6.6-stable review patch. If anyone has any objections, please let me know.
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From: Mauro Carvalho Chehab mchehab+huawei@kernel.org
[ Upstream commit a976d790f49499ccaa0f991788ad8ebf92e7fd5c ]
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".
Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Acked-by: Borislav Petkov (AMD) bp@alien8.de Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 35c37f667781c..cd34ef9384f1e 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 c1a7dc3251215..f792e4b3df907 100644 --- a/include/linux/cper.h +++ b/include/linux/cper.h @@ -561,6 +561,8 @@ 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 *,