cmd: cache: Fix non-cached memory cachability
If dcache is switched OFF to ON state and if non-cached memory is
used, this non-cached memory must be re-declared as uncached to mmu
each time dcache is set ON.
Introduce noncached_set_region() to set this non-cached region's mmu
settings. Let architecture override it by defining it as a weak
function.
For ARM architecture, noncached_set_region() defines all noncached
region as non-cacheable.
Issue found on STM32MP1 platform using dwc_eth_qos ethernet driver,
when going from dcache OFF to dcache ON state, ethernet driver issued
TX timeout errors when performing dhcp or ping.
It can be reproduced with the following sequence:
dhcp
while true ; do
ping 192.168.1.300 ;
dcache off ;
ping 192.168.1.300 ;
dcache on ;
done
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Cc: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c
index 44dde26..224f2ae 100644
--- a/arch/arm/lib/cache.c
+++ b/arch/arm/lib/cache.c
@@ -75,6 +75,15 @@
static unsigned long noncached_end;
static unsigned long noncached_next;
+void noncached_set_region(void)
+{
+#if !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
+ mmu_set_region_dcache_behaviour(noncached_start,
+ noncached_end - noncached_start,
+ DCACHE_OFF);
+#endif
+}
+
void noncached_init(void)
{
phys_addr_t start, end;
@@ -91,9 +100,7 @@
noncached_end = end;
noncached_next = start;
-#if !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
- mmu_set_region_dcache_behaviour(noncached_start, size, DCACHE_OFF);
-#endif
+ noncached_set_region();
}
phys_addr_t noncached_alloc(size_t size, size_t align)
diff --git a/cmd/cache.c b/cmd/cache.c
index 27dcec0..7678615 100644
--- a/cmd/cache.c
+++ b/cmd/cache.c
@@ -20,6 +20,10 @@
puts("No arch specific invalidate_icache_all available!\n");
}
+__weak void noncached_set_region(void)
+{
+}
+
static int do_icache(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
switch (argc) {
@@ -64,6 +68,7 @@
break;
case 1:
dcache_enable();
+ noncached_set_region();
break;
case 2:
flush_dcache_all();