linux/arch/ia64
Logan Gunthorpe bfeb022f8f 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>
2020-04-10 15:36:21 -07:00
..
configs Char/Misc driver patches for 5.7-rc1 2020-04-03 13:22:40 -07:00
hp/common dma-mapping updates for 5.4: 2019-09-19 13:27:23 -07:00
include mm/special: create generic fallbacks for pte_special() and pte_mkspecial() 2020-04-10 15:36:21 -07:00
kernel kasan: stackdepot: move filter_irq_stacks() to stackdepot.c 2020-04-07 10:43:43 -07:00
lib ia64: remove now unused machvec indirections 2019-08-16 11:33:57 -07:00
mm mm/memory_hotplug: add pgprot_t to mhp_params 2020-04-10 15:36:21 -07:00
oprofile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pci ia64: remove support for machvecs 2019-08-16 14:32:26 -07:00
scripts ia64: convert unwcheck.py to python3 2018-03-05 14:35:01 -08:00
uv ia64: remove support for machvecs 2019-08-16 14:32:26 -07:00
install.sh
Kconfig dma-direct: provide mmap and get_sgtable method overrides 2019-11-11 10:52:15 +01:00
Kconfig.debug ia64: remove support for machvecs 2019-08-16 14:32:26 -07:00
Makefile Kbuild updates for v5.4 2019-09-20 08:36:47 -07:00
module.lds License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00