diff options
Diffstat (limited to 'kernel/arch/sh/mm/tlb-sh5.c')
| -rw-r--r-- | kernel/arch/sh/mm/tlb-sh5.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/kernel/arch/sh/mm/tlb-sh5.c b/kernel/arch/sh/mm/tlb-sh5.c new file mode 100644 index 000000000..e4bb2a8e0 --- /dev/null +++ b/kernel/arch/sh/mm/tlb-sh5.c @@ -0,0 +1,224 @@ +/* + * arch/sh/mm/tlb-sh5.c + * + * Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org> + * Copyright (C) 2003 Richard Curnow <richard.curnow@superh.com> + * + * 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/init.h> +#include <asm/page.h> +#include <asm/tlb.h> +#include <asm/mmu_context.h> + +/** + * sh64_tlb_init - Perform initial setup for the DTLB and ITLB. + */ +int sh64_tlb_init(void) +{ + /* Assign some sane DTLB defaults */ + cpu_data->dtlb.entries = 64; + cpu_data->dtlb.step = 0x10; + + cpu_data->dtlb.first = DTLB_FIXED | cpu_data->dtlb.step; + cpu_data->dtlb.next = cpu_data->dtlb.first; + + cpu_data->dtlb.last = DTLB_FIXED | + ((cpu_data->dtlb.entries - 1) * + cpu_data->dtlb.step); + + /* And again for the ITLB */ + cpu_data->itlb.entries = 64; + cpu_data->itlb.step = 0x10; + + cpu_data->itlb.first = ITLB_FIXED | cpu_data->itlb.step; + cpu_data->itlb.next = cpu_data->itlb.first; + cpu_data->itlb.last = ITLB_FIXED | + ((cpu_data->itlb.entries - 1) * + cpu_data->itlb.step); + + return 0; +} + +/** + * sh64_next_free_dtlb_entry - Find the next available DTLB entry + */ +unsigned long long sh64_next_free_dtlb_entry(void) +{ + return cpu_data->dtlb.next; +} + +/** + * sh64_get_wired_dtlb_entry - Allocate a wired (locked-in) entry in the DTLB + */ +unsigned long long sh64_get_wired_dtlb_entry(void) +{ + unsigned long long entry = sh64_next_free_dtlb_entry(); + + cpu_data->dtlb.first += cpu_data->dtlb.step; + cpu_data->dtlb.next += cpu_data->dtlb.step; + + return entry; +} + +/** + * sh64_put_wired_dtlb_entry - Free a wired (locked-in) entry in the DTLB. + * + * @entry: Address of TLB slot. + * + * Works like a stack, last one to allocate must be first one to free. + */ +int sh64_put_wired_dtlb_entry(unsigned long long entry) +{ + __flush_tlb_slot(entry); + + /* + * We don't do any particularly useful tracking of wired entries, + * so this approach works like a stack .. last one to be allocated + * has to be the first one to be freed. + * + * We could potentially load wired entries into a list and work on + * rebalancing the list periodically (which also entails moving the + * contents of a TLB entry) .. though I have a feeling that this is + * more trouble than it's worth. + */ + + /* + * Entry must be valid .. we don't want any ITLB addresses! + */ + if (entry <= DTLB_FIXED) + return -EINVAL; + + /* + * Next, check if we're within range to be freed. (ie, must be the + * entry beneath the first 'free' entry! + */ + if (entry < (cpu_data->dtlb.first - cpu_data->dtlb.step)) + return -EINVAL; + + /* If we are, then bring this entry back into the list */ + cpu_data->dtlb.first -= cpu_data->dtlb.step; + cpu_data->dtlb.next = entry; + + return 0; +} + +/** + * sh64_setup_tlb_slot - Load up a translation in a wired slot. + * + * @config_addr: Address of TLB slot. + * @eaddr: Virtual address. + * @asid: Address Space Identifier. + * @paddr: Physical address. + * + * Load up a virtual<->physical translation for @eaddr<->@paddr in the + * pre-allocated TLB slot @config_addr (see sh64_get_wired_dtlb_entry). + */ +void sh64_setup_tlb_slot(unsigned long long config_addr, unsigned long eaddr, + unsigned long asid, unsigned long paddr) +{ + unsigned long long pteh, ptel; + + pteh = neff_sign_extend(eaddr); + pteh &= PAGE_MASK; + pteh |= (asid << PTEH_ASID_SHIFT) | PTEH_VALID; + ptel = neff_sign_extend(paddr); + ptel &= PAGE_MASK; + ptel |= (_PAGE_CACHABLE | _PAGE_READ | _PAGE_WRITE); + + asm volatile("putcfg %0, 1, %1\n\t" + "putcfg %0, 0, %2\n" + : : "r" (config_addr), "r" (ptel), "r" (pteh)); +} + +/** + * sh64_teardown_tlb_slot - Teardown a translation. + * + * @config_addr: Address of TLB slot. + * + * Teardown any existing mapping in the TLB slot @config_addr. + */ +void sh64_teardown_tlb_slot(unsigned long long config_addr) + __attribute__ ((alias("__flush_tlb_slot"))); + +static int dtlb_entry; +static unsigned long long dtlb_entries[64]; + +void tlb_wire_entry(struct vm_area_struct *vma, unsigned long addr, pte_t pte) +{ + unsigned long long entry; + unsigned long paddr, flags; + + BUG_ON(dtlb_entry == ARRAY_SIZE(dtlb_entries)); + + local_irq_save(flags); + + entry = sh64_get_wired_dtlb_entry(); + dtlb_entries[dtlb_entry++] = entry; + + paddr = pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK; + paddr &= ~PAGE_MASK; + + sh64_setup_tlb_slot(entry, addr, get_asid(), paddr); + + local_irq_restore(flags); +} + +void tlb_unwire_entry(void) +{ + unsigned long long entry; + unsigned long flags; + + BUG_ON(!dtlb_entry); + + local_irq_save(flags); + entry = dtlb_entries[dtlb_entry--]; + + sh64_teardown_tlb_slot(entry); + sh64_put_wired_dtlb_entry(entry); + + local_irq_restore(flags); +} + +void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte) +{ + unsigned long long ptel; + unsigned long long pteh=0; + struct tlb_info *tlbp; + unsigned long long next; + unsigned int fault_code = get_thread_fault_code(); + + /* Get PTEL first */ + ptel = pte.pte_low; + + /* + * Set PTEH register + */ + pteh = neff_sign_extend(address & MMU_VPN_MASK); + + /* Set the ASID. */ + pteh |= get_asid() << PTEH_ASID_SHIFT; + pteh |= PTEH_VALID; + + /* Set PTEL register, set_pte has performed the sign extension */ + ptel &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */ + + if (fault_code & FAULT_CODE_ITLB) + tlbp = &cpu_data->itlb; + else + tlbp = &cpu_data->dtlb; + + next = tlbp->next; + __flush_tlb_slot(next); + asm volatile ("putcfg %0,1,%2\n\n\t" + "putcfg %0,0,%1\n" + : : "r" (next), "r" (pteh), "r" (ptel) ); + + next += TLB_STEP; + if (next > tlbp->last) + next = tlbp->first; + tlbp->next = next; +} |