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From: Stephen Boyd <swboyd@chromium.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org,
	Wei-Ning Huang <wnhuang@chromium.org>,
	Julius Werner <jwerner@chromium.org>,
	Brian Norris <briannorris@chromium.org>,
	Samuel Holland <samuel@sholland.org>
Subject: [PATCH v3 7/7] firmware: coreboot: Request table region for exclusive access
Date: Thu,  9 Aug 2018 10:17:22 -0700
Message-ID: <20180809171722.144325-8-swboyd@chromium.org> (raw)
In-Reply-To: <20180809171722.144325-1-swboyd@chromium.org>

Call request_mem_region() on the entire coreboot table to make sure
other devices don't attempt to map the coreboot table in their drivers.
If drivers need that support, it would be better to provide bus APIs
they can use to do that through the mapping created in this file.

Cc: Wei-Ning Huang <wnhuang@chromium.org>
Cc: Julius Werner <jwerner@chromium.org>
Cc: Brian Norris <briannorris@chromium.org>
Cc: Samuel Holland <samuel@sholland.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 drivers/firmware/google/coreboot_table.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/google/coreboot_table.c b/drivers/firmware/google/coreboot_table.c
index 814913606d22..94c41d814ea5 100644
--- a/drivers/firmware/google/coreboot_table.c
+++ b/drivers/firmware/google/coreboot_table.c
@@ -132,6 +132,7 @@ static int coreboot_table_probe(struct platform_device *pdev)
 	struct coreboot_table_header *header;
 	struct resource *res;
 	struct device *dev = &pdev->dev;
+	const char *name;
 	void *ptr;
 	int ret;
 
@@ -153,10 +154,17 @@ static int coreboot_table_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	ptr = devm_memremap(dev, res->start,
-			    header->header_bytes + header->table_bytes,
-			    MEMREMAP_WB);
+	len = header->header_bytes + header->table_bytes;
+	res->end = res->start + len - 1;
+	name = res->name ?: dev_name(dev);
 	memunmap(header);
+
+	if (!devm_request_mem_region(dev, res->start, len, name)) {
+		dev_err(dev, "can't request region for resource %pR\n", res);
+		return -EBUSY;
+	}
+
+	ptr = devm_memremap(dev, res->start, len, MEMREMAP_WB);
 	if (!ptr)
 		return -ENOMEM;
 
-- 
Sent by a computer through tubes


  parent reply index

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-09 17:17 [PATCH v3 0/7] firmware: coreboot: Fix probe and simplify code Stephen Boyd
2018-08-09 17:17 ` [PATCH v3 1/7] firmware: coreboot: Let OF core populate platform device Stephen Boyd
2018-08-09 17:31   ` Brian Norris
2018-08-09 17:17 ` [PATCH v3 2/7] firmware: coreboot: Unmap ioregion on failure Stephen Boyd
2018-08-09 17:49   ` Brian Norris
2018-08-09 19:40     ` Stephen Boyd
2018-08-09 19:52       ` Brian Norris
2018-08-09 23:25         ` Stephen Boyd
2018-08-09 17:17 ` [PATCH v3 3/7] firmware: coreboot: Make bus registration symmetric Stephen Boyd
2018-08-09 18:10   ` Julius Werner
2018-08-09 23:30     ` Stephen Boyd
2018-08-09 17:17 ` [PATCH v3 4/7] firmware: coreboot: Collapse platform drivers into bus core Stephen Boyd
2018-08-09 17:17 ` [PATCH v3 5/7] firmware: coreboot: Remap RAM with memremap() instead of ioremap() Stephen Boyd
2018-08-09 18:24   ` Julius Werner
2018-08-09 22:07     ` Stephen Boyd
2018-08-09 17:17 ` [PATCH v3 6/7] firmware: coreboot: Only populate devices in coreboot_table_init() Stephen Boyd
2018-08-09 21:02   ` Julius Werner
2018-08-09 23:43     ` Stephen Boyd
2018-08-09 17:17 ` Stephen Boyd [this message]
2018-08-09 21:07   ` [PATCH v3 7/7] firmware: coreboot: Request table region for exclusive access Julius Werner
2018-08-09 23:03     ` Stephen Boyd
2018-08-09 23:37       ` Julius Werner
2018-08-09 23:44         ` Julius Werner
2018-08-10  2:54           ` Stephen Boyd
2018-08-10 23:24             ` Stephen Boyd
2018-08-09 18:03 ` [PATCH v3 0/7] firmware: coreboot: Fix probe and simplify code Brian Norris

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