diff options
Diffstat (limited to 'kernel/arch/avr32/mm/tlb.c')
-rw-r--r-- | kernel/arch/avr32/mm/tlb.c | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/kernel/arch/avr32/mm/tlb.c b/kernel/arch/avr32/mm/tlb.c new file mode 100644 index 000000000..0da23109f --- /dev/null +++ b/kernel/arch/avr32/mm/tlb.c @@ -0,0 +1,375 @@ +/* + * AVR32 TLB operations + * + * Copyright (C) 2004-2006 Atmel Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/mm.h> + +#include <asm/mmu_context.h> + +/* TODO: Get the correct number from the CONFIG1 system register */ +#define NR_TLB_ENTRIES 32 + +static void show_dtlb_entry(unsigned int index) +{ + u32 tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save; + unsigned long flags; + + local_irq_save(flags); + mmucr_save = sysreg_read(MMUCR); + tlbehi_save = sysreg_read(TLBEHI); + mmucr = SYSREG_BFINS(DRP, index, mmucr_save); + sysreg_write(MMUCR, mmucr); + + __builtin_tlbr(); + cpu_sync_pipeline(); + + tlbehi = sysreg_read(TLBEHI); + tlbelo = sysreg_read(TLBELO); + + printk("%2u: %c %c %02x %05x %05x %o %o %c %c %c %c\n", + index, + SYSREG_BFEXT(TLBEHI_V, tlbehi) ? '1' : '0', + SYSREG_BFEXT(G, tlbelo) ? '1' : '0', + SYSREG_BFEXT(ASID, tlbehi), + SYSREG_BFEXT(VPN, tlbehi) >> 2, + SYSREG_BFEXT(PFN, tlbelo) >> 2, + SYSREG_BFEXT(AP, tlbelo), + SYSREG_BFEXT(SZ, tlbelo), + SYSREG_BFEXT(TLBELO_C, tlbelo) ? 'C' : ' ', + SYSREG_BFEXT(B, tlbelo) ? 'B' : ' ', + SYSREG_BFEXT(W, tlbelo) ? 'W' : ' ', + SYSREG_BFEXT(TLBELO_D, tlbelo) ? 'D' : ' '); + + sysreg_write(MMUCR, mmucr_save); + sysreg_write(TLBEHI, tlbehi_save); + cpu_sync_pipeline(); + local_irq_restore(flags); +} + +void dump_dtlb(void) +{ + unsigned int i; + + printk("ID V G ASID VPN PFN AP SZ C B W D\n"); + for (i = 0; i < NR_TLB_ENTRIES; i++) + show_dtlb_entry(i); +} + +static void update_dtlb(unsigned long address, pte_t pte) +{ + u32 tlbehi; + u32 mmucr; + + /* + * We're not changing the ASID here, so no need to flush the + * pipeline. + */ + tlbehi = sysreg_read(TLBEHI); + tlbehi = SYSREG_BF(ASID, SYSREG_BFEXT(ASID, tlbehi)); + tlbehi |= address & MMU_VPN_MASK; + tlbehi |= SYSREG_BIT(TLBEHI_V); + sysreg_write(TLBEHI, tlbehi); + + /* Does this mapping already exist? */ + __builtin_tlbs(); + mmucr = sysreg_read(MMUCR); + + if (mmucr & SYSREG_BIT(MMUCR_N)) { + /* Not found -- pick a not-recently-accessed entry */ + unsigned int rp; + u32 tlbar = sysreg_read(TLBARLO); + + rp = 32 - fls(tlbar); + if (rp == 32) { + rp = 0; + sysreg_write(TLBARLO, -1L); + } + + mmucr = SYSREG_BFINS(DRP, rp, mmucr); + sysreg_write(MMUCR, mmucr); + } + + sysreg_write(TLBELO, pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK); + + /* Let's go */ + __builtin_tlbw(); +} + +void update_mmu_cache(struct vm_area_struct *vma, + unsigned long address, pte_t *ptep) +{ + unsigned long flags; + + /* ptrace may call this routine */ + if (vma && current->active_mm != vma->vm_mm) + return; + + local_irq_save(flags); + update_dtlb(address, *ptep); + local_irq_restore(flags); +} + +static void __flush_tlb_page(unsigned long asid, unsigned long page) +{ + u32 mmucr, tlbehi; + + /* + * Caller is responsible for masking out non-PFN bits in page + * and changing the current ASID if necessary. This means that + * we don't need to flush the pipeline after writing TLBEHI. + */ + tlbehi = page | asid; + sysreg_write(TLBEHI, tlbehi); + + __builtin_tlbs(); + mmucr = sysreg_read(MMUCR); + + if (!(mmucr & SYSREG_BIT(MMUCR_N))) { + unsigned int entry; + u32 tlbarlo; + + /* Clear the "valid" bit */ + sysreg_write(TLBEHI, tlbehi); + + /* mark the entry as "not accessed" */ + entry = SYSREG_BFEXT(DRP, mmucr); + tlbarlo = sysreg_read(TLBARLO); + tlbarlo |= (0x80000000UL >> entry); + sysreg_write(TLBARLO, tlbarlo); + + /* update the entry with valid bit clear */ + __builtin_tlbw(); + } +} + +void flush_tlb_page(struct vm_area_struct *vma, unsigned long page) +{ + if (vma->vm_mm && vma->vm_mm->context != NO_CONTEXT) { + unsigned long flags, asid; + unsigned long saved_asid = MMU_NO_ASID; + + asid = vma->vm_mm->context & MMU_CONTEXT_ASID_MASK; + page &= PAGE_MASK; + + local_irq_save(flags); + if (vma->vm_mm != current->mm) { + saved_asid = get_asid(); + set_asid(asid); + } + + __flush_tlb_page(asid, page); + + if (saved_asid != MMU_NO_ASID) + set_asid(saved_asid); + local_irq_restore(flags); + } +} + +void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) +{ + struct mm_struct *mm = vma->vm_mm; + + if (mm->context != NO_CONTEXT) { + unsigned long flags; + int size; + + local_irq_save(flags); + size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT; + + if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */ + mm->context = NO_CONTEXT; + if (mm == current->mm) + activate_context(mm); + } else { + unsigned long asid; + unsigned long saved_asid; + + asid = mm->context & MMU_CONTEXT_ASID_MASK; + saved_asid = MMU_NO_ASID; + + start &= PAGE_MASK; + end += (PAGE_SIZE - 1); + end &= PAGE_MASK; + + if (mm != current->mm) { + saved_asid = get_asid(); + set_asid(asid); + } + + while (start < end) { + __flush_tlb_page(asid, start); + start += PAGE_SIZE; + } + if (saved_asid != MMU_NO_ASID) + set_asid(saved_asid); + } + local_irq_restore(flags); + } +} + +/* + * This function depends on the pages to be flushed having the G + * (global) bit set in their pte. This is true for all + * PAGE_KERNEL(_RO) pages. + */ +void flush_tlb_kernel_range(unsigned long start, unsigned long end) +{ + unsigned long flags; + int size; + + size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT; + if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */ + flush_tlb_all(); + } else { + unsigned long asid; + + local_irq_save(flags); + asid = get_asid(); + + start &= PAGE_MASK; + end += (PAGE_SIZE - 1); + end &= PAGE_MASK; + + while (start < end) { + __flush_tlb_page(asid, start); + start += PAGE_SIZE; + } + local_irq_restore(flags); + } +} + +void flush_tlb_mm(struct mm_struct *mm) +{ + /* Invalidate all TLB entries of this process by getting a new ASID */ + if (mm->context != NO_CONTEXT) { + unsigned long flags; + + local_irq_save(flags); + mm->context = NO_CONTEXT; + if (mm == current->mm) + activate_context(mm); + local_irq_restore(flags); + } +} + +void flush_tlb_all(void) +{ + unsigned long flags; + + local_irq_save(flags); + sysreg_write(MMUCR, sysreg_read(MMUCR) | SYSREG_BIT(MMUCR_I)); + local_irq_restore(flags); +} + +#ifdef CONFIG_PROC_FS + +#include <linux/seq_file.h> +#include <linux/proc_fs.h> +#include <linux/init.h> + +static void *tlb_start(struct seq_file *tlb, loff_t *pos) +{ + static unsigned long tlb_index; + + if (*pos >= NR_TLB_ENTRIES) + return NULL; + + tlb_index = 0; + return &tlb_index; +} + +static void *tlb_next(struct seq_file *tlb, void *v, loff_t *pos) +{ + unsigned long *index = v; + + if (*index >= NR_TLB_ENTRIES - 1) + return NULL; + + ++*pos; + ++*index; + return index; +} + +static void tlb_stop(struct seq_file *tlb, void *v) +{ + +} + +static int tlb_show(struct seq_file *tlb, void *v) +{ + unsigned int tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save; + unsigned long flags; + unsigned long *index = v; + + if (*index == 0) + seq_puts(tlb, "ID V G ASID VPN PFN AP SZ C B W D\n"); + + BUG_ON(*index >= NR_TLB_ENTRIES); + + local_irq_save(flags); + mmucr_save = sysreg_read(MMUCR); + tlbehi_save = sysreg_read(TLBEHI); + mmucr = SYSREG_BFINS(DRP, *index, mmucr_save); + sysreg_write(MMUCR, mmucr); + + /* TLBR might change the ASID */ + __builtin_tlbr(); + cpu_sync_pipeline(); + + tlbehi = sysreg_read(TLBEHI); + tlbelo = sysreg_read(TLBELO); + + sysreg_write(MMUCR, mmucr_save); + sysreg_write(TLBEHI, tlbehi_save); + cpu_sync_pipeline(); + local_irq_restore(flags); + + seq_printf(tlb, "%2lu: %c %c %02x %05x %05x %o %o %c %c %c %c\n", + *index, + SYSREG_BFEXT(TLBEHI_V, tlbehi) ? '1' : '0', + SYSREG_BFEXT(G, tlbelo) ? '1' : '0', + SYSREG_BFEXT(ASID, tlbehi), + SYSREG_BFEXT(VPN, tlbehi) >> 2, + SYSREG_BFEXT(PFN, tlbelo) >> 2, + SYSREG_BFEXT(AP, tlbelo), + SYSREG_BFEXT(SZ, tlbelo), + SYSREG_BFEXT(TLBELO_C, tlbelo) ? '1' : '0', + SYSREG_BFEXT(B, tlbelo) ? '1' : '0', + SYSREG_BFEXT(W, tlbelo) ? '1' : '0', + SYSREG_BFEXT(TLBELO_D, tlbelo) ? '1' : '0'); + + return 0; +} + +static const struct seq_operations tlb_ops = { + .start = tlb_start, + .next = tlb_next, + .stop = tlb_stop, + .show = tlb_show, +}; + +static int tlb_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &tlb_ops); +} + +static const struct file_operations proc_tlb_operations = { + .open = tlb_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static int __init proctlb_init(void) +{ + proc_create("tlb", 0, NULL, &proc_tlb_operations); + return 0; +} +late_initcall(proctlb_init); +#endif /* CONFIG_PROC_FS */ |