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 E609BC5AC7A for ; Fri, 7 Aug 2026 06:41:22 +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: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:In-Reply-To:References:List-Owner; bh=cfbg4OKMiHxX0/fCplY4WZEaCh6mteG/jz44Jr9wKjY=; b=VcFeBlkvf4J9WQsCuKsrmfbGTp TivLI9X2sJgGn43q+hrGcgLoNvxI3Z3U0/zMIIXny1A9Tqo7Cd//WJBGAfel4mMiFwLDjyDzh1ldA wn/rSTTzt8ekGRbAy9zEr+ZfeNpUvuNb9aNdtpa7Mo0n49A/LK68o+zSa0dIXtzMquopq9/Io6hhQ qo+UPNwV5NiziQ7lsVmAxR4AqiijgpB3bWK96BUKqRkU6LC6cAy7JBVxQeNboWHe1MU7E/fKEPOsI /lPkkZWh0Tq0VZC0dH/HAlV/U4fUeUAhUO34BukYHyf+Xk4IyxdVUwDZZQazRomYCqTJYi3ecC5pr H/ohhXkA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wsEGZ-00000007BbG-222t; Fri, 07 Aug 2026 06:41:15 +0000 Received: from mail-wr1-x42e.google.com ([2a00:1450:4864:20::42e]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wsEGW-00000007BaY-2e4C for linux-arm-kernel@lists.infradead.org; Fri, 07 Aug 2026 06:41:13 +0000 Received: by mail-wr1-x42e.google.com with SMTP id ffacd0b85a97d-47f59f25ec4so1253655f8f.2 for ; Thu, 06 Aug 2026 23:41:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1786084870; x=1786689670; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=cfbg4OKMiHxX0/fCplY4WZEaCh6mteG/jz44Jr9wKjY=; b=qAOLZQQ4y2BnXYdTkSucz9dXvpjcmqSEQ536GIU5w6KBvVvke2i8+TK7pVSnJhaN+i H3kP/JCA/iVEHnPBwQraVqJfOwpW0sKrl5LSRkfr70vf106YO9J69qFX9ygmCDr3Xd25 9PtayQuzus47EO0XkF9PXpF7gu+k6h89C8MZzeg8Rjo/grpAO5mzngGG912aqZBiyTpo /MCr6aK+NuEoZ++lcGcd+uJ2iIkWNY2c6PkGNYrl7mKc88ZpPFt33sR8FhmNDTpc9JhK DiiN7Peb0NfWbU7b1No066mDyOkQHygz1m7a6eIriDZQf/+e1v+KBaXkxZy74O/du/xK HIrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786084870; x=1786689670; h=content-transfer-encoding:mime-version: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=cfbg4OKMiHxX0/fCplY4WZEaCh6mteG/jz44Jr9wKjY=; b=eFLebjsqW36jNvqsoJAstffVvrNJoOvodxbTzYbWt7DnVo6g8w3c3hnJj7nrKvueri OGJMnqD2v69JvcRsCt0RU15iIjeMVwTh0OtkS5URNaOxbs8FfBGPlie7tkDwnHIQx0hh iJcp54w7pUsL+11LjrLoIwwaUoWN/XaVZ5sBTDklo6EJfK2s7LdI+JbQnuGrL3xK7jHP CfdhprSBEZ5v4WeB+y2s/mB9K9IxZW9lhrLXNsudQCxfsIv7pZC2XMk/PBJhpJmm3AsG wEEV/PY9Ch9SxJgJEoytEy/6JBo1dxbq+GhB+qMLIKkKj5pu8dBiHTzPxR8mB3ZUq3lw XBBg== X-Forwarded-Encrypted: i=1; AHgh+Rojn00Ij20pRR5dfTsDEp931rVteAW6m3dWcudB+5+a/cY8Ldo8HXR0P/rIYv4qZWXyAHQ+t4Io5ygXQZ00skvg@lists.infradead.org X-Gm-Message-State: AOJu0YwSMaxmbFYXG3ppBhagYNE5rKJvWW5GBrTmxYbbrQv3mpZUAtDZ sdjyjZd99pnLf8NzEW7vFrBAVcM5iy5lPfUmZmETVOb31mLKjP961o8W X-Gm-Gg: AR+sD10JeSYgcwy+zO04pAZL4tU8w+XZw0DoQIzK3wvYfQR8obpsD7D76aWfvo64POm HmW3KT4bldopOeyBUigOqAALVEYiZK+qVITj9wfLEtgxgDCaQZyNJMZPMm5g+QkEn1EzJvTbp3B 8ZV1P1HGNHwdycUk4wuW8DWcO7F6EiCcryMMRul3EODOgK1QSsxoWddZuao9clP4tdtw0VjxDxd B+WBcHtkUBrLHHM4dQ/mqBKj9JUhnvC1Lo7J0Axme8SHmQkLIFsB6SxE/ciaVrH01IzkPkuGOww cwqUZ/EvkCsul3uYvR6HTSc4n8IM7uHRfzLGImd96X+JtyjEziwOmrXOgZ6um2Obp3Guue7cDOF SfpV3wxZUHxZyYSLKQ6Wf7QD6MCvotQWfYpaCSOwBYr+F4miQaiRDzQF4Qe5VxEf0CXNfP5k5rH JUm39VWBm43mi9YIG6NTrPTGXxO+IOkory177lbZGun/NA/b9U3C0hWCM= X-Received: by 2002:a05:6000:2981:20b0:476:7036:f854 with SMTP id ffacd0b85a97d-47ffd93cfadmr8835774f8f.21.1786084870270; Thu, 06 Aug 2026 23:41:10 -0700 (PDT) Received: from fedora ([46.205.219.253]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48002150804sm2655044f8f.13.2026.08.06.23.41.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Aug 2026 23:41:09 -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 v4] net: airoha: npu: use coherent DMA for mailbox messages Date: Fri, 7 Aug 2026 08:40:58 +0200 Message-ID: <20260807064058.1117747-1-pawlik.dan@gmail.com> X-Mailer: git-send-email 2.55.0 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_234112_695880_B52F2068 X-CRM114-Status: GOOD ( 21.78 ) 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 per NPU core 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. Introduce __airoha_npu_send_msg() with an optional reply pointer so GET callers can copy the trailing response payload once. Keep airoha_npu_send_msg() as a thin wrapper for SET paths. 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/ Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260806072601.1815487-1-pawlik.dan@gmail.com/ Assisted-by: Cursor:composer-2 Signed-off-by: Daniel Pawlik --- v4: - drop rsp_off; copy trailing reply_len bytes into reply pointer - split __airoha_npu_send_msg() + thin airoha_npu_send_msg() wrapper so SET callers stay unchanged - fix reverse-christmas-tree local variable ordering - constify data argument; clarify reply copy comment v3: - move coherent mailbox buffer into struct airoha_npu_core (buf/addr) - allocate one buffer per core at probe - add optional reply buffer to avoid the extra copy in airoha_npu_wlan_msg_get() - document AIROHA_NPU_MBOX_SIZE vs ppe_mbox_data / WLAN payloads 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 | 70 +++++++++++++++++------ include/linux/soc/airoha/airoha_offload.h | 3 + 2 files changed, 54 insertions(+), 19 deletions(-) diff --git a/drivers/net/ethernet/airoha/airoha_npu.c b/drivers/net/ethernet/airoha/airoha_npu.c index b679bed952de..74da3c4d06e4 100644 --- a/drivers/net/ethernet/airoha/airoha_npu.c +++ b/drivers/net/ethernet/airoha/airoha_npu.c @@ -23,6 +23,12 @@ #define NPU_EN7581_FIRMWARE_RV32_MAX_SIZE 0x200000 #define NPU_EN7581_FIRMWARE_DATA_MAX_SIZE 0x10000 #define NPU_DUMP_SIZE 512 +/* + * Mailbox DMA payload size. Covers sizeof(struct ppe_mbox_data) (28) and + * WLAN TLV messages (header + payload); largest in-tree WLAN payload today + * is 16 bytes (INODE_TXRX_REG_ADDR). Keep headroom for future commands. + */ +#define AIROHA_NPU_MBOX_SIZE 256 #define REG_NPU_LOCAL_SRAM 0x0 @@ -160,23 +166,32 @@ struct wlan_mbox_data { DECLARE_FLEX_ARRAY(u8, d); }; -static int airoha_npu_send_msg(struct airoha_npu *npu, int func_id, - void *p, int size) +static int __airoha_npu_send_msg(struct airoha_npu *npu, int func_id, + const void *data, int len, void *reply, + int reply_len) { - u16 core = 0; /* FIXME */ - u32 val, offset = core << 4; - dma_addr_t dma_addr; + struct airoha_npu_core *c = &npu->cores[0]; /* FIXME: core */ + u32 val, offset = 0; 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 (len > AIROHA_NPU_MBOX_SIZE || + (reply && (reply_len < 0 || reply_len > len))) + return -EINVAL; - spin_lock_bh(&npu->cores[core].lock); + /* + * 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(&c->lock); + + memcpy(c->buf, data, len); - regmap_write(npu->regmap, REG_CR_MBQ0_CTRL(0) + offset, dma_addr); - regmap_write(npu->regmap, REG_CR_MBQ0_CTRL(1) + offset, size); + regmap_write(npu->regmap, REG_CR_MBQ0_CTRL(0) + offset, c->addr); + regmap_write(npu->regmap, REG_CR_MBQ0_CTRL(1) + offset, len); regmap_read(npu->regmap, REG_CR_MBQ0_CTRL(2) + offset, &val); regmap_write(npu->regmap, REG_CR_MBQ0_CTRL(2) + offset, val + 1); val = FIELD_PREP(MBOX_MSG_FUNC_ID, func_id) | MBOX_MSG_WAIT_RSP; @@ -189,13 +204,21 @@ 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); + /* Copy the trailing reply_len bytes of the response. */ + if (!ret && reply) + memcpy(reply, c->buf + len - reply_len, reply_len); - dma_unmap_single(npu->dev, dma_addr, size, DMA_BIDIRECTIONAL); + spin_unlock_bh(&c->lock); return ret; } +static inline int airoha_npu_send_msg(struct airoha_npu *npu, int func_id, + const void *data, int len) +{ + return __airoha_npu_send_msg(npu, func_id, data, len, NULL, 0); +} + static int airoha_npu_load_firmware(struct device *dev, void __iomem *addr, const char *fw_name, int fw_max_size) { @@ -442,8 +465,9 @@ static int airoha_npu_ppe_stats_setup(struct airoha_npu *npu, ppe_data->func_id = PPE_FUNC_SET_WAIT_FLOW_STATS_SETUP; ppe_data->stats_info.foe_stats_addr = foe_stats_addr; - err = airoha_npu_send_msg(npu, NPU_FUNC_PPE, ppe_data, - sizeof(*ppe_data)); + err = __airoha_npu_send_msg(npu, NPU_FUNC_PPE, ppe_data, + sizeof(*ppe_data), ppe_data, + sizeof(*ppe_data)); if (err) goto out; @@ -497,9 +521,8 @@ static int airoha_npu_wlan_msg_get(struct airoha_npu *npu, int ifindex, wlan_data->func_type = NPU_OP_GET; wlan_data->func_id = func_id; - err = airoha_npu_send_msg(npu, NPU_FUNC_WIFI, wlan_data, len); - if (!err) - memcpy(data, wlan_data->d, data_len); + err = __airoha_npu_send_msg(npu, NPU_FUNC_WIFI, wlan_data, len, + data, data_len); kfree(wlan_data); return err; @@ -770,6 +793,15 @@ static int airoha_npu_probe(struct platform_device *pdev) if (err) return err; + for (i = 0; i < ARRAY_SIZE(npu->cores); i++) { + struct airoha_npu_core *core = &npu->cores[i]; + + core->buf = dmam_alloc_coherent(dev, AIROHA_NPU_MBOX_SIZE, + &core->addr, GFP_KERNEL); + if (!core->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..16a988ad7467 100644 --- a/include/linux/soc/airoha/airoha_offload.h +++ b/include/linux/soc/airoha/airoha_offload.h @@ -173,6 +173,9 @@ struct airoha_npu { /* protect concurrent npu memory accesses */ spinlock_t lock; struct work_struct wdt_work; + /* Coherent bounce buffer for mailbox cmd/rsp */ + void *buf; + dma_addr_t addr; } cores[NPU_NUM_CORES]; int irqs[NPU_NUM_IRQ]; -- 2.55.0