Hi Bin, On Fri, 2019-03-15 at 09:54 +0800, Bin Meng wrote: > Hi Lukas, > > On Fri, Mar 15, 2019 at 5:01 AM Auer, Lukas > <lukas.a...@aisec.fraunhofer.de> wrote: > > Hi Bin, > > > > On Wed, 2019-03-13 at 09:51 +0800, Bin Meng wrote: > > > Hi Lukas, > > > > > > On Tue, Mar 12, 2019 at 10:39 PM Auer, Lukas > > > <lukas.a...@aisec.fraunhofer.de> wrote: > > > > Hi Bin, > > > > > > > > On Mon, 2019-03-11 at 23:28 +0800, Bin Meng wrote: > > > > > Hi Lukas, > > > > > > > > > > On Mon, Mar 11, 2019 at 2:03 AM Auer, Lukas > > > > > <lukas.a...@aisec.fraunhofer.de> wrote: > > > > > > Hi Bin, > > > > > > > > > > > > On Sun, 2019-03-10 at 22:57 +0800, Bin Meng wrote: > > > > > > > Hi Lukas, > > > > > > > > > > > > > > On Sun, Mar 10, 2019 at 9:44 PM Auer, Lukas > > > > > > > <lukas.a...@aisec.fraunhofer.de> wrote: > > > > > > > > Hi Bin, > > > > > > > > > > > > > > > > On Sun, 2019-03-10 at 09:07 +0800, Bin Meng wrote: > > > > > > > > > Hi Lukas, > > > > > > > > > > > > > > > > > > On Mon, Feb 11, 2019 at 6:13 AM Lukas Auer > > > > > > > > > <lukas.a...@aisec.fraunhofer.de> wrote: > > > > > > > > > > Re-add the previous compatible string "riscv- > > > > > > > > > > virtio- > > > > > > > > > > soc" to > > > > > > > > > > the > > > > > > > > > > soc > > > > > > > > > > device tree node to allow U-Boot and Linux to bind > > > > > > > > > > machine- > > > > > > > > > > specific > > > > > > > > > > drivers to it. The current compatible string > > > > > > > > > > "simple- > > > > > > > > > > bus" > > > > > > > > > > is > > > > > > > > > > retained. > > > > > > > > > > > > > > > > > > > > This is required by U-Boot to bind devices early, > > > > > > > > > > as > > > > > > > > > > part > > > > > > > > > > of > > > > > > > > > > the > > > > > > > > > > pre-relocation driver model. > > > > > > > > > > > > > > > > > > > > > > > > > > > > I see no problem with U-Boot working with current > > > > > > > > > compatible > > > > > > > > > string > > > > > > > > > "simple-bus". In fact I had planned to remove the > > > > > > > > > compatible > > > > > > > > > string > > > > > > > > > "riscv-virtio-soc" in U-Boot but did not get time to > > > > > > > > > work > > > > > > > > > on > > > > > > > > > it. > > > > > > > > > > > > > > > > > > > > > > > > > It is only required if U-Boot is running in machine- > > > > > > > > mode. > > > > > > > > For > > > > > > > > relocation it needs to use the CLINT driver to send > > > > > > > > appropriate > > > > > > > > IPIs to > > > > > > > > the other harts. To be able to probe the driver, the > > > > > > > > device > > > > > > > > and > > > > > > > > its > > > > > > > > parent device tree node (soc) must therefore be > > > > > > > > available > > > > > > > > in > > > > > > > > the > > > > > > > > pre- > > > > > > > > relocation device model. > > > > > > > > This patch was the easiest way I could think of for > > > > > > > > achieving > > > > > > > > this. > > > > > > > > It > > > > > > > > could be that there is a better way of solving this. > > > > > > > > > > > > > > > > > > > > > > I tested your SMP U-Boot series in both M-mode and S- > > > > > > > mode, > > > > > > > using > > > > > > > a 4 > > > > > > > core 'virt' target. Works fine. I am using QEMU 3.1.0 so > > > > > > > it > > > > > > > is > > > > > > > "simple-bus". > > > > > > > > > > > > > > > > > > > That is actually my fault, it should not work. > > > > > > What is happening is that U-Boot fails to relocate the > > > > > > secondary > > > > > > harts, > > > > > > because the CLINT driver cannot get the memory address of > > > > > > the > > > > > > CLINT > > > > > > device. This error is currently silently ignored. > > > > > > > > > > I still don't understand. Why does the CLINT driver fail to > > > > > get > > > > > the > > > > > memory address? U-Boot has been supporting "simpile-bus" for > > > > > a > > > > > long > > > > > time. It was because QEMU 3.0.0 generated the /soc node with > > > > > "riscv-virtio-soc" compatible string, U-Boot was taught to > > > > > treat > > > > > such > > > > > compatible string as a "simple-bus" too (that was the U-Boot > > > > > commit > > > > > 27dc2c130e29) > > > > > > > > That's correct. The problem with the default simple-bus U-Boot > > > > driver > > > > is that it does not have the DM_FLAG_PRE_RELOC flag set. The > > > > /soc > > > > and > > > > /soc/clint nodes are therefore not available before relocation, > > > > meaning > > > > that IPIs cannot be sent to relocate the secondary harts. > > > > > > > > > > Thanks for the clarifications. Now I see the problem. But I think > > > we > > > should fix U-Boot "simple-bus" driver instead. As seen on FU540 > > > or > > > likely other hardware, QEMU generates the "simple-bus" compatible > > > string for the /soc node, as well as the DT provided by the > > > hardware. > > > > > > > That makes sense, I can send a patch to set the DM_FLAG_PRE_RELOC > > flag > > in the simple-bus U-Boot driver. I think it's best to send it > > separately from the SMP patch series, since it could affect other > > boards and it's a bit late in the release cycle. What do you think? > > > > Yes, agreed that the "simple-bus" driver changes should be next U- > Boot > release. We should try to get the U-Boot SMP series in the v2019.04 > release. >
Yes definitely, I have just sent version 3 of the series. I hope it is ready to go into mainline now. Thanks, Lukas
