On 2021/6/7 20:38, Marek Vasut wrote:
On 6/7/21 2:05 PM, Frieder Schrempf wrote:
From: Frieder Schrempf frieder.schrempf@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 ?
That could cause extra mem copy. Bounce buffer would be good for systems that take U-Boot as UEFI firmware, because U-Boot would be located at high end, but in the middle just top of 4GB.
I not object this patch, but it also be good if bounce buffer be added for improvement.
Reviewed-by: Peng Fan peng.fan@nxp.com