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From:   Robert Richter <rrichter@amd.com>
To:     Alison Schofield <alison.schofield@intel.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Ira Weiny <ira.weiny@intel.com>,
        Ben Widawsky <bwidawsk@kernel.org>,
        Dan Williams <dan.j.williams@intel.com>
CC:     <linux-cxl@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <lenb@kernel.org>, Robert Richter <rrichter@amd.com>
Subject: [PATCH 02/15] cxl/core: Check physical address before mapping it in devm_cxl_iomap_block()
Date:   Wed, 31 Aug 2022 10:15:50 +0200
Message-ID: <20220831081603.3415-3-rrichter@amd.com>
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The physical base address of a CXL range can be invalid and is then
set to CXL_RESOURCE_NONE. Early check this case before mapping a
memory block in devm_cxl_iomap_block().

Signed-off-by: Robert Richter <rrichter@amd.com>
---
 drivers/cxl/core/regs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
index 39a129c57d40..f216c017a474 100644
--- a/drivers/cxl/core/regs.c
+++ b/drivers/cxl/core/regs.c
@@ -165,6 +165,9 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr,
 	void __iomem *ret_val;
 	struct resource *res;
 
+	if (addr == CXL_RESOURCE_NONE)
+		return NULL;
+
 	res = devm_request_mem_region(dev, addr, length, dev_name(dev));
 	if (!res) {
 		resource_size_t end = addr + length - 1;
-- 
2.30.2