Re: Xen on RP4

[Elliott Mitchell <ehem+xen@xxxxxxx>]

On Fri, Oct 23, 2020 at 04:59:30PM -0700, Stefano Stabellini wrote:
> Note that I tried to repro the issue here at my end but it works for me
> with device tree. So the swiotlb_init memory allocation failure probably
> only shows on ACPI, maybe because ACPI is reserving too much low memory.

Found it.  Take a look at 437b0aa06a014ce174e24c0d3530b3e9ab19b18b

 PLATFORM_START(rpi4, "Raspberry Pi 4")
     .compatible     = rpi4_dt_compat,
     .blacklist_dev  = rpi4_blacklist_dev,
+    .dma_bitsize    = 30,
 PLATFORM_END

Where this is used to match against a *device-tree*.  ACPI has a distinct
means of specifying a limited DMA-width; the above fails, because it
assumes a *device-tree*.


-- 
(\___(\___(\______          --=> 8-) EHM <=--          ______/)___/)___/)
 \BS (    |         ehem+sigmsg@xxxxxxx  PGP 87145445         |    )   /
  \_CS\   |  _____  -O #include <stddisclaimer.h> O-   _____  |   /  _/
8A19\___\_|_/58D2 7E3D DDF4 7BA6 <-PGP-> 41D1 B375 37D0 8714\_|_/___/5445