sh: Enable shared page fault handler for _32/_64.

This moves the now generic _32 page fault handling code to a shared place
and adapts the _64 implementation to make use of it.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 0 insertions, 264 deletions

diff --git a/arch/sh/mm/fault_64.c b/arch/sh/mm/fault_64.c
deleted file mode 100644
index 33a921962d02..000000000000
--- a/arch/sh/mm/fault_64.c
+++ /dev/null
@@ -1,264 +0,0 @@
-/*
- * The SH64 TLB miss.
- *
- * Original code from fault.c
- * Copyright (C) 2000, 2001  Paolo Alberelli
- *
- * Fast PTE->TLB refill path
- * Copyright (C) 2003 Richard.Curnow@superh.com
- *
- * IMPORTANT NOTES :
- * The do_fast_page_fault function is called from a context in entry.S
- * where very few registers have been saved.  In particular, the code in
- * this file must be compiled not to use ANY caller-save registers that
- * are not part of the restricted save set.  Also, it means that code in
- * this file must not make calls to functions elsewhere in the kernel, or
- * else the excepting context will see corruption in its caller-save
- * registers.  Plus, the entry.S save area is non-reentrant, so this code
- * has to run with SR.BL==1, i.e. no interrupts taken inside it and panic
- * on any exception.
- *
- * 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/signal.h>
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/types.h>
-#include <linux/ptrace.h>
-#include <linux/mman.h>
-#include <linux/mm.h>
-#include <linux/smp.h>
-#include <linux/interrupt.h>
-#include <asm/tlb.h>
-#include <asm/io.h>
-#include <asm/uaccess.h>
-#include <asm/pgalloc.h>
-#include <asm/mmu_context.h>
-#include <cpu/registers.h>
-
-/* Callable from fault.c, so not static */
-inline void __do_tlb_refill(unsigned long address,
-                            unsigned long long is_text_not_data, pte_t *pte)
-{
-	unsigned long long ptel;
-	unsigned long long pteh=0;
-	struct tlb_info *tlbp;
-	unsigned long long next;
-
-	/* Get PTEL first */
-	ptel = pte_val(*pte);
-
-	/*
-	 * 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 */
-
-	tlbp = is_text_not_data ? &(cpu_data->itlb) : &(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;
-
-}
-
-static int handle_vmalloc_fault(struct mm_struct *mm,
-				unsigned long protection_flags,
-                                unsigned long long textaccess,
-				unsigned long address)
-{
-	pgd_t *dir;
-	pud_t *pud;
-	pmd_t *pmd;
-	static pte_t *pte;
-	pte_t entry;
-
-	dir = pgd_offset_k(address);
-
-	pud = pud_offset(dir, address);
-	if (pud_none_or_clear_bad(pud))
-		return 0;
-
-	pmd = pmd_offset(pud, address);
-	if (pmd_none_or_clear_bad(pmd))
-		return 0;
-
-	pte = pte_offset_kernel(pmd, address);
-	entry = *pte;
-
-	if (pte_none(entry) || !pte_present(entry))
-		return 0;
-	if ((pte_val(entry) & protection_flags) != protection_flags)
-		return 0;
-
-        __do_tlb_refill(address, textaccess, pte);
-
-	return 1;
-}
-
-static int handle_tlbmiss(struct mm_struct *mm,
-			  unsigned long long protection_flags,
-			  unsigned long long textaccess,
-			  unsigned long address)
-{
-	pgd_t *dir;
-	pud_t *pud;
-	pmd_t *pmd;
-	pte_t *pte;
-	pte_t entry;
-
-	/* NB. The PGD currently only contains a single entry - there is no
-	   page table tree stored for the top half of the address space since
-	   virtual pages in that region should never be mapped in user mode.
-	   (In kernel mode, the only things in that region are the 512Mb super
-	   page (locked in), and vmalloc (modules) +  I/O device pages (handled
-	   by handle_vmalloc_fault), so no PGD for the upper half is required
-	   by kernel mode either).
-
-	   See how mm->pgd is allocated and initialised in pgd_alloc to see why
-	   the next test is necessary.  - RPC */
-	if (address >= (unsigned long) TASK_SIZE)
-		/* upper half - never has page table entries. */
-		return 0;
-
-	dir = pgd_offset(mm, address);
-	if (pgd_none(*dir) || !pgd_present(*dir))
-		return 0;
-	if (!pgd_present(*dir))
-		return 0;
-
-	pud = pud_offset(dir, address);
-	if (pud_none(*pud) || !pud_present(*pud))
-		return 0;
-
-	pmd = pmd_offset(pud, address);
-	if (pmd_none(*pmd) || !pmd_present(*pmd))
-		return 0;
-
-	pte = pte_offset_kernel(pmd, address);
-	entry = *pte;
-
-	if (pte_none(entry) || !pte_present(entry))
-		return 0;
-
-	/*
-	 * If the page doesn't have sufficient protection bits set to
-	 * service the kind of fault being handled, there's not much
-	 * point doing the TLB refill.  Punt the fault to the general
-	 * handler.
-	 */
-	if ((pte_val(entry) & protection_flags) != protection_flags)
-		return 0;
-
-        __do_tlb_refill(address, textaccess, pte);
-
-	return 1;
-}
-
-/*
- * Put all this information into one structure so that everything is just
- * arithmetic relative to a single base address.  This reduces the number
- * of movi/shori pairs needed just to load addresses of static data.
- */
-struct expevt_lookup {
-	unsigned short protection_flags[8];
-	unsigned char  is_text_access[8];
-	unsigned char  is_write_access[8];
-};
-
-#define PRU (1<<9)
-#define PRW (1<<8)
-#define PRX (1<<7)
-#define PRR (1<<6)
-
-#define DIRTY (_PAGE_DIRTY | _PAGE_ACCESSED)
-#define YOUNG (_PAGE_ACCESSED)
-
-/* Sized as 8 rather than 4 to allow checking the PTE's PRU bit against whether
-   the fault happened in user mode or privileged mode. */
-static struct expevt_lookup expevt_lookup_table = {
-	.protection_flags = {PRX, PRX, 0, 0, PRR, PRR, PRW, PRW},
-	.is_text_access   = {1,   1,   0, 0, 0,   0,   0,   0}
-};
-
-/*
-   This routine handles page faults that can be serviced just by refilling a
-   TLB entry from an existing page table entry.  (This case represents a very
-   large majority of page faults.) Return 1 if the fault was successfully
-   handled.  Return 0 if the fault could not be handled.  (This leads into the
-   general fault handling in fault.c which deals with mapping file-backed
-   pages, stack growth, segmentation faults, swapping etc etc)
- */
-asmlinkage int do_fast_page_fault(unsigned long long ssr_md,
-				  unsigned long long expevt,
-			          unsigned long address)
-{
-	struct task_struct *tsk;
-	struct mm_struct *mm;
-	unsigned long long textaccess;
-	unsigned long long protection_flags;
-	unsigned long long index;
-	unsigned long long expevt4;
-
-	/* The next few lines implement a way of hashing EXPEVT into a
-	 * small array index which can be used to lookup parameters
-	 * specific to the type of TLBMISS being handled.
-	 *
-	 * Note:
-	 *	ITLBMISS has EXPEVT==0xa40
-	 *	RTLBMISS has EXPEVT==0x040
-	 *	WTLBMISS has EXPEVT==0x060
-	 */
-	expevt4 = (expevt >> 4);
-	/* TODO : xor ssr_md into this expression too. Then we can check
-	 * that PRU is set when it needs to be. */
-	index = expevt4 ^ (expevt4 >> 5);
-	index &= 7;
-	protection_flags = expevt_lookup_table.protection_flags[index];
-	textaccess       = expevt_lookup_table.is_text_access[index];
-
-	/* SIM
-	 * Note this is now called with interrupts still disabled
-	 * This is to cope with being called for a missing IO port
-	 * address with interrupts disabled. This should be fixed as
-	 * soon as we have a better 'fast path' miss handler.
-	 *
-	 * Plus take care how you try and debug this stuff.
-	 * For example, writing debug data to a port which you
-	 * have just faulted on is not going to work.
-	 */
-
-	tsk = current;
-	mm = tsk->mm;
-
-	if ((address >= VMALLOC_START && address < VMALLOC_END)) {
-		if (ssr_md)
-			/*
-			 * Process-contexts can never have this address
-			 * range mapped
-			 */
-			if (handle_vmalloc_fault(mm, protection_flags,
-						 textaccess, address))
-				return 1;
-	} else if (!in_interrupt() && mm) {
-		if (handle_tlbmiss(mm, protection_flags, textaccess, address))
-			return 1;
-	}
-
-	return 0;
-}