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 0A17E1C232C; Tue, 2 Jul 2024 17:17:16 +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=1719940636; cv=none; b=bVm/86VjKtBJr9gFMuXmixlYqTr0pg1IhYzcYM97spqrISnaZoooISmUlIifpVPe0zWKrDDXPslYtv09pGsif+ee1HItIN7oK3mENsqhq010jshRili2b6vuCC988fc2+s/zJtSA6qKVp+44r9xNPFRmQzo0gvIA0nUcH791xA8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719940636; c=relaxed/simple; bh=2Caxiraizr16XfD4xaynyZsX845GzRO202UK/iwJrr0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aQEHnigABGZ/TI6CnOl2ihnSltnkaiTZ7qhvzNHPWBOLgiFnqzv+uuolj3JWSM8Flx0JyofY8FLdv4P8Pd5pKNnI9OUHk8FWAHPoe+DLqSFH3UgqlP2YSZn8UDlkzL6l7a7pFnDmZ9Kk7lknr0XYCOei5QU/juvpEgEY4BldxyI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eyeJJl46; 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="eyeJJl46" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F183C116B1; Tue, 2 Jul 2024 17:17:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1719940635; bh=2Caxiraizr16XfD4xaynyZsX845GzRO202UK/iwJrr0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eyeJJl46OqH4XLR41CjXMAbJ9urrTDY9WzT4irTD+FNNef05wNe7GdHG+Scy3Q5rv Y5zT2UVh/gqbn3egQlg7tGhfFFJWiP/dWjTVh8WGtbaUf76+vXzhrbNRqTRU71MuAI B6H34pm+ECufTQsSIzYmkert0wYgdeJZ4PDDno4w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Williams , Li Ming , Alison Schofield , Jonathan Cameron , Dave Jiang , Sasha Levin Subject: [PATCH 6.9 213/222] cxl/mem: Fix no cxl_nvd during pmem region auto-assembling Date: Tue, 2 Jul 2024 19:04:11 +0200 Message-ID: <20240702170252.128195746@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240702170243.963426416@linuxfoundation.org> References: <20240702170243.963426416@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Ming [ Upstream commit 84ec985944ef34a34a1605b93ce401aa8737af96 ] When CXL subsystem is auto-assembling a pmem region during cxl endpoint port probing, always hit below calltrace. BUG: kernel NULL pointer dereference, address: 0000000000000078 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:cxl_pmem_region_probe+0x22e/0x360 [cxl_pmem] Call Trace: ? __die+0x24/0x70 ? page_fault_oops+0x82/0x160 ? do_user_addr_fault+0x65/0x6b0 ? exc_page_fault+0x7d/0x170 ? asm_exc_page_fault+0x26/0x30 ? cxl_pmem_region_probe+0x22e/0x360 [cxl_pmem] ? cxl_pmem_region_probe+0x1ac/0x360 [cxl_pmem] cxl_bus_probe+0x1b/0x60 [cxl_core] really_probe+0x173/0x410 ? __pfx___device_attach_driver+0x10/0x10 __driver_probe_device+0x80/0x170 driver_probe_device+0x1e/0x90 __device_attach_driver+0x90/0x120 bus_for_each_drv+0x84/0xe0 __device_attach+0xbc/0x1f0 bus_probe_device+0x90/0xa0 device_add+0x51c/0x710 devm_cxl_add_pmem_region+0x1b5/0x380 [cxl_core] cxl_bus_probe+0x1b/0x60 [cxl_core] The cxl_nvd of the memdev needs to be available during the pmem region probe. Currently the cxl_nvd is registered after the endpoint port probe. The endpoint probe, in the case of autoassembly of regions, can cause a pmem region probe requiring the not yet available cxl_nvd. Adjust the sequence so this dependency is met. This requires adding a port parameter to cxl_find_nvdimm_bridge() that can be used to query the ancestor root port. The endpoint port is not yet available, but will share a common ancestor with its parent, so start the query from there instead. Fixes: f17b558d6663 ("cxl/pmem: Refactor nvdimm device registration, delete the workqueue") Co-developed-by: Dan Williams Signed-off-by: Dan Williams Signed-off-by: Li Ming Tested-by: Alison Schofield Reviewed-by: Jonathan Cameron Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20240612064423.2567625-1-ming4.li@intel.com Signed-off-by: Dave Jiang Signed-off-by: Sasha Levin --- drivers/cxl/core/pmem.c | 16 +++++++++++----- drivers/cxl/core/region.c | 2 +- drivers/cxl/cxl.h | 4 ++-- drivers/cxl/mem.c | 17 +++++++++-------- 4 files changed, 23 insertions(+), 16 deletions(-) diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c index e69625a8d6a1d..c00f3a933164f 100644 --- a/drivers/cxl/core/pmem.c +++ b/drivers/cxl/core/pmem.c @@ -62,10 +62,14 @@ static int match_nvdimm_bridge(struct device *dev, void *data) return is_cxl_nvdimm_bridge(dev); } -struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_memdev *cxlmd) +/** + * cxl_find_nvdimm_bridge() - find a bridge device relative to a port + * @port: any descendant port of an nvdimm-bridge associated + * root-cxl-port + */ +struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_port *port) { - struct cxl_root *cxl_root __free(put_cxl_root) = - find_cxl_root(cxlmd->endpoint); + struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port); struct device *dev; if (!cxl_root) @@ -242,18 +246,20 @@ static void cxlmd_release_nvdimm(void *_cxlmd) /** * devm_cxl_add_nvdimm() - add a bridge between a cxl_memdev and an nvdimm + * @parent_port: parent port for the (to be added) @cxlmd endpoint port * @cxlmd: cxl_memdev instance that will perform LIBNVDIMM operations * * Return: 0 on success negative error code on failure. */ -int devm_cxl_add_nvdimm(struct cxl_memdev *cxlmd) +int devm_cxl_add_nvdimm(struct cxl_port *parent_port, + struct cxl_memdev *cxlmd) { struct cxl_nvdimm_bridge *cxl_nvb; struct cxl_nvdimm *cxl_nvd; struct device *dev; int rc; - cxl_nvb = cxl_find_nvdimm_bridge(cxlmd); + cxl_nvb = cxl_find_nvdimm_bridge(parent_port); if (!cxl_nvb) return -ENODEV; diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index bcb30e04e0963..857afc8b72ff1 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2712,7 +2712,7 @@ static int cxl_pmem_region_alloc(struct cxl_region *cxlr) * bridge for one device is the same for all. */ if (i == 0) { - cxl_nvb = cxl_find_nvdimm_bridge(cxlmd); + cxl_nvb = cxl_find_nvdimm_bridge(cxlmd->endpoint); if (!cxl_nvb) return -ENODEV; cxlr->cxl_nvb = cxl_nvb; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 72fa477407689..2b82dcaf70aa6 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -848,8 +848,8 @@ struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host, struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev); bool is_cxl_nvdimm(struct device *dev); bool is_cxl_nvdimm_bridge(struct device *dev); -int devm_cxl_add_nvdimm(struct cxl_memdev *cxlmd); -struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_memdev *cxlmd); +int devm_cxl_add_nvdimm(struct cxl_port *parent_port, struct cxl_memdev *cxlmd); +struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_port *port); #ifdef CONFIG_CXL_REGION bool is_cxl_pmem_region(struct device *dev); diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 0c79d9ce877cc..2f1b49bfe162f 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -152,6 +152,15 @@ static int cxl_mem_probe(struct device *dev) return -ENXIO; } + if (resource_size(&cxlds->pmem_res) && IS_ENABLED(CONFIG_CXL_PMEM)) { + rc = devm_cxl_add_nvdimm(parent_port, cxlmd); + if (rc) { + if (rc == -ENODEV) + dev_info(dev, "PMEM disabled by platform\n"); + return rc; + } + } + if (dport->rch) endpoint_parent = parent_port->uport_dev; else @@ -174,14 +183,6 @@ static int cxl_mem_probe(struct device *dev) if (rc) return rc; - if (resource_size(&cxlds->pmem_res) && IS_ENABLED(CONFIG_CXL_PMEM)) { - rc = devm_cxl_add_nvdimm(cxlmd); - if (rc == -ENODEV) - dev_info(dev, "PMEM disabled by platform\n"); - else - return rc; - } - /* * The kernel may be operating out of CXL memory on this device, * there is no spec defined way to determine whether this device -- 2.43.0