Hi Atish
On Thu, 2019-11-07 at 19:41 +0800, Rick Chen wrote:
Hi Anup & Lukas
Anup Patel anup@brainfault.org 於 2019年11月7日 週四 下午6:44寫道：
On Thu, Nov 7, 2019 at 3:11 PM Auer, Lukas lukas.auer@aisec.fraunhofer.de wrote:
On Thu, 2019-11-07 at 11:48 +0530, Anup Patel wrote:
On Thu, Nov 7, 2019 at 11:40 AM Rick Chen <rickchen36@gmail.com
wrote: Hi Anup
> On Thu, Nov 7, 2019 at 10:45 AM Anup Patel < > anup@brainfault.org> wrote: > > On Thu, Nov 7, 2019 at 7:04 AM Rick Chen < > > rickchen36@gmail.com> wrote: > > > Hi Anup > > > > > > > On Wed, Nov 6, 2019 at 2:51 PM Rick Chen < > > > > rickchen36@gmail.com> wrote: > > > > > Hi Anup > > > > > > > > > > > On Wed, Nov 6, 2019 at 2:18 PM Anup Patel < > > > > > > anup@brainfault.org> wrote: > > > > > > > On Wed, Nov 6, 2019 at 12:14 PM Rick Chen < > > > > > > > rickchen36@gmail.com> wrote: > > > > > > > > Hi Anup > > > > > > > > > > > > > > > > > On Tue, Nov 5, 2019 at 7:19 AM Rick Chen < > > > > > > > > > rickchen36@gmail.com> wrote: > > > > > > > > > > Hi Anup > > > > > > > > > > > > > > > > > > > > > > On Thu, Oct 31, 2019 at 1:42 PM Anup > > > > > > > > > > > > Patel anup@brainfault.org wrote: > > > > > > > > > > > > > On Thu, Oct 31, 2019 at 6:30 AM > > > > > > > > > > > > > Alan Kao alankao@andestech.com > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > Hi Bin, > > > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks for the critics. Comments > > > > > > > > > > > > > > below. > > > > > > > > > > > > > > On Wed, Oct 30, 2019 at > > > > > > > > > > > > > > 06:38:00PM +0800, Bin Meng wrote: > > > > > > > > > > > > > > > Hi Rick, > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Wed, Oct 30, 2019 at 10:50 > > > > > > > > > > > > > > > AM Rick Chen < > > > > > > > > > > > > > > > rickchen36@gmail.com> wrote: > > > > > > > > > > > > > > > > Hi Bin > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi Rick, > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Fri, Oct 25, 2019 at > > > > > > > > > > > > > > > > > 2:18 PM Andes < > > > > > > > > > > > > > > > > > uboot@andestech.com> wrote: > > > > > > > > > > > > > > > > > > From: Rick Chen < > > > > > > > > > > > > > > > > > > rick@andestech.com> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > It will work fine due to > > > > > > > > > > > > > > > > > > hart 0 always will be > > > > > > > > > > > > > > > > > > main > > > > > > > > > > > > > > > > > > hart coincidentally. When > > > > > > > > > > > > > > > > > > develop SPL flow, I try > > > > > > > > > > > > > > > > > > to > > > > > > > > > > > > > > > > > > force other harts to be > > > > > > > > > > > > > > > > > > main hart. And it will go > > > > > > > > > > > > > > > > > > wrong in sending IPI > > > > > > > > > > > > > > > > > > flow. So fix it. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Fix what? Does this commit > > > > > > > > > > > > > > > > > contain 2 fixes, or just 1 > > > > > > > > > > > > > > > > > fix? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Yes, it include two fixs. But > > > > > > > > > > > > > > > > they will cause one negative > > > > > > > > > > > > > > > > result > > > > > > > > > > > > > > > > that only hart 0 can send ipi > > > > > > > > > > > > > > > > to other harts. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Having this fix, any hart > > > > > > > > > > > > > > > > > > can be main hart in U- > > > > > > > > > > > > > > > > > > Boot SPL > > > > > > > > > > > > > > > > > > theoretically, but it > > > > > > > > > > > > > > > > > > still fail somewhere. > > > > > > > > > > > > > > > > > > After dig in > > > > > > > > > > > > > > > > > > and found there is an > > > > > > > > > > > > > > > > > > assumption that hart 0 > > > > > > > > > > > > > > > > > > shall be > > > > > > > > > > > > > > > > > > main hart in OpenSbi. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > So does this mean there is > > > > > > > > > > > > > > > > > a bug in OpenSBI too? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I am not sure if it is a bug. > > > > > > > > > > > > > > > > Maybe it is a compatible > > > > > > > > > > > > > > > > issue. > > > > > > > > > > > > > > > > There is a limitation that > > > > > > > > > > > > > > > > only hart 0 can be main hart > > > > > > > > > > > > > > > > in OpenSBI. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I don't think OpenSBI has such > > > > > > > > > > > > > > > limitation. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Please check the source. > > > > > > > > > > > > > > https://github.com/riscv/opensbi/blob/master/firmware/fw_base.S#L54 > > > > > > > > > > > > > > > > > > > > > > > > > > > > Apparently, the FIRST TWO LINEs > > > > > > > > > > > > > > of the initialization are the > > > > > > > > > > > > > > 1. get hart ID. > > > > > > > > > > > > > > 2. determine which route to take > > > > > > > > > > > > > > based on their ID respectively. > > > > > > > > > > > > > > > > > > > > > > > > > > > > So, I do think OpenSBI has this > > > > > > > > > > > > > > signature, if you are not willing > > > > > > > > > > > > > > to call it > > > > > > > > > > > > > > a limitation. > > > > > > > > > > > > > > > > > > > > > > > > > > This dependency on hart id #0 was > > > > > > > > > > > > > not there until we added self- > > > > > > > > > > > > > relocation > > > > > > > > > > > > > in OpenSBI for FW_DYNAMIC. > > > > > > > > > > > > > > > > > > > > > > > > > > I will try to fix this in OpenSBI > > > > > > > > > > > > > but we might end-up having > > > > > > > > > > > > > boot_lottery. > > > > > > > > > > > > > > > > > > > > > > > > I have send a patch to fix this > > > > > > > > > > > > OpenSBI: > > > > > > > > > > > > "[PATCH] firmware: Introduce > > > > > > > > > > > > relocation lottery" > > > > > > > > > > > > > > > > > > > > > > > > Can you try above patch and see if > > > > > > > > > > > > that helps ? > > > > > > > > > > > > > > > > > > > > > > > > It will be great if you can provide > > > > > > > > > > > > Tested-by to my patch as well. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I can not find this patch in mailing > > > > > > > > > > list. > > > > > > > > > > Can you provide a hyperlink ? > > > > > > > > > > > > > > > > > > You can try latest riscv/opensbi master. > > > > > > > > > > > > > > > > > > I have tested the patch on SiFive Unleashed > > > > > > > > > multiple times. > > > > > > > > > > > > > > > > I have tried this patch, but it fail > > > > > > > > firmware: Introduce relocation lottery( > > > > > > > > 98f4a208995b027662a7b04a25e4fa5df5f3eefe) > > > > > > > > > > > > > > > > The scenario was as below: > > > > > > > > There are 4 harts run in U-Boot SPL, hart 0 > > > > > > > > play as main hart. > > > > > > > > The hart 1 will receive ipi and come into > > > > > > > > OpenSBI(0x1000000) from > > > > > > > > U-Boot SPL(0x0), meanwhile hart 0,2,3 still > > > > > > > > run in U-Boot SPL. > > > > > > > > Then hart 1 will do _relocate_copy_to_lower > > > > > > > > which will copy data from > > > > > > > > 0x1000000 to 0x0. > > > > > > > > And it will corrupt U-Boot SPL. > > > > > > > > > > > > > > The self-relocation in OpenSBI firmwares > > > > > > > ensures that OpenSBI firmware > > > > > > > are moved to the FW_TEXT_START before entering > > > > > > > C code. This helps > > > > > > > us load OpenSBI firmwares anywhere in RAM. > > > > > > > > > > > > > > However, OpenSBI firmwares don't know where the > > > > > > > U-Boot SPL is running. > > > > > > > > > > > > > > In your case, both OpenSBI FW_DYNAMIC and U- > > > > > > > Boot SPL are linked to > > > > > > > address same address 0x0. This means secondary > > > > > > > HARTs cannot safely > > > > > > > wait while primary HART enters OpenSBI. You > > > > > > > should hold secondary HARTs > > > > > > > in U-Boot SPL only till OpenSBI FW_DYNAMIC and > > > > > > > U-Boot proper are > > > > > > > loaded in RAM by primary HART. All your HARTs > > > > > > > should jump to OpenSBI > > > > > > > at the same time after everything is loaded in > > > > > > > RAM. > > > > > > > > > > > > I see the issue now. > > > > > > > > > > > > The U-Boot SPL is first letting secondary HART > > > > > > jump to OpenSBI and primary > > > > > > HART jumps to OpenSBI at the end. > > > > > > (Refer, jump_to_image_no_args() in > > > > > > arch/riscv/lib/spl.c) > > > > > > > > > > > > The real issue is FW_TEXT_START being same as U- > > > > > > Boot SPL TEXT_START. > > > > > > > > > > > > If possible please change TEXT base for U-Boot > > > > > > SPL or OpenSBI. I think > > > > > > changing U-Boot SPL TEXT_START would be > > > > > > convenient since this series > > > > > > is under review. Thoughts ? > > > > > > > > > > Yes. > > > > > I know it can avoid corrupting issue with > > > > > changing U-Boot SPL > > > > > TEXT_START not equal to OpenSBI TEXT base. > > > > > > > > I think this issue will be seen on U-Boot SPL running > > > > on QEMU as well. > > > > > > > > > With the following changes, U-Boot SPL text base > > > > > can equal to OpenSBI text base > > > > > 1 U-Boot pass main hart information (a2) when > > > > > jumping to OpenSBI > > > > > 2 OpenSBI pick up $a2 to keep playing as main hart, > > > > > other harts go to > > > > > _wait_relocate_copy_done > > > > > > > > Overall it's a good suggestion but we cannot use a2 > > > > register because this > > > > will break FW_JUMP and FW_PAYLOAD. Instead, we should > > > > pass preferred > > > > boot HART id in struct fw_dynamic_info. > > > > > > Sorry, what I want to say shall be a3. > > > > > > > I have a patch for this in preferred_boot_hart_v1 > > > > branch of > > > > https://github.com/avpatel/opensbi.git > > > > > > > > Can you try OpenSBI from above branch ? > > > > > > > > You will have to update the "struct fw_dynamic_info" > > > > passed to > > > > OpenSBI by U-Boot SPL. > > > > > > Main hart will pass struct "fw_dynamic_info" to OpenSBI > > > by U-Boot SPL. > > > But other harts will NOT pass struct "fw_dynamic_info" > > > to OpenSBI by U-Boot SPL. > > > > That's wrong in U-Boot SPL. > > > > All HARTs have to follow FW_DYNAMIC protocol and pass > > "struct fw_dynamic_info" pointer in 'a2' register. > > > > > So if U-Boot SPL can pass main hart information via a3, > > > OpenSBI just > > > have the following change > > > blt zero, a6, _wait_relocate_copy_done > > > change to > > > bne a3, a6, _wait_relocate_copy_done > > > before this commit > > > 98f4a208995b027662a7b04a25e4fa5df5f3eefe > > > firmware: Introduce relocation lottery > > > > What about FW_JUMP and FW_PAYLOAD? We have no way of > > passing > > value in a3 for these firmwares because these are not > > booted by U-Boot > > SPL. > > > > Also, U-Boot-2019.10 already uses U-Boot SPL support > > which does not > > pass anything in 'a3' register. > > > > We should definitely use "struct fw_dynamic_info" for > > this so that we can > > maintain backward compatibility as well. > > > > Please make sure that U-Boot SPL passes "struct > > fw_dynamic_info" > > pointer in 'a2' register for all HARTs. > > > > > But after this commit 98f4a, main hart become chosen > > > from lottery mechanism. > > > Maybe I will prefer to change U-Boot SPL text base not > > > overlap with > > > OpenSBI text start. :) > > > > Like I mentioned, we have this issue for U-Boot SPL on > > QEMU as well. It's > > just that most of us did not notice it for U-Boot SPL on > > QEMU. > > > > Let's fix this in the right way from start itself. > > I double checked spl_invoke_opensbi() and it is doing the > right thing > by passing "struct fw_dyanmic_info" pointer in 'a2' > register. > (Refer, common/spl/spl_opensbi.c) > > Not sure, why it is not passing 'a2' register correctly for > you ?? >
Yes, you are right. I reply too quickly. Other harts will pass struct fw_dyanmic_info in a2 to OpenSBI.
Thanks for your corrections
No problem, I am happy to help.
BTW, I tried to play around with U-Boot SPL on QEMU.
Maybe below changes can help you...
Thanks for looking into this issue! I successfully tested it on QEMU, I had to add a short delay between sending the IPIs to trigger the problem.
We might still run into problems however. Right now, we are assuming that the main hart is the last one to enter OpenSBI. If this is not the case (some delay when handling the IPI), we will have the same problem again. To fix this we could pass the hart mask, containing all harts that have entered U-Boot, to OpenSBI and wait for all harts to be running in OpenSBI. I am not sure how realistic this scenario is, so this might not be needed.
I agree that we might still run into this issue if primary HART enters OpenSBI before secondary HARTs. I think this situation can only happen on QEMU where each CPU is a thread running on host but very unlikely/impossible on real HW.
Maybe a delay on primary HART in U-Boot SPL after SMP calls to secondary HARTs and before jumping to OpenSBI ?
Regarding hart_mask in fw_dynamic_info, I think the issue will be the size of the hart_mask. It is possible in-future SOC vendors come-up with SOC having huge number of HARTs OR SOC with discontinuous HART IDs which can cause a 64bit hart_mask to be not sufficient for all HARTs.
Also, waiting for all HARTs to enter OpenSBI will be one more wait- loop in fw_base.S which will add to the boot-time as well.
I still think the root cause of the issue is that TEXT_START of U-Boot SPL and OpenSBI FW_DYNAMIC is same. Maybe we can insist SOC vendors to not use same TEXT_START ?
I have try your changes about boot_hart for U-Boot SPL with OpenSBI, preferred_boot_hart_v2 branch It still encounter some booting problems. I try to find out the root cause but in vain.
Just wanted to make sure that you have tried this patch.
http://lists.infradead.org/pipermail/opensbi/2019-November/000672.html
We should investigate the issue why it did not work for you if this patch did not work for you.
Yes, I try with this commit 831aa3c1ad2546a2b35ddf5b1aa0ce91cdc7fe89 firmware: Add preferred boot HART field in struct fw_dynamic_info
It fail randomly yesterday, but this morning I try several times it will pass. I will keep trying.
Thanks Rick
I am very agree with options of Lukas. After modifying U-Boot SPL text base not equal to zero and the booting progress will be pass.
Thanks Rick
Regards, Anup
-- Regards, Atish