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Message-ID: <5a3a7033-0cc3-40cd-8560-2dfa6939fe7f@quicinc.com>
Date: Wed, 5 Jun 2024 12:51:27 +0800
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Subject: Re: [PATCH v9 2/4] arm64: dts: qcom: qcs8550: introduce qcs8550 dtsi
To: Caleb Connolly <caleb.connolly@linaro.org>,
        Tengfei Fan
	<quic_tengfan@quicinc.com>, <andersson@kernel.org>,
        <konrad.dybcio@linaro.org>, <robh@kernel.org>, <krzk+dt@kernel.org>,
        <conor+dt@kernel.org>, <dmitry.baryshkov@linaro.org>
CC: <linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <kernel@quicinc.com>
References: <20240529100926.3166325-1-quic_tengfan@quicinc.com>
 <20240529100926.3166325-3-quic_tengfan@quicinc.com>
 <a95fed63-f48d-42c6-856b-0636a50c9dd4@linaro.org>
 <18ff1bf2-be4d-4d82-a4b3-28242b1d1d59@quicinc.com>
 <580f629d-6fae-4cf7-9137-f98b901ae29d@linaro.org>
From: "Aiqun Yu (Maria)" <quic_aiquny@quicinc.com>
Content-Language: en-US
In-Reply-To: <580f629d-6fae-4cf7-9137-f98b901ae29d@linaro.org>
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On 6/4/2024 7:20 PM, Caleb Connolly wrote:
> 
> 
> On 04/06/2024 12:51, Aiqun Yu (Maria) wrote:
>>
>>
>> On 6/3/2024 5:20 PM, Caleb Connolly wrote:
>>> Hi Tengfei,
>>>
>>> On 29/05/2024 12:09, 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.
>>>
>>> Are you describing some particular quirk of the platform here, or just
>>> standard UEFI booting?
>>
>> It's standard UEFI booting efi config table.
> 
> Ok, thanks for confirming.
>>>
>>> When booting with UEFI, the memory map is passed via the ESRT, so having
>>> memory that the kernel shouldn't use it pretty simple (and typical).
> 
> woo! \o/
>>
>> yes. It is very simple. And the bootloader firmware config the
>> "reserved" region in the efi config table from the uefi firmware.
>>>> 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.
>>>
>>> Again, is there something non-standard here? If not I would suggest
>>> dropping these detail comments as they might be misleading.
>>
>> Detailed comments is used to describe current device tree reserved
>> memory regions.
>>
>> Current patch is not creating a new mechanism to have memory map
>> described. But it is the first time qcom device trees use this design,
>> and have a simplified(also more compatible) device tree reserved memory
>> region(memory map). Previously, bootloader(apps bootloader) only pass
>> the whole physical memory base and size, and use reserved memory nodes
>> only in device tree(which is also a standard choose).
>>
>> So that's why it is detailed comments for other qcom platform reference.
> 
> Doesn't the rb3gen2 also use this design?

Checked current qcs6490-rb3gen2.dts still use the device tree to have
all the reserved regions, even have detailed regions like "Firmware
related regions which aren't shared with kernel."

Not sure current qcs6490 firmware efi config table looks like, if it
have all the reserved region marked carefully on efi config table, then
device tree don't need to mention the reserved regions which is not
shared to kernel.

The qcom memory map in device tree discussion was happened after qcs6490
rb3gen2 time frame. efi config table is standard. But we still need to
check what's the final config placed in the table for different
platforms. I will suggest to have current qcs8550 as an example to
config the current memory non-kernel needed to know region inside the
efi config table in bootloader, and have kernel shared reserved region
marked in the device tree.

>>
>>>
>>> Thanks and regards,
>>>> 3. Remoteproc regions.
>>>>       Remoteproc regions will be reserved and then assigned to
>>>> subsystem
>>>> firmware later.
>>>> Here is a reserved memory map for this platform:
>>>> 0x100000000 +-------------------+
>>>>               |                   |
>>>>               | Firmware Related  |
>>>>               |                   |
>>>>    0xd4d00000 +-------------------+
>>>>               |                   |
>>>>               | Kernel Available  |
>>>>               |                   |
>>>>    0xa7000000 +-------------------+
>>>>               |                   |
>>>>               | Remoteproc Region |
>>>>               |                   |
>>>>    0x8a800000 +-------------------+
>>>>               |                   |
>>>>               | Firmware Related  |
>>>>               |                   |
>>>>    0x80000000 +-------------------+
>>>>
>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>> Signed-off-by: Tengfei Fan <quic_tengfan@quicinc.com>
>>>> ---
>>>>    arch/arm64/boot/dts/qcom/qcs8550.dtsi | 167
>>>> ++++++++++++++++++++++++++
>>>>    1 file changed, 167 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..685668c6ad14
>>>> --- /dev/null
>>>> +++ b/arch/arm64/boot/dts/qcom/qcs8550.dtsi
>>>> @@ -0,0 +1,167 @@
>>>> +// 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.
>>>> +         * 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.
>>>> +         * 3. Remoteproc regions.
>>>> +         *     Remoteproc regions will be reserved and then
>>>> assigned to
>>>> +         * subsystem firmware later.
>>>> +         * Here is a reserved memory map for this platform:
>>>> +         * 0x100000000 +-------------------+
>>>> +         *             |                   |
>>>> +         *             | Firmware Related  |
>>>> +         *             |                   |
>>>> +         *  0xd4d00000 +-------------------+
>>>> +         *             |                   |
>>>> +         *             | Kernel Available  |
>>>> +         *             |                   |
>>>> +         *  0xa7000000 +-------------------+
>>>> +         *             |                   |
>>>> +         *             | Remoteproc Region |
>>>> +         *             |                   |
>>>> +         *  0x8a800000 +-------------------+
>>>> +         *             |                   |
>>>> +         *             | Firmware Related  |
>>>> +         *             |                   |
>>>> +         *  0x80000000 +-------------------+
>>>> +         */
>>>> +
>>>> +        /*
>>>> +         * Firmware related regions, bootloader will possible reserve
>>>> parts of
>>>> +         * region from 0x80000000..0x8a800000.
>>>> +         */
>>>> +        aop_image_mem: aop-image-region@81c00000 {
>>>> +            reg = <0x0 0x81c00000 0x0 0x60000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        aop_cmd_db_mem: aop-cmd-db-region@81c60000 {
>>>> +            compatible = "qcom,cmd-db";
>>>> +            reg = <0x0 0x81c60000 0x0 0x20000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        aop_config_mem: aop-config-region@81c80000 {
>>>> +            no-map;
>>>> +            reg = <0x0 0x81c80000 0x0 0x20000>;
>>>> +        };
>>>> +
>>>> +        smem_mem: smem-region@81d00000 {
>>>> +            compatible = "qcom,smem";
>>>> +            reg = <0x0 0x81d00000 0x0 0x200000>;
>>>> +            hwlocks = <&tcsr_mutex 3>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        adsp_mhi_mem: adsp-mhi-region@81f00000 {
>>>> +            reg = <0x0 0x81f00000 0x0 0x20000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        /* PIL region */
>>>> +        mpss_mem: mpss-region@8a800000 {
>>>> +            reg = <0x0 0x8a800000 0x0 0x10800000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        q6_mpss_dtb_mem: q6-mpss-dtb-region@9b000000 {
>>>> +            reg = <0x0 0x9b000000 0x0 0x80000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        ipa_fw_mem: ipa-fw-region@9b080000 {
>>>> +            reg = <0x0 0x9b080000 0x0 0x10000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        ipa_gsi_mem: ipa-gsi-region@9b090000 {
>>>> +            reg = <0x0 0x9b090000 0x0 0xa000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        gpu_micro_code_mem: gpu-micro-code-region@9b09a000 {
>>>> +            reg = <0x0 0x9b09a000 0x0 0x2000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        spss_region_mem: spss-region@9b100000 {
>>>> +            reg = <0x0 0x9b100000 0x0 0x180000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        spu_secure_shared_memory_mem:
>>>> spu-secure-shared-memory-region@9b280000 {
>>>> +            reg = <0x0 0x9b280000 0x0 0x80000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        camera_mem: camera-region@9b300000 {
>>>> +            reg = <0x0 0x9b300000 0x0 0x800000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        video_mem: video-region@9bb00000 {
>>>> +            reg = <0x0 0x9bb00000 0x0 0x700000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        cvp_mem: cvp-region@9c200000 {
>>>> +            reg = <0x0 0x9c200000 0x0 0x700000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        cdsp_mem: cdsp-region@9c900000 {
>>>> +            reg = <0x0 0x9c900000 0x0 0x2000000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        q6_cdsp_dtb_mem: q6-cdsp-dtb-region@9e900000 {
>>>> +            reg = <0x0 0x9e900000 0x0 0x80000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        q6_adsp_dtb_mem: q6-adsp-dtb-region@9e980000 {
>>>> +            reg = <0x0 0x9e980000 0x0 0x80000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        adspslpi_mem: adspslpi-region@9ea00000 {
>>>> +            reg = <0x0 0x9ea00000 0x0 0x4080000>;
>>>> +            no-map;
>>>> +        };
>>>> +
>>>> +        /*
>>>> +         * Firmware related regions, bootloader will possible reserve
>>>> parts of
>>>> +         * region from 0xd8000000..0x100000000.
>>>> +         */
>>>> +        mpss_dsm_mem: mpss_dsm_region@d4d00000 {
>>>> +            reg = <0x0 0xd4d00000 0x0 0x3300000>;
>>>> +            no-map;
>>>> +        };
>>>> +    };
>>>> +};
>>>
>>
> 

-- 
Thx and BRs,
Aiqun(Maria) Yu