kernel/linux.git/arch/mips/mm/ioremap.c, branch linux-7.0.y

mm/ioremap: pass pgprot_t to ioremap_prot() instead of unsigned long

2025-03-17T05:06:23+00:00

ioremap_prot() currently accepts pgprot_val parameter as an unsigned long, thus implicitly assuming that pgprot_val and pgprot_t could never be bigger than unsigned long. But this assumption soon will not be true on arm64 when using D128 pgtables. In 128 bit page table configuration, unsigned long is 64 bit, but pgprot_t is 128 bit. Passing platform abstracted pgprot_t argument is better as compared to size based data types. Let's change the parameter to directly pass pgprot_t like another similar helper generic_ioremap_prot(). Without this change in place, D128 configuration does not work on arm64 as the top 64 bits gets silently stripped when passing the protection value to this function. Link: https://lkml.kernel.org/r/20250218101954.415331-1-anshuman.khandual@arm.com Signed-off-by: Ryan Roberts Co-developed-by: Anshuman Khandual Signed-off-by: Anshuman Khandual Acked-by: Catalin Marinas [arm64] Signed-off-by: Andrew Morton

mips: mm: add slab availability checking in ioremap_prot

2023-12-21T14:32:46+00:00

Recent commit a5f616483110 ("mm/ioremap: add slab availability checking in ioremap_prot") added the slab availability check to the generic ioremap_prot() implementation. It is reasonable to be done for the MIPS32-specific method too since it also relies on the get_vm_area_caller() function (by means of get_vm_area()) which requires the slab allocator being up and running before being called. Signed-off-by: Serge Semin Signed-off-by: Thomas Bogendoerfer

MIPS: use ioremap_page_range

2020-04-19T14:13:18+00:00

Use the generic ioremap_page_range helper instead of reimplementing it. Signed-off-by: Christoph Hellwig Signed-off-by: Thomas Bogendoerfer

MIPS: move ioremap_prot und iounmap out of line

2020-04-19T14:12:31+00:00

Neither of these interfaces is anywhere near the fast path. Move them out of line and avoid exposing implementation details to the drivers. Signed-off-by: Christoph Hellwig Signed-off-by: Thomas Bogendoerfer

mips: add support for folded p4d page tables

2019-11-22T18:51:22+00:00

Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate, replace 5leve-fixup.h with pgtable-nop4d.h and drop usage of __ARCH_USE_5LEVEL_HACK. Signed-off-by: Mike Rapoport Signed-off-by: Paul Burton Cc: Ralf Baechle Cc: James Hogan Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Mike Rapoport

MIPS: Fix ioremap() RAM check

2018-07-05T21:43:21+00:00

We currently attempt to check whether a physical address range provided to __ioremap() may be in use by the page allocator by examining the value of PageReserved for each page in the region - lowmem pages not marked reserved are presumed to be in use by the page allocator, and requests to ioremap them fail. The way we check this has been broken since commit 92923ca3aace ("mm: meminit: only set page reserved in the memblock region"), because memblock will typically not have any knowledge of non-RAM pages and therefore those pages will not have the PageReserved flag set. Thus when we attempt to ioremap a region outside of RAM we incorrectly fail believing that the region is RAM that may be in use. In most cases ioremap() on MIPS will take a fast-path to use the unmapped kseg1 or xkphys virtual address spaces and never hit this path, so the only way to hit it is for a MIPS32 system to attempt to ioremap() an address range in lowmem with flags other than _CACHE_UNCACHED. Perhaps the most straightforward way to do this is using ioremap_uncached_accelerated(), which is how the problem was discovered. Fix this by making use of walk_system_ram_range() to test the address range provided to __ioremap() against only RAM pages, rather than all lowmem pages. This means that if we have a lowmem I/O region, which is very common for MIPS systems, we're free to ioremap() address ranges within it. A nice bonus is that the test is no longer limited to lowmem. The approach here matches the way x86 performed the same test after commit c81c8a1eeede ("x86, ioremap: Speed up check for RAM pages") until x86 moved towards a slightly more complicated check using walk_mem_res() for unrelated reasons with commit 0e4c12b45aa8 ("x86/mm, resource: Use PAGE_KERNEL protection for ioremap of memory pages"). Signed-off-by: Paul Burton Reported-by: Serge Semin Tested-by: Serge Semin Fixes: 92923ca3aace ("mm: meminit: only set page reserved in the memblock region") Cc: James Hogan Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.2+ Patchwork: https://patchwork.linux-mips.org/patch/19786/

sched/headers: Prepare to remove the dependency from

2017-03-02T07:42:37+00:00

Update code that relied on sched.h including various MM types for them. This will allow us to remove the include from . Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

MIPS: mm: Audit and remove any unnecessary uses of module.h

2016-10-04T23:31:20+00:00

Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance for the presence of either and replace as needed. Signed-off-by: Paul Gortmaker Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14033/ Signed-off-by: Ralf Baechle

MIPS: Replace use of phys_t with phys_addr_t.

2014-11-24T21:47:31+00:00

Signed-off-by: Ralf Baechle

MIPS: Whitespace cleanup.

2013-02-01T09:00:22+00:00

Having received another series of whitespace patches I decided to do this once and for all rather than dealing with this kind of patches trickling in forever. Signed-off-by: Ralf Baechle