Re: [PATCH v2] ACPI: Drop rcu usage for MMIO mappings

[kbuild test robot <lkp@intel.com>]

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TO: Dan Williams <dan.j.williams@intel.com>
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CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Hi Dan,

I love your patch! Perhaps something to improve:

[auto build test WARNING on pm/linux-next]
[also build test WARNING on v5.7-rc5 next-20200511]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Dan-Williams/ACPI-Drop-rcu-usage-for-MMIO-mappings/20200509-013208
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
:::::: branch date: 3 days ago
:::::: commit date: 3 days ago

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

New smatch warnings:
drivers/acpi/osl.c:707 acpi_os_rw_map() warn: inconsistent returns 'acpi_ioremap_lock'.

Old smatch warnings:
drivers/acpi/osl.c:326 acpi_os_map_iomem() warn: impossible condition '(phys > (~0)) => (0-u64max > u64max)'

# https://github.com/0day-ci/linux/commit/5a91d41f89e8874053e12766fa8eb5eaa997d277
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 5a91d41f89e8874053e12766fa8eb5eaa997d277
vim +/acpi_ioremap_lock +707 drivers/acpi/osl.c

eeb2d80d502af2 Srinivas Pandruvada 2017-10-05  687  
5a91d41f89e887 Dan Williams        2020-05-07  688  static void __iomem *acpi_os_rw_map(acpi_physical_address phys_addr,
5a91d41f89e887 Dan Williams        2020-05-07  689  				    unsigned int size, bool *did_fallback)
5a91d41f89e887 Dan Williams        2020-05-07  690  {
5a91d41f89e887 Dan Williams        2020-05-07  691  	void __iomem *virt_addr;
5a91d41f89e887 Dan Williams        2020-05-07  692  
5a91d41f89e887 Dan Williams        2020-05-07  693  	if (WARN_ONCE(in_interrupt(), "ioremap in interrupt context\n"))
5a91d41f89e887 Dan Williams        2020-05-07  694  		return NULL;
5a91d41f89e887 Dan Williams        2020-05-07  695  
5a91d41f89e887 Dan Williams        2020-05-07  696  	/* Try to use a cached mapping and fallback otherwise */
5a91d41f89e887 Dan Williams        2020-05-07  697  	*did_fallback = false;
5a91d41f89e887 Dan Williams        2020-05-07  698  	mutex_lock(&acpi_ioremap_lock);
5a91d41f89e887 Dan Williams        2020-05-07  699  	virt_addr = acpi_map_vaddr_lookup(phys_addr, size);
5a91d41f89e887 Dan Williams        2020-05-07  700  	if (virt_addr)
5a91d41f89e887 Dan Williams        2020-05-07  701  		return virt_addr;
5a91d41f89e887 Dan Williams        2020-05-07  702  	mutex_unlock(&acpi_ioremap_lock);
5a91d41f89e887 Dan Williams        2020-05-07  703  
5a91d41f89e887 Dan Williams        2020-05-07  704  	virt_addr = acpi_os_ioremap(phys_addr, size);
5a91d41f89e887 Dan Williams        2020-05-07  705  	*did_fallback = true;
5a91d41f89e887 Dan Williams        2020-05-07  706  
5a91d41f89e887 Dan Williams        2020-05-07 @707  	return virt_addr;
5a91d41f89e887 Dan Williams        2020-05-07  708  }
5a91d41f89e887 Dan Williams        2020-05-07  709  

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