On 02.08.21 12:48, Marek Vasut wrote:
On 8/2/21 11:37 AM, Jan Kiszka wrote:
On 02.08.21 02:54, Marek Vasut wrote:
On 7/29/21 6:58 PM, Tom Rini wrote:
[...]
so when did rcar3 introduce something there that shouldn't be reserved? And you had phrased this to me on IRC as about reserving spot for ATAGS, and that not being needed of course on arm64. But that's not what's going on. Perhaps the answer is that rcar3 needs to introduce a board_lmb_reserve to free the normal arch one and provide whatever more narrow scope it needs.
Based on the commit message 2359fa7a878 ("arm: bootm: Disable LMB reservation for command line and board info on arm64") , this is about ATAGS and we really don't need to reserve those on arm64.
Commit 2359fa7a878 disables the entire arch_lmb_reserve function on aarch64, yes. I assumed when we had talked that it was a small area being set aside and perhaps mis-recalled that ATAGS tended to live at DDR_BASE + 0x800 or so.
That arch_lmb_reserve() is responsible for reserving architecture specific memory. On arm32 it is ATAGS, on arm64 it is nothing as far as I can tell (and see below regarding the TLB).
This reservation is not at that spot, and a lot more than that.
Can you please elaborate on this "lot more" part ? Because as much as I studied the reservation code, the "lot more" was ATAGS on arm32 and nothing on arm64.
See my commit log.
This is not particularly useful answer, considering the commit log says: "lot of crucial things", "Possibly more", "likely also on other boards" and other opaque statements. But really, the problem so far happens on one K3 board.
"Such things are the page table (tlb_addr), relocated U-Boot and the active stack."
Jan