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

[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

arch/powerpc/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -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"

arch/powerpc/kernel/setup-common.c

+41 −0
Original line number Diff line number Diff line
@@ -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 */

arch/powerpc/platforms/embedded6xx/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ config MPC10X_BRIDGE 
config MV64X60

	bool

	select PPC_INDIRECT_PCI

	select CONFIG_CHECK_CACHE_COHERENCY



config MPC10X_OPENPIC

	bool