From 5e0404ff85fca50b5ac41bf08bbe46e6de4903e7 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Tue, 27 Aug 2019 11:54:31 -0600 Subject: board_f: fix noncached reservation calculation The current code in reserve_noncached() has two issues: 1) The first update of gd->start_addr_sp always rounds down to a section start. However, the equivalent calculation in cache.c:noncached_init() always first rounds up to a section start, then subtracts a section size. These two calculations differ if the initial value is already rounded to section alignment. 2) The second update of gd->start_addr_sp subtracts exactly CONFIG_SYS_NONCACHED_MEMORY, whereas the equivalent calculation in cache.c:noncached_init() rounds the noncached size up to section alignment before subtracting it. The two calculations differ if the noncached region size is not a multiple of the MMU section size. In practice, one/both of those issues causes a practical problem on Jetson TX1; U-Boot triggers a synchronous abort during initialization, likely due to overlapping use of some memory region. This change fixes both these issues by duplicating the exact calculations from noncached_init() into reserve_noncached(). However, this fix assumes that gd->start_addr_sp on entry to reserve_noncached() exactly matches mem_malloc_start on entry to noncached_init(). I haven't traced the code to see whether it absolutely guarantees this in all (or indeed any!) cases. Consequently, I added some comments in the hope that this condition will continue to be true. Fixes: 5f7adb5b1c02 ("board_f: reserve noncached space below malloc area") Cc: Vikas Manocha Signed-off-by: Stephen Warren --- common/board_r.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'common/board_r.c') diff --git a/common/board_r.c b/common/board_r.c index b7f68bba4a7..d6fb5047a26 100644 --- a/common/board_r.c +++ b/common/board_r.c @@ -247,6 +247,10 @@ static int initr_malloc(void) gd->malloc_ptr / 1024); #endif /* The malloc area is immediately below the monitor copy in DRAM */ + /* + * This value MUST match the value of gd->start_addr_sp in board_f.c: + * reserve_noncached(). + */ malloc_start = gd->relocaddr - TOTAL_MALLOC_LEN; mem_malloc_init((ulong)map_sysmem(malloc_start, TOTAL_MALLOC_LEN), TOTAL_MALLOC_LEN); -- cgit v1.2.3