On 2023-10-18 21:53, Chris Packham wrote:
Since commit 6cdf6b7a340d ("arm64: Use FEAT_HAFDBS to track dirty pages
when available") the default get_page_table_size() sets some flags for
more efficient handling of dirty page table entries. This causes
problems on the AC5/AC5X SoC (specifically a lockup when calling
__asm_switch_ttbr() via mmu_set_region_dcache_behaviour()).
The reason for the lockup isn't at all clear but it can be avoided if
we
provide our own get_page_table_size() which stops gd->arch.has_hafdbs
from being set to true effectively returning the AC5/AC5X to the older
behaviour. This also opts for a simple fixed page table size rather
than
trying to duplicate the more complicated logic to optimise the table
size.
Signed-off-by: Chris Packham <judge.pack...@gmail.com>
---
arch/arm/mach-mvebu/alleycat5/cpu.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/arm/mach-mvebu/alleycat5/cpu.c
b/arch/arm/mach-mvebu/alleycat5/cpu.c
index 8204d9627515..7ba57ae75e76 100644
--- a/arch/arm/mach-mvebu/alleycat5/cpu.c
+++ b/arch/arm/mach-mvebu/alleycat5/cpu.c
@@ -63,6 +63,11 @@ static struct mm_region ac5_mem_map[] = {
struct mm_region *mem_map = ac5_mem_map;
+u64 get_page_table_size(void)
+{
+ return 0x80000;
+}
+
void reset_cpu(void)
{
}
This looks terribly wrong. In all honesty, if the original
patch creates problems and that people add this sort of stuff
to paper over it, I'd rather your *revert* my patch altogether.
M.
--
Jazz is not dead. It just smells funny...
