1 files changed, 0 insertions, 89 deletions
diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index e335d89ddad7..11fac09e3a8c 100644
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -15,9 +15,6 @@
 #include <linux/pci_ids.h>
 #include <asm/amd_nb.h>
 
-/* Protect the PCI config register pairs used for SMN. */
-static DEFINE_MUTEX(smn_mutex);
-
 static u32 *flush_words;
 
 static const struct pci_device_id amd_nb_misc_ids[] = {
@@ -59,92 +56,6 @@ struct amd_northbridge *node_to_amd_nb(int node)
 }
 EXPORT_SYMBOL_GPL(node_to_amd_nb);
 
-/*
- * SMN accesses may fail in ways that are difficult to detect here in the called
- * functions amd_smn_read() and amd_smn_write(). Therefore, callers must do
- * their own checking based on what behavior they expect.
- *
- * For SMN reads, the returned value may be zero if the register is Read-as-Zero.
- * Or it may be a "PCI Error Response", e.g. all 0xFFs. The "PCI Error Response"
- * can be checked here, and a proper error code can be returned.
- *
- * But the Read-as-Zero response cannot be verified here. A value of 0 may be
- * correct in some cases, so callers must check that this correct is for the
- * register/fields they need.
- *
- * For SMN writes, success can be determined through a "write and read back"
- * However, this is not robust when done here.
- *
- * Possible issues:
- *
- * 1) Bits that are "Write-1-to-Clear". In this case, the read value should
- *    *not* match the write value.
- *
- * 2) Bits that are "Read-as-Zero"/"Writes-Ignored". This information cannot be
- *    known here.
- *
- * 3) Bits that are "Reserved / Set to 1". Ditto above.
- *
- * Callers of amd_smn_write() should do the "write and read back" check
- * themselves, if needed.
- *
- * For #1, they can see if their target bits got cleared.
- *
- * For #2 and #3, they can check if their target bits got set as intended.
- *
- * This matches what is done for RDMSR/WRMSR. As long as there's no #GP, then
- * the operation is considered a success, and the caller does their own
- * checking.
- */
-static int __amd_smn_rw(u16 node, u32 address, u32 *value, bool write)
-{
-	struct pci_dev *root;
-	int err = -ENODEV;
-
-	if (node >= amd_northbridges.num)
-		goto out;
-
-	root = node_to_amd_nb(node)->root;
-	if (!root)
-		goto out;
-
-	mutex_lock(&smn_mutex);
-
-	err = pci_write_config_dword(root, 0x60, address);
-	if (err) {
-		pr_warn("Error programming SMN address 0x%x.\n", address);
-		goto out_unlock;
-	}
-
-	err = (write ? pci_write_config_dword(root, 0x64, *value)
-		     : pci_read_config_dword(root, 0x64, value));
-
-out_unlock:
-	mutex_unlock(&smn_mutex);
-
-out:
-	return err;
-}
-
-int __must_check amd_smn_read(u16 node, u32 address, u32 *value)
-{
-	int err = __amd_smn_rw(node, address, value, false);
-
-	if (PCI_POSSIBLE_ERROR(*value)) {
-		err = -ENODEV;
-		*value = 0;
-	}
-
-	return err;
-}
-EXPORT_SYMBOL_GPL(amd_smn_read);
-
-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_northbridges(void)
 {
 	struct amd_northbridge *nb;