From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A6C2F3BC4ED; Thu, 15 Jan 2026 17:22:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768497761; cv=none; b=bouSfAdcRl8M379I/nIdNjivcvE4rHHB60aLdl/AjrV2NliG7qXUuVBlo7XhaFTD+BxAn1jr3Bp1pTb4pWkMT91EazWUP/aHbQKBzqHJGomh/hGezJ/t4Y7qPiiQuxLzp7egMe6VWZij1ZjYG2yDe7lehK9tULC1SxHhb9BkDC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768497761; c=relaxed/simple; bh=vhDD2qxh7hXIShv0jTGtzbQaT4QNUAv6p0Ql0MeDO4c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=E4vuQsQNoCaTWUxEkjNWPOwmih9e23mIjqVGtbrnePZn7huM4KtxgSd9XwAC565EMsQQkhq20OUKHcMrgp6b9+y6vJ/cjOOK1+orv5pojdE9a7EQpMEN9ZxqQ0MEp/f098L03Po4bu0qCp17tQwVkb6w7zYFVv8t+/akqYNLCjk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hWuXyC54; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hWuXyC54" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33F51C116D0; Thu, 15 Jan 2026 17:22:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1768497761; bh=vhDD2qxh7hXIShv0jTGtzbQaT4QNUAv6p0Ql0MeDO4c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hWuXyC543hU6ae0Ps769P1LFrCR/NJSFZ/Z61tO6f/jT9Q0J3CvYK4Y28vo5HjBZ4 WrR3/+h5P8uE3IVif5uLOt8QIxzYe6KACHAQqvDRCV/MrfwNq6JOoCRz4B0v9k+1/h CxXVx+tQo+JbWEvNDXnJh8gOYnkpSZBgYEKsn04w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jonathan Cameron , Mauro Carvalho Chehab , "Borislav Petkov (AMD)" , Ard Biesheuvel , Sasha Levin Subject: [PATCH 5.15 194/554] efi/cper: Add a new helper function to print bitmasks Date: Thu, 15 Jan 2026 17:44:20 +0100 Message-ID: <20260115164253.281249443@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260115164246.225995385@linuxfoundation.org> References: <20260115164246.225995385@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mauro Carvalho Chehab [ 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 Signed-off-by: Mauro Carvalho Chehab Acked-by: Borislav Petkov (AMD) Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin --- 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 6ec8edec63296..d0668452dca9e 100644 --- a/drivers/firmware/efi/cper.c +++ b/drivers/firmware/efi/cper.c @@ -12,6 +12,7 @@ * Specification version 2.4. */ +#include #include #include #include @@ -105,6 +106,65 @@ 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 6a511a1078ca0..724a5e3c122d6 100644 --- a/include/linux/cper.h +++ b/include/linux/cper.h @@ -560,6 +560,8 @@ const char *cper_severity_str(unsigned int); const char *cper_mem_err_type_str(unsigned int); 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 *, -- 2.51.0