From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.204 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793624536; b=EUIkLBY74iI+kLLPyMQrf10hiu9v5ev6ATS6+DjGulxDzrmnA5VpXwMqy5oTD+ogWrsy B7E3B7LxcGXoZRuQmDeC85m7hVbzfr0fYB6WtnDf2opstyv4kV9xM4aDqk9Sr3yD66bSB /8fWXjJwc9KLPMapIXO3Nczt2FwKNAR5GTlkcnVGVvkjyvhhgotedc+elatdrHlmxlnGV ZY/7P+uSKPG47o1+VGxXFHWyTeFOFZS3DPjcDLW3baSRb5EF2qWrnFO7+uj1uIiB83KlC F9T3xSlhbZWWx2nKZZERVaqUlpF+cbu936H6vYEvsKUoaJO7RaNwZbOzpqT1zK00txw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793624536; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=L806xsiGlwO13TAwrjN8i31kZe6YvPSlLcIj0vmc54w=; b=RrxR9oFrpXSTEUiD3rzXx/AV7lL34danx49DuCzqzzO3VIjamH//0fMOpMF1BLryQj97 FlFu6pJ78FLBRQmvEFBf6gbaPuJur7uVAWiwGxHHD7stXvwUjj9DaYx4a0qixYP6r/3BE K2xs3Kil762KYro3eDMdCOSwJ2/BrUSM2C6q0I6SQX2Ya++vQt4a+vVF2qhag3lckvDsd ePIvkNsZ+BNJwlImGqPmrlk4XhmkZN9LdrNo7XlxjWHXxY7eJbplNq2v+Nd7J/JmJ01BP iTNRL7cH3UWcYToUpxcyxCTm4VNEqaleLL//DbL5QXuBbBnxKxwetSpFDTii2lfoeCg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=TjAx56T7; arc=none smtp.remote-ip=95.215.58.204 Received: from mta1.migadu.com (out-204.mta1.migadu.com [95.215.58.204]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 516F760A2601 for ; Mon, 2 Nov 2026 13:02:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 516F760A2601 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=TjAx56T7 X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=CBH6n7O8BP/HoFkIHe06UxiI77aEmPLQp99OnnXWeHY=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793624533; v=1; x=1794229333; b=TjAx56T7pLXnuPa7R0RTirXIC9JVUa5pjHj0na8JD9eN/L8lGgpXvIVDx7vbE6wuCeX0Y67r sBTcJ3ODe9528XLhf/EkggfVJdLTpxNiFFdd6bRU4CH+fJi1wqTGNmOIfrg0grgZwfayhAi+dop b2gxLjHpwWRzIAKodRKg0Am0= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id a4c58a5f30d34fbb; Mon, 02 Nov 2026 13:02:13 +0000 X-Mizu-Trace-ID: a4c58a5f30d34fbb X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: Marc Zyngier , Oliver Upton Cc: Will Deacon , Catalin Marinas , Joey Gouly , Mark Rutland , Suzuki K Poulose , Raghavendra Rao Ananta , Sascha Bischoff , Thomas Gleixner , Sebastian Ene , =?UTF-8?q?Bart=C5=82omiej=20Grzesik?= , Mostafa Saleh , Vincent Donnefort , Vladimir Murzin , Zenghui Yu , Zenghui Yu , Steffen Eiden , Radu Rendec , Fuad Tabba , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 05/13] irqchip/gic-v3-its: Compute the wait target under the ITS lock Date: Mon, 2 Nov 2026 13:01:25 +0000 Message-ID: <20261102130133.3684226-6-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261102130133.3684226-1-fuad.tabba@linux.dev> References: <20261102130133.3684226-1-fuad.tabba@linux.dev> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit its_wait_for_range_completion() converts the posted command pointer into a queue offset against its->cmd_base, after the caller has dropped its->lock. That's fine while cmd_base never changes, but the protected KVM takeover in a later patch switches cmd_base to a copy of the queue under the lock, and a wait racing with it would compute its target against the wrong base. Compute the offset in its_post_commands(), under the lock, and pass it to the wait instead of the pointer. No functional change intended. Signed-off-by: Fuad Tabba --- drivers/irqchip/irq-gic-v3-its.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 8cc1bd8e7835b..f06da58cccf3d 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -1144,13 +1144,13 @@ static struct its_cmd_block *its_allocate_entry(struct its_node *its) return cmd; } -static struct its_cmd_block *its_post_commands(struct its_node *its) +static u64 its_post_commands(struct its_node *its) { u64 wr = its_cmd_ptr_to_offset(its, its->cmd_write); writel_relaxed(wr, its->base + GITS_CWRITER); - return its->cmd_write; + return wr; } static void its_flush_cmd(struct its_node *its, struct its_cmd_block *cmd) @@ -1167,13 +1167,12 @@ static void its_flush_cmd(struct its_node *its, struct its_cmd_block *cmd) static int its_wait_for_range_completion(struct its_node *its, u64 prev_idx, - struct its_cmd_block *to) + u64 to_idx) { - u64 rd_idx, to_idx, linear_idx; + u64 rd_idx, linear_idx; u32 count = 1000000; /* 1s! */ /* Linearize to_idx if the command set has wrapped around */ - to_idx = its_cmd_ptr_to_offset(its, to); if (to_idx < prev_idx) to_idx += ITS_CMD_QUEUE_SZ; @@ -1216,10 +1215,10 @@ void name(struct its_node *its, \ buildtype builder, \ struct its_cmd_desc *desc) \ { \ - struct its_cmd_block *cmd, *sync_cmd, *next_cmd; \ + struct its_cmd_block *cmd, *sync_cmd; \ synctype *sync_obj; \ unsigned long flags; \ - u64 rd_idx; \ + u64 rd_idx, wr_idx; \ \ raw_spin_lock_irqsave(&its->lock, flags); \ \ @@ -1242,10 +1241,10 @@ void name(struct its_node *its, \ \ post: \ rd_idx = readl_relaxed(its->base + GITS_CREADR); \ - next_cmd = its_post_commands(its); \ + wr_idx = its_post_commands(its); \ raw_spin_unlock_irqrestore(&its->lock, flags); \ \ - if (its_wait_for_range_completion(its, rd_idx, next_cmd)) \ + if (its_wait_for_range_completion(its, rd_idx, wr_idx)) \ pr_err_ratelimited("ITS cmd %ps failed\n", builder); \ } -- 2.47.3