Hello *,
Sorry for delay, but i have to understand a lot things before answering (:

On 23/11/2016 14:25, Nico Huber wrote:
Hi,

On 23.11.2016 11:09, Pitrolle Jean-Jacques wrote:
Hello *,
I try to integrate coreboot *libpayload usb stack* in a custom binary
for x86.
I already succeed integration of *ehci* for *qemu* and *core 2 duo*
platforms.

But things seems to be not so easy for *xhci*.
When I try to run coreboot master branch (with hash 8bf3f7a) on qemu
(version 2.7.0)
with following line :
  % qemu-system-x86_64 -bios build/coreboot.rom -serial stdio -drive
if=none,id=usbstick,file=/tmp/qemu_usb.disk -usb -device
nec-usb-xhci,id=xhci -device usb-storage,bus=xhci.0,drive=usbstick

I get these output lines concerning xHCI controller (nec-usb-xhci) :
8<---
[..]
00:04.0 0194:1033.0 xHCI controller
xhci_init: regbase: 0xfe070000
xhci_init: caplen:  0x40
xhci_init: rtsoff:  0x1000
xhci_init: dboff:   0x2000
xhci_init: hciversion: 0.0
xhci_init: Unsupported xHCI version
[..]
--->8

The same result is reached with qemu-system-i386...

Is it the expected result on qemu?
it looks odd to me. We wrote the ancestor of this xHCI driver against
qemu but stopped testing it when we switched to real hardware. I would
have expected an hciversion around 0.9*. The libpayload driver currently
checks for hciversion > 0.96. The values above hciversion look sane, so
I suspect  qemu to tell a bad version.

The functions that access virtual xHCI only works for 4 bytes access.
For example, if i read capability register
  - access to offset 0, size access 4 bytes : 1000040
  - access to offset 2, size access 2 bytes : 00  *wrong value*
  - access to offset 2 and 3, size access 1 bytes: 0 - 0 *wrong value*
The 8bit/16bit reads are not properly honored.

Moreover, the previous *used* qemu (2.7.0) compiled by my own with custom configuration
seems to be broken (i don't go too deep in investigation right now)..
Everything is ok with *upstream* qemu (hash : 00227f - version : 2.7.91 _ v2.8.0-rc1-dirty)
I don't have any motherboard supported by coreboot, so I try a custom
binary  on
How is this custom binary build? In which environment does it run? It's
hard to make assumptions about the driver without knowing the details.

a *Xeon* processor (processor D-1500).
So you are using the xHCI controller built into the SoC? or an extension
card?
I use xHCI controller built into SoC.
The xHCI version is supported (hciversion: 1.0) but things turn bad when
starting
xHCI controller i.e xhci->opreg->usbcmd |= USBCMD_RS in *xhci_start* :
the program hangs...
The registers usbcmd and usbsts before this command seems to have proper
values (a usb key
is connected.)
8<---
[..]
  xhci_start - usbcmd:0 - usbsts:11
[..]
--->8

This seems to be related to interrupter configuration. When I comment
out the two lines
in *xhci_reinit*
8<---
[..]
     xhci->hcrreg->intrrs[0].erstba_lo = virt_to_phys(xhci->ev_ring_table);
I'd suspect that the address returned by virt_to_phys() is wrong or not
accessible by the controller.
Hmm, seems not as it work properly with rigth qemu version.
     xhci->hcrreg->intrrs[0].erstba_hi = 0;
Are you sure it's a 32-bit address?
I used a 32 bits compiler, so i expect it..
Do i need to setup something else (in bios for example)?
[..]
--->8
xhci_start works as expected i.e not hangs.

But the sequence following with *NOOP* to test command ring and event
ring mechanism fails.
8<---
[..]
NOOP run #0
Transfer TRB (@0x8051700):
  PTR_L  0x00000000
  PTR_H  0x00000000
  STATUS 0x00000000
  CNTRL  0x00005c00
  TL     0x0000
  TDS    0x0000
  C      0x0000
  ISP    0x0000
  CH     0x0000
  IOC    0x0000
  IDT    0x0000
  TT     0x0017
  DIR    0x0000
Command 23 (@0x8051700)
Warning: Timed out waiting for TRB_EV_CMD_CMPL.
Command ring is running
[..]
--->8

As I understand it is mandatory to have the first interrupter configure
to manage
at least one event ring (4.9.4 Event Ring Management - eXtensible Host
Controller Interface
Revision 1.1).

Does someone succeed with xHCI support for x86 board?
Did I miss something concerning xHCI configuration?
It's working in coreboot payloads in many production systems.
With values read from registers dboff (0x3000) and rtsoff (0x2000) and not values provided in datasheet (*wrong values*) write to USBCMD register to start controller works as expected : there
is no weird hanging.
The problem came from *extended capability register* xCAP. In my case it is mandatory to release xHCI controller from BIOS. "HC BIOS Owned Semaphore" must be set to 0 and "HC OS Owned Semaphore" must
be set to 1.
Nico
So things go ahead :
  - enumeration of a usb-key on *qemu* works properly.
  - *but* i still have a problem on Xeon (Broadwell-DE SoC).

The problem concerns event ring during enable slot command :
8<---
[..]
Command 9 (@0x8052240)
Transfer TRB (@0x8052240):
 PTR_L  0x00000000
 PTR_H  0x00000000
 STATUS 0x00000000
 CNTRL  0x00002400
 TL     0x0000
 TDS    0x0000
 C      0x0000
 ISP    0x0000
 CH     0x0000
 IOC    0x0000
 IDT    0x0000
 TT     0x0009
 DIR    0x0000
_____address:8052240 phys:d79240 low:0 high:0 s:0 c:8052240
--->8

The dump of TRB is located in *xhci_post_command* just after xhci_debug and before TRB_SET.

The line "_____address:8052240 phys:d79240 low:0 high:0 s:0 c:8052240" is located in *xhci_wait_for_command_done* just before while (xhci_wait_for_event_type(xhci, TRB_EV_CMD_CMPL, &timeout_us))

Do i need to flush cache if event and command rings are located in "normal" memory? I use a custom allocator and for now it is not possible to allocate memory as "uncachable"

Is is possible to check proper initialization of event and command rings?
I see nothing relevant in xHCI standard concerning this.

Thanks.

--
Jean-Jacques PITROLLE
Phone: +33 1 30 09 12 70
SYSGO S.A.S


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