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From: Damien Le Moal <Damien.LeMoal@wdc.com>
To: Sean Anderson <seanga2@gmail.com>, Anup Patel <anup@brainfault.org>
Cc: "linux-riscv@lists.infradead.org"
	<linux-riscv@lists.infradead.org>,
	Anup Patel <Anup.Patel@wdc.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>
Subject: Re: [PATCH 00/10] Kendryte k210 SoC boards support
Date: Mon, 2 Mar 2020 05:11:55 +0000
Message-ID: <BYAPR04MB58168C0C89145F91AE8E964FE7E70@BYAPR04MB5816.namprd04.prod.outlook.com> (raw)
In-Reply-To: <b8aa9598-a34d-fa8c-01e7-3b7fc06d635a@gmail.com>

On 2020/03/02 14:02, Sean Anderson wrote:
> On 3/1/20 11:48 PM, Damien Le Moal wrote:
>> On 2020/03/02 13:17, Anup Patel wrote:
>>> On Mon, Mar 2, 2020 at 9:23 AM Sean Anderson <seanga2@gmail.com> wrote:
>>>>
>>>> On 3/1/20 10:01 PM, Damien Le Moal wrote:
>>>>> On 2020/02/29 5:32, Sean Anderson wrote:
>>>>>> Hi,
>>>>>>
>>>>>> When booting from U-Boot I get an OOM. Perhaps this is related to the
>>>>>> second cpu not coming up?
>>>>>
>>>>> Unlikely. It looks like your user space needs 2MB per shell (order 9
>>>>> allocation). Since you have only 5.5MB free, that may explain the allocation
>>>>> failure (if init is forking another shell especially).
>>>>
>>>> This should be before init comes up; when comparing this to your syslog
>>>> output there are several more messages before init gets started.
>>>>
>>>>> For the second core not coming up, an IPI needs to be sent to the non-boot core
>>>>> to wake it up. A Kendryte thing. U-boot should probably do it before jumping to
>>>>> the kernel. I thought I had that in the kernel though. Will check again.
>>>>
>>>> I think it's a RISC-V thing. I should have U-Boot set up to start linux
>>>> on both cores, but something may be misconfigured on that end.
>>>
>>> You have to booti or bootm on U-Boot M-mode to make all CPUs jump to
>>> Linux NOMMU.
>>>
>>> Based on you log, it seems the second CPU is still spinning in U-Boot
>>> M-mode and when Linux NOMMU tries to touch memory where second
>>> CPU is spinning everything gets corrupted.
>>
>> Yes, I understand. But in the case of the K210, that last 2MB segment is really
>> special as by default it is not usable as regular SRAM. I think it may be better
>> to reflect that in the device tree. The K210 soc_early_init() call back can
>> probe for that special entry too to see if it has to be turned on for use as
>> regular memory or not (i.e. if a kpu driver will use it).
>>
>> Since booting Linux with 6MB of memory will be even more challenging than with
>> 8, I agree that we may never see the case of a kpu driver being used. But I
>> personally like making that special case clear in the device tree. No strong
>> objection to your simplification though. So if you really object, I will go with it.
> 
> The way I have it set up is like this
> 
> 
> 	sram0: memory@80000000 {
> 		device_type = "memory";
> 		compatible = "kendryte,k210-sram";
> 		reg = <0x80000000 0x400000>;
> 		clocks = <&sysclk K210_CLK_SRAM0>;
> 	};
> 
> 	sram1: memory@80400000 {
> 		device_type = "memory";
> 		reg = <0x80400000 0x200000>;
> 		compatible = "kendryte,k210-sram";
> 		clocks = <&sysclk K210_CLK_SRAM1>;
> 	};
> 
> 	airam: memory@80600000 {
> 		device_type = "memory";
> 		reg = <0x80600000 0x200000>;
> 		compatible = "kendryte,k210-airam";
> 		clocks = <&sysclk K210_CLK_AI>;
> 	};
> 
> 	reserved-memory {
> 		#address-cells = <1>;
> 		#size-cells = <1>;
> 		ranges;
> 
> 		ai_reserved: ai@80600000 {
> 			reg = <0x80600000 0x200000>;
> 			reusable;
> 		};
> 	};>
> And then the kpu has 'memory-region = <&ai_reserved>;'. This way the
> memory is documented as being used by the kpu, but also free when the
> KPU is not in use.

I tried to use your syntax above initially but (if I remember correctly), the
"reserved-memory" entry prevents the initial ram setup to add the kpu segment,
so you can never see it as regular memory. So I dropped that and that memory is
usable with the v1 of the series I sent. The soc_early_init() enables it by
turning on pll1.

> 
> However, I have been unable to get the AI ram to work; any time I
> access it the CPU hangs. I have tried all combinations of
> 
> * Enabling/disabling the AI clock
> * Enabling/disabling PLL1 (the AI clock's parent) but not the AI clock
> * Asserting/deasserting the KPU reset
> 
> but I have not been able to get it working. Have you had any luck?

See k210_soc_early_init() in drivers/soc/kendryte/k210-sysctl.c. That works.
You did already point out the clock initialization that is not enough and
working only because most of the values are the default. Maybe U-boot is
changing some of them resulting in the worng clock frequencies being set in the
kernel ?

> 
> There's also the issue that all DMAs should happen from the uncached
> memory area, but I think there is some existing infrastructure to
> "translate" IO addresses, so this doesn't need to be added to the device
> tree.
> 
> --Sean
> 
> 


-- 
Damien Le Moal
Western Digital Research


  reply index

Thread overview: 89+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-12 10:34 Damien Le Moal
2020-02-12 10:34 ` [PATCH 01/10] riscv: Fix gitignore Damien Le Moal
2020-02-20  0:15   ` Palmer Dabbelt
2020-02-12 10:34 ` [PATCH 02/10] riscv: Force flat memory model with no-mmu Damien Le Moal
2020-02-14 20:18   ` Sean Anderson
2020-02-15  2:15     ` Damien Le Moal
2020-02-15  2:26       ` Sean Anderson
2020-02-15  2:40         ` Damien Le Moal
2020-03-02  3:48   ` Anup Patel
2020-03-04 18:38   ` Palmer Dabbelt
2020-02-12 10:34 ` [PATCH 03/10] riscv: Unaligned load/store handling for M_MODE Damien Le Moal
2020-03-02  3:57   ` Anup Patel
2020-03-04 19:28   ` Palmer Dabbelt
2020-02-12 10:34 ` [PATCH 04/10] riscv: Add BUILTIN_DTB support Damien Le Moal
2020-03-02  3:58   ` Anup Patel
2020-03-04 19:28   ` Palmer Dabbelt
2020-03-05  4:58     ` Anup Patel
2020-03-05  5:14       ` Damien Le Moal
2020-03-05  5:37         ` Anup Patel
2020-03-05  6:13           ` Damien Le Moal
2020-03-08  6:10             ` Anup Patel
2020-03-05  8:18         ` Atish Patra
2020-03-07  0:02           ` Sean Anderson
2020-03-07  1:51             ` Atish Patra
2020-03-07  2:08               ` Sean Anderson
2020-03-06 23:56         ` Sean Anderson
2020-02-12 10:34 ` [PATCH 05/10] riscv: Add SOC early init support Damien Le Moal
2020-03-04 19:28   ` Palmer Dabbelt
2020-02-12 10:34 ` [PATCH 06/10] riscv: Add Kendryte K210 SoC support Damien Le Moal
2020-02-14 20:31   ` Sean Anderson
2020-03-04 19:38   ` Palmer Dabbelt
2020-02-12 10:34 ` [PATCH 07/10] riscv: Select required drivers for Kendryte SOC Damien Le Moal
2020-03-02  3:59   ` Anup Patel
2020-03-04 19:44   ` Palmer Dabbelt
2020-02-12 10:34 ` [PATCH 08/10] riscv: Add Kendryte K210 device tree Damien Le Moal
2020-02-14 20:51   ` Sean Anderson
2020-02-15  2:34     ` Damien Le Moal
2020-02-15  2:48       ` Sean Anderson
2020-02-15  3:00         ` Damien Le Moal
2020-02-18 14:12           ` Carlos Eduardo de Paula
2020-02-18 14:18             ` Sean Anderson
2020-02-18 14:30               ` Carlos Eduardo de Paula
2020-02-18 17:48                 ` Sean Anderson
2020-02-18 19:26                   ` Carlos Eduardo de Paula
2020-02-19  9:06                     ` Wladimir J. van der Laan
2020-02-19 22:28                       ` Sean Anderson
2020-02-20 10:48                         ` Wladimir J. van der Laan
2020-02-22 19:07                       ` Wladimir J. van der Laan
2020-04-01 17:55                         ` Drew Fustini
2020-04-02  2:24                           ` Damien Le Moal
2020-02-19  8:50                   ` Wladimir J. van der Laan
2020-02-27 19:43       ` Sean Anderson
2020-03-02  4:06   ` Anup Patel
2020-03-02  4:15     ` Damien Le Moal
2020-03-02  4:22       ` Anup Patel
2020-03-02  4:51         ` Damien Le Moal
2020-03-02  5:05           ` Anup Patel
2020-03-02  5:08             ` Damien Le Moal
2020-03-07  0:18               ` Sean Anderson
2020-03-07  4:11                 ` Anup Patel
2020-03-04 19:44   ` Palmer Dabbelt
2020-02-12 10:34 ` [PATCH 09/10] riscv: Kendryte K210 default config Damien Le Moal
2020-03-02  4:07   ` Anup Patel
2020-03-04 19:44   ` Palmer Dabbelt
2020-02-12 10:34 ` [PATCH 10/10] riscv: create a loader.bin for the kendryte kflash.py tool Damien Le Moal
2020-03-02  4:08   ` Anup Patel
2020-03-04 19:44   ` Palmer Dabbelt
2020-02-14 15:05 ` [PATCH 00/10] Kendryte k210 SoC boards support Carlos Eduardo de Paula
2020-02-15  2:02   ` Damien Le Moal
2020-02-17 13:28     ` Carlos Eduardo de Paula
2020-02-26 21:31       ` Carlos Eduardo de Paula
2020-02-27  2:18         ` Damien Le Moal
2020-02-28 20:32 ` Sean Anderson
2020-03-02  3:01   ` Damien Le Moal
2020-03-02  3:53     ` Sean Anderson
2020-03-02  4:11       ` Damien Le Moal
2020-03-02  4:18         ` Sean Anderson
2020-03-02  4:54           ` Damien Le Moal
2020-03-02  4:56             ` Sean Anderson
2020-03-02  5:03               ` Damien Le Moal
2020-03-02  4:17       ` Anup Patel
2020-03-02  4:21         ` Sean Anderson
2020-03-02  4:48         ` Damien Le Moal
2020-03-02  4:51           ` Damien Le Moal
2020-03-02  5:02           ` Sean Anderson
2020-03-02  5:11             ` Damien Le Moal [this message]
2020-03-02  5:25               ` Sean Anderson
2020-03-02  5:43                 ` Damien Le Moal
2020-03-04 19:44 ` Palmer Dabbelt

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