Add a helper function to print a string with names associated
to each bit field.
A typical example is:
const char * const bits[] = {
"bit 3 name",
"bit 4 name",
"bit 5 name",
};
char str[120];
unsigned int bitmask = BIT(3) | BIT(5);
#define MASK GENMASK(5,3)
cper_bits_to_str(str, sizeof(str), FIELD_GET(MASK, bitmask),
bits, ARRAY_SIZE(bits));
The above code fills string "str" with "bit 3 name|bit 5 name".
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Reviewed-by; Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
drivers/firmware/efi/cper.c | 60 +++++++++++++++++++++++++++++++++++++
include/linux/cper.h | 2 ++
2 files changed, 62 insertions(+)
diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index 7d2cdd9e2227..f60fe7367e3b 100644
--- a/drivers/firmware/efi/cper.c
+++ b/drivers/firmware/efi/cper.c
@@ -12,6 +12,7 @@
* Specification version 2.4.
*/
+#include <linux/bitmap.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/time.h>
@@ -106,6 +107,65 @@ void cper_print_bits(const char *pfx, unsigned int bits,
printk("%s\n", buf);
}
+/**
+ * cper_bits_to_str - return a string for set bits
+ * @buf: buffer to store the output string
+ * @buf_size: size of the output string buffer
+ * @bits: bit mask
+ * @strs: string array, indexed by bit position
+ * @strs_size: size of the string array: @strs
+ *
+ * Add to @buf the bitmask in hexadecimal. Then, for each set bit in @bits,
+ * add the corresponding string describing the bit in @strs to @buf.
+ *
+ * A typical example is::
+ *
+ * const char * const bits[] = {
+ * "bit 3 name",
+ * "bit 4 name",
+ * "bit 5 name",
+ * };
+ * char str[120];
+ * unsigned int bitmask = BIT(3) | BIT(5);
+ * #define MASK GENMASK(5,3)
+ *
+ * cper_bits_to_str(str, sizeof(str), FIELD_GET(MASK, bitmask),
+ * bits, ARRAY_SIZE(bits));
+ *
+ * The above code fills the string ``str`` with ``bit 3 name|bit 5 name``.
+ *
+ * Return: number of bytes stored or an error code if lower than zero.
+ */
+int cper_bits_to_str(char *buf, int buf_size, unsigned long bits,
+ const char * const strs[], unsigned int strs_size)
+{
+ int len = buf_size;
+ char *str = buf;
+ int i, size;
+
+ *buf = '\0';
+
+ for_each_set_bit(i, &bits, strs_size) {
+ if (!(bits & BIT_ULL(i)))
+ continue;
+
+ if (*buf && len > 0) {
+ *str = '|';
+ len--;
+ str++;
+ }
+
+ size = strscpy(str, strs[i], len);
+ if (size < 0)
+ return size;
+
+ len -= size;
+ str += size;
+ }
+ return len - buf_size;
+}
+EXPORT_SYMBOL_GPL(cper_bits_to_str);
+
static const char * const proc_type_strs[] = {
"IA32/X64",
"IA64",
diff --git a/include/linux/cper.h b/include/linux/cper.h
index 265b0f8fc0b3..25858a7608b7 100644
--- a/include/linux/cper.h
+++ b/include/linux/cper.h
@@ -584,6 +584,8 @@ const char *cper_mem_err_type_str(unsigned int);
const char *cper_mem_err_status_str(u64 status);
void cper_print_bits(const char *prefix, unsigned int bits,
const char * const strs[], unsigned int strs_size);
+int cper_bits_to_str(char *buf, int buf_size, unsigned long bits,
+ const char * const strs[], unsigned int strs_size);
void cper_mem_err_pack(const struct cper_sec_mem_err *,
struct cper_mem_err_compact *);
const char *cper_mem_err_unpack(struct trace_seq *,
--
2.46.0
