Commit a976d790 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab Committed by Ard Biesheuvel
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efi/cper: Add a new helper function to print bitmasks 



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: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent 8ad2c72e

drivers/firmware/efi/cper.c

+60 −0
Original line number Diff line number Diff line
@@ -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",

include/linux/cper.h

+2 −0
Original line number Diff line number Diff line
@@ -588,6 +588,8 @@ 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 *,