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Message-ID: <97cf35b5-1286-91a0-c0d4-df7fe8a983e6@nvidia.com>
Date:   Tue, 24 May 2022 18:50:37 +0100
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Subject: Re: [PATCH 4.9 00/25] 4.9.316-rc1 review
Content-Language: en-US
To:     Florian Fainelli <f.fainelli@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Ard Biesheuvel <ardb@kernel.org>, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org, torvalds@linux-foundation.org,
        akpm@linux-foundation.org, linux@roeck-us.net, shuah@kernel.org,
        patches@kernelci.org, lkft-triage@lists.linaro.org, pavel@denx.de,
        sudipm.mukherjee@gmail.com, slade@sladewatkins.com,
        "linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>
References: <20220523165743.398280407@linuxfoundation.org>
 <6f4034a5-f692-8a64-a09d-8bfe49767b78@nvidia.com>
 <YozK4DvamHBJ1qdX@kroah.com>
 <fbeb9833-4166-1919-e6ab-9ac7625a21d6@nvidia.com>
 <Yoz0Xv59MrUwFkMT@kroah.com> <883fc4cf-dce0-a433-5cf7-7de68be17ffb@gmail.com>
From:   Jon Hunter <jonathanh@nvidia.com>
In-Reply-To: <883fc4cf-dce0-a433-5cf7-7de68be17ffb@gmail.com>
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On 24/05/2022 17:30, Florian Fainelli wrote:

...

> Jonathan any chance this is Tegra specific? Our ARCH_BRCMSTB SoCs which 
> use a Brahma-B15 which uses nearly the same ca15 processor functions 
> defined in arch/arm/mm/proc-v7.S reports the following *before* changes:
> 
> [    0.001641] CPU: Testing write buffer coherency: ok
> [    0.001685] CPU0: Spectre v2: using ICIALLU workaround
> [    0.001703] ftrace: allocating 30541 entries in 120 pages
> [    0.044600] CPU0: update cpu_capacity 1024
> [    0.044633] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
> [    0.044662] Setting up static identity map for 0x200000 - 0x200060
> [    0.047410] brcmstb: biuctrl: MCP: Write pairing already disabled
> [    0.048974] CPU1: update cpu_capacity 1024
> [    0.048978] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001
> [    0.048981] CPU1: Spectre v2: using ICIALLU workaround
> [    0.050234] CPU2: update cpu_capacity 1024
> [    0.050238] CPU2: thread -1, cpu 2, socket 0, mpidr 80000002
> [    0.050241] CPU2: Spectre v2: using ICIALLU workaround
> [    0.051437] CPU3: update cpu_capacity 1024
> [    0.051441] CPU3: thread -1, cpu 3, socket 0, mpidr 80000003
> [    0.051444] CPU3: Spectre v2: using ICIALLU workaround
> [    0.051532] Brought up 4 CPUs
> 
> and this *after* merging 4.9.316-rc1:
> 
> [    0.001626] CPU: Testing write buffer coherency: ok
> [    0.001670] CPU0: Spectre v2: using ICIALLU workaround
> [    0.001689] CPU0: Spectre BHB: using loop workaround
> [    0.001705] ftrace: allocating 30542 entries in 120 pages
> [    0.043752] CPU0: update cpu_capacity 1024
> [    0.043784] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
> [    0.043813] Setting up static identity map for 0x200000 - 0x200060
> [    0.046547] brcmstb: biuctrl: MCP: Write pairing already disabled
> [    0.048121] CPU1: update cpu_capacity 1024
> [    0.048124] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001
> [    0.048129] CPU1: Spectre v2: using ICIALLU workaround
> [    0.048165] CPU1: Spectre BHB: using loop workaround
> [    0.049398] CPU2: update cpu_capacity 1024
> [    0.049402] CPU2: thread -1, cpu 2, socket 0, mpidr 80000002
> [    0.049405] CPU2: Spectre v2: using ICIALLU workaround
> [    0.049440] CPU2: Spectre BHB: using loop workaround
> [    0.050613] CPU3: update cpu_capacity 1024
> [    0.050617] CPU3: thread -1, cpu 3, socket 0, mpidr 80000003
> [    0.050619] CPU3: Spectre v2: using ICIALLU workaround
> [    0.050653] CPU3: Spectre BHB: using loop workaround
> [    0.050722] Brought up 4 CPUs
> [    0.050738] SMP: Total of 4 processors activated (216.00 BogoMIPS).
> [    0.050753] CPU: All CPU(s) started in HYP mode.


Does your platform support CPU idle? I see this being triggered
during CPU idle transitions ...

[    4.415167] CPU0: Spectre BHB: using loop workaround
[    4.417621] [<c01109a0>] (unwind_backtrace) from [<c010b7ac>] (show_stack+0x10/0x14)
[    4.430291] [<c010b7ac>] (show_stack) from [<c09c2b38>] (dump_stack+0xc0/0xd4)
[    4.437512] [<c09c2b38>] (dump_stack) from [<c011a6c8>] (cpu_v7_spectre_bhb_init+0xd8/0x190)
[    4.445943] [<c011a6c8>] (cpu_v7_spectre_bhb_init) from [<c010dee8>] (cpu_suspend+0xac/0xc8)
[    4.454377] [<c010dee8>] (cpu_suspend) from [<c011e7e4>] (tegra114_idle_power_down+0x74/0x78)
[    4.462898] [<c011e7e4>] (tegra114_idle_power_down) from [<c06d3b44>] (cpuidle_enter_state+0x130/0x524)
[    4.472286] [<c06d3b44>] (cpuidle_enter_state) from [<c0164a30>] (do_idle+0x1b0/0x200)
[    4.480199] [<c0164a30>] (do_idle) from [<c0164d28>] (cpu_startup_entry+0x18/0x1c)
[    4.487762] [<c0164d28>] (cpu_startup_entry) from [<801018cc>] (0x801018cc)

Jon

-- 
nvpublic