Commit 556e4c62 authored by Woods, Brian's avatar Woods, Brian Committed by Borislav Petkov
Browse files

x86/amd_nb: Add support for newer PCI topologies 



Add support for new processors which have multiple PCI root complexes
per data fabric/system management network interface.  If there are (N)
multiple PCI roots per DF/SMN interface, then the PCI roots are
redundant (as far as SMN/DF access goes).  For each DF/SMN interface:
map to the first available PCI root and skip the next N-1 PCI roots so
the following DF/SMN interface get mapped to a correct PCI root.

Ex:
DF/SMN 0 -> 60
	    40
	    20
	    00
DF/SMN 1 -> e0
	    c0
	    a0
	    80

Signed-off-by: default avatarBrian Woods <brian.woods@amd.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Clemens Ladisch <clemens@ladisch.de>
CC: Guenter Roeck <linux@roeck-us.net>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: Jean Delvare <jdelvare@suse.com>
CC: Jia Zhang <qianyue.zj@alibaba-inc.com>
CC: <linux-hwmon@vger.kernel.org>
CC: <linux-pci@vger.kernel.org>
CC: Pu Wen <puwen@hygon.cn>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20181106200754.60722-3-brian.woods@amd.com
parent dedf7dce

arch/x86/kernel/amd_nb.c

+38 −6
Original line number Diff line number Diff line
@@ -213,7 +213,10 @@ int amd_cache_northbridges(void) 
	const struct pci_device_id *root_ids = amd_root_ids;

	struct pci_dev *root, *misc, *link;

	struct amd_northbridge *nb;

	u16 i = 0;

	u16 roots_per_misc = 0;

	u16 misc_count = 0;

	u16 root_count = 0;

	u16 i, j;



	if (amd_northbridges.num)

		return 0;
@@ -226,26 +229,55 @@ int amd_cache_northbridges(void) 


	misc = NULL;

	while ((misc = next_northbridge(misc, misc_ids)) != NULL)

		i++;

		misc_count++;



	if (!i)

	if (!misc_count)

		return -ENODEV;



	nb = kcalloc(i, sizeof(struct amd_northbridge), GFP_KERNEL);

	root = NULL;

	while ((root = next_northbridge(root, root_ids)) != NULL)

		root_count++;



	if (root_count) {

		roots_per_misc = root_count / misc_count;



		/*

		 * There should be _exactly_ N roots for each DF/SMN

		 * interface.

		 */

		if (!roots_per_misc || (root_count % roots_per_misc)) {

			pr_info("Unsupported AMD DF/PCI configuration found\n");

			return -ENODEV;

		}

	}



	nb = kcalloc(misc_count, sizeof(struct amd_northbridge), GFP_KERNEL);

	if (!nb)

		return -ENOMEM;



	amd_northbridges.nb = nb;

	amd_northbridges.num = i;

	amd_northbridges.num = misc_count;



	link = misc = root = NULL;

	for (i = 0; i != amd_northbridges.num; i++) {

	for (i = 0; i < amd_northbridges.num; i++) {

		node_to_amd_nb(i)->root = root =

			next_northbridge(root, root_ids);

		node_to_amd_nb(i)->misc = misc =

			next_northbridge(misc, misc_ids);

		node_to_amd_nb(i)->link = link =

			next_northbridge(link, link_ids);



		/*

		 * If there are more PCI root devices than data fabric/

		 * system management network interfaces, then the (N)

		 * PCI roots per DF/SMN interface are functionally the

		 * same (for DF/SMN access) and N-1 are redundant.  N-1

		 * PCI roots should be skipped per DF/SMN interface so

		 * the following DF/SMN interfaces get mapped to

		 * correct PCI roots.

		 */

		for (j = 1; j < roots_per_misc; j++)

			root = next_northbridge(root, root_ids);

	}



	if (amd_gart_present())

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