linux/arch/powerpc/include/asm/mmu-40x.h
Benjamin Herrenschmidt 2ca8cf7389 powerpc/mm: Rework context management for CPUs with no hash table
This reworks the context management code used by 4xx,8xx and
freescale BookE.  It adds support for SMP by implementing a
concept of stale context map to lazily flush the TLB on
processors where a context may have been invalidated.  This
also contains the ground work for generalizing such lazy TLB
flushing by just picking up a new PID and marking the old one
stale.  This will be implemented later.

This is a first implementation that uses a global spinlock.

Ideally, we should try to get at least the fast path (context ID
already assigned) lockless or limited to a per context lock,
but for now this will do.

I tried to keep the UP case reasonably simple to avoid adding
too much overhead to 8xx which does a lot of context stealing
since it effectively has only 16 PIDs available.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-12-21 14:21:15 +11:00

65 lines
1.8 KiB
C

#ifndef _ASM_POWERPC_MMU_40X_H_
#define _ASM_POWERPC_MMU_40X_H_
/*
* PPC40x support
*/
#define PPC40X_TLB_SIZE 64
/*
* TLB entries are defined by a "high" tag portion and a "low" data
* portion. On all architectures, the data portion is 32-bits.
*
* TLB entries are managed entirely under software control by reading,
* writing, and searchoing using the 4xx-specific tlbre, tlbwr, and tlbsx
* instructions.
*/
#define TLB_LO 1
#define TLB_HI 0
#define TLB_DATA TLB_LO
#define TLB_TAG TLB_HI
/* Tag portion */
#define TLB_EPN_MASK 0xFFFFFC00 /* Effective Page Number */
#define TLB_PAGESZ_MASK 0x00000380
#define TLB_PAGESZ(x) (((x) & 0x7) << 7)
#define PAGESZ_1K 0
#define PAGESZ_4K 1
#define PAGESZ_16K 2
#define PAGESZ_64K 3
#define PAGESZ_256K 4
#define PAGESZ_1M 5
#define PAGESZ_4M 6
#define PAGESZ_16M 7
#define TLB_VALID 0x00000040 /* Entry is valid */
/* Data portion */
#define TLB_RPN_MASK 0xFFFFFC00 /* Real Page Number */
#define TLB_PERM_MASK 0x00000300
#define TLB_EX 0x00000200 /* Instruction execution allowed */
#define TLB_WR 0x00000100 /* Writes permitted */
#define TLB_ZSEL_MASK 0x000000F0
#define TLB_ZSEL(x) (((x) & 0xF) << 4)
#define TLB_ATTR_MASK 0x0000000F
#define TLB_W 0x00000008 /* Caching is write-through */
#define TLB_I 0x00000004 /* Caching is inhibited */
#define TLB_M 0x00000002 /* Memory is coherent */
#define TLB_G 0x00000001 /* Memory is guarded from prefetch */
#ifndef __ASSEMBLY__
typedef struct {
unsigned int id;
unsigned int active;
unsigned long vdso_base;
} mm_context_t;
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_POWERPC_MMU_40X_H_ */