diff options
Diffstat (limited to 'arch/x86/kernel/amd_node.c')
| -rw-r--r-- | arch/x86/kernel/amd_node.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/x86/kernel/amd_node.c b/arch/x86/kernel/amd_node.c index d2ec7fd555c5..b670fa85c61b 100644 --- a/arch/x86/kernel/amd_node.c +++ b/arch/x86/kernel/amd_node.c @@ -8,6 +8,7 @@ * Author: Yazen Ghannam <Yazen.Ghannam@amd.com> */ +#include <linux/debugfs.h> #include <asm/amd_node.h> /* @@ -93,10 +94,14 @@ static struct pci_dev **amd_roots; /* Protect the PCI config register pairs used for SMN. */ static DEFINE_MUTEX(smn_mutex); +static bool smn_exclusive; #define SMN_INDEX_OFFSET 0x60 #define SMN_DATA_OFFSET 0x64 +#define HSMP_INDEX_OFFSET 0xc4 +#define HSMP_DATA_OFFSET 0xc8 + /* * 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 @@ -146,6 +151,9 @@ static int __amd_smn_rw(u8 i_off, u8 d_off, u16 node, u32 address, u32 *value, b if (!root) return err; + if (!smn_exclusive) + return err; + guard(mutex)(&smn_mutex); err = pci_write_config_dword(root, i_off, address); @@ -179,6 +187,93 @@ int __must_check amd_smn_write(u16 node, u32 address, u32 value) } EXPORT_SYMBOL_GPL(amd_smn_write); +int __must_check amd_smn_hsmp_rdwr(u16 node, u32 address, u32 *value, bool write) +{ + return __amd_smn_rw(HSMP_INDEX_OFFSET, HSMP_DATA_OFFSET, node, address, value, write); +} +EXPORT_SYMBOL_GPL(amd_smn_hsmp_rdwr); + +static struct dentry *debugfs_dir; +static u16 debug_node; +static u32 debug_address; + +static ssize_t smn_node_write(struct file *file, const char __user *userbuf, + size_t count, loff_t *ppos) +{ + u16 node; + int ret; + + ret = kstrtou16_from_user(userbuf, count, 0, &node); + if (ret) + return ret; + + if (node >= amd_num_nodes()) + return -ENODEV; + + debug_node = node; + return count; +} + +static int smn_node_show(struct seq_file *m, void *v) +{ + seq_printf(m, "0x%08x\n", debug_node); + return 0; +} + +static ssize_t smn_address_write(struct file *file, const char __user *userbuf, + size_t count, loff_t *ppos) +{ + int ret; + + ret = kstrtouint_from_user(userbuf, count, 0, &debug_address); + if (ret) + return ret; + + return count; +} + +static int smn_address_show(struct seq_file *m, void *v) +{ + seq_printf(m, "0x%08x\n", debug_address); + return 0; +} + +static int smn_value_show(struct seq_file *m, void *v) +{ + u32 val; + int ret; + + ret = amd_smn_read(debug_node, debug_address, &val); + if (ret) + return ret; + + seq_printf(m, "0x%08x\n", val); + return 0; +} + +static ssize_t smn_value_write(struct file *file, const char __user *userbuf, + size_t count, loff_t *ppos) +{ + u32 val; + int ret; + + ret = kstrtouint_from_user(userbuf, count, 0, &val); + if (ret) + return ret; + + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); + + ret = amd_smn_write(debug_node, debug_address, val); + if (ret) + return ret; + + return count; +} + +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(); @@ -193,6 +288,48 @@ static int amd_cache_roots(void) return 0; } +static int reserve_root_config_spaces(void) +{ + 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) + 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; + } + } + + smn_exclusive = true; + return 0; +} + +static bool enable_dfs; + +static int __init amd_smn_enable_dfs(char *str) +{ + enable_dfs = true; + return 1; +} +__setup("amd_smn_debugfs_enable", amd_smn_enable_dfs); + static int __init amd_smn_init(void) { int err; @@ -209,6 +346,18 @@ static int __init amd_smn_init(void) if (err) return err; + err = reserve_root_config_spaces(); + if (err) + return err; + + if (enable_dfs) { + debugfs_dir = debugfs_create_dir("amd_smn", arch_debugfs_dir); + + debugfs_create_file("node", 0600, debugfs_dir, NULL, &smn_node_fops); + debugfs_create_file("address", 0600, debugfs_dir, NULL, &smn_address_fops); + debugfs_create_file("value", 0600, debugfs_dir, NULL, &smn_value_fops); + } + return 0; } |