[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / powerpc / include / asm / pte-8xx.h

#ifndef _ASM_POWERPC_PTE_8xx_H
#define _ASM_POWERPC_PTE_8xx_H
#ifdef __KERNEL__

/*
 * The PowerPC MPC8xx uses a TLB with hardware assisted, software tablewalk.
 * We also use the two level tables, but we can put the real bits in them
 * needed for the TLB and tablewalk.  These definitions require Mx_CTR.PPM = 0,
 * Mx_CTR.PPCS = 0, and MD_CTR.TWAM = 1.  The level 2 descriptor has
 * additional page protection (when Mx_CTR.PPCS = 1) that allows TLB hit
 * based upon user/super access.  The TLB does not have accessed nor write
 * protect.  We assume that if the TLB get loaded with an entry it is
 * accessed, and overload the changed bit for write protect.  We use
 * two bits in the software pte that are supposed to be set to zero in
 * the TLB entry (24 and 25) for these indicators.  Although the level 1
 * descriptor contains the guarded and writethrough/copyback bits, we can
 * set these at the page level since they get copied from the Mx_TWC
 * register when the TLB entry is loaded.  We will use bit 27 for guard, since
 * that is where it exists in the MD_TWC, and bit 26 for writethrough.
 * These will get masked from the level 2 descriptor at TLB load time, and
 * copied to the MD_TWC before it gets loaded.
 * Large page sizes added.  We currently support two sizes, 4K and 8M.
 * This also allows a TLB hander optimization because we can directly
 * load the PMD into MD_TWC.  The 8M pages are only used for kernel
 * mapping of well known areas.  The PMD (PGD) entries contain control
 * flags in addition to the address, so care must be taken that the
 * software no longer assumes these are only pointers.
 */

/* Definitions for 8xx embedded chips. */
#define _PAGE_PRESENT	0x0001	/* Page is valid */
#define _PAGE_FILE	0x0002	/* when !present: nonlinear file mapping */
#define _PAGE_NO_CACHE	0x0002	/* I: cache inhibit */
#define _PAGE_SHARED	0x0004	/* No ASID (context) compare */
#define _PAGE_SPECIAL	0x0008	/* SW entry, forced to 0 by the TLB miss */
#define _PAGE_DIRTY	0x0100	/* C: page changed */

/* These 4 software bits must be masked out when the entry is loaded
 * into the TLB, 1 SW bit left(0x0080).
 */
#define _PAGE_GUARDED	0x0010	/* software: guarded access */
#define _PAGE_ACCESSED	0x0020	/* software: page referenced */
#define _PAGE_WRITETHRU	0x0040	/* software: caching is write through */

/* Setting any bits in the nibble with the follow two controls will
 * require a TLB exception handler change.  It is assumed unused bits
 * are always zero.
 */
#define _PAGE_RW	0x0400	/* lsb PP bits, inverted in HW */
#define _PAGE_USER	0x0800	/* msb PP bits */

#define _PMD_PRESENT	0x0001
#define _PMD_BAD	0x0ff0
#define _PMD_PAGE_MASK	0x000c
#define _PMD_PAGE_8M	0x000c

#define _PTE_NONE_MASK _PAGE_ACCESSED

/* Until my rework is finished, 8xx still needs atomic PTE updates */
#define PTE_ATOMIC_UPDATES	1

/* We need to add _PAGE_SHARED to kernel pages */
#define _PAGE_KERNEL_RO	(_PAGE_SHARED)
#define _PAGE_KERNEL_RW	(_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE)

#endif /* __KERNEL__ */
#endif /*  _ASM_POWERPC_PTE_8xx_H */
Commit	Line	Data
c605782b BH	1	#ifndef _ASM_POWERPC_PTE_8xx_H
	2	#define _ASM_POWERPC_PTE_8xx_H
	3	#ifdef __KERNEL__
	4
	5	/*
	6	* The PowerPC MPC8xx uses a TLB with hardware assisted, software tablewalk.
	7	* We also use the two level tables, but we can put the real bits in them
	8	* needed for the TLB and tablewalk. These definitions require Mx_CTR.PPM = 0,
	9	* Mx_CTR.PPCS = 0, and MD_CTR.TWAM = 1. The level 2 descriptor has
	10	* additional page protection (when Mx_CTR.PPCS = 1) that allows TLB hit
	11	* based upon user/super access. The TLB does not have accessed nor write
	12	* protect. We assume that if the TLB get loaded with an entry it is
	13	* accessed, and overload the changed bit for write protect. We use
	14	* two bits in the software pte that are supposed to be set to zero in
	15	* the TLB entry (24 and 25) for these indicators. Although the level 1
	16	* descriptor contains the guarded and writethrough/copyback bits, we can
	17	* set these at the page level since they get copied from the Mx_TWC
	18	* register when the TLB entry is loaded. We will use bit 27 for guard, since
	19	* that is where it exists in the MD_TWC, and bit 26 for writethrough.
	20	* These will get masked from the level 2 descriptor at TLB load time, and
	21	* copied to the MD_TWC before it gets loaded.
	22	* Large page sizes added. We currently support two sizes, 4K and 8M.
	23	* This also allows a TLB hander optimization because we can directly
	24	* load the PMD into MD_TWC. The 8M pages are only used for kernel
	25	* mapping of well known areas. The PMD (PGD) entries contain control
	26	* flags in addition to the address, so care must be taken that the
	27	* software no longer assumes these are only pointers.
	28	*/
	29
	30	/* Definitions for 8xx embedded chips. */
	31	#define _PAGE_PRESENT 0x0001 /* Page is valid */
	32	#define _PAGE_FILE 0x0002 /* when !present: nonlinear file mapping */
	33	#define _PAGE_NO_CACHE 0x0002 /* I: cache inhibit */
	34	#define _PAGE_SHARED 0x0004 /* No ASID (context) compare */
f32af63e	35	#define _PAGE_SPECIAL 0x0008 /* SW entry, forced to 0 by the TLB miss */
fe11dc3f	36	#define _PAGE_DIRTY 0x0100 /* C: page changed */
c605782b	37
0c466169 JT	38	/* These 4 software bits must be masked out when the entry is loaded
0c466169 JT	39	* into the TLB, 1 SW bit left(0x0080).
c605782b	40	*/
c605782b	41	#define _PAGE_GUARDED 0x0010 /* software: guarded access */
fe11dc3f	42	#define _PAGE_ACCESSED 0x0020 /* software: page referenced */
0c466169	43	#define _PAGE_WRITETHRU 0x0040 /* software: caching is write through */
c605782b BH	44
	45	/* Setting any bits in the nibble with the follow two controls will
	46	* require a TLB exception handler change. It is assumed unused bits
	47	* are always zero.
	48	*/
fe11dc3f JT	49	#define _PAGE_RW 0x0400 /* lsb PP bits, inverted in HW */
fe11dc3f JT	50	#define _PAGE_USER 0x0800 /* msb PP bits */
c605782b BH	51
	52	#define _PMD_PRESENT 0x0001
	53	#define _PMD_BAD 0x0ff0
	54	#define _PMD_PAGE_MASK 0x000c
	55	#define _PMD_PAGE_8M 0x000c
	56
	57	#define _PTE_NONE_MASK _PAGE_ACCESSED
	58
	59	/* Until my rework is finished, 8xx still needs atomic PTE updates */
	60	#define PTE_ATOMIC_UPDATES 1
	61
8d1cf34e BH	62	/* We need to add _PAGE_SHARED to kernel pages */
	63	#define _PAGE_KERNEL_RO (_PAGE_SHARED)
	64	#define _PAGE_KERNEL_RW (_PAGE_DIRTY \| _PAGE_RW \| _PAGE_HWWRITE)
c605782b BH	65
	66	#endif /* __KERNEL__ */
	67	#endif /* _ASM_POWERPC_PTE_8xx_H */