diff mbox series

[v5,2/4] efi/cper: Add a new helper function to print bitmasks

Message ID b5a425bd61f211a17a2b296a3c9ac251b3c3a20b.1719219886.git.mchehab+huawei@kernel.org
State New
Headers show
Series fix CPER issues related to UEFI 2.9A Errata | expand

Commit Message

Mauro Carvalho Chehab June 24, 2024, 9:19 a.m. UTC
Sometimes it is desired to produce a single log line for errors.
Add a new helper function for such purpose.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/firmware/efi/cper.c | 41 +++++++++++++++++++++++++++++++++++++
 include/linux/cper.h        |  2 ++
 2 files changed, 43 insertions(+)
diff mbox series

Patch

diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index 7d2cdd9e2227..4cf56657afde 100644
--- a/drivers/firmware/efi/cper.c
+++ b/drivers/firmware/efi/cper.c
@@ -106,6 +106,47 @@  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
+ * @mask: a continuous bitmask used to detect the first valid bit of the
+ *        bitmap.
+ *
+ * Add to @buf the bitmask in hexadecimal. Then, for each set bit in @bits
+ * mask, add the corresponding string describing the bit in @strs to @buf.
+ */
+char *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;
+
+	for_each_set_bit(i, &bits, strs_size) {
+		if (!(bits & (1U << (i))))
+			continue;
+
+		if (*buf && len > 0) {
+			*str = '|';
+			len--;
+			str++;
+		}
+
+		size = strscpy(str, strs[i], len);
+		if (size < 0)
+			break;
+
+		len -= size;
+		str += size;
+	}
+	return buf;
+}
+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..c2f14b916bfb 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);
+char *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 *,