[PATCH v2 for-4.14 3/3] xen/arm: plat: Allocate as much as possible memory below 1GB for dom0 for RPI

[Julien Grall <julien@xxxxxxx>]

From: Julien Grall <jgrall@xxxxxxxxxx>

The raspberry PI 4 has devices that can only DMA into the first GB of
the RAM. Therefore we want allocate as much as possible memory below 1GB
for dom0.

Use the recently introduced dma_bitsize field to specify the DMA width
supported.

Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
Reported-by: Corey Minyard <minyard@xxxxxxx>
Tested-by: Corey Minyard <cminyard@xxxxxxxxxx>

---
    Changes in v2:
        - 1G is 30 bits not 10!
        - Add Corey's tested-by
---
 xen/arch/arm/platforms/brcm-raspberry-pi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xen/arch/arm/platforms/brcm-raspberry-pi.c 
b/xen/arch/arm/platforms/brcm-raspberry-pi.c
index b697fa2c6c0e..f5ae58a7d5f2 100644
--- a/xen/arch/arm/platforms/brcm-raspberry-pi.c
+++ b/xen/arch/arm/platforms/brcm-raspberry-pi.c
@@ -43,6 +43,7 @@ static const struct dt_device_match rpi4_blacklist_dev[] 
__initconst =
 PLATFORM_START(rpi4, "Raspberry Pi 4")
     .compatible     = rpi4_dt_compat,
     .blacklist_dev  = rpi4_blacklist_dev,
+    .dma_bitsize    = 30,
 PLATFORM_END
 
 /*
-- 
2.17.1