kernel/arch/arm/mm/highmem.c, branch linux-4.15.y

kmap_atomic_to_page() has no users, remove it

2015-11-09T23:11:24Z

Removal started in commit 5bbeed12bdc3 ("sparc32: drop unused kmap_atomic_to_page"). Let's do it across the whole tree. Signed-off-by: Nicolas Pitre Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ARM: 8415/1: early fixmap support for earlycon

2015-08-18T13:00:29Z

Add early fixmap support, initially to support permanent, fixed mapping support for early console. A temporary, early pte is created which is migrated to a permanent mapping in paging_init. This is also needed since the attributes may change as the memory types are initialized. The 3MiB range of fixmap spans two pte tables, but currently only one pte is created for early fixmap support. Re-add FIX_KMAP_BEGIN to the index calculation in highmem.c since the index for kmap does not start at zero anymore. This reverts 4221e2e6b316 ("ARM: 8031/1: fixmap: remove FIX_KMAP_BEGIN and FIX_KMAP_END") to some extent. Cc: Mark Salter Cc: Kees Cook Cc: Laura Abbott Cc: Arnd Bergmann Cc: Ard Biesheuvel Signed-off-by: Rob Herring Signed-off-by: Stefan Agner Signed-off-by: Russell King

sched/preempt, mm/kmap: Explicitly disable/enable preemption in kmap_atomic_*

2015-05-19T06:39:14Z

The existing code relies on pagefault_disable() implicitly disabling preemption, so that no schedule will happen between kmap_atomic() and kunmap_atomic(). Let's make this explicit, to prepare for pagefault_disable() not touching preemption anymore. Reviewed-and-tested-by: Thomas Gleixner Signed-off-by: David Hildenbrand Signed-off-by: Peter Zijlstra (Intel) Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-5-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar

Merge branch 'devel-stable' into for-next

2014-12-05T16:30:54Z

ARM: 8180/1: mm: implement no-highmem fast path in kmap_atomic_pfn()

2014-10-29T17:22:07Z

Since CONFIG_HIGHMEM got enabled on ARMv5 Kirkwood, we have noticed a very significant drop in networking performance. The test were conducted on an OpenBlocks A7 board. Without this patch, the outgoing performance measured with iperf are: - highmem OFF, TSO OFF 544 Mbit/s - highmem OFF, TSO ON 942 Mbit/s - highmem ON, TSO OFF 306 Mbit/s - highmem ON, TSO ON 246 Mbit/s On this Kirkwood platform, the L2 cache is a Feroceon cache, and with this cache, all the range operations have to be done on virtual addresses and not physical addresses. Therefore, whenever CONFIG_HIGHMEM is enabled, the cache maintenance operations call kmap_atomic_pfn() and kunmap_atomic(). However, kmap_atomic_pfn() does not implement the same fast path for non-highmem pages as the one implemented in kmap_atomic(), and this is one of the reason for the performance drop. While this patch does not fully restore the performances, it clearly improves them a lot: without patch with patch - highmem ON, TSO OFF 306 Mbit/s 387 Mbit/s - highmem ON, TSO ON 246 Mbit/s 434 Mbit/s We're still far from the !CONFIG_HIGHMEM performances, but it does improve a bit the situation. Thanks a lot to Ezequiel Garcia and Gregory Clement for all the testing work around this topic. Signed-off-by: Thomas Petazzoni Signed-off-by: Russell King

ARM: expand fixmap region to 3MB

2014-10-16T21:38:52Z

With commit a05e54c103b0 ("ARM: 8031/2: change fixmap mapping region to support 32 CPUs"), the fixmap region was expanded to 2MB, but it precluded any other uses of the fixmap region. In order to support other uses the fixmap region needs to be expanded beyond 2MB. Fortunately, the adjacent 1MB range 0xffe00000-0xfff00000 is availabe. Remove fixmap_page_table ptr and lookup the page table via the virtual address so that the fixmap region can span more that one pmd. The 2nd pmd is already created since it is shared with the vector page. Signed-off-by: Rob Herring [kees: fixed CONFIG_DEBUG_HIGHMEM get_fixmap() calls] [kees: moved pte allocation outside of CONFIG_HIGHMEM] Signed-off-by: Kees Cook Acked-by: Nicolas Pitre

ARM: 8031/2: change fixmap mapping region to support 32 CPUs

2014-04-23T10:09:42Z

In 32-bit ARM systems, the fixmap mapping region can support no more than 14 CPUs(total: 896k; one CPU: 64K). And we can configure NR_CPUS up to 32. So there is a mismatch. This patch moves fixmapping region downwards to region 0xffc00000- 0xffe00000. Then the fixmap mapping region can support up to 32 CPUs. Reviewed-by: Nicolas Pitre Signed-off-by: Liu Hua Signed-off-by: Russell King

ARM: 8031/1: fixmap: remove FIX_KMAP_BEGIN and FIX_KMAP_END

2014-04-23T10:09:27Z

It seems that these two macros are not used by non architecture specific code. And on ARM FIX_KMAP_BEGIN equals zero. This patch removes these two macros. Instead, using FIX_KMAP_NR_PTES to tell the pte number belonged to fixmap mapping region. The code will become clearer when I introduce a bugfix on fixmap mapping region. Reviewed-by: Nicolas Pitre Signed-off-by: Liu Hua Signed-off-by: Russell King

Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm

2012-03-29T23:53:48Z

Pull more ARM updates from Russell King. This got a fair number of conflicts with the split, but also with some other sparse-irq and header file include cleanups. They all looked pretty trivial, though. * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits) ARM: fix Kconfig warning for HAVE_BPF_JIT ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds ARM: 7349/1: integrator: convert to sparse irqs ARM: 7259/3: net: JIT compiler for packet filters ARM: 7334/1: add jump label support ARM: 7333/2: jump label: detect %c support for ARM ARM: 7338/1: add support for early console output via semihosting ARM: use set_current_blocked() and block_sigmask() ARM: exec: remove redundant set_fs(USER_DS) ARM: 7332/1: extract out code patch function from kprobes ARM: 7331/1: extract out insn generation code from ftrace ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format ARM: 7351/1: ftrace: remove useless memory checks ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path ARM: Versatile Express: add NO_IOPORT ARM: get rid of asm/irq.h in asm/prom.h ARM: 7319/1: Print debug info for SIGBUS in user faults ARM: 7318/1: gic: refactor irq_start assignment ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop ARM: 7315/1: perf: add support for the Cortex-A7 PMU ...

highmem: kill all __kmap_atomic()

2012-03-20T13:48:30Z

[swarren@nvidia.com: highmem: Fix ARM build break due to __kmap_atomic rename] Signed-off-by: Stephen Warren Signed-off-by: Cong Wang