From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 35bd8c07db2ce8fd2834ef866240613a4ef982e7 ]
Sometimes debugging a device is easiest using devmem on its register map, and that can be seen with /proc/iomem. But some device drivers have many memory regions. Take for example a networking switch. Its memory map used to look like this in /proc/iomem:
1fc000000-1fc3fffff : pcie@1f0000000 1fc000000-1fc3fffff : 0000:00:00.5 1fc010000-1fc01ffff : sys 1fc030000-1fc03ffff : rew 1fc060000-1fc0603ff : s2 1fc070000-1fc0701ff : devcpu_gcb 1fc080000-1fc0800ff : qs 1fc090000-1fc0900cb : ptp 1fc100000-1fc10ffff : port0 1fc110000-1fc11ffff : port1 1fc120000-1fc12ffff : port2 1fc130000-1fc13ffff : port3 1fc140000-1fc14ffff : port4 1fc150000-1fc15ffff : port5 1fc200000-1fc21ffff : qsys 1fc280000-1fc28ffff : ana
But after the patch in Fixes: was applied, the information is now presented in a much more opaque way:
1fc000000-1fc3fffff : pcie@1f0000000 1fc000000-1fc3fffff : 0000:00:00.5 1fc010000-1fc01ffff : 0000:00:00.5 1fc030000-1fc03ffff : 0000:00:00.5 1fc060000-1fc0603ff : 0000:00:00.5 1fc070000-1fc0701ff : 0000:00:00.5 1fc080000-1fc0800ff : 0000:00:00.5 1fc090000-1fc0900cb : 0000:00:00.5 1fc100000-1fc10ffff : 0000:00:00.5 1fc110000-1fc11ffff : 0000:00:00.5 1fc120000-1fc12ffff : 0000:00:00.5 1fc130000-1fc13ffff : 0000:00:00.5 1fc140000-1fc14ffff : 0000:00:00.5 1fc150000-1fc15ffff : 0000:00:00.5 1fc200000-1fc21ffff : 0000:00:00.5 1fc280000-1fc28ffff : 0000:00:00.5
That patch made a fair comment that /proc/iomem might be confusing when it shows resources without an associated device, but we can do better than just hide the resource name altogether. Namely, we can print the device name _and_ the resource name. Like this:
1fc000000-1fc3fffff : pcie@1f0000000 1fc000000-1fc3fffff : 0000:00:00.5 1fc010000-1fc01ffff : 0000:00:00.5 sys 1fc030000-1fc03ffff : 0000:00:00.5 rew 1fc060000-1fc0603ff : 0000:00:00.5 s2 1fc070000-1fc0701ff : 0000:00:00.5 devcpu_gcb 1fc080000-1fc0800ff : 0000:00:00.5 qs 1fc090000-1fc0900cb : 0000:00:00.5 ptp 1fc100000-1fc10ffff : 0000:00:00.5 port0 1fc110000-1fc11ffff : 0000:00:00.5 port1 1fc120000-1fc12ffff : 0000:00:00.5 port2 1fc130000-1fc13ffff : 0000:00:00.5 port3 1fc140000-1fc14ffff : 0000:00:00.5 port4 1fc150000-1fc15ffff : 0000:00:00.5 port5 1fc200000-1fc21ffff : 0000:00:00.5 qsys 1fc280000-1fc28ffff : 0000:00:00.5 ana
Fixes: 8d84b18f5678 ("devres: always use dev_name() in devm_ioremap_resource()") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Link: https://lore.kernel.org/r/20200601095826.1757621-1-olteanv@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- lib/devres.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/lib/devres.c b/lib/devres.c index 6ef51f159c54b..ca0d28727ccef 100644 --- a/lib/devres.c +++ b/lib/devres.c @@ -119,6 +119,7 @@ __devm_ioremap_resource(struct device *dev, const struct resource *res, { resource_size_t size; void __iomem *dest_ptr; + char *pretty_name;
BUG_ON(!dev);
@@ -129,7 +130,15 @@ __devm_ioremap_resource(struct device *dev, const struct resource *res,
size = resource_size(res);
- if (!devm_request_mem_region(dev, res->start, size, dev_name(dev))) { + if (res->name) + pretty_name = devm_kasprintf(dev, GFP_KERNEL, "%s %s", + dev_name(dev), res->name); + else + pretty_name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL); + if (!pretty_name) + return IOMEM_ERR_PTR(-ENOMEM); + + if (!devm_request_mem_region(dev, res->start, size, pretty_name)) { dev_err(dev, "can't request region for resource %pR\n", res); return IOMEM_ERR_PTR(-EBUSY); }