diff options
| author | Logan Gunthorpe | 2020-04-10 14:33:36 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2020-04-10 15:36:21 -0700 |
| commit | bfeb022f8fe4c5afdcfd7a3d868fac9765f9bcad (patch) | |
| tree | 19458a2679b0184c7e53156b5025415fdac0d4c9 /arch/ia64 | |
| parent | 4e00c5affdd4b04e6392001716333971932f3d0c (diff) | |
mm/memory_hotplug: add pgprot_t to mhp_params
devm_memremap_pages() is currently used by the PCI P2PDMA code to create
struct page mappings for IO memory. At present, these mappings are
created with PAGE_KERNEL which implies setting the PAT bits to be WB.
However, on x86, an mtrr register will typically override this and force
the cache type to be UC-. In the case firmware doesn't set this
register it is effectively WB and will typically result in a machine
check exception when it's accessed.
Other arches are not currently likely to function correctly seeing they
don't have any MTRR registers to fall back on.
To solve this, provide a way to specify the pgprot value explicitly to
arch_add_memory().
Of the arches that support MEMORY_HOTPLUG: x86_64, and arm64 need a
simple change to pass the pgprot_t down to their respective functions
which set up the page tables. For x86_32, set the page tables
explicitly using _set_memory_prot() (seeing they are already mapped).
For ia64, s390 and sh, reject anything but PAGE_KERNEL settings -- this
should be fine, for now, seeing these architectures don't support
ZONE_DEVICE.
A check in __add_pages() is also added to ensure the pgprot parameter
was set for all arches.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-7-logang@deltatee.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/ia64')
| -rw-r--r-- | arch/ia64/mm/init.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c index 97bbc23ea1e3..d637b4ea3147 100644 --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -676,6 +676,9 @@ int arch_add_memory(int nid, u64 start, u64 size, unsigned long nr_pages = size >> PAGE_SHIFT; int ret; + if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot)) + return -EINVAL; + ret = __add_pages(nid, start_pfn, nr_pages, params); if (ret) printk("%s: Problem encountered in __add_pages() as ret=%d\n", |