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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 6EE27C55838 for ; Thu, 6 Aug 2026 07:26:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KZGj/L3nadsNc5+G4zPPi1gGSB5LzCydIBvRZmooxYk=; b=kVnDsd1X3T+V6VqAqH3y2mxaHX LOuvobUcaQDA3InbvARBDwR66qyLlXQjyQzgwx3UbSa6oQ+OC2oKtIlNY+MlrUgSYzong+j/BQvA9 xBiwil4Fq43cENeqbJRXVprKXacRZ+squtSKEWfaStxgiPglze0PbowafagSfYMbvzR5tRrQh412R JUuRuk1/zEK0oAg2cseKXXmC2IuRiXrSJhM2FukY/TYFjAEnTSh32LRRbaUPMmDp75ZfEIkEHzJEs xOsVF99DOY5bASAMGr+0d74yeLT77kp4ZapErhTO32RTy7p1ZH6s8WgugWRn+BDnzFGkWpd9leZrl 8HB07TZQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wrsUe-000000058i3-3VLY; Thu, 06 Aug 2026 07:26:20 +0000 Received: from mail-wr1-x436.google.com ([2a00:1450:4864:20::436]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wrsUc-000000058gZ-2jxX for linux-arm-kernel@lists.infradead.org; Thu, 06 Aug 2026 07:26:20 +0000 Received: by mail-wr1-x436.google.com with SMTP id ffacd0b85a97d-47f3b39f2a1so1362478f8f.2 for ; Thu, 06 Aug 2026 00:26:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1786001176; x=1786605976; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=KZGj/L3nadsNc5+G4zPPi1gGSB5LzCydIBvRZmooxYk=; b=sJmUwmC0zRuI7t3x4GZ6ugI36yhVUrcYIHZpfNt292ktKDg8I5KurZPJY7RgY5cljM kmYzVKhJaVxzda6pjrPZ/XHPzhdW8XwcnRy+JPSY+EDXmmG792oMM+3HL55qu7VJMSWj J1TSFHg0Bdjq7klfTQ8rzAZPgcRianUpzW6BUY0493XphwJ/JL0ycaxpVsht/0R592Kk 1xmZ8LfbrClWqm/FJDrJJDq6cXnAsMf8Bz+kGyfXmc+2GyR7Tb9iGzHYfdvKvF4leFxk D9sOLou31/QxhuCj5NOfF4uKlbM60B2GO+IZkXtthpZdCmvn4awoD/h8pc6Pe1dibmGS Yyaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786001176; x=1786605976; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=KZGj/L3nadsNc5+G4zPPi1gGSB5LzCydIBvRZmooxYk=; b=rGqdu7I2kI0lI74h3pVHoe2dWp8Q3zjjINZ/OyO6xX7uR3Xuu3Bmma3R6I6wjfogvZ M8KkHK/nsUsk6RRX4rJONrTW1LYsmyyA4gercJepZRm0hL6PgVv6SrD6iVeNcm0b8i1+ g3sVZiXahwHnS4Lc2BYD4jmRwZzWuc4RgS+v/qPFosDC6S188v7WAmPSH0ITliiLq/4E EKQ47Z+eqnO20qmC3HA/Wgcd7zgkPXZTYV7eAyct+2iyqyiMu7Hzrc0SvH8t2/E/0uyg ggaj7BNiKybfxEN+VpIunobwdLLWLI8npBrO6WanJnW7V5y28NASEs2V8KWRT8K4pDMY JThA== X-Forwarded-Encrypted: i=1; AHgh+RoWpOkqmG2OBYaQ1CNGPb/1vLKFmgedVlaRJ+oDUZ/0WUtuFQftxM+O7vdo7VMMqIfUUvH64TTB3ZC+5t9/k9iB@lists.infradead.org X-Gm-Message-State: AOJu0Yxl9spkPoMXk9NV3ONWYrX0Y60r2PUEG7YaDYz9bSdAw3kBBRNp f2jzTpNZmang38xgub8ztGnQUSHPdM0WeNhoYQ82gWFGcETZmTpyt+eg X-Gm-Gg: AR+sD10dJ7jVFj6DpjaJf176Bc7rE3eThaXQFPXXiZMcHunXW6Ywg7tR0qtGDVfXCbl dMjuomHRRxY7SiYqGMyFZAbNXKdXA5I/oXRkUllh0z4bXAZKV/m0VvKQM+Mx7dwbu0YRzj2ic4g dk6kMKlEWNoqnOpx3HnJHCcgsx4YpjaBE0f+/X5izo6xZefZ8DwZc9G42g65DeRUM+qBlKOZAAj Qa7aTttevOO0e8uh3BAGtbMlC8UxFHY1ziRvLNQdruHUOCT/xr47Cu4g6VMWA/eC9jsJ02Hp9VR 1JGCi2XeYpOGDrVWDyoNWaKsUmDisBhKnZfiBnLwcSyh6v5Gl8O65XKb9VF+k+bku73V3oq/T6i bXF+JbOSxOxckq7aDPnDxpO4JMMKRSsbD6ZNTc78DBIhgNFJfWTVC5m33ncTwKYid4gJFmNZOFK fWYQo8lEA7Wuq4Aj6LPtmuVt2Cy+diu4TpszyXYAxETxqIc0XfFR+C4L8= X-Received: by 2002:adf:e992:0:b0:47f:c648:e280 with SMTP id ffacd0b85a97d-47fec519539mr16086894f8f.18.1786001176240; Thu, 06 Aug 2026 00:26:16 -0700 (PDT) Received: from fedora ([46.205.219.211]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-47ff7b25b4asm3900021f8f.26.2026.08.06.00.26.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Aug 2026 00:26:15 -0700 (PDT) From: Daniel Pawlik To: netdev@vger.kernel.org Cc: lorenzo@kernel.org, win847@gmail.com, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Daniel Pawlik Subject: [PATCH v2] net: airoha: npu: use coherent DMA for mailbox messages Date: Thu, 6 Aug 2026 09:26:01 +0200 Message-ID: <20260806072601.1815487-1-pawlik.dan@gmail.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260805070851.2885888-1-pawlik.dan@gmail.com> References: <20260805070851.2885888-1-pawlik.dan@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260806_002618_707851_1CC777DF X-CRM114-Status: GOOD ( 18.35 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Commit 6f884eb87a79 ("net: airoha: Fix DMA direction for NPU mailbox buffer") switched airoha_npu_send_msg() to DMA_BIDIRECTIONAL so non-coherent CPUs invalidate caches before reading NPU GET responses. On EN7581 + MT7996 that change regresses probe: the mailbox completes successfully, but WLAN_FUNC_GET_WAIT_NPU_VERSION still reads as 0.0 and mt76 never binds NPU offload. Healthy boards report 0.1111. airoha_npu_send_msg() is also used from PPE foe_commit under spin_lock_bh(), so per-message dma_alloc_coherent(GFP_ATOMIC) is a poor fit. Allocate one device-managed coherent bounce buffer at probe and reuse it under the existing per-core mailbox lock. That also keeps the buffer valid if the NPU completes a write after a mailbox timeout. Verified on Quantum Fiber / Gemtek W1700K (EN7581 + MT7996). Fixes: 6f884eb87a79 ("net: airoha: Fix DMA direction for NPU mailbox buffer") Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260805070851.2885888-1-pawlik.dan@gmail.com/ Assisted-by: Cursor:composer-2 Signed-off-by: Daniel Pawlik --- v2: - allocate one coherent mailbox buffer at probe and reuse it under the per-core lock instead of per-message dma_alloc_coherent(GFP_ATOMIC) drivers/net/ethernet/airoha/airoha_npu.c | 31 +++++++++++++++++------ include/linux/soc/airoha/airoha_offload.h | 4 +++ 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/drivers/net/ethernet/airoha/airoha_npu.c b/drivers/net/ethernet/airoha/airoha_npu.c index b679bed952de..dfa09fed907e 100644 --- a/drivers/net/ethernet/airoha/airoha_npu.c +++ b/drivers/net/ethernet/airoha/airoha_npu.c @@ -23,6 +23,8 @@ #define NPU_EN7581_FIRMWARE_RV32_MAX_SIZE 0x200000 #define NPU_EN7581_FIRMWARE_DATA_MAX_SIZE 0x10000 #define NPU_DUMP_SIZE 512 +/* Enough for struct ppe_mbox_data and small WLAN TLV payloads */ +#define AIROHA_NPU_MBOX_SIZE 256 #define REG_NPU_LOCAL_SRAM 0x0 @@ -165,17 +167,24 @@ static int airoha_npu_send_msg(struct airoha_npu *npu, int func_id, { u16 core = 0; /* FIXME */ u32 val, offset = core << 4; - dma_addr_t dma_addr; int ret; - dma_addr = dma_map_single(npu->dev, p, size, DMA_BIDIRECTIONAL); - ret = dma_mapping_error(npu->dev, dma_addr); - if (ret) - return ret; + if (size > AIROHA_NPU_MBOX_SIZE) + return -EINVAL; + /* + * Mailbox payloads are bidirectional (CPU request, NPU response). + * On EN7581+MT7996, streaming DMA_BIDIRECTIONAL against the + * caller kzalloc() buffer can leave WLAN_FUNC_GET_WAIT_NPU_VERSION + * reading as 0.0 despite MBOX success. Reuse a probe-time coherent + * bounce buffer under the per-core lock (also used from PPE + * foe_commit under atomic context). + */ spin_lock_bh(&npu->cores[core].lock); - regmap_write(npu->regmap, REG_CR_MBQ0_CTRL(0) + offset, dma_addr); + memcpy(npu->mbox_buf, p, size); + + regmap_write(npu->regmap, REG_CR_MBQ0_CTRL(0) + offset, npu->mbox_dma); regmap_write(npu->regmap, REG_CR_MBQ0_CTRL(1) + offset, size); regmap_read(npu->regmap, REG_CR_MBQ0_CTRL(2) + offset, &val); regmap_write(npu->regmap, REG_CR_MBQ0_CTRL(2) + offset, val + 1); @@ -189,9 +198,10 @@ static int airoha_npu_send_msg(struct airoha_npu *npu, int func_id, if (!ret && FIELD_GET(MBOX_MSG_STATUS, val) != NPU_MBOX_SUCCESS) ret = -EINVAL; - spin_unlock_bh(&npu->cores[core].lock); + if (!ret) + memcpy(p, npu->mbox_buf, size); - dma_unmap_single(npu->dev, dma_addr, size, DMA_BIDIRECTIONAL); + spin_unlock_bh(&npu->cores[core].lock); return ret; } @@ -770,6 +780,11 @@ static int airoha_npu_probe(struct platform_device *pdev) if (err) return err; + npu->mbox_buf = dmam_alloc_coherent(dev, AIROHA_NPU_MBOX_SIZE, + &npu->mbox_dma, GFP_KERNEL); + if (!npu->mbox_buf) + return -ENOMEM; + err = airoha_npu_run_firmware(dev, base, &res); if (err) return dev_err_probe(dev, err, "failed to run npu firmware\n"); diff --git a/include/linux/soc/airoha/airoha_offload.h b/include/linux/soc/airoha/airoha_offload.h index 7589fccfeef6..afd481233489 100644 --- a/include/linux/soc/airoha/airoha_offload.h +++ b/include/linux/soc/airoha/airoha_offload.h @@ -179,6 +179,10 @@ struct airoha_npu { struct airoha_foe_stats __iomem *stats; + /* Coherent bounce buffer for mailbox cmd/rsp (airoha_npu_send_msg) */ + void *mbox_buf; + dma_addr_t mbox_dma; + struct { int (*ppe_init)(struct airoha_npu *npu); int (*ppe_deinit)(struct airoha_npu *npu); -- 2.55.0