On Tue, Dec 1, 2015 at 5:50 AM, Borislav Petkov <[email protected]> wrote: > On Tue, Nov 24, 2015 at 03:33:36PM -0700, Toshi Kani wrote: >> region_intersects() checks if a specified region partially overlaps >> or fully eclipses a resource identified by @name. It currently sets >> resource flags statically, which prevents the caller from specifying >> a non-RAM region, such as persistent memory. Add @flags so that >> any region can be specified to the function. >> >> A helper function, region_intersects_ram(), is added so that the >> callers that check a RAM region do not have to specify its iomem >> resource name and flags. This interface is exported for modules, >> such as the EINJ driver. >> >> Signed-off-by: Toshi Kani <[email protected]> >> Reviewed-by: Dan Williams <[email protected]> >> Cc: Andrew Morton <[email protected]> >> Cc: Vishal Verma <[email protected]> >> --- >> include/linux/mm.h | 4 +++- >> kernel/memremap.c | 5 ++--- >> kernel/resource.c | 23 ++++++++++++++++------- >> 3 files changed, 21 insertions(+), 11 deletions(-) >> >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index 00bad77..c776af3 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -362,7 +362,9 @@ enum { >> REGION_MIXED, >> }; >> >> -int region_intersects(resource_size_t offset, size_t size, const char >> *type); >> +int region_intersects(resource_size_t offset, size_t size, const char *type, >> + unsigned long flags); >> +int region_intersects_ram(resource_size_t offset, size_t size); >> >> /* Support for virtually mapped pages */ >> struct page *vmalloc_to_page(const void *addr); >> diff --git a/kernel/memremap.c b/kernel/memremap.c >> index 7658d32..98f52f1 100644 >> --- a/kernel/memremap.c >> +++ b/kernel/memremap.c >> @@ -57,7 +57,7 @@ static void *try_ram_remap(resource_size_t offset, size_t >> size) >> */ >> void *memremap(resource_size_t offset, size_t size, unsigned long flags) >> { >> - int is_ram = region_intersects(offset, size, "System RAM"); > > Ok, question: why do those resource things types gets identified with > a string?! We have here "System RAM" and next patch adds "Persistent > Memory". > > And "persistent memory" or "System RaM" won't work and this is just > silly. > > Couldn't struct resource have gained some typedef flags instead which we > can much easily test? Using the strings looks really yucky. >
At least in the case of region_intersects() I was just following existing strcmp() convention from walk_system_ram_range. We could define 'const char *system_ram = "System RAM"' somewhere and then do pointer comparisons to cut down on the thrash of adding new flags to 'struct resource'? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
