arch/blackfin/kernel/cplb-mpu/cplbmgr.c - arm/linux - Git at Google

 /*
  * Blackfin CPLB exception handling for when MPU in on
  *
  * Copyright 2008-2009 Analog Devices Inc.
  *
  * Licensed under the GPL-2 or later.
  */

 #include <linux/module.h>
 #include <linux/mm.h>

 #include <asm/blackfin.h>
 #include <asm/cacheflush.h>
 #include <asm/cplb.h>
 #include <asm/cplbinit.h>
 #include <asm/mmu_context.h>

 /*
  * WARNING
  *
  * This file is compiled with certain -ffixed-reg options.  We have to
  * make sure not to call any functions here that could clobber these
  * registers.
  */

 int page_mask_nelts;
 int page_mask_order;
 unsigned long *current_rwx_mask[NR_CPUS];

 int nr_dcplb_miss[NR_CPUS], nr_icplb_miss[NR_CPUS];
 int nr_icplb_supv_miss[NR_CPUS], nr_dcplb_prot[NR_CPUS];
 int nr_cplb_flush[NR_CPUS];

 #ifdef CONFIG_EXCPT_IRQ_SYSC_L1
 #define MGR_ATTR __attribute__((l1_text))
 #else
 #define MGR_ATTR
 #endif

 /*
  * Given the contents of the status register, return the index of the
  * CPLB that caused the fault.
  */
 static inline int faulting_cplb_index(int status)
 {
 	int signbits = __builtin_bfin_norm_fr1x32(status & 0xFFFF);
 	return 30 - signbits;
 }

 /*
  * Given the contents of the status register and the DCPLB_DATA contents,
  * return true if a write access should be permitted.
  */
 static inline int write_permitted(int status, unsigned long data)
 {
 	if (status & FAULT_USERSUPV)
 		return !!(data & CPLB_SUPV_WR);
 	else
 		return !!(data & CPLB_USER_WR);
 }

 /* Counters to implement round-robin replacement.  */
 static int icplb_rr_index[NR_CPUS], dcplb_rr_index[NR_CPUS];

 /*
  * Find an ICPLB entry to be evicted and return its index.
  */
 MGR_ATTR static int evict_one_icplb(unsigned int cpu)
 {
 	int i;
 	for (i = first_switched_icplb; i < MAX_CPLBS; i++)
 		if ((icplb_tbl[cpu][i].data & CPLB_VALID) == 0)
 			return i;
 	i = first_switched_icplb + icplb_rr_index[cpu];
 	if (i >= MAX_CPLBS) {
 		i -= MAX_CPLBS - first_switched_icplb;
 		icplb_rr_index[cpu] -= MAX_CPLBS - first_switched_icplb;
 	}
 	icplb_rr_index[cpu]++;
 	return i;
 }

 MGR_ATTR static int evict_one_dcplb(unsigned int cpu)
 {
 	int i;
 	for (i = first_switched_dcplb; i < MAX_CPLBS; i++)
 		if ((dcplb_tbl[cpu][i].data & CPLB_VALID) == 0)
 			return i;
 	i = first_switched_dcplb + dcplb_rr_index[cpu];
 	if (i >= MAX_CPLBS) {
 		i -= MAX_CPLBS - first_switched_dcplb;
 		dcplb_rr_index[cpu] -= MAX_CPLBS - first_switched_dcplb;
 	}
 	dcplb_rr_index[cpu]++;
 	return i;
 }

 MGR_ATTR static noinline int dcplb_miss(unsigned int cpu)
 {
 	unsigned long addr = bfin_read_DCPLB_FAULT_ADDR();
 	int status = bfin_read_DCPLB_STATUS();
 	unsigned long *mask;
 	int idx;
 	unsigned long d_data;

 	nr_dcplb_miss[cpu]++;

 	d_data = CPLB_SUPV_WR | CPLB_VALID | CPLB_DIRTY | PAGE_SIZE_4KB;
 #ifdef CONFIG_BFIN_EXTMEM_DCACHEABLE
 	if (bfin_addr_dcacheable(addr)) {
 		d_data |= CPLB_L1_CHBL | ANOMALY_05000158_WORKAROUND;
 # ifdef CONFIG_BFIN_EXTMEM_WRITETHROUGH
 		d_data |= CPLB_L1_AOW | CPLB_WT;
 # endif
 	}
 #endif

 	if (L2_LENGTH && addr >= L2_START && addr < L2_START + L2_LENGTH) {
 		addr = L2_START;
 		d_data = L2_DMEMORY;
 	} else if (addr >= physical_mem_end) {
 		if (addr >= ASYNC_BANK0_BASE && addr < ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE) {
 #if defined(CONFIG_ROMFS_ON_MTD) && defined(CONFIG_MTD_ROM)
 			mask = current_rwx_mask[cpu];
 			if (mask) {
 				int page = (addr - (ASYNC_BANK0_BASE - _ramend)) >> PAGE_SHIFT;
 				int idx = page >> 5;
 				int bit = 1 << (page & 31);

 				if (mask[idx] & bit)
 					d_data |= CPLB_USER_RD;
 			}
 #endif
 		} else if (addr >= BOOT_ROM_START && addr < BOOT_ROM_START + BOOT_ROM_LENGTH
 		    && (status & (FAULT_RW | FAULT_USERSUPV)) == FAULT_USERSUPV) {
 			addr &= ~(1 * 1024 * 1024 - 1);
 			d_data &= ~PAGE_SIZE_4KB;
 			d_data |= PAGE_SIZE_1MB;
 		} else
 			return CPLB_PROT_VIOL;
 	} else if (addr >= _ramend) {
 		d_data |= CPLB_USER_RD | CPLB_USER_WR;
 		if (reserved_mem_dcache_on)
 			d_data |= CPLB_L1_CHBL;
 	} else {
 		mask = current_rwx_mask[cpu];
 		if (mask) {
 			int page = addr >> PAGE_SHIFT;
 			int idx = page >> 5;
 			int bit = 1 << (page & 31);

 			if (mask[idx] & bit)
 				d_data |= CPLB_USER_RD;

 			mask += page_mask_nelts;
 			if (mask[idx] & bit)
 				d_data |= CPLB_USER_WR;
 		}
 	}
 	idx = evict_one_dcplb(cpu);

 	addr &= PAGE_MASK;
 	dcplb_tbl[cpu][idx].addr = addr;
 	dcplb_tbl[cpu][idx].data = d_data;

 	_disable_dcplb();
 	bfin_write32(DCPLB_DATA0 + idx * 4, d_data);
 	bfin_write32(DCPLB_ADDR0 + idx * 4, addr);
 	_enable_dcplb();

 	return 0;
 }

 MGR_ATTR static noinline int icplb_miss(unsigned int cpu)
 {
 	unsigned long addr = bfin_read_ICPLB_FAULT_ADDR();
 	int status = bfin_read_ICPLB_STATUS();
 	int idx;
 	unsigned long i_data;

 	nr_icplb_miss[cpu]++;

 	/* If inside the uncached DMA region, fault.  */
 	if (addr >= _ramend - DMA_UNCACHED_REGION && addr < _ramend)
 		return CPLB_PROT_VIOL;

 	if (status & FAULT_USERSUPV)
 		nr_icplb_supv_miss[cpu]++;

 	/*
 	 * First, try to find a CPLB that matches this address.  If we
 	 * find one, then the fact that we're in the miss handler means
 	 * that the instruction crosses a page boundary.
 	 */
 	for (idx = first_switched_icplb; idx < MAX_CPLBS; idx++) {
 		if (icplb_tbl[cpu][idx].data & CPLB_VALID) {
 			unsigned long this_addr = icplb_tbl[cpu][idx].addr;
 			if (this_addr <= addr && this_addr + PAGE_SIZE > addr) {
 				addr += PAGE_SIZE;
 				break;
 			}
 		}
 	}

 	i_data = CPLB_VALID | CPLB_PORTPRIO | PAGE_SIZE_4KB;

 #ifdef CONFIG_BFIN_EXTMEM_ICACHEABLE
 	/*
 	 * Normal RAM, and possibly the reserved memory area, are
 	 * cacheable.
 	 */
 	if (addr < _ramend ||
 	    (addr < physical_mem_end && reserved_mem_icache_on))
 		i_data |= CPLB_L1_CHBL | ANOMALY_05000158_WORKAROUND;
 #endif

 	if (L2_LENGTH && addr >= L2_START && addr < L2_START + L2_LENGTH) {
 		addr = L2_START;
 		i_data = L2_IMEMORY;
 	} else if (addr >= physical_mem_end) {
 		if (addr >= ASYNC_BANK0_BASE && addr < ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE) {
 			if (!(status & FAULT_USERSUPV)) {
 				unsigned long *mask = current_rwx_mask[cpu];

 				if (mask) {
 					int page = (addr - (ASYNC_BANK0_BASE - _ramend)) >> PAGE_SHIFT;
 					int idx = page >> 5;
 					int bit = 1 << (page & 31);

 					mask += 2 * page_mask_nelts;
 					if (mask[idx] & bit)
 						i_data |= CPLB_USER_RD;
 				}
 			}
 		} else if (addr >= BOOT_ROM_START && addr < BOOT_ROM_START + BOOT_ROM_LENGTH
 		    && (status & FAULT_USERSUPV)) {
 			addr &= ~(1 * 1024 * 1024 - 1);
 			i_data &= ~PAGE_SIZE_4KB;
 			i_data |= PAGE_SIZE_1MB;
 		} else
 		    return CPLB_PROT_VIOL;
 	} else if (addr >= _ramend) {
 		i_data |= CPLB_USER_RD;
 		if (reserved_mem_icache_on)
 			i_data |= CPLB_L1_CHBL;
 	} else {
 		/*
 		 * Two cases to distinguish - a supervisor access must
 		 * necessarily be for a module page; we grant it
 		 * unconditionally (could do better here in the future).
 		 * Otherwise, check the x bitmap of the current process.
 		 */
 		if (!(status & FAULT_USERSUPV)) {
 			unsigned long *mask = current_rwx_mask[cpu];

 			if (mask) {
 				int page = addr >> PAGE_SHIFT;
 				int idx = page >> 5;
 				int bit = 1 << (page & 31);

 				mask += 2 * page_mask_nelts;
 				if (mask[idx] & bit)
 					i_data |= CPLB_USER_RD;
 			}
 		}
 	}
 	idx = evict_one_icplb(cpu);
 	addr &= PAGE_MASK;
 	icplb_tbl[cpu][idx].addr = addr;
 	icplb_tbl[cpu][idx].data = i_data;

 	_disable_icplb();
 	bfin_write32(ICPLB_DATA0 + idx * 4, i_data);
 	bfin_write32(ICPLB_ADDR0 + idx * 4, addr);
 	_enable_icplb();

 	return 0;
 }

 MGR_ATTR static noinline int dcplb_protection_fault(unsigned int cpu)
 {
 	int status = bfin_read_DCPLB_STATUS();

 	nr_dcplb_prot[cpu]++;

 	if (status & FAULT_RW) {
 		int idx = faulting_cplb_index(status);
 		unsigned long data = dcplb_tbl[cpu][idx].data;
 		if (!(data & CPLB_WT) && !(data & CPLB_DIRTY) &&
 		    write_permitted(status, data)) {
 			data |= CPLB_DIRTY;
 			dcplb_tbl[cpu][idx].data = data;
 			bfin_write32(DCPLB_DATA0 + idx * 4, data);
 			return 0;
 		}
 	}
 	return CPLB_PROT_VIOL;
 }

 MGR_ATTR int cplb_hdr(int seqstat, struct pt_regs *regs)
 {
 	int cause = seqstat & 0x3f;
 	unsigned int cpu = raw_smp_processor_id();
 	switch (cause) {
 	case 0x23:
 		return dcplb_protection_fault(cpu);
 	case 0x2C:
 		return icplb_miss(cpu);
 	case 0x26:
 		return dcplb_miss(cpu);
 	default:
 		return 1;
 	}
 }

 void flush_switched_cplbs(unsigned int cpu)
 {
 	int i;
 	unsigned long flags;

 	nr_cplb_flush[cpu]++;

 	flags = hard_local_irq_save();
 	_disable_icplb();
 	for (i = first_switched_icplb; i < MAX_CPLBS; i++) {
 		icplb_tbl[cpu][i].data = 0;
 		bfin_write32(ICPLB_DATA0 + i * 4, 0);
 	}
 	_enable_icplb();

 	_disable_dcplb();
 	for (i = first_switched_dcplb; i < MAX_CPLBS; i++) {
 		dcplb_tbl[cpu][i].data = 0;
 		bfin_write32(DCPLB_DATA0 + i * 4, 0);
 	}
 	_enable_dcplb();
 	hard_local_irq_restore(flags);

 }

 void set_mask_dcplbs(unsigned long *masks, unsigned int cpu)
 {
 	int i;
 	unsigned long addr = (unsigned long)masks;
 	unsigned long d_data;
 	unsigned long flags;

 	if (!masks) {
 		current_rwx_mask[cpu] = masks;
 		return;
 	}

 	flags = hard_local_irq_save();
 	current_rwx_mask[cpu] = masks;

 	if (L2_LENGTH && addr >= L2_START && addr < L2_START + L2_LENGTH) {
 		addr = L2_START;
 		d_data = L2_DMEMORY;
 	} else {
 		d_data = CPLB_SUPV_WR | CPLB_VALID | CPLB_DIRTY | PAGE_SIZE_4KB;
 #ifdef CONFIG_BFIN_EXTMEM_DCACHEABLE
 		d_data |= CPLB_L1_CHBL;
 # ifdef CONFIG_BFIN_EXTMEM_WRITETHROUGH
 		d_data |= CPLB_L1_AOW | CPLB_WT;
 # endif
 #endif
 	}

 	_disable_dcplb();
 	for (i = first_mask_dcplb; i < first_switched_dcplb; i++) {
 		dcplb_tbl[cpu][i].addr = addr;
 		dcplb_tbl[cpu][i].data = d_data;
 		bfin_write32(DCPLB_DATA0 + i * 4, d_data);
 		bfin_write32(DCPLB_ADDR0 + i * 4, addr);
 		addr += PAGE_SIZE;
 	}
 	_enable_dcplb();
 	hard_local_irq_restore(flags);
 }
	/*
	* Blackfin CPLB exception handling for when MPU in on
	*
	* Copyright 2008-2009 Analog Devices Inc.
	*
	* Licensed under the GPL-2 or later.
	*/

	#include <linux/module.h>
	#include <linux/mm.h>

	#include <asm/blackfin.h>
	#include <asm/cacheflush.h>
	#include <asm/cplb.h>
	#include <asm/cplbinit.h>
	#include <asm/mmu_context.h>

	/*
	* WARNING
	*
	* This file is compiled with certain -ffixed-reg options. We have to
	* make sure not to call any functions here that could clobber these
	* registers.
	*/

	int page_mask_nelts;
	int page_mask_order;
	unsigned long *current_rwx_mask[NR_CPUS];

	int nr_dcplb_miss[NR_CPUS], nr_icplb_miss[NR_CPUS];
	int nr_icplb_supv_miss[NR_CPUS], nr_dcplb_prot[NR_CPUS];
	int nr_cplb_flush[NR_CPUS];

	#ifdef CONFIG_EXCPT_IRQ_SYSC_L1
	#define MGR_ATTR __attribute__((l1_text))
	#else
	#define MGR_ATTR
	#endif

	/*
	* Given the contents of the status register, return the index of the
	* CPLB that caused the fault.
	*/
	static inline int faulting_cplb_index(int status)
	{
	int signbits = __builtin_bfin_norm_fr1x32(status & 0xFFFF);
	return 30 - signbits;
	}

	/*
	* Given the contents of the status register and the DCPLB_DATA contents,
	* return true if a write access should be permitted.
	*/
	static inline int write_permitted(int status, unsigned long data)
	{
	if (status & FAULT_USERSUPV)
	return !!(data & CPLB_SUPV_WR);
	else
	return !!(data & CPLB_USER_WR);
	}

	/* Counters to implement round-robin replacement. */
	static int icplb_rr_index[NR_CPUS], dcplb_rr_index[NR_CPUS];

	/*
	* Find an ICPLB entry to be evicted and return its index.
	*/
	MGR_ATTR static int evict_one_icplb(unsigned int cpu)
	{
	int i;
	for (i = first_switched_icplb; i < MAX_CPLBS; i++)
	if ((icplb_tbl[cpu][i].data & CPLB_VALID) == 0)
	return i;
	i = first_switched_icplb + icplb_rr_index[cpu];
	if (i >= MAX_CPLBS) {
	i -= MAX_CPLBS - first_switched_icplb;
	icplb_rr_index[cpu] -= MAX_CPLBS - first_switched_icplb;
	}
	icplb_rr_index[cpu]++;
	return i;
	}

	MGR_ATTR static int evict_one_dcplb(unsigned int cpu)
	{
	int i;
	for (i = first_switched_dcplb; i < MAX_CPLBS; i++)
	if ((dcplb_tbl[cpu][i].data & CPLB_VALID) == 0)
	return i;
	i = first_switched_dcplb + dcplb_rr_index[cpu];
	if (i >= MAX_CPLBS) {
	i -= MAX_CPLBS - first_switched_dcplb;
	dcplb_rr_index[cpu] -= MAX_CPLBS - first_switched_dcplb;
	}
	dcplb_rr_index[cpu]++;
	return i;
	}

	MGR_ATTR static noinline int dcplb_miss(unsigned int cpu)
	{
	unsigned long addr = bfin_read_DCPLB_FAULT_ADDR();
	int status = bfin_read_DCPLB_STATUS();
	unsigned long *mask;
	int idx;
	unsigned long d_data;

	nr_dcplb_miss[cpu]++;

	d_data = CPLB_SUPV_WR \| CPLB_VALID \| CPLB_DIRTY \| PAGE_SIZE_4KB;
	#ifdef CONFIG_BFIN_EXTMEM_DCACHEABLE
	if (bfin_addr_dcacheable(addr)) {
	d_data \|= CPLB_L1_CHBL \| ANOMALY_05000158_WORKAROUND;
	# ifdef CONFIG_BFIN_EXTMEM_WRITETHROUGH
	d_data \|= CPLB_L1_AOW \| CPLB_WT;
	# endif
	}
	#endif

	if (L2_LENGTH && addr >= L2_START && addr < L2_START + L2_LENGTH) {
	addr = L2_START;
	d_data = L2_DMEMORY;
	} else if (addr >= physical_mem_end) {
	if (addr >= ASYNC_BANK0_BASE && addr < ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE) {
	#if defined(CONFIG_ROMFS_ON_MTD) && defined(CONFIG_MTD_ROM)
	mask = current_rwx_mask[cpu];
	if (mask) {
	int page = (addr - (ASYNC_BANK0_BASE - _ramend)) >> PAGE_SHIFT;
	int idx = page >> 5;
	int bit = 1 << (page & 31);

	if (mask[idx] & bit)
	d_data \|= CPLB_USER_RD;
	}
	#endif
	} else if (addr >= BOOT_ROM_START && addr < BOOT_ROM_START + BOOT_ROM_LENGTH
	&& (status & (FAULT_RW \| FAULT_USERSUPV)) == FAULT_USERSUPV) {
	addr &= ~(1 * 1024 * 1024 - 1);
	d_data &= ~PAGE_SIZE_4KB;
	d_data \|= PAGE_SIZE_1MB;
	} else
	return CPLB_PROT_VIOL;
	} else if (addr >= _ramend) {
	d_data \|= CPLB_USER_RD \| CPLB_USER_WR;
	if (reserved_mem_dcache_on)
	d_data \|= CPLB_L1_CHBL;
	} else {
	mask = current_rwx_mask[cpu];
	if (mask) {
	int page = addr >> PAGE_SHIFT;
	int idx = page >> 5;
	int bit = 1 << (page & 31);

	if (mask[idx] & bit)
	d_data \|= CPLB_USER_RD;

	mask += page_mask_nelts;
	if (mask[idx] & bit)
	d_data \|= CPLB_USER_WR;
	}
	}
	idx = evict_one_dcplb(cpu);

	addr &= PAGE_MASK;
	dcplb_tbl[cpu][idx].addr = addr;
	dcplb_tbl[cpu][idx].data = d_data;

	_disable_dcplb();
	bfin_write32(DCPLB_DATA0 + idx * 4, d_data);
	bfin_write32(DCPLB_ADDR0 + idx * 4, addr);
	_enable_dcplb();

	return 0;
	}

	MGR_ATTR static noinline int icplb_miss(unsigned int cpu)
	{
	unsigned long addr = bfin_read_ICPLB_FAULT_ADDR();
	int status = bfin_read_ICPLB_STATUS();
	int idx;
	unsigned long i_data;

	nr_icplb_miss[cpu]++;

	/* If inside the uncached DMA region, fault. */
	if (addr >= _ramend - DMA_UNCACHED_REGION && addr < _ramend)
	return CPLB_PROT_VIOL;

	if (status & FAULT_USERSUPV)
	nr_icplb_supv_miss[cpu]++;

	/*
	* First, try to find a CPLB that matches this address. If we
	* find one, then the fact that we're in the miss handler means
	* that the instruction crosses a page boundary.
	*/
	for (idx = first_switched_icplb; idx < MAX_CPLBS; idx++) {
	if (icplb_tbl[cpu][idx].data & CPLB_VALID) {
	unsigned long this_addr = icplb_tbl[cpu][idx].addr;
	if (this_addr <= addr && this_addr + PAGE_SIZE > addr) {
	addr += PAGE_SIZE;
	break;
	}
	}
	}

	i_data = CPLB_VALID \| CPLB_PORTPRIO \| PAGE_SIZE_4KB;

	#ifdef CONFIG_BFIN_EXTMEM_ICACHEABLE
	/*
	* Normal RAM, and possibly the reserved memory area, are
	* cacheable.
	*/
	if (addr < _ramend \|\|
	(addr < physical_mem_end && reserved_mem_icache_on))
	i_data \|= CPLB_L1_CHBL \| ANOMALY_05000158_WORKAROUND;
	#endif

	if (L2_LENGTH && addr >= L2_START && addr < L2_START + L2_LENGTH) {
	addr = L2_START;
	i_data = L2_IMEMORY;
	} else if (addr >= physical_mem_end) {
	if (addr >= ASYNC_BANK0_BASE && addr < ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE) {
	if (!(status & FAULT_USERSUPV)) {
	unsigned long *mask = current_rwx_mask[cpu];

	if (mask) {
	int page = (addr - (ASYNC_BANK0_BASE - _ramend)) >> PAGE_SHIFT;
	int idx = page >> 5;
	int bit = 1 << (page & 31);

	mask += 2 * page_mask_nelts;
	if (mask[idx] & bit)
	i_data \|= CPLB_USER_RD;
	}
	}
	} else if (addr >= BOOT_ROM_START && addr < BOOT_ROM_START + BOOT_ROM_LENGTH
	&& (status & FAULT_USERSUPV)) {
	addr &= ~(1 * 1024 * 1024 - 1);
	i_data &= ~PAGE_SIZE_4KB;
	i_data \|= PAGE_SIZE_1MB;
	} else
	return CPLB_PROT_VIOL;
	} else if (addr >= _ramend) {
	i_data \|= CPLB_USER_RD;
	if (reserved_mem_icache_on)
	i_data \|= CPLB_L1_CHBL;
	} else {
	/*
	* Two cases to distinguish - a supervisor access must
	* necessarily be for a module page; we grant it
	* unconditionally (could do better here in the future).
	* Otherwise, check the x bitmap of the current process.
	*/
	if (!(status & FAULT_USERSUPV)) {
	unsigned long *mask = current_rwx_mask[cpu];

	if (mask) {
	int page = addr >> PAGE_SHIFT;
	int idx = page >> 5;
	int bit = 1 << (page & 31);

	mask += 2 * page_mask_nelts;
	if (mask[idx] & bit)
	i_data \|= CPLB_USER_RD;
	}
	}
	}
	idx = evict_one_icplb(cpu);
	addr &= PAGE_MASK;
	icplb_tbl[cpu][idx].addr = addr;
	icplb_tbl[cpu][idx].data = i_data;

	_disable_icplb();
	bfin_write32(ICPLB_DATA0 + idx * 4, i_data);
	bfin_write32(ICPLB_ADDR0 + idx * 4, addr);
	_enable_icplb();

	return 0;
	}

	MGR_ATTR static noinline int dcplb_protection_fault(unsigned int cpu)
	{
	int status = bfin_read_DCPLB_STATUS();

	nr_dcplb_prot[cpu]++;

	if (status & FAULT_RW) {
	int idx = faulting_cplb_index(status);
	unsigned long data = dcplb_tbl[cpu][idx].data;
	if (!(data & CPLB_WT) && !(data & CPLB_DIRTY) &&
	write_permitted(status, data)) {
	data \|= CPLB_DIRTY;
	dcplb_tbl[cpu][idx].data = data;
	bfin_write32(DCPLB_DATA0 + idx * 4, data);
	return 0;
	}
	}
	return CPLB_PROT_VIOL;
	}

	MGR_ATTR int cplb_hdr(int seqstat, struct pt_regs *regs)
	{
	int cause = seqstat & 0x3f;
	unsigned int cpu = raw_smp_processor_id();
	switch (cause) {
	case 0x23:
	return dcplb_protection_fault(cpu);
	case 0x2C:
	return icplb_miss(cpu);
	case 0x26:
	return dcplb_miss(cpu);
	default:
	return 1;
	}
	}

	void flush_switched_cplbs(unsigned int cpu)
	{
	int i;
	unsigned long flags;

	nr_cplb_flush[cpu]++;

	flags = hard_local_irq_save();
	_disable_icplb();
	for (i = first_switched_icplb; i < MAX_CPLBS; i++) {
	icplb_tbl[cpu][i].data = 0;
	bfin_write32(ICPLB_DATA0 + i * 4, 0);
	}
	_enable_icplb();

	_disable_dcplb();
	for (i = first_switched_dcplb; i < MAX_CPLBS; i++) {
	dcplb_tbl[cpu][i].data = 0;
	bfin_write32(DCPLB_DATA0 + i * 4, 0);
	}
	_enable_dcplb();
	hard_local_irq_restore(flags);

	}

	void set_mask_dcplbs(unsigned long *masks, unsigned int cpu)
	{
	int i;
	unsigned long addr = (unsigned long)masks;
	unsigned long d_data;
	unsigned long flags;

	if (!masks) {
	current_rwx_mask[cpu] = masks;
	return;
	}

	flags = hard_local_irq_save();
	current_rwx_mask[cpu] = masks;

	if (L2_LENGTH && addr >= L2_START && addr < L2_START + L2_LENGTH) {
	addr = L2_START;
	d_data = L2_DMEMORY;
	} else {
	d_data = CPLB_SUPV_WR \| CPLB_VALID \| CPLB_DIRTY \| PAGE_SIZE_4KB;
	#ifdef CONFIG_BFIN_EXTMEM_DCACHEABLE
	d_data \|= CPLB_L1_CHBL;
	# ifdef CONFIG_BFIN_EXTMEM_WRITETHROUGH
	d_data \|= CPLB_L1_AOW \| CPLB_WT;
	# endif
	#endif
	}

	_disable_dcplb();
	for (i = first_mask_dcplb; i < first_switched_dcplb; i++) {
	dcplb_tbl[cpu][i].addr = addr;
	dcplb_tbl[cpu][i].data = d_data;
	bfin_write32(DCPLB_DATA0 + i * 4, d_data);
	bfin_write32(DCPLB_ADDR0 + i * 4, addr);
	addr += PAGE_SIZE;
	}
	_enable_dcplb();
	hard_local_irq_restore(flags);
	}