From 1a48b0be93d48f9ec5498297ec775fb572d3d150 Mon Sep 17 00:00:00 2001
From: Sughosh Ganu <sughosh.ganu@linaro.org>
Date: Mon, 2 Dec 2024 12:36:24 +0530
Subject: [PATCH] lmb: prohibit allocations above ram_top even from same bank
There are platforms which set the value of ram_top based on certain
restrictions that the platform might have in accessing memory above
ram_top, even when the memory region is in the same DRAM bank. So,
even though the LMB allocator works as expected, when trying to
allocate memory above ram_top, prohibit this by marking all memory
above ram_top as reserved, even if the said memory region is from the
same bank.
Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Tested-by: Andreas Schwab <schwab@suse.de>
---
lib/lmb.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/lib/lmb.c b/lib/lmb.c
index 3a765c11be..b03237bc06 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -606,6 +606,7 @@ static __maybe_unused void lmb_reserve_common_spl(void)
void lmb_add_memory(void)
{
int i;
+ phys_addr_t bank_end;
phys_size_t size;
u64 ram_top = gd->ram_top;
struct bd_info *bd = gd->bd;
@@ -619,6 +620,8 @@ void lmb_add_memory(void)
for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
size = bd->bi_dram[i].size;
+ bank_end = bd->bi_dram[i].start + size;
+
if (size) {
lmb_add(bd->bi_dram[i].start, size);
@@ -630,6 +633,9 @@ void lmb_add_memory(void)
if (bd->bi_dram[i].start >= ram_top)
lmb_reserve_flags(bd->bi_dram[i].start, size,
LMB_NOOVERWRITE);
+ else if (bank_end > ram_top)
+ lmb_reserve_flags(ram_top, bank_end - ram_top,
+ LMB_NOOVERWRITE);
}
}
}
--
2.39.5