[PATCH 5/6] edac, mce_amd_inj: Add README file

Aravind Gopalakrishnan
2015-05-27T18:55:02Z

Provides information about each file and the usages.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
---
drivers/edac/mce_amd_inj.c | 68 +++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 61 insertions(+), 7 deletions(-)

diff --git a/drivers/edac/mce_amd_inj.c b/drivers/edac/mce_amd_inj.c
index f1c1433..ca5b29f 100644
--- a/drivers/edac/mce_amd_inj.c
+++ b/drivers/edac/mce_amd_inj.c
@@ -291,17 +291,71 @@ MCE_INJECT_GET(bank);

DEFINE_SIMPLE_ATTRIBUTE(bank_fops, inj_bank_get, inj_bank_set, "%llu\n");

+static const char readme_msg[] =
+ "\nDescription of the files and their usages:\n\n"
+ "status: Set a value to be programmed into MCx_STATUS(bank)\n"
+ "\t The status bits provide insight into the type of\n"
+ "\t error that caused the MCE.\n\n"
+ "misc: Set value of MCx_MISC(bank)\n"
+ "\t misc register provides auxiliary info about the error. This\n"
+ "\t register is typically used for error thresholding purpose and\n"
+ "\t validity of the register is indicated by MCx_STATUS[MiscV]\n\n"
+ "addr: Error address value to be written to MCx_ADDR(bank)\n"
+ "\t This register is used to log address information associated\n"
+ "\t with the error.\n\n"
+ "Note: See respective BKDGs for the exact bit definitions of the\n"
+ "\t above registers as they mirror the MCi_[STATUS | MISC | ADDR]\n"
+ "\t hardware registers.\n\n"
+ "bank: Specify the bank you want to inject the error into.\n"
+ "\t The number of banks in a processor varies and is family/model\n"
+ "\t dependent. So, a sanity check performed while writing.\n"
+ "\t Writing to this file will trigger a #MC or APIC interrupts or\n"
+ "\t invoke the error decoder routines for AMD processors. The value\n"
+ "\t in 'flags' file decides which of above actions is triggered.\n\n"
+ "flags: Write to this file to speficy the error injection policy.\n"
+ "\t Allowed values:\n"
+ "\t\t\"sw\" - SW error injection, Only calls error decoder\n"
+ "\t\t\troutines to print error info in human readable format\n"
+ "\t\t\"hw\" - HW error injection, Forces a #MC,\n"
+ "\t\t\tcauses exception handler to handle the error\n"
+ "\t\t\tif UC or poll handler catches it if CE\n"
+ "\t\t\tWarning: Might cause system panic if MCx_STATUS[PCC]\n"
+ "\t\t\tis set. For debug purposes, consider setting\n"
+ "\t\t\t/<debugfs_mountpoint>/mce/fake_panic\n"
+ "\t\t\"dfr\" - Trigger APIC interrupt for Deferred error\n"
+ "\t\t\tError is handled by deferred error apic handler if\n"
+ "\t\t\tfeature is present in HW.\n"
+ "\t\t\"thr\" - Trigger APIC interrupt for threshold error\n"
+ "\t\t\tError is handled by threshold apic handler\n\n"
+ "cpu: The cpu to inject the error on.\n\n"
+;
+
+static ssize_t
+inj_readme_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_read_from_buffer(ubuf, cnt, ppos,
+ readme_msg, strlen(readme_msg));
+}
+
+static const struct file_operations readme_fops = {
+ .read = inj_readme_read,
+};
+
static struct dfs_node {
char *name;
struct dentry *d;
const struct file_operations *fops;
+ umode_t perm;
} dfs_fls[] = {
- { .name = "status", .fops = &status_fops },
- { .name = "misc", .fops = &misc_fops },
- { .name = "addr", .fops = &addr_fops },
- { .name = "bank", .fops = &bank_fops },
- { .name = "flags", .fops = &flags_fops },
- { .name = "cpu", .fops = &extcpu_fops },
+ { .name = "status", .fops = &status_fops, S_IRUSR | S_IWUSR },
+ { .name = "misc", .fops = &misc_fops, S_IRUSR | S_IWUSR },
+ { .name = "addr", .fops = &addr_fops, S_IRUSR | S_IWUSR },
+ { .name = "bank", .fops = &bank_fops, S_IRUSR | S_IWUSR },
+ { .name = "flags", .fops = &flags_fops, S_IRUSR | S_IWUSR },
+ { .name = "cpu", .fops = &extcpu_fops, S_IRUSR | S_IWUSR },
+ { .name = "README", .fops = &readme_fops, S_IRUSR | S_IRGRP |
+ S_IROTH },
};

static int __init init_mce_inject(void)
@@ -318,7 +372,7 @@ static int __init init_mce_inject(void)

for (i = 0; i < ARRAY_SIZE(dfs_fls); i++) {
dfs_fls[i].d = debugfs_create_file(dfs_fls[i].name,
- S_IRUSR | S_IWUSR,
+ dfs_fls[i].perm,
dfs_inj,
&i_mce,
dfs_fls[i].fops);
--
2.4.0