* Re: 回复: Re: 回复: Re: [PATCH v1 1/2] drm/qxl: replace ioremap by ioremap_cache on arm64
2022-03-23 10:00 回复: Re: 回复: Re: [PATCH v1 1/2] drm/qxl: replace ioremap by ioremap_cache on arm64 liucong2
@ 2022-03-23 10:17 ` Christian König
0 siblings, 0 replies; 2+ messages in thread
From: Christian König @ 2022-03-23 10:17 UTC (permalink / raw)
To: liucong2, airlied, kraxel, airlied, daniel, ray.huang,
virtualization, spice-devel, dri-devel
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Hi Cong,
yes I've seen that, but that is still not sufficient.
You need to update the check in ttm_module.c as well or otherwise your
userspace mapping might not work correctly either.
Regards,
Christian.
Am 23.03.22 um 11:00 schrieb liucong2@kylinos.cn:
>
> Hi Christian,
>
>
> another commit fix the case in ttm. I send two patches at the same
> time, but seems I miss
>
> '--cover-letter' when run format-patch or some other bad operation.
>
> ----
>
>
> Regards,
>
> Cong.
>
>
>
>
> *主 题：*Re: 回复: Re: [PATCH v1 1/2] drm/qxl: replace ioremap by
> ioremap_cache on arm64
> *日 期：*2022-03-23 17:34
> *发件人：*Christian König
> *收件人：*liucong2@kylinos.cnairlied@redhat.comkraxel@redhat.comairlied@linux.iedaniel@ffwll.chray.huang@amd.comvirtualization@lists.linux-foundation.orgspice-devel@lists.freedesktop.orgdri-devel@lists.freedesktop.org
>
>
> Hi Cong,
>
> well than Dave must decide what to do here.
>
> When QXL emulates a device it should also not use memory accesses
> which won't work on a physical device.
>
> BTW: Your patch is really buggy, it misses the cases in ttm_module.c
>
> Regards,
> Christian.
>
> Am 23.03.22 um 09:48 schrieb liucong2@kylinos.cn:
>>
>> Hi Christian,
>>
>>
>> according to 'Arm Architecture Reference Manual Armv8,for Armv8-A
>>
>> architecture profile' pdf E2.6.5
>>
>>
>> E2.6.5 Generation of Alignment faults by load/store multiple
>> accesses to
>>
>> Device memory
>>
>>
>> When FEAT_LSMAOC is implemented and the value of the
>> applicable nTLSMD
>>
>> field is 0, any memory access by an AArch32 Load Multiple or
>> Store
>>
>> Multiple instruction to an address that the stage 1 translation
>>
>> assigns as Device-nGRE, Device-nGnRE, or Device-nGnRnE generates
>>
>> an Alignment fault.
>>
>>
>> so it seems not just some ARM boards doesn't allow unaligned
>> access to MMIO
>>
>> space, all pci memory mapped as Device-nGnRE in arm64 cannot
>> support
>>
>> unaligned access. and qxl is a device simulated by qemu, it
>> should be able to access
>>
>> to MMIO space in a more flexible way(PROT_NORMAL) than the real
>> physical
>>
>> graphics card.
>>
>>
>> ----
>>
>>
>>
>> Cong.
>>
>>
>>
>>
>>
>> *主 题：*Re: [PATCH v1 1/2] drm/qxl: replace ioremap by
>> ioremap_cache on arm64
>> *日 期：*2022-03-23 15:15
>> *发件人：*Christian König
>> *收件人：*CongLiuairlied@redhat.comkraxel@redhat.comairlied@linux.iedaniel@ffwll.chray.huang@amd.comvirtualization@lists.linux-foundation.orgspice-devel@lists.freedesktop.orgdri-devel@lists.freedesktop.org
>>
>>
>>
>> Am 22.03.22 um 10:34 schrieb Cong Liu:
>> > qxl use ioremap to map ram_header and rom, in the arm64
>> implementation,
>> > the device is mapped as DEVICE_nGnRE, it can not support
>> unaligned
>> > access.
>>
>> Well that some ARM boards doesn't allow unaligned access to
>> MMIO space
>> is a well known bug of those ARM boards.
>>
>> So as far as I know this is a hardware bug you are trying to
>> workaround
>> here and I'm not 100% sure that this is correct.
>>
>> Christian.
>>
>> >
>> > 6.620515] pc : setup_hw_slot+0x24/0x60 [qxl]
>> > [ 6.620961] lr : setup_slot+0x34/0xf0 [qxl]
>> > [ 6.621376] sp : ffff800012b73760
>> > [ 6.621701] x29: ffff800012b73760 x28: 0000000000000001
>> x27: 0000000010000000
>> > [ 6.622400] x26: 0000000000000001 x25: 0000000004000000
>> x24: ffffcf376848c000
>> > [ 6.623099] x23: ffff0000c4087400 x22: ffffcf3718e17140
>> x21: 0000000000000000
>> > [ 6.623823] x20: ffff0000c4086000 x19: ffff0000c40870b0
>> x18: 0000000000000014
>> > [ 6.624519] x17: 000000004d3605ab x16: 00000000bb3b6129
>> x15: 000000006e771809
>> > [ 6.625214] x14: 0000000000000001 x13: 007473696c5f7974
>> x12: 696e696666615f65
>> > [ 6.625909] x11: 00000000d543656a x10: 0000000000000000
>> x9 : ffffcf3718e085a4
>> > [ 6.626616] x8 : 00000000006c7871 x7 : 000000000000000a
>> x6 : 0000000000000017
>> > [ 6.627343] x5 : 0000000000001400 x4 : ffff800011f63400
>> x3 : 0000000014000000
>> > [ 6.628047] x2 : 0000000000000000 x1 : ffff0000c40870b0
>> x0 : ffff0000c4086000
>> > [ 6.628751] Call trace:
>> > [ 6.628994] setup_hw_slot+0x24/0x60 [qxl]
>> > [ 6.629404] setup_slot+0x34/0xf0 [qxl]
>> > [ 6.629790] qxl_device_init+0x6f0/0x7f0 [qxl]
>> > [ 6.630235] qxl_pci_probe+0xdc/0x1d0 [qxl]
>> > [ 6.630654] local_pci_probe+0x48/0xb8
>> > [ 6.631027] pci_device_probe+0x194/0x208
>> > [ 6.631464] really_probe+0xd0/0x458
>> > [ 6.631818] __driver_probe_device+0x124/0x1c0
>> > [ 6.632256] driver_probe_device+0x48/0x130
>> > [ 6.632669] __driver_attach+0xc4/0x1a8
>> > [ 6.633049] bus_for_each_dev+0x78/0xd0
>> > [ 6.633437] driver_attach+0x2c/0x38
>> > [ 6.633789] bus_add_driver+0x154/0x248
>> > [ 6.634168] driver_register+0x6c/0x128
>> > [ 6.635205] __pci_register_driver+0x4c/0x58
>> > [ 6.635628] qxl_init+0x48/0x1000 [qxl]
>> > [ 6.636013] do_one_initcall+0x50/0x240
>> > [ 6.636390] do_init_module+0x60/0x238
>> > [ 6.636768] load_module+0x2458/0x2900
>> > [ 6.637136] __do_sys_finit_module+0xbc/0x128
>> > [ 6.637561] __arm64_sys_finit_module+0x28/0x38
>> > [ 6.638004] invoke_syscall+0x74/0xf0
>> > [ 6.638366] el0_svc_common.constprop.0+0x58/0x1a8
>> > [ 6.638836] do_el0_svc+0x2c/0x90
>> > [ 6.639216] el0_svc+0x40/0x190
>> > [ 6.639526] el0t_64_sync_handler+0xb0/0xb8
>> > [ 6.639934] el0t_64_sync+0x1a4/0x1a8
>> > [ 6.640294] Code: 910003fd f9484804 f9400c23 8b050084
>> (f809c083)
>> > [ 6.640889] ---[ end trace 95615d89b7c87f95 ]---
>> >
>> > Signed-off-by: Cong Liu
>> > ---
>> > drivers/gpu/drm/qxl/qxl_kms.c | 10 ++++++++++
>> > 1 file changed, 10 insertions(+)
>> >
>> > diff --git a/drivers/gpu/drm/qxl/qxl_kms.c
>> b/drivers/gpu/drm/qxl/qxl_kms.c
>> > index 4dc5ad13f12c..0e61ac04d8ad 100644
>> > --- a/drivers/gpu/drm/qxl/qxl_kms.c
>> > +++ b/drivers/gpu/drm/qxl/qxl_kms.c
>> > @@ -165,7 +165,11 @@ int qxl_device_init(struct
>> qxl_device *qdev,
>> > (int)qdev->surfaceram_size / 1024,
>> > (sb == 4) ? "64bit" : "32bit");
>> >
>> > +#ifdef CONFIG_ARM64
>> > + qdev->rom = ioremap_cache(qdev->rom_base, qdev->rom_size);
>> > +#else
>> > qdev->rom = ioremap(qdev->rom_base, qdev->rom_size);
>> > +#endif
>> > if (!qdev->rom) {
>> > pr_err("Unable to ioremap ROM\n");
>> > r = -ENOMEM;
>> > @@ -183,9 +187,15 @@ int qxl_device_init(struct
>> qxl_device *qdev,
>> > goto rom_unmap;
>> > }
>> >
>> > +#ifdef CONFIG_ARM64
>> > + qdev->ram_header = ioremap_cache(qdev->vram_base +
>> > + qdev->rom->ram_header_offset,
>> > + sizeof(*qdev->ram_header));
>> > +#else
>> > qdev->ram_header = ioremap(qdev->vram_base +
>> > qdev->rom->ram_header_offset,
>> > sizeof(*qdev->ram_header));
>> > +#endif
>> > if (!qdev->ram_header) {
>> > DRM_ERROR("Unable to ioremap RAM header\n");
>> > r = -ENOMEM;
>>
>
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