Commit 77466b79 authored by Yazen Ghannam's avatar Yazen Ghannam Committed by Borislav Petkov (AMD)
Browse files

x86/amd_node: Remove dependency on AMD_NB 



Cache the root devices locally so that there are no more dependencies on
AMD_NB.

Signed-off-by: default avatarYazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20241206161210.163701-13-yazen.ghannam@amd.com
parent 35df7976

arch/x86/kernel/amd_node.c

+39 −3
Original line number Diff line number Diff line
@@ -8,7 +8,6 @@ 
 * Author: Yazen Ghannam <Yazen.Ghannam@amd.com>

 */



#include <asm/amd_nb.h>

#include <asm/amd_node.h>



/*
@@ -90,6 +89,8 @@ struct pci_dev *amd_node_get_root(u16 node) 
	return root;

}



static struct pci_dev **amd_roots;



/* Protect the PCI config register pairs used for SMN. */

static DEFINE_MUTEX(smn_mutex);
@@ -135,10 +136,10 @@ static int __amd_smn_rw(u16 node, u32 address, u32 *value, bool write) 
	struct pci_dev *root;

	int err = -ENODEV;



	if (node >= amd_nb_num())

	if (node >= amd_num_nodes())

		return err;



	root = node_to_amd_nb(node)->root;

	root = amd_roots[node];

	if (!root)

		return err;
@@ -174,3 +175,38 @@ int __must_check amd_smn_write(u16 node, u32 address, u32 value) 
	return __amd_smn_rw(node, address, &value, true);

}

EXPORT_SYMBOL_GPL(amd_smn_write);



static int amd_cache_roots(void)

{

	u16 node, num_nodes = amd_num_nodes();



	amd_roots = kcalloc(num_nodes, sizeof(*amd_roots), GFP_KERNEL);

	if (!amd_roots)

		return -ENOMEM;



	for (node = 0; node < num_nodes; node++)

		amd_roots[node] = amd_node_get_root(node);



	return 0;

}



static int __init amd_smn_init(void)

{

	int err;



	if (!cpu_feature_enabled(X86_FEATURE_ZEN))

		return 0;



	guard(mutex)(&smn_mutex);



	if (amd_roots)

		return 0;



	err = amd_cache_roots();

	if (err)

		return err;



	return 0;

}



fs_initcall(amd_smn_init);