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author | Matt Fleming <matt@console-pimps.org> | 2009-11-17 21:05:31 (GMT) |
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committer | Matt Fleming <matt@console-pimps.org> | 2010-01-16 14:28:57 (GMT) |
commit | 8eda55142080f0373b1f0268fe6d6807f193e713 (patch) | |
tree | 6d103af69153dc5bfd78ebe89930cf3c66ec5b2b /arch/sh/mm/tlb-sh4.c | |
parent | 7dcaa8e8e67b2cfbe0097c9bb52e23aed5443b8b (diff) | |
download | linux-fsl-qoriq-8eda55142080f0373b1f0268fe6d6807f193e713.tar.xz |
sh: New extended page flag to wire/unwire TLB entries
Provide a new extended page flag, _PAGE_WIRED and an SH4 implementation
for wiring TLB entries and use it in the fixmap code path so that we can
wire the fixmap TLB entry.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Diffstat (limited to 'arch/sh/mm/tlb-sh4.c')
-rw-r--r-- | arch/sh/mm/tlb-sh4.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/arch/sh/mm/tlb-sh4.c b/arch/sh/mm/tlb-sh4.c index 8cf550e..4c62347 100644 --- a/arch/sh/mm/tlb-sh4.c +++ b/arch/sh/mm/tlb-sh4.c @@ -81,3 +81,69 @@ void __uses_jump_to_uncached local_flush_tlb_one(unsigned long asid, ctrl_outl(data, addr); back_to_cached(); } + +/* + * Load the entry for 'addr' into the TLB and wire the entry. + */ +void tlb_wire_entry(struct vm_area_struct *vma, unsigned long addr, pte_t pte) +{ + unsigned long status, flags; + int urb; + + local_irq_save(flags); + + /* Load the entry into the TLB */ + __update_tlb(vma, addr, pte); + + /* ... and wire it up. */ + status = ctrl_inl(MMUCR); + urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT; + status &= ~MMUCR_URB; + + /* + * Make sure we're not trying to wire the last TLB entry slot. + */ + BUG_ON(!--urb); + + urb = urb % MMUCR_URB_NENTRIES; + + status |= (urb << MMUCR_URB_SHIFT); + ctrl_outl(status, MMUCR); + ctrl_barrier(); + + local_irq_restore(flags); +} + +/* + * Unwire the last wired TLB entry. + * + * It should also be noted that it is not possible to wire and unwire + * TLB entries in an arbitrary order. If you wire TLB entry N, followed + * by entry N+1, you must unwire entry N+1 first, then entry N. In this + * respect, it works like a stack or LIFO queue. + */ +void tlb_unwire_entry(void) +{ + unsigned long status, flags; + int urb; + + local_irq_save(flags); + + status = ctrl_inl(MMUCR); + urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT; + status &= ~MMUCR_URB; + + /* + * Make sure we're not trying to unwire a TLB entry when none + * have been wired. + */ + BUG_ON(urb++ == MMUCR_URB_NENTRIES); + + urb = urb % MMUCR_URB_NENTRIES; + + status |= (urb << MMUCR_URB_SHIFT); + ctrl_outl(status, MMUCR); + ctrl_barrier(); + + local_irq_restore(flags); +} |