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authorJakub Kicinski <kuba@kernel.org>2025-11-13 12:32:50 -0800
committerJakub Kicinski <kuba@kernel.org>2025-11-13 12:35:38 -0800
commitc99ebb6132595b4b288a413981197eb076547c5a (patch)
tree6ef2de29b7afb5f1107b8e11489c09f0a5290260 /arch/x86/kernel/amd_node.c
parentf694d215d34035cc64b1d176fd82db0d1f2428d4 (diff)
parentd0309c054362a235077327b46f727bc48878a3bc (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.18-rc6). No conflicts, adjacent changes in: drivers/net/phy/micrel.c 96a9178a29a6 ("net: phy: micrel: lan8814 fix reset of the QSGMII interface") 61b7ade9ba8c ("net: phy: micrel: Add support for non PTP SKUs for lan8814") and a trivial one in tools/testing/selftests/drivers/net/Makefile. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'arch/x86/kernel/amd_node.c')
-rw-r--r--arch/x86/kernel/amd_node.c150
1 files changed, 51 insertions, 99 deletions
diff --git a/arch/x86/kernel/amd_node.c b/arch/x86/kernel/amd_node.c
index a40176b62eb5..3d0a4768d603 100644
--- a/arch/x86/kernel/amd_node.c
+++ b/arch/x86/kernel/amd_node.c
@@ -34,62 +34,6 @@ struct pci_dev *amd_node_get_func(u16 node, u8 func)
return pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(AMD_NODE0_PCI_SLOT + node, func));
}
-#define DF_BLK_INST_CNT 0x040
-#define DF_CFG_ADDR_CNTL_LEGACY 0x084
-#define DF_CFG_ADDR_CNTL_DF4 0xC04
-
-#define DF_MAJOR_REVISION GENMASK(27, 24)
-
-static u16 get_cfg_addr_cntl_offset(struct pci_dev *df_f0)
-{
- u32 reg;
-
- /*
- * Revision fields added for DF4 and later.
- *
- * Major revision of '0' is found pre-DF4. Field is Read-as-Zero.
- */
- if (pci_read_config_dword(df_f0, DF_BLK_INST_CNT, &reg))
- return 0;
-
- if (reg & DF_MAJOR_REVISION)
- return DF_CFG_ADDR_CNTL_DF4;
-
- return DF_CFG_ADDR_CNTL_LEGACY;
-}
-
-struct pci_dev *amd_node_get_root(u16 node)
-{
- struct pci_dev *root;
- u16 cntl_off;
- u8 bus;
-
- if (!cpu_feature_enabled(X86_FEATURE_ZEN))
- return NULL;
-
- /*
- * D18F0xXXX [Config Address Control] (DF::CfgAddressCntl)
- * Bits [7:0] (SecBusNum) holds the bus number of the root device for
- * this Data Fabric instance. The segment, device, and function will be 0.
- */
- struct pci_dev *df_f0 __free(pci_dev_put) = amd_node_get_func(node, 0);
- if (!df_f0)
- return NULL;
-
- cntl_off = get_cfg_addr_cntl_offset(df_f0);
- if (!cntl_off)
- return NULL;
-
- if (pci_read_config_byte(df_f0, cntl_off, &bus))
- return NULL;
-
- /* Grab the pointer for the actual root device instance. */
- root = pci_get_domain_bus_and_slot(0, bus, 0);
-
- pci_dbg(root, "is root for AMD node %u\n", node);
- return root;
-}
-
static struct pci_dev **amd_roots;
/* Protect the PCI config register pairs used for SMN. */
@@ -274,51 +218,21 @@ DEFINE_SHOW_STORE_ATTRIBUTE(smn_node);
DEFINE_SHOW_STORE_ATTRIBUTE(smn_address);
DEFINE_SHOW_STORE_ATTRIBUTE(smn_value);
-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 reserve_root_config_spaces(void)
+static struct pci_dev *get_next_root(struct pci_dev *root)
{
- struct pci_dev *root = NULL;
- struct pci_bus *bus = NULL;
-
- while ((bus = pci_find_next_bus(bus))) {
- /* Root device is Device 0 Function 0 on each Primary Bus. */
- root = pci_get_slot(bus, 0);
- if (!root)
+ while ((root = pci_get_class(PCI_CLASS_BRIDGE_HOST << 8, root))) {
+ /* Root device is Device 0 Function 0. */
+ if (root->devfn)
continue;
if (root->vendor != PCI_VENDOR_ID_AMD &&
root->vendor != PCI_VENDOR_ID_HYGON)
continue;
- pci_dbg(root, "Reserving PCI config space\n");
-
- /*
- * There are a few SMN index/data pairs and other registers
- * that shouldn't be accessed by user space.
- * So reserve the entire PCI config space for simplicity rather
- * than covering specific registers piecemeal.
- */
- if (!pci_request_config_region_exclusive(root, 0, PCI_CFG_SPACE_SIZE, NULL)) {
- pci_err(root, "Failed to reserve config space\n");
- return -EEXIST;
- }
+ break;
}
- smn_exclusive = true;
- return 0;
+ return root;
}
static bool enable_dfs;
@@ -332,7 +246,8 @@ __setup("amd_smn_debugfs_enable", amd_smn_enable_dfs);
static int __init amd_smn_init(void)
{
- int err;
+ u16 count, num_roots, roots_per_node, node, num_nodes;
+ struct pci_dev *root;
if (!cpu_feature_enabled(X86_FEATURE_ZEN))
return 0;
@@ -342,13 +257,48 @@ static int __init amd_smn_init(void)
if (amd_roots)
return 0;
- err = amd_cache_roots();
- if (err)
- return err;
+ num_roots = 0;
+ root = NULL;
+ while ((root = get_next_root(root))) {
+ pci_dbg(root, "Reserving PCI config space\n");
- err = reserve_root_config_spaces();
- if (err)
- return err;
+ /*
+ * There are a few SMN index/data pairs and other registers
+ * that shouldn't be accessed by user space. So reserve the
+ * entire PCI config space for simplicity rather than covering
+ * specific registers piecemeal.
+ */
+ if (!pci_request_config_region_exclusive(root, 0, PCI_CFG_SPACE_SIZE, NULL)) {
+ pci_err(root, "Failed to reserve config space\n");
+ return -EEXIST;
+ }
+
+ num_roots++;
+ }
+
+ pr_debug("Found %d AMD root devices\n", num_roots);
+
+ if (!num_roots)
+ return -ENODEV;
+
+ num_nodes = amd_num_nodes();
+ amd_roots = kcalloc(num_nodes, sizeof(*amd_roots), GFP_KERNEL);
+ if (!amd_roots)
+ return -ENOMEM;
+
+ roots_per_node = num_roots / num_nodes;
+
+ count = 0;
+ node = 0;
+ root = NULL;
+ while (node < num_nodes && (root = get_next_root(root))) {
+ /* Use one root for each node and skip the rest. */
+ if (count++ % roots_per_node)
+ continue;
+
+ pci_dbg(root, "is root for AMD node %u\n", node);
+ amd_roots[node++] = root;
+ }
if (enable_dfs) {
debugfs_dir = debugfs_create_dir("amd_smn", arch_debugfs_dir);
@@ -358,6 +308,8 @@ static int __init amd_smn_init(void)
debugfs_create_file("value", 0600, debugfs_dir, NULL, &smn_value_fops);
}
+ smn_exclusive = true;
+
return 0;
}