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linux/arch/sh/mm/tlb-sh4.c
Stuart Menefy cbaa118ecf sh: Preparation for uncached jumps through PMB.
Presently most of the 29-bit physical parts do P1/P2 segmentation
with a 1:1 cached/uncached mapping, jumping between the two to
control the caching behaviour. This provides the basic infrastructure
to maintain this behaviour on 32-bit physical parts that don't map
P1/P2 at all, using a shiny new linker section and corresponding
fixmap entry.

Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-01-28 13:18:59 +09:00

99 lines
2.4 KiB
C

/*
* arch/sh/mm/tlb-sh4.c
*
* SH-4 specific TLB operations
*
* Copyright (C) 1999 Niibe Yutaka
* Copyright (C) 2002 - 2007 Paul Mundt
*
* Released under the terms of the GNU GPL v2.0.
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <asm/system.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
void update_mmu_cache(struct vm_area_struct * vma,
unsigned long address, pte_t pte)
{
unsigned long flags;
unsigned long pteval;
unsigned long vpn;
/* Ptrace may call this routine. */
if (vma && current->active_mm != vma->vm_mm)
return;
#ifndef CONFIG_CACHE_OFF
{
unsigned long pfn = pte_pfn(pte);
if (pfn_valid(pfn)) {
struct page *page = pfn_to_page(pfn);
if (!test_bit(PG_mapped, &page->flags)) {
unsigned long phys = pte_val(pte) & PTE_PHYS_MASK;
__flush_wback_region((void *)P1SEGADDR(phys),
PAGE_SIZE);
__set_bit(PG_mapped, &page->flags);
}
}
}
#endif
local_irq_save(flags);
/* Set PTEH register */
vpn = (address & MMU_VPN_MASK) | get_asid();
ctrl_outl(vpn, MMU_PTEH);
pteval = pte.pte_low;
/* Set PTEA register */
#ifdef CONFIG_X2TLB
/*
* For the extended mode TLB this is trivial, only the ESZ and
* EPR bits need to be written out to PTEA, with the remainder of
* the protection bits (with the exception of the compat-mode SZ
* and PR bits, which are cleared) being written out in PTEL.
*/
ctrl_outl(pte.pte_high, MMU_PTEA);
#else
if (cpu_data->flags & CPU_HAS_PTEA)
/* TODO: make this look less hacky */
ctrl_outl(((pteval >> 28) & 0xe) | (pteval & 0x1), MMU_PTEA);
#endif
/* Set PTEL register */
pteval &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */
#ifdef CONFIG_CACHE_WRITETHROUGH
pteval |= _PAGE_WT;
#endif
/* conveniently, we want all the software flags to be 0 anyway */
ctrl_outl(pteval, MMU_PTEL);
/* Load the TLB */
asm volatile("ldtlb": /* no output */ : /* no input */ : "memory");
local_irq_restore(flags);
}
void __uses_jump_to_uncached local_flush_tlb_one(unsigned long asid,
unsigned long page)
{
unsigned long addr, data;
/*
* NOTE: PTEH.ASID should be set to this MM
* _AND_ we need to write ASID to the array.
*
* It would be simple if we didn't need to set PTEH.ASID...
*/
addr = MMU_UTLB_ADDRESS_ARRAY | MMU_PAGE_ASSOC_BIT;
data = page | asid; /* VALID bit is off */
jump_to_uncached();
ctrl_outl(data, addr);
back_to_cached();
}