From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9D883C48297 for ; Tue, 6 Feb 2024 14:08:17 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=gm1 header.b=TL7MHqnQ; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4TTlTC6cRMz3dhY for ; Wed, 7 Feb 2024 01:08:15 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=gm1 header.b=TL7MHqnQ; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=bootlin.com (client-ip=217.70.183.197; helo=relay5-d.mail.gandi.net; envelope-from=herve.codina@bootlin.com; receiver=lists.ozlabs.org) Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4TTlSJ4cDGz3c53 for ; Wed, 7 Feb 2024 01:07:26 +1100 (AEDT) Received: by mail.gandi.net (Postfix) with ESMTPA id 55B6A1C0005; Tue, 6 Feb 2024 14:07:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1707228444; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dO1lu7mTt2Z5I540dnIACd6uZE/pOpssk6saKJ+PaEA=; b=TL7MHqnQ0+uB5N7+X/6hGEH5W6RVRcamg9X8+7ETWscpnRHcpj73bczSJMtNWsOwJgPtmy M71+fHKZL6Fe4b3gCxV+ROY/+aRdyURUnpSI3HyXZrkdmzCvlcFGiuN8idSNtvaDQdhI2m 7SKV1aevvSxQQqFrlvFtO3SEznXN9cMLnxILuoQUkiw0SUj9iOMTQbmRpOFWQZLK2qc8EM 7iW9PPgDEJ2c/cVsIisLCb8sgCapKgw1zeKfLsSA7A3uleAsCSnzTPDERmcXoL6Z5jtY4M lmD+/04gOoso1QQtetWGa2h0eR03q/KFpEfWL8m0WgBy9Tt/MMRcD5h24qZkWQ== From: Herve Codina To: Vadim Fedorenko , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Herve Codina Subject: [PATCH v3 4/6] bitmap: Introduce bitmap_off() Date: Tue, 6 Feb 2024 15:07:14 +0100 Message-ID: <20240206140717.107930-5-herve.codina@bootlin.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240206140717.107930-1-herve.codina@bootlin.com> References: <20240206140717.107930-1-herve.codina@bootlin.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-GND-Sasl: herve.codina@bootlin.com X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrew Lunn , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Mark Brown , Thomas Petazzoni , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" The bitmap_onto() function translates one bitmap relative to another but no function are present to perform the reverse translation. Introduce bitmap_off() to fill this hole. Signed-off-by: Herve Codina --- include/linux/bitmap.h | 3 +++ lib/bitmap.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+) diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 99451431e4d6..5ecfcbbc91f4 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -65,6 +65,7 @@ struct device; * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit) * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap + * bitmap_off(dst, orig, relmap, nbits) *dst = bitmap_onto() reverse operation * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf @@ -208,6 +209,8 @@ int bitmap_bitremap(int oldbit, const unsigned long *old, const unsigned long *new, int bits); void bitmap_onto(unsigned long *dst, const unsigned long *orig, const unsigned long *relmap, unsigned int bits); +void bitmap_off(unsigned long *dst, const unsigned long *orig, + const unsigned long *relmap, unsigned int bits); void bitmap_fold(unsigned long *dst, const unsigned long *orig, unsigned int sz, unsigned int nbits); diff --git a/lib/bitmap.c b/lib/bitmap.c index 2feccb5047dc..71343967335e 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -682,6 +682,48 @@ void bitmap_onto(unsigned long *dst, const unsigned long *orig, } EXPORT_SYMBOL(bitmap_onto); +/** + * bitmap_off - revert operation done by bitmap_onto() + * @dst: resulting translated bitmap + * @orig: original untranslated bitmap + * @relmap: bitmap relative to which translated + * @bits: number of bits in each of these bitmaps + * + * Suppose onto computed using bitmap_onto(onto, src, relmap, n) + * The operation bitmap_off(result, onto, relmap, n) leads to a + * result equal or equivalent to src. + * + * The result can be 'equivalent' because bitmap_onto() and + * bitmap_off() are not bijective. + * The result and src values are equivalent in that sense that a + * call to bitmap_onto(onto, src, relmap, n) and a call to + * bitmap_onto(onto, result, relmap, n) will lead to the same onto + * value. + * + * If either of @orig or @relmap is empty (no set bits), then @dst + * will be returned empty. + * + * All bits in @dst not set by the above rule are cleared. + */ +void bitmap_off(unsigned long *dst, const unsigned long *orig, + const unsigned long *relmap, unsigned int bits) +{ + unsigned int n, m; /* same meaning as in above comment */ + + if (dst == orig) /* following doesn't handle inplace mappings */ + return; + bitmap_zero(dst, bits); + + m = 0; + for_each_set_bit(n, relmap, bits) { + /* m == bitmap_pos_to_ord(relmap, n, bits) */ + if (test_bit(n, orig)) + set_bit(m, dst); + m++; + } +} +EXPORT_SYMBOL(bitmap_off); + #ifdef CONFIG_NUMA /** * bitmap_fold - fold larger bitmap into smaller, modulo specified size -- 2.43.0