[PATCH 4/6] imx8m: Restrict usable memory to space below 4G boundary

[Marek Vasut]

On 6/7/21 2:05 PM, Frieder Schrempf wrote:
> From: Frieder Schrempf <frieder.schrempf at kontron.de>
> 
> Some IPs have their accessible address space restricted by the
> interconnect. Let's make sure U-Boot only ever uses the space below
> the 4G address boundary (which is 3GiB big), even when the effective
> available memory is bigger.
> 
> We implement board_get_usable_ram_top() for all i.MX8M SoCs, as the
> whole family is affected by this.

Shouldn't only those specific IP drivers handle buffers in the 64bit 
space somehow ? E.g. using a bounce buffer ?