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Message-Id: <20180723142503eucas1p24f8d96f8c4ec25dbdb80e27e2f1444c2~EBZNDRgPc2952429524eucas1p2C@eucas1p2.samsung.com>
Date: Mon, 23 Jul 2018 16:24:53 +0200
From: Marek Szyprowski <m.szyprowski@...sung.com>
To: Krzysztof Kozlowski <krzk@...nel.org>,
Kukjin Kim <kgene@...nel.org>,
Russell King <linux@...linux.org.uk>,
Pankaj Dubey <pankaj.dubey@...sung.com>,
linux-arm-kernel@...ts.infradead.org,
linux-samsung-soc@...r.kernel.org, linux-doc@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
Chanwoo Choi <cw00.choi@...sung.com>,
Alim Akhtar <alim.akhtar@...sung.com>
Subject: Re: [RFC] ARM: exynos: Fix imprecise abort during Exynos5422
suspend to RAM
Hi Krzysztof,
On 2018-07-18 21:59, Krzysztof Kozlowski wrote:
> Suspend to RAM on Odroid XU3/XU4/HC1 family (Exynos5422) causes
> imprecise abort:
>
> PM: Syncing filesystems ... done.
> Freezing user space processes ... (elapsed 0.003 seconds) done.
> OOM killer disabled.
> Freezing remaining freezable tasks ... (elapsed 0.003 seconds) done.
> wake enabled for irq 139
> Disabling non-boot CPUs ...
> IRQ51 no longer affine to CPU1
> IRQ52 no longer affine to CPU2
> IRQ53 no longer affine to CPU3
> IRQ54 no longer affine to CPU4
> IRQ55 no longer affine to CPU5
> IRQ56 no longer affine to CPU6
> cpu cpu4: Dropping the link to regulator.40
> IRQ57 no longer affine to CPU7
> Unhandled fault: external abort on non-linefetch (0x1008) at 0xf081a028
> Internal error: : 1008 [#1] PREEMPT SMP ARM
>
> with last call trace in exynos_suspend_enter().
>
> The abort is caused by writing to register in secure part of sysram.
> All Exynos5422 devices, including Hardkernel Odroid boards, boot with
> TrustZone in non-secure mode therefore they should access non-secure
> sysram.
>
> Signed-off-by: Krzysztof Kozlowski <krzk@...nel.org>
>
> ---
>
> Comments, whether my understanding is correct, are welcomed!
The decision, weather to use secure or non-secure sysram depends on the
enabled TrustZone interface IMHO. Exynos5420 PeachPIT and Exynos5800 PeachPI
don't use TrustZone and don't have 'firmware' node in dts, thus they should
keep existing code.
> ---
> Documentation/arm/Samsung/Bootloader-interface.txt | 1 +
> arch/arm/mach-exynos/suspend.c | 6 +++---
> 2 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/arm/Samsung/Bootloader-interface.txt b/Documentation/arm/Samsung/Bootloader-interface.txt
> index ed494ac0beb2..d17ed518a7ea 100644
> --- a/Documentation/arm/Samsung/Bootloader-interface.txt
> +++ b/Documentation/arm/Samsung/Bootloader-interface.txt
> @@ -26,6 +26,7 @@ Offset Value Purpose
> 0x20 0xfcba0d10 (Magic cookie) AFTR
> 0x24 exynos_cpu_resume_ns AFTR
> 0x28 + 4*cpu 0x8 (Magic cookie, Exynos3250) AFTR
> +0x28 0x0 or last value during resume (Exynos542x) System suspend
>
>
> 2. Secure mode
> diff --git a/arch/arm/mach-exynos/suspend.c b/arch/arm/mach-exynos/suspend.c
> index d3db306a5a70..0ec52f442b97 100644
> --- a/arch/arm/mach-exynos/suspend.c
> +++ b/arch/arm/mach-exynos/suspend.c
> @@ -256,7 +256,7 @@ static int exynos5420_cpu_suspend(unsigned long arg)
> unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
> unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
>
> - writel_relaxed(0x0, sysram_base_addr + EXYNOS5420_CPU_STATE);
> + writel_relaxed(0x0, sysram_ns_base_addr + EXYNOS5420_CPU_STATE);
>
> if (IS_ENABLED(CONFIG_EXYNOS5420_MCPM)) {
> mcpm_set_entry_vector(cpu, cluster, exynos_cpu_resume);
> @@ -328,7 +328,7 @@ static void exynos5420_pm_prepare(void)
> * needs to restore it back in case, the primary cpu fails to
> * suspend for any reason.
> */
> - exynos5420_cpu_state = readl_relaxed(sysram_base_addr +
> + exynos5420_cpu_state = readl_relaxed(sysram_ns_base_addr +
> EXYNOS5420_CPU_STATE);
>
> exynos_pm_enter_sleep_mode();
> @@ -448,7 +448,7 @@ static void exynos5420_pm_resume(void)
>
> /* Restore the sysram cpu state register */
> writel_relaxed(exynos5420_cpu_state,
> - sysram_base_addr + EXYNOS5420_CPU_STATE);
> + sysram_ns_base_addr + EXYNOS5420_CPU_STATE);
>
> pmu_raw_writel(EXYNOS5420_USE_STANDBY_WFI_ALL,
> S5P_CENTRAL_SEQ_OPTION);
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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