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<div class="moz-cite-prefix">Hi Monk,<br>
<br>
<blockquote type="cite">
You see that for UMD, it can use 0 to HOLE_START</blockquote>
Let me say it once more: The UMD nor anybody else CAN'T use 0 to
HOLE_START, that region is reserved for the ATC hardware!<br>
<br>
We unfortunately didn't knew that initially and also didn't used
the ATC, so we didn't ran into a problem.<br>
<br>
But ROCm now uses the ATC on Raven/Picasso and I have a branch
where I enable it on Vega as well. So when we don't fix that we
will run into problems here.<br>
<br>
The ATC isn't usable in combination with SRIOV and I don't think
Windows uses it either, so they probably never ran into any
issues.<br>
<br>
<blockquote type="cite"><span style="color:black">Do you mean even
UMD should not use virtual address that dropped in range from
0 to HOLE_START ?</span></blockquote>
Yes, exactly! That in combination with ATC use can have quite a
bunch of strange and hard to track down effects because two parts
of the driver are using the same address space.<br>
<br>
<blockquote type="cite">That way where should UMD work in ?and I
assume our UMD now still using this range, this part make me
puzzle
<span style="color:windowtext"></span></blockquote>
At least Mesa now uses the high address space from
HOLE_END..0xFFFF FFFF FFFF FFFF.<br>
<br>
Regards,<br>
Christian.<br>
<br>
Am 18.01.19 um 02:32 schrieb Liu, Monk:<br>
</div>
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<div class="WordSection1">
<p class="MsoNormal"><span style="color:windowtext">Thanks
Christian,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:windowtext"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:windowtext">Questions I
have now:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:windowtext"><o:p> </o:p></span></p>
<ol style="margin-top:0in" start="1" type="1">
<li class="MsoListParagraph"
style="color:windowtext;margin-left:0in;mso-list:l2 level1
lfo7">
You see that for UMD, it can use 0 to HOLE_START, so why CSA
cannot use that range although the range is as you said
reserved to ATC h/w ? Be note that for windows KMD, the CSA
is allocated by UMD driver so CSA shares the same aperture
/space range with other UMD BO, which mean CSA in windows
also located in ATC range, if that’s a problem why windows
still works well.<o:p></o:p>
<ol style="margin-top:0in" start="1" type="a">
<li class="MsoListParagraph"
style="color:windowtext;margin-left:0in;mso-list:l2
level2 lfo7">
Can you illustrate this limitation with more details ?
we need to understand why CSA couldn’t be put in ATC
range.<o:p></o:p></li>
</ol>
</li>
<li class="MsoListParagraph"
style="color:windowtext;margin-left:0in;mso-list:l2 level1
lfo7">
According to your previous description :” <span
style="color:black">Now on Vega/Raven/Picasso etc..
(everything with a GFX9) the lower range (0x0-0x8000 0000
0000) is reserved for SVA/ATC use. Since we
<b>unfortunately didn't knew that initially we exposed
those to older user space as usable</b> and also put the
CSA in there.”</span><o:p></o:p>
<ol style="margin-top:0in" start="1" type="a">
<li class="MsoListParagraph"
style="color:windowtext;margin-left:0in;mso-list:l2
level2 lfo7">
<span style="color:black">Do you mean even UMD should
not use virtual address that dropped in range from 0
to HOLE_START ?</span><o:p></o:p></li>
</ol>
</li>
</ol>
<p class="MsoListParagraph" style="margin-left:1.0in">that way
where should UMD work in ?and I assume our UMD now still using
this range, this part make me puzzle
<span style="color:windowtext"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:windowtext"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:windowtext">/Monk<o:p></o:p></span></p>
<div>
<div style="border:none;border-top:solid #E1E1E1
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="color:windowtext">From:</span></b><span
style="color:windowtext"> amd-gfx
<a class="moz-txt-link-rfc2396E" href="mailto:amd-gfx-bounces@lists.freedesktop.org"><amd-gfx-bounces@lists.freedesktop.org></a>
<b>On Behalf Of </b>Koenig, Christian<br>
<b>Sent:</b> Thursday, January 17, 2019 9:26 PM<br>
<b>To:</b> Liu, Monk <a class="moz-txt-link-rfc2396E" href="mailto:Monk.Liu@amd.com"><Monk.Liu@amd.com></a>; Lou,
Wentao <a class="moz-txt-link-rfc2396E" href="mailto:Wentao.Lou@amd.com"><Wentao.Lou@amd.com></a>;
<a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a>; Zhu, Rex
<a class="moz-txt-link-rfc2396E" href="mailto:Rex.Zhu@amd.com"><Rex.Zhu@amd.com></a><br>
<b>Cc:</b> Deng, Emily <a class="moz-txt-link-rfc2396E" href="mailto:Emily.Deng@amd.com"><Emily.Deng@amd.com></a><br>
<b>Subject:</b> Re: [PATCH] drm/amdgpu: csa_vaddr should
not larger than AMDGPU_GMC_HOLE_START<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<p class="MsoNormal">Hi Monk,<br>
<br>
<br>
<o:p></o:p></p>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">Regarding with above sentence, do you
mean this range (0->HOLE_START) shouldn’t be exposed to
user space ? I don’t get your point here …<o:p></o:p></p>
</blockquote>
<p class="MsoNormal">Yes exactly. As I said the problem is
that 0->HOLE_START is reserved for the ATC hardware, we
should not touch it at all.<br>
<br>
<br>
<o:p></o:p></p>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Putting
CSA in 0~HOLD_START is the legacy approach we selected for
a long time since very early stage, how comes that you
think it is a problem now ?<o:p></o:p></p>
</blockquote>
<p class="MsoNormal">That turned out to be never a good idea
in the first place.<br>
<br>
What we could do is reduce the max_pfn for SRIOV because the
ATC doesn't work in that configuration anyway. But I would
only do this as last resort.<br>
<br>
Any idea why an address above the hole doesn't work with
SRIOV? It seems to work fine in the bare metal case.<br>
<br>
Regards,<br>
Christian.<br>
<br>
Am 17.01.19 um 14:19 schrieb Liu, Monk:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"><span style="color:windowtext">Hi
Christian </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext">Thanks for
explaining the HOLD for us,
</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext">My
understanding is we still could put CSA to 0~HOLE_START,
because we can report UMD the max space is
HOLD_START-CSA_SIZE , thus no colliding will hit.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext">></span>
Now on Vega/Raven/Picasso etc.. (everything with a GFX9) the
lower range (0x0-0x8000 0000 0000) is reserved for SVA/ATC
use. Since we unfortunately didn't knew that initially we
exposed those to older userspace as usable and also put the
CSA in there.<br>
<br>
<br>
<o:p></o:p></p>
<p class="MsoNormal">Regarding with above sentence, do you
mean this range (0->HOLE_START) shouldn’t be exposed to
user space ? I don’t get your point here …<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Putting CSA in 0~HOLD_START is the legacy
approach we selected for a long time since very early stage,
how comes that you think it is a problem now ?<o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext">/Monk</span><o:p></o:p></p>
<div>
<div style="border:none;border-top:solid #E1E1E1
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="color:windowtext">From:</span></b><span
style="color:windowtext"> amd-gfx
<a href="mailto:amd-gfx-bounces@lists.freedesktop.org"
moz-do-not-send="true"><amd-gfx-bounces@lists.freedesktop.org></a>
<b>On Behalf Of </b>Koenig, Christian<br>
<b>Sent:</b> Thursday, January 17, 2019 4:30 PM<br>
<b>To:</b> Liu, Monk <a
href="mailto:Monk.Liu@amd.com"
moz-do-not-send="true"><Monk.Liu@amd.com></a>;
Lou, Wentao
<a href="mailto:Wentao.Lou@amd.com"
moz-do-not-send="true"><Wentao.Lou@amd.com></a>;
<a href="mailto:amd-gfx@lists.freedesktop.org"
moz-do-not-send="true">
amd-gfx@lists.freedesktop.org</a>; Zhu, Rex <a
href="mailto:Rex.Zhu@amd.com" moz-do-not-send="true"><Rex.Zhu@amd.com></a><br>
<b>Cc:</b> Deng, Emily <a
href="mailto:Emily.Deng@amd.com"
moz-do-not-send="true"><Emily.Deng@amd.com></a><br>
<b>Subject:</b> Re: [PATCH] drm/amdgpu: csa_vaddr
should not larger than AMDGPU_GMC_HOLE_START</span><o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"> <o:p></o:p></p>
<div>
<p class="MsoNormal">Hi Monk,<br>
<br>
ok let me explain a bit more how the hardware works.<br>
<br>
The GMC manages a virtual 64bit address space, but only
48bit of that virtual address space are handled by the
page table walker.<br>
<br>
The 48bits of address space are sign extended, so bit 47
of that are extended into bits 48-63.<br>
<br>
This gives us the following memory layout:<br>
0x0<br>
.... virtual address space<br>
0x8000 0000 0000<br>
.... hole<br>
0xFFFF 8000 0000 0000<br>
.... virtual address space<br>
0xFFFF FFFF FFFF FFFF<br>
<br>
Trying to access the hole results in a range fault
interrupt IIRC.<br>
<br>
When doing the VM page table walk the topmost 16bits are
ignored, so when programming the page table walker you cut
those of and use a linear address again. This is what
AMDGPU_GMC_HOLE_MASK is good for.<br>
<br>
Now on Vega/Raven/Picasso etc.. (everything with a GFX9)
the lower range (0x0-0x8000 0000 0000) is reserved for
SVA/ATC use. Since we unfortunately didn't knew that
initially we exposed those to older userspace as usable
and also put the CSA in there.<br>
<br>
The most likely cause of this is that we still have a bug
somewhere about this, e.g. not correctly using sign
extended addresses *OR* using sign extended addresses
where we should use linear instead.<br>
<br>
Regards,<br>
Christian.<br>
<br>
Am 17.01.19 um 09:04 schrieb Liu, Monk:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"><span style="color:windowtext">Hi
Christian </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext">I
believe Wentao can fix the issue we it by below step:</span><o:p></o:p></p>
<ol style="margin-top:0in" start="1" type="1">
<li class="MsoNormal" style="color:windowtext;mso-list:l0
level1 lfo3">Return <b>
Virtual_address_max</b> (UMD use it) to HOLE_START –
RESERVED_SIZE <o:p></o:p></li>
<li class="MsoNormal" style="color:windowtext;mso-list:l0
level1 lfo3">[optional] Still Keep
virtual_address_offset to RESERVED_SIZE (current way, I
think it’s because previously we put CSA in 0
<span style="font-family:Wingdings">à</span>
RESERVED_SIZE space) <o:p></o:p></li>
<li class="MsoNormal" style="color:windowtext;mso-list:l0
level1 lfo3">Put CSA in HOLE_START – RESERVED_SIZE
<span style="font-family:Wingdings">è</span> HOLE_START
(it’s current design) <o:p>
</o:p></li>
</ol>
<p class="MsoNormal"><span style="color:windowtext"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext">I don’t
get where above scheme is not correct … can you give
more explain for the GMC_HOLE_START ?</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext">e.g.</span><o:p></o:p></p>
<ol style="margin-top:0in" start="1" type="1">
<li class="MsoNormal"
style="color:windowtext;margin-left:2.5pt;mso-list:l4
level1 lfo6">
why you set GMC_HOLE_START to 0x8’000’0000’0000 (half
size of MAX of 48bit address space) ? is it for HSA
purpose to make sure GPU address can also be used for
CPU address ?
<o:p></o:p></li>
<li class="MsoNormal"
style="color:windowtext;margin-left:2.5pt;mso-list:l4
level1 lfo6">
now MAX_PFN is 1’000’0000’0000, do you need to change
GMC_HOLE_START ? <o:p></o:p></li>
</ol>
<p class="MsoNormal"><span style="color:windowtext"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext">thanks </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext">we need
some catch up </span>
<o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext">/Monk</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:windowtext"> </span><o:p></o:p></p>
<div>
<div style="border:none;border-top:solid #E1E1E1
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="color:windowtext">From:</span></b><span
style="color:windowtext"> amd-gfx
<a
href="mailto:amd-gfx-bounces@lists.freedesktop.org"
moz-do-not-send="true"><amd-gfx-bounces@lists.freedesktop.org></a>
<b>On Behalf Of </b>Koenig, Christian<br>
<b>Sent:</b> Thursday, January 17, 2019 3:39 PM<br>
<b>To:</b> Lou, Wentao <a
href="mailto:Wentao.Lou@amd.com"
moz-do-not-send="true"><Wentao.Lou@amd.com></a>;
Liu, Monk
<a href="mailto:Monk.Liu@amd.com"
moz-do-not-send="true"><Monk.Liu@amd.com></a>;
<a href="mailto:amd-gfx@lists.freedesktop.org"
moz-do-not-send="true">
amd-gfx@lists.freedesktop.org</a>; Zhu, Rex <a
href="mailto:Rex.Zhu@amd.com"
moz-do-not-send="true"><Rex.Zhu@amd.com></a><br>
<b>Cc:</b> Deng, Emily <a
href="mailto:Emily.Deng@amd.com"
moz-do-not-send="true"><Emily.Deng@amd.com></a><br>
<b>Subject:</b> Re: [PATCH] drm/amdgpu: csa_vaddr
should not larger than AMDGPU_GMC_HOLE_START</span><o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"> <o:p></o:p></p>
<div>
<p class="MsoNormal">Am 17.01.19 um 04:17 schrieb Lou,
Wentao:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">Hi Christian,<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Your solution as:<o:p></o:p></p>
<p class="MsoNormal">addr = (max_pfn -
(AMDGPU_VA_RESERVED_SIZE >> AMDGPU_PAGE_SHIFT))
<< AMDGPU_PAGE_SHIFT;<o:p></o:p></p>
<p class="MsoNormal">now max_pfn = 0x10 0000 0000,
AMDGPU_VA_RESERVED_SIZE = 0x10 0000, AMDGPU_PAGE_SHIFT =
12<o:p></o:p></p>
<p class="MsoNormal">Still got addr = 0xFFFF FFF0 0000,
which would cause ring gfx timeout.<o:p></o:p></p>
</blockquote>
<p class="MsoNormal"><br>
But 0xFFFF FFF0 0000 is the correct address, if that is
causing a problem then there is a bug somewhere else.<br>
<br>
Please try to use
AMDGPU_GMC_HOLE_START-AMDGPU_VA_RESERVED_SIZE as well.
Does that work?<br>
<br>
<br>
<br>
<br>
<o:p></o:p></p>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Before commit
1bf621c42137926ac249af761c0190a9258aa0db, vm_size was
32GB, and csa_addr was under AMDGPU_GMC_HOLE_START.<o:p></o:p></p>
</blockquote>
<p class="MsoNormal"><br>
Wait a second why was the vm_size 32GB? This is on a
Vega10 isn't it?<br>
<br>
<br>
<br>
<br>
<o:p></o:p></p>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">I didn’t understand why csa_addr need
to be above AMDGPU_GMC_HOLE_START now.<o:p></o:p></p>
</blockquote>
<p class="MsoNormal"><br>
On Vega10 the lower range, e.g. everything below
AMDGPU_GMC_HOLE_START is reserved for SVA.<br>
<br>
Regards,<br>
Christian.<br>
<br>
<br>
<br>
<br>
<o:p></o:p></p>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">Thanks.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">BR,<o:p></o:p></p>
<p class="MsoNormal">Wentao<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<div>
<div style="border:none;border-top:solid #E1E1E1
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> Koenig, Christian <a
href="mailto:Christian.Koenig@amd.com"
moz-do-not-send="true">
<Christian.Koenig@amd.com></a> <br>
<b>Sent:</b> Wednesday, January 16, 2019 5:48 PM<br>
<b>To:</b> Lou, Wentao <a
href="mailto:Wentao.Lou@amd.com"
moz-do-not-send="true"><Wentao.Lou@amd.com></a>;
Liu, Monk
<a href="mailto:Monk.Liu@amd.com"
moz-do-not-send="true"><Monk.Liu@amd.com></a>;
<a href="mailto:amd-gfx@lists.freedesktop.org"
moz-do-not-send="true">
amd-gfx@lists.freedesktop.org</a>; Zhu, Rex <a
href="mailto:Rex.Zhu@amd.com"
moz-do-not-send="true"><Rex.Zhu@amd.com></a><br>
<b>Cc:</b> Deng, Emily <a
href="mailto:Emily.Deng@amd.com"
moz-do-not-send="true"><Emily.Deng@amd.com></a><br>
<b>Subject:</b> Re: [PATCH] drm/amdgpu: csa_vaddr
should not larger than AMDGPU_GMC_HOLE_START<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"> <o:p></o:p></p>
<div>
<p class="MsoNormal">Hi Wentao,<br>
<br>
well the problem is you don't seem to understand how
the hardware works.<br>
<br>
See the engines see an MC address space with a hole in
the middle, similar to the how x86 64bit CPU address
space works. But the page tables are programmed
linearly.<br>
<br>
So the calculation in amdgpu_driver_open_kms() is
correct because it takes the MC address and mages a
linear page table index from it again.<br>
<br>
The only thing we might need to fix here is shifting
max_pfn before the subtraction and I doubt that even
that is necessary.<br>
<br>
Regards,<br>
Christian.<br>
<br>
Am 16.01.19 um 10:34 schrieb Lou, Wentao:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoPlainText">Hi Christian,<o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">Now vm_size was set to <span
style="background:yellow;mso-highlight:yellow">
0x4 0000</span> GB by below commit:<o:p></o:p></p>
<p class="MsoPlainText">1bf621c42137926ac249af761c0190a9258aa0db
drm/amdgpu: Remove unnecessary VM size calculations<o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">So that max_pfn would be <span
style="background:yellow;mso-highlight:yellow">
0x10 0000 0000.</span><o:p></o:p></p>
<p class="MsoPlainText">amdgpu_csa_vaddr would make
max_pfn << 12 to get 0x1 0000 0000 0000, and
then minus AMDGPU_VA_RESERVED_SIZE, to get
<span style="background:yellow;mso-highlight:yellow">0xFFFF
FFF0 0000</span><o:p></o:p></p>
<p class="MsoPlainText">unfortunately this number was
between AMDGPU_GMC_HOLE_START and AMDGPU_GMC_HOLE_END,
so that amdgpu_gmc_sign_extend was called to make it
<span style="background:yellow;mso-highlight:yellow">0xFFFF
FFFF FFF0 0000</span><o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">in amdgpu_driver_open_kms,
extended csa_addr cannot be passed into
amdgpu_map_static_csa directly, it would be above the
limit of max_pfn.<o:p></o:p></p>
<p class="MsoPlainText">So that csa_addr was restricted
by AMDGPU_GMC_HOLE_MASK to make it possible for
amdgpu_vm_alloc_pts.<o:p></o:p></p>
<p class="MsoPlainText">But this restriction by
AMDGPU_GMC_HOLE_MASK would make the address fall back
into AMDGPU_GMC_HOLE again, which causing GPU reset.<o:p></o:p></p>
<p class="MsoPlainText">We just put amdgpu_csa_vaddr
back to AMDGPU_GMC_HOLE_START, to avoid the address
touching AMDGPU_GMC_HOLE.<o:p></o:p></p>
<p class="MsoPlainText">By the way, if max_pfn was shift
much to the left, it would always get zero, with or
without min(*,*).<o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">BR,<o:p></o:p></p>
<p class="MsoPlainText">Wentao<o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">-----Original Message-----<br>
From: Koenig, Christian <a
href="mailto:Christian.Koenig@amd.com"
moz-do-not-send="true"><Christian.Koenig@amd.com></a>
<br>
Sent: Tuesday, January 15, 2019 4:02 PM<br>
To: Liu, Monk <a href="mailto:Monk.Liu@amd.com"
moz-do-not-send="true"><Monk.Liu@amd.com></a>;
Lou, Wentao
<a href="mailto:Wentao.Lou@amd.com"
moz-do-not-send="true"><Wentao.Lou@amd.com></a>;
<a href="mailto:amd-gfx@lists.freedesktop.org"
moz-do-not-send="true">
amd-gfx@lists.freedesktop.org</a>; Zhu, Rex <a
href="mailto:Rex.Zhu@amd.com" moz-do-not-send="true"><Rex.Zhu@amd.com></a><br>
Subject: Re: [PATCH] drm/amdgpu: csa_vaddr should not
larger than AMDGPU_GMC_HOLE_START<o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">Am 15.01.19 um 07:19 schrieb
Liu, Monk:<o:p></o:p></p>
<p class="MsoPlainText">> The max_pfn is now
1'0000'0000'0000'0000 (bytes) which is above 48 bit
now, and it with AMDGPU_GMC_HOLE_MASK make it to zero
....<o:p></o:p></p>
<p class="MsoPlainText">> <o:p></o:p></p>
<p class="MsoPlainText">> And in code
"amdgpu_driver_open_kms()" I saw @Zhu, Rex write the
code as :<o:p></o:p></p>
<p class="MsoPlainText">> <o:p></o:p></p>
<p class="MsoPlainText">> "csa_addr =
amdgpu_csa_vadr(adev) & AMDGPU_GMC_HOLE_MASK", I
think this is wrong since you intentionally place the
csa above GMC hole, right ?<o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">The fix is just completely
incorrect since min(adev->vm_manager.max_pfn
<< AMDGPU_GPU_PAGE_SHIFT, AMDGPU_GMC_HOLE_START)
still gives you 0 when we shift max_pfn to much to the
left.<o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">The correct solution is to
substract the reserved size first and then shift.
E.g.:<o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">addr = (max_pfn -
(AMDGPU_VA_RESERVED_SIZE >> AMDGPU_PAGE_SHIFT))
<< AMDGPU_PAGE_SHIFT;<o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">Regards,<o:p></o:p></p>
<p class="MsoPlainText">Christian.<o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
<p class="MsoPlainText">> <o:p></o:p></p>
<p class="MsoPlainText">> Looks like we should
modify this place<o:p></o:p></p>
<p class="MsoPlainText">> <o:p></o:p></p>
<p class="MsoPlainText">> /Monk<o:p></o:p></p>
<p class="MsoPlainText">> <o:p></o:p></p>
<p class="MsoPlainText">> -----Original Message-----<o:p></o:p></p>
<p class="MsoPlainText">> From: amd-gfx <<a
href="mailto:amd-gfx-bounces@lists.freedesktop.org"
moz-do-not-send="true"><span
style="text-decoration:none">amd-gfx-bounces@lists.freedesktop.org</span></a>>
On Behalf Of
<o:p></o:p></p>
<p class="MsoPlainText">> Christian K?nig<o:p></o:p></p>
<p class="MsoPlainText">> Sent: Monday, January 14,
2019 9:05 PM<o:p></o:p></p>
<p class="MsoPlainText">> To: Lou, Wentao <<a
href="mailto:Wentao.Lou@amd.com"
moz-do-not-send="true"><span
style="text-decoration:none">Wentao.Lou@amd.com</span></a>>;
<a href="mailto:amd-gfx@lists.freedesktop.org"
moz-do-not-send="true"><span
style="text-decoration:none">amd-gfx@lists.freedesktop.org</span></a><o:p></o:p></p>
<p class="MsoPlainText">> Subject: Re: [PATCH]
drm/amdgpu: csa_vaddr should not larger than
<o:p></o:p></p>
<p class="MsoPlainText">> AMDGPU_GMC_HOLE_START<o:p></o:p></p>
<p class="MsoPlainText">> <o:p></o:p></p>
<p class="MsoPlainText">> Am 14.01.19 um 09:40
schrieb wentalou:<o:p></o:p></p>
<p class="MsoPlainText">>> After removing
unnecessary VM size calculations, vm_manager.max_pfn
<o:p></o:p></p>
<p class="MsoPlainText">>> would reach
0x10,0000,0000 max_pfn << AMDGPU_GPU_PAGE_SHIFT
exceeding
<o:p></o:p></p>
<p class="MsoPlainText">>> AMDGPU_GMC_HOLE_START
would caused GPU reset.<o:p></o:p></p>
<p class="MsoPlainText">>> <o:p></o:p></p>
<p class="MsoPlainText">>> Change-Id:
I47ad0be2b0bd9fb7490c4e1d7bb7bdacf71132cb<o:p></o:p></p>
<p class="MsoPlainText">>> Signed-off-by: wentalou
<<a href="mailto:Wentao.Lou@amd.com"
moz-do-not-send="true"><span
style="text-decoration:none">Wentao.Lou@amd.com</span></a>><o:p></o:p></p>
<p class="MsoPlainText">> NAK, that is incorrect. We
intentionally place the csa above the GMC hole.<o:p></o:p></p>
<p class="MsoPlainText">> <o:p></o:p></p>
<p class="MsoPlainText">> Regards,<o:p></o:p></p>
<p class="MsoPlainText">> Christian.<o:p></o:p></p>
<p class="MsoPlainText">> <o:p></o:p></p>
<p class="MsoPlainText">>> ---<o:p></o:p></p>
<p class="MsoPlainText">>>
drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c | 3 ++-<o:p></o:p></p>
<p class="MsoPlainText">>> 1 file changed, 2
insertions(+), 1 deletion(-)<o:p></o:p></p>
<p class="MsoPlainText">>> <o:p></o:p></p>
<p class="MsoPlainText">>> diff --git
a/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c<o:p></o:p></p>
<p class="MsoPlainText">>>
b/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c<o:p></o:p></p>
<p class="MsoPlainText">>> index 7e22be7..dd3bd01
100644<o:p></o:p></p>
<p class="MsoPlainText">>> ---
a/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c<o:p></o:p></p>
<p class="MsoPlainText">>> +++
b/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c<o:p></o:p></p>
<p class="MsoPlainText">>> @@ -26,7 +26,8 @@<o:p></o:p></p>
<p class="MsoPlainText">>> <o:p></o:p></p>
<p class="MsoPlainText">>> uint64_t
amdgpu_csa_vaddr(struct amdgpu_device *adev)<o:p></o:p></p>
<p class="MsoPlainText">>> {<o:p></o:p></p>
<p class="MsoPlainText">>> - uint64_t addr
= adev->vm_manager.max_pfn <<
AMDGPU_GPU_PAGE_SHIFT;<o:p></o:p></p>
<p class="MsoPlainText">>> + uint64_t addr =
min(adev->vm_manager.max_pfn <<
AMDGPU_GPU_PAGE_SHIFT,<o:p></o:p></p>
<p class="MsoPlainText">>>
+
AMDGPU_GMC_HOLE_START);<o:p></o:p></p>
<p class="MsoPlainText">>> <o:p></o:p></p>
<p class="MsoPlainText">>> addr -=
AMDGPU_VA_RESERVED_SIZE;<o:p></o:p></p>
<p class="MsoPlainText">>> addr =
amdgpu_gmc_sign_extend(addr);<o:p></o:p></p>
<p class="MsoPlainText">>
_______________________________________________<o:p></o:p></p>
<p class="MsoPlainText">> amd-gfx mailing list<o:p></o:p></p>
<p class="MsoPlainText">> <a
href="mailto:amd-gfx@lists.freedesktop.org"
moz-do-not-send="true"><span
style="text-decoration:none">amd-gfx@lists.freedesktop.org</span></a><o:p></o:p></p>
<p class="MsoPlainText">> <a
href="https://lists.freedesktop.org/mailman/listinfo/amd-gfx"
moz-do-not-send="true">
<span style="text-decoration:none">https://lists.freedesktop.org/mailman/listinfo/amd-gfx</span></a><o:p></o:p></p>
<p class="MsoPlainText"> <o:p></o:p></p>
</blockquote>
<p class="MsoNormal"> <o:p></o:p></p>
</blockquote>
<p class="MsoNormal"> <o:p></o:p></p>
</blockquote>
<p class="MsoNormal"> <o:p></o:p></p>
</blockquote>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
amd-gfx mailing list
<a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a>
<a class="moz-txt-link-freetext" href="https://lists.freedesktop.org/mailman/listinfo/amd-gfx">https://lists.freedesktop.org/mailman/listinfo/amd-gfx</a>
</pre>
</blockquote>
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