Commit 4e562c11 authored by Guo Ren's avatar Guo Ren
Browse files

csky: Improve tlb operation with help of asid 



There are two generations of tlb operation instruction for C-SKY.
First generation is use mcr register and it need software do more
things, second generation is use specific instructions, eg:
 tlbi.va, tlbi.vas, tlbi.alls

We implemented the following functions:

 - flush_tlb_range (a range of entries)
 - flush_tlb_page (one entry)

 Above functions use asid from vma->mm to invalid tlb entries and
 we could use tlbi.vas instruction for newest generation csky cpu.

 - flush_tlb_kernel_range
 - flush_tlb_one

 Above functions don't care asid and it invalid the tlb entries only
 with vpn and we could use tlbi.vaas instruction for newest generat-
 ion csky cpu.

Signed-off-by: default avatarGuo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
parent 22d55f02

arch/csky/mm/tlb.c

+132 −4
Original line number Diff line number Diff line
@@ -10,6 +10,13 @@ 
#include <asm/pgtable.h>

#include <asm/setup.h>



/*

 * One C-SKY MMU TLB entry contain two PFN/page entry, ie:

 * 1VPN -> 2PFN

 */

#define TLB_ENTRY_SIZE		(PAGE_SIZE * 2)

#define TLB_ENTRY_SIZE_MASK	(PAGE_MASK << 1)



void flush_tlb_all(void)

{

	tlb_invalid_all();
@@ -17,27 +24,148 @@ void flush_tlb_all(void) 


void flush_tlb_mm(struct mm_struct *mm)

{

#ifdef CONFIG_CPU_HAS_TLBI

	asm volatile("tlbi.asids %0"::"r"(cpu_asid(mm)));

#else

	tlb_invalid_all();

#endif

}



/*

 * MMU operation regs only could invalid tlb entry in jtlb and we

 * need change asid field to invalid I-utlb & D-utlb.

 */

#ifndef CONFIG_CPU_HAS_TLBI

#define restore_asid_inv_utlb(oldpid, newpid) \

do { \

	if (oldpid == newpid) \

		write_mmu_entryhi(oldpid + 1); \

	write_mmu_entryhi(oldpid); \

} while (0)

#endif



void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,

			unsigned long end)

{

	tlb_invalid_all();

	unsigned long newpid = cpu_asid(vma->vm_mm);



	start &= TLB_ENTRY_SIZE_MASK;

	end   += TLB_ENTRY_SIZE - 1;

	end   &= TLB_ENTRY_SIZE_MASK;



#ifdef CONFIG_CPU_HAS_TLBI

	while (start < end) {

		asm volatile("tlbi.vas %0"::"r"(start | newpid));

		start += 2*PAGE_SIZE;

	}

	sync_is();

#else

	{

	unsigned long flags, oldpid;



	local_irq_save(flags);

	oldpid = read_mmu_entryhi() & ASID_MASK;

	while (start < end) {

		int idx;



		write_mmu_entryhi(start | newpid);

		start += 2*PAGE_SIZE;

		tlb_probe();

		idx = read_mmu_index();

		if (idx >= 0)

			tlb_invalid_indexed();

	}

	restore_asid_inv_utlb(oldpid, newpid);

	local_irq_restore(flags);

	}

#endif

}



void flush_tlb_kernel_range(unsigned long start, unsigned long end)

{

	tlb_invalid_all();

	start &= TLB_ENTRY_SIZE_MASK;

	end   += TLB_ENTRY_SIZE - 1;

	end   &= TLB_ENTRY_SIZE_MASK;



#ifdef CONFIG_CPU_HAS_TLBI

	while (start < end) {

		asm volatile("tlbi.vaas %0"::"r"(start));

		start += 2*PAGE_SIZE;

	}

	sync_is();

#else

	{

	unsigned long flags, oldpid;



	local_irq_save(flags);

	oldpid = read_mmu_entryhi() & ASID_MASK;

	while (start < end) {

		int idx;



		write_mmu_entryhi(start | oldpid);

		start += 2*PAGE_SIZE;

		tlb_probe();

		idx = read_mmu_index();

		if (idx >= 0)

			tlb_invalid_indexed();

	}

	restore_asid_inv_utlb(oldpid, oldpid);

	local_irq_restore(flags);

	}

#endif

}



void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)

{

	tlb_invalid_all();

	int newpid = cpu_asid(vma->vm_mm);



	addr &= TLB_ENTRY_SIZE_MASK;



#ifdef CONFIG_CPU_HAS_TLBI

	asm volatile("tlbi.vas %0"::"r"(addr | newpid));

	sync_is();

#else

	{

	int oldpid, idx;

	unsigned long flags;



	local_irq_save(flags);

	oldpid = read_mmu_entryhi() & ASID_MASK;

	write_mmu_entryhi(addr | newpid);

	tlb_probe();

	idx = read_mmu_index();

	if (idx >= 0)

		tlb_invalid_indexed();



	restore_asid_inv_utlb(oldpid, newpid);

	local_irq_restore(flags);

	}

#endif

}



void flush_tlb_one(unsigned long addr)

{

	tlb_invalid_all();

	addr &= TLB_ENTRY_SIZE_MASK;



#ifdef CONFIG_CPU_HAS_TLBI

	asm volatile("tlbi.vaas %0"::"r"(addr));

	sync_is();

#else

	{

	int oldpid, idx;

	unsigned long flags;



	local_irq_save(flags);

	oldpid = read_mmu_entryhi() & ASID_MASK;

	write_mmu_entryhi(addr | oldpid);

	tlb_probe();

	idx = read_mmu_index();

	if (idx >= 0)

		tlb_invalid_indexed();



	restore_asid_inv_utlb(oldpid, oldpid);

	local_irq_restore(flags);

	}

#endif

}

EXPORT_SYMBOL(flush_tlb_one);

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