| Paul Mundt | bb29c67 | 2010-01-19 15:20:35 +0900 | [diff] [blame] | 1 | /* |
| 2 | * arch/sh/mm/tlb-urb.c |
| 3 | * |
| 4 | * TLB entry wiring helpers for URB-equipped parts. |
| 5 | * |
| 6 | * Copyright (C) 2010 Matt Fleming |
| 7 | * |
| 8 | * This file is subject to the terms and conditions of the GNU General Public |
| 9 | * License. See the file "COPYING" in the main directory of this archive |
| 10 | * for more details. |
| 11 | */ |
| 12 | #include <linux/mm.h> |
| 13 | #include <linux/io.h> |
| 14 | #include <asm/tlb.h> |
| 15 | #include <asm/mmu_context.h> |
| 16 | |
| 17 | /* |
| 18 | * Load the entry for 'addr' into the TLB and wire the entry. |
| 19 | */ |
| 20 | void tlb_wire_entry(struct vm_area_struct *vma, unsigned long addr, pte_t pte) |
| 21 | { |
| 22 | unsigned long status, flags; |
| 23 | int urb; |
| 24 | |
| 25 | local_irq_save(flags); |
| 26 | |
| 27 | /* Load the entry into the TLB */ |
| 28 | __update_tlb(vma, addr, pte); |
| 29 | |
| 30 | /* ... and wire it up. */ |
| 31 | status = __raw_readl(MMUCR); |
| 32 | urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT; |
| 33 | status &= ~MMUCR_URB; |
| 34 | |
| 35 | /* |
| 36 | * Make sure we're not trying to wire the last TLB entry slot. |
| 37 | */ |
| 38 | BUG_ON(!--urb); |
| 39 | |
| 40 | urb = urb % MMUCR_URB_NENTRIES; |
| 41 | |
| 42 | status |= (urb << MMUCR_URB_SHIFT); |
| 43 | __raw_writel(status, MMUCR); |
| 44 | ctrl_barrier(); |
| 45 | |
| 46 | local_irq_restore(flags); |
| 47 | } |
| 48 | |
| 49 | /* |
| 50 | * Unwire the last wired TLB entry. |
| 51 | * |
| 52 | * It should also be noted that it is not possible to wire and unwire |
| 53 | * TLB entries in an arbitrary order. If you wire TLB entry N, followed |
| 54 | * by entry N+1, you must unwire entry N+1 first, then entry N. In this |
| 55 | * respect, it works like a stack or LIFO queue. |
| 56 | */ |
| 57 | void tlb_unwire_entry(void) |
| 58 | { |
| 59 | unsigned long status, flags; |
| 60 | int urb; |
| 61 | |
| 62 | local_irq_save(flags); |
| 63 | |
| 64 | status = __raw_readl(MMUCR); |
| 65 | urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT; |
| 66 | status &= ~MMUCR_URB; |
| 67 | |
| 68 | /* |
| 69 | * Make sure we're not trying to unwire a TLB entry when none |
| 70 | * have been wired. |
| 71 | */ |
| 72 | BUG_ON(urb++ == MMUCR_URB_NENTRIES); |
| 73 | |
| 74 | urb = urb % MMUCR_URB_NENTRIES; |
| 75 | |
| 76 | status |= (urb << MMUCR_URB_SHIFT); |
| 77 | __raw_writel(status, MMUCR); |
| 78 | ctrl_barrier(); |
| 79 | |
| 80 | local_irq_restore(flags); |
| 81 | } |