diff options
author | David S. Miller <davem@davemloft.net> | 2010-02-28 19:23:06 -0800 |
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committer | David S. Miller <davem@davemloft.net> | 2010-02-28 19:23:06 -0800 |
commit | 47871889c601d8199c51a4086f77eebd77c29b0b (patch) | |
tree | 40cdcac3bff0ee40cc33dcca61d0577cdf965f77 /arch/sh/mm/tlb-urb.c | |
parent | c16cc0b464b8876cfd57ce1c1dbcb6f9a6a0bce3 (diff) | |
parent | 30ff056c42c665b9ea535d8515890857ae382540 (diff) |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
drivers/firmware/iscsi_ibft.c
Diffstat (limited to 'arch/sh/mm/tlb-urb.c')
-rw-r--r-- | arch/sh/mm/tlb-urb.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/sh/mm/tlb-urb.c b/arch/sh/mm/tlb-urb.c new file mode 100644 index 00000000000..bb5b9098956 --- /dev/null +++ b/arch/sh/mm/tlb-urb.c @@ -0,0 +1,81 @@ +/* + * arch/sh/mm/tlb-urb.c + * + * TLB entry wiring helpers for URB-equipped parts. + * + * Copyright (C) 2010 Matt Fleming + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include <linux/mm.h> +#include <linux/io.h> +#include <asm/tlb.h> +#include <asm/mmu_context.h> + +/* + * 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 = __raw_readl(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); + __raw_writel(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 = __raw_readl(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); + __raw_writel(status, MMUCR); + ctrl_barrier(); + + local_irq_restore(flags); +} |