>>> + };
>>> +
>>> + q6_mpss_dtb_mem: q6-mpss-dtb-region@...00000 {
>>> + reg = <0x0 0x9b000000 0x0 0x80000>;
>>> + no-map;
>>> + };
>>> +
>>> + ipa_fw_mem: ipa-fw-region@...80000 {
>>> + reg = <0x0 0x9b080000 0x0 0x10000>;
>>> + no-map;
>>> + };
>>> +
>>> + ipa_gsi_mem: ipa-gsi-region@...90000 {
>>> + reg = <0x0 0x9b090000 0x0 0xa000>;
>>> + no-map;
>>> + };
>>> +
>>> + gpu_micro_code_mem: gpu-micro-code-region@...9a000 {
>>> + reg = <0x0 0x9b09a000 0x0 0x2000>;
>>> + no-map;
>>> + };
>>> +
>>> + spss_region_mem: spss-region@...00000 {
>>> + reg = <0x0 0x9b100000 0x0 0x180000>;
>>> + no-map;
>>> + };
>>> +
>>> + spu_secure_shared_memory_mem:
>>> spu-secure-shared-memory-region@...80000 {
>>> + reg = <0x0 0x9b280000 0x0 0x80000>;
>>> + no-map;
>>> + };
>>> +
>>> + camera_mem: camera-region@...00000 {
>>> + reg = <0x0 0x9b300000 0x0 0x800000>;
>>> + no-map;
>>> + };
>>> +
>>> + video_mem: video-region@...00000 {
>>> + reg = <0x0 0x9bb00000 0x0 0x700000>;
>>> + no-map;
>>> + };
>>> +
>>> + cvp_mem: cvp-region@...00000 {
>>> + reg = <0x0 0x9c200000 0x0 0x700000>;
>>> + no-map;
>>> + };
>>> +
>>> + cdsp_mem: cdsp-region@...00000 {
>>> + reg = <0x0 0x9c900000 0x0 0x2000000>;
>>> + no-map;
>>> + };
>>> +
>>> + q6_cdsp_dtb_mem: q6-cdsp-dtb-region@...00000 {
>>> + reg = <0x0 0x9e900000 0x0 0x80000>;
>>> + no-map;
>>> + };
>>> +
>>> + q6_adsp_dtb_mem: q6-adsp-dtb-region@...80000 {
>>> + reg = <0x0 0x9e980000 0x0 0x80000>;
>>> + no-map;
>>> + };
>>> +
>>> + adspslpi_mem: adspslpi-region@...00000 {
>>> + reg = <0x0 0x9ea00000 0x0 0x4080000>;
>>> + no-map;
>>> + };
>>> +
>>> + mpss_dsm_mem: mpss_dsm_region@...00000 {
>>> + reg = <0x0 0xd4d00000 0x0 0x3300000>;
>>> + no-map;
>>> + };
>>> + };
>>> +};
>>
>
--
// Caleb (they/them)
Powered by blists - more mailing lists