/*
* Copyright (C) 2006 Martin Decky
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <arch/mm/tlb.h>
#include <arch/types.h>
#include <mm/tlb.h>
#include <mm/frame.h>
#include <mm/page.h>
#include <mm/as.h>
#include <arch.h>
#include <print.h>
#include <symtab.h>
static phte_t *phte;
/** Initialize Page Hash Table.
*
* Setup the Page Hash Table with no entries.
*
*/
void tlb_arch_init(void)
{
phte_t *physical_phte = (phte_t *) PFN2ADDR(frame_alloc(PHT_ORDER, FRAME_KA | FRAME_PANIC));
phte =(phte_t *) PA2KA((__address) physical_phte);
ASSERT((__address) physical_phte % (1 << PHT_BITS) == 0);
memsetb((__address) phte, 1 << PHT_BITS, 0);
asm volatile (
"mtsdr1 %0\n"
:
: "r" ((__address) physical_phte)
);
}
/** Try to find PTE for faulting address
*
* Try to find PTE for faulting address.
* The AS->lock must be held on entry to this function.
*
* @param badvaddr Faulting virtual address.
* @param istate Pointer to interrupted state.
* @param pfrc Pointer to variable where as_page_fault() return code will be stored.
* @return PTE on success, NULL otherwise.
*
*/
static pte_t *find_mapping_and_check(__address badvaddr, istate_t *istate, int *pfcr)
{
/*
* Check if the mapping exists in page tables.
*/
pte_t *pte = page_mapping_find(AS, badvaddr);
if ((pte) && (pte->p)) {
/*
* Mapping found in page tables.
* Immediately succeed.
*/
return pte;
} else {
int rc;
/*
* Mapping not found in page tables.
* Resort to higher-level page fault handler.
*/
page_table_unlock(AS, true);
switch (rc = as_page_fault(badvaddr, istate)) {
case AS_PF_OK:
/*
* The higher-level page fault handler succeeded,
* The mapping ought to be in place.
*/
page_table_lock(AS, true);
pte = page_mapping_find(AS, badvaddr);
ASSERT((pte) && (pte->p));
return pte;
break;
case AS_PF_DEFER:
page_table_lock(AS, true);
*pfcr = rc;
return NULL;
break;
case AS_PF_FAULT:
page_table_lock(AS, true);
*pfcr = rc;
return NULL;
break;
default:
panic("unexpected rc (%d)\n", rc);
break;
}
}
}
static void pht_refill_fail(__address badvaddr, istate_t *istate)
{
char *symbol = "";
char *sym2 = "";
char *s = get_symtab_entry(istate->pc);
if (s)
symbol = s;
s = get_symtab_entry(istate->lr);
if (s)
sym2 = s;
panic("%p: PHT Refill Exception at %p (%s<-%s)\n", badvaddr, istate->pc, symbol, sym2);
}
/** Process Instruction/Data Storage Interrupt
*
* @param data True if Data Storage Interrupt.
* @param istate Interrupted register context.
*
*/
void pht_refill(bool data, istate_t *istate)
{
asid_t asid;
__address badvaddr;
pte_t *pte;
__u32 page;
__u32 api;
__u32 vsid;
__u32 hash;
__u32 i;
int pfcr;
if (data) {
asm volatile (
"mfdar %0\n"
: "=r" (badvaddr)
);
} else
badvaddr = istate->pc;
spinlock_lock(&AS->lock);
asid = AS->asid;
spinlock_unlock(&AS->lock);
page_table_lock(AS, true);
pte = find_mapping_and_check(badvaddr, istate, &pfcr);
if (!pte) {
switch (pfcr) {
case AS_PF_FAULT:
goto fail;
break;
case AS_PF_DEFER:
/*
* The page fault came during copy_from_uspace()
* or copy_to_uspace().
*/
page_table_unlock(AS, true);
return;
default:
panic("Unexpected pfrc (%d)\n", pfcr);
break;
}
}
/* Record access to PTE */
pte->a = 1;
page = (badvaddr >> 12) & 0xffff;
api = (badvaddr >> 22) & 0x3f;
asm volatile (
"mfsrin %0, %1\n"
: "=r" (vsid)
: "r" (badvaddr)
);
/* Primary hash (xor) */
hash = ((vsid ^ page) & 0x3ff) << 3;
/* Find invalid PTE in PTEG */
for (i = 0; i < 8; i++) {
if (!phte[hash + i].v)
break;
}
// TODO: Check access/change bits, secondary hash
if (i == 8)
i = page % 8;
phte[hash + i].v = 1;
phte[hash + i].vsid = vsid;
phte[hash + i].h = 0;
phte[hash + i].api = api;
phte[hash + i].rpn = pte->pfn;
phte[hash + i].r = 0;
phte[hash + i].c = 0;
phte[hash + i].pp = 2; // FIXME
page_table_unlock(AS, true);
return;
fail:
page_table_unlock(AS, true);
pht_refill_fail(badvaddr, istate);
}
/** Print contents of Page Hash Table. */
void tlb_print(void)
{
}