Commit 06cce43c authored by Dale Farnsworth's avatar Dale Farnsworth Committed by Paul Mackerras

[POWERPC] Check cache coherency of kernel vs firmware

check_cache_coherency() verifies that the cache coherency setting of
the kernel (CONFIG_NOT_COHERENT_CACHE) matches that left by the firmware,
as indicated by coherency-off device tree property.
Signed-off-by: default avatarDale Farnsworth <dale@farnsworth.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent e1a3107b
......@@ -389,6 +389,9 @@ config NOT_COHERENT_CACHE
bool
depends on 4xx || 8xx || E200
default y
config CONFIG_CHECK_CACHE_COHERENCY
bool
endmenu
source "init/Kconfig"
......
......@@ -530,3 +530,44 @@ void __init setup_panic(void)
{
atomic_notifier_chain_register(&panic_notifier_list, &ppc_panic_block);
}
#ifdef CONFIG_CHECK_CACHE_COHERENCY
/*
* For platforms that have configurable cache-coherency. This function
* checks that the cache coherency setting of the kernel matches the setting
* left by the firmware, as indicated in the device tree. Since a mismatch
* will eventually result in DMA failures, we print * and error and call
* BUG() in that case.
*/
#ifdef CONFIG_NOT_COHERENT_CACHE
#define KERNEL_COHERENCY 0
#else
#define KERNEL_COHERENCY 1
#endif
static int __init check_cache_coherency(void)
{
struct device_node *np;
const void *prop;
int devtree_coherency;
np = of_find_node_by_path("/");
prop = of_get_property(np, "coherency-off", NULL);
of_node_put(np);
devtree_coherency = prop ? 0 : 1;
if (devtree_coherency != KERNEL_COHERENCY) {
printk(KERN_ERR
"kernel coherency:%s != device tree_coherency:%s\n",
KERNEL_COHERENCY ? "on" : "off",
devtree_coherency ? "on" : "off");
BUG();
}
return 0;
}
late_initcall(check_cache_coherency);
#endif /* CONFIG_CHECK_CACHE_COHERENCY */
......@@ -49,6 +49,7 @@ config MPC10X_BRIDGE
config MV64X60
bool
select PPC_INDIRECT_PCI
select CONFIG_CHECK_CACHE_COHERENCY
config MPC10X_OPENPIC
bool
......
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