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Commit 6f457e1a authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

[S390] Fix tlb flushing with idte. 



The clear-by-asce operation of the idte instruction gets an asce
(address-space-control-element) as argument to specify which TLBs
need to get flushed. The current code passes a plain pointer to
the start of the pgd without the additional bits which would make
the pointer an asce. The current machines don't mind the difference
but a future model might want to use the designation type control
bits in the asce as a filter for the TLBs to flush.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 4b28a8fe

arch/s390/kernel/head64.S

+1 −1
Original line number Diff line number Diff line
@@ -157,7 +157,7 @@ startup_continue: 
	.long	0xb2b10000		# store facility list

	tm	0xc8,0x08		# check bit for clearing-by-ASCE

	bno	0f-.LPG1(%r13)

	lhi	%r1,2094

	lhi	%r1,2048

	lhi	%r2,0

	.long	0xb98e2001

	oi	7(%r12),0x80		# set IDTE flag

include/asm-s390/mmu_context.h

+12 −15
Original line number Diff line number Diff line
@@ -12,10 +12,15 @@ 
#include <asm/pgalloc.h>

#include <asm-generic/mm_hooks.h>



/*

 * get a new mmu context.. S390 don't know about contexts.

 */

#define init_new_context(tsk,mm)        0

static inline int init_new_context(struct task_struct *tsk,

				   struct mm_struct *mm)

{

	mm->context = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;

#ifdef CONFIG_64BIT

	mm->context |= _ASCE_TYPE_REGION3;

#endif

	return 0;

}



#define destroy_context(mm)             do { } while (0)
@@ -27,19 +32,11 @@ 


static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)

{

	pgd_t *pgd = mm->pgd;

	unsigned long asce_bits;



	/* Calculate asce bits from the first pgd table entry. */

	asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;

#ifdef CONFIG_64BIT

	asce_bits |= _ASCE_TYPE_REGION3;

#endif

	S390_lowcore.user_asce = asce_bits | __pa(pgd);

	S390_lowcore.user_asce = mm->context | __pa(mm->pgd);

	if (switch_amode) {

		/* Load primary space page table origin. */

		pgd_t *shadow_pgd = get_shadow_table(pgd) ? : pgd;

		S390_lowcore.user_exec_asce = asce_bits | __pa(shadow_pgd);

		pgd_t *shadow_pgd = get_shadow_table(mm->pgd) ? : mm->pgd;

		S390_lowcore.user_exec_asce = mm->context | __pa(shadow_pgd);

		asm volatile(LCTL_OPCODE" 1,1,%0\n"

			     : : "m" (S390_lowcore.user_exec_asce) );

	} else

include/asm-s390/tlbflush.h

+6 −6
Original line number Diff line number Diff line
@@ -42,11 +42,11 @@ static inline void __tlb_flush_global(void) 
/*

 * Flush all tlb entries of a page table on all cpus.

 */

static inline void __tlb_flush_idte(pgd_t *pgd)

static inline void __tlb_flush_idte(unsigned long asce)

{

	asm volatile(

		"	.insn	rrf,0xb98e0000,0,%0,%1,0"

		: : "a" (2048), "a" (__pa(pgd) & PAGE_MASK) : "cc" );

		: : "a" (2048), "a" (asce) : "cc" );

}



static inline void __tlb_flush_mm(struct mm_struct * mm)
@@ -61,11 +61,11 @@ static inline void __tlb_flush_mm(struct mm_struct * mm) 
	 * only ran on the local cpu.

	 */

	if (MACHINE_HAS_IDTE) {

		pgd_t *shadow_pgd = get_shadow_table(mm->pgd);

		pgd_t *shadow = get_shadow_table(mm->pgd);



		if (shadow_pgd)

			__tlb_flush_idte(shadow_pgd);

		__tlb_flush_idte(mm->pgd);

		if (shadow)

			__tlb_flush_idte((unsigned long) shadow | mm->context);

		__tlb_flush_idte((unsigned long) mm->pgd | mm->context);

		return;

	}

	preempt_disable();