89 lines
3.7 KiB
C
89 lines
3.7 KiB
C
|
/* SPDX-License-Identifier: GPL-2.0 */
|
||
|
|
#ifndef _ASM_POWERPC_NOHASH_32_PTE_40x_H
|
||
|
|
#define _ASM_POWERPC_NOHASH_32_PTE_40x_H
|
||
|
|
#ifdef __KERNEL__
|
||
|
|
|
||
|
|
/*
|
||
|
|
* At present, all PowerPC 400-class processors share a similar TLB
|
||
|
|
* architecture. The instruction and data sides share a unified,
|
||
|
|
* 64-entry, fully-associative TLB which is maintained totally under
|
||
|
|
* software control. In addition, the instruction side has a
|
||
|
|
* hardware-managed, 4-entry, fully-associative TLB which serves as a
|
||
|
|
* first level to the shared TLB. These two TLBs are known as the UTLB
|
||
|
|
* and ITLB, respectively (see "mmu.h" for definitions).
|
||
|
|
*
|
||
|
|
* There are several potential gotchas here. The 40x hardware TLBLO
|
||
|
|
* field looks like this:
|
||
|
|
*
|
||
|
|
* 0 1 2 3 4 ... 18 19 20 21 22 23 24 25 26 27 28 29 30 31
|
||
|
|
* RPN..................... 0 0 EX WR ZSEL....... W I M G
|
||
|
|
*
|
||
|
|
* Where possible we make the Linux PTE bits match up with this
|
||
|
|
*
|
||
|
|
* - bits 20 and 21 must be cleared, because we use 4k pages (40x can
|
||
|
|
* support down to 1k pages), this is done in the TLBMiss exception
|
||
|
|
* handler.
|
||
|
|
* - We use only zones 0 (for kernel pages) and 1 (for user pages)
|
||
|
|
* of the 16 available. Bit 24-26 of the TLB are cleared in the TLB
|
||
|
|
* miss handler. Bit 27 is PAGE_USER, thus selecting the correct
|
||
|
|
* zone.
|
||
|
|
* - PRESENT *must* be in the bottom two bits because swap cache
|
||
|
|
* entries use the top 30 bits. Because 40x doesn't support SMP
|
||
|
|
* anyway, M is irrelevant so we borrow it for PAGE_PRESENT. Bit 30
|
||
|
|
* is cleared in the TLB miss handler before the TLB entry is loaded.
|
||
|
|
* - All other bits of the PTE are loaded into TLBLO without
|
||
|
|
* modification, leaving us only the bits 20, 21, 24, 25, 26, 30 for
|
||
|
|
* software PTE bits. We actually use bits 21, 24, 25, and
|
||
|
|
* 30 respectively for the software bits: ACCESSED, DIRTY, RW, and
|
||
|
|
* PRESENT.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define _PAGE_GUARDED 0x001 /* G: page is guarded from prefetch */
|
||
|
|
#define _PAGE_PRESENT 0x002 /* software: PTE contains a translation */
|
||
|
|
#define _PAGE_NO_CACHE 0x004 /* I: caching is inhibited */
|
||
|
|
#define _PAGE_WRITETHRU 0x008 /* W: caching is write-through */
|
||
|
|
#define _PAGE_USER 0x010 /* matches one of the zone permission bits */
|
||
|
|
#define _PAGE_SPECIAL 0x020 /* software: Special page */
|
||
|
|
#define _PAGE_DIRTY 0x080 /* software: dirty page */
|
||
|
|
#define _PAGE_RW 0x100 /* hardware: WR, anded with dirty in exception */
|
||
|
|
#define _PAGE_EXEC 0x200 /* hardware: EX permission */
|
||
|
|
#define _PAGE_ACCESSED 0x400 /* software: R: page referenced */
|
||
|
|
|
||
|
|
/* No page size encoding in the linux PTE */
|
||
|
|
#define _PAGE_PSIZE 0
|
||
|
|
|
||
|
|
/* cache related flags non existing on 40x */
|
||
|
|
#define _PAGE_COHERENT 0
|
||
|
|
|
||
|
|
#define _PAGE_KERNEL_RO 0
|
||
|
|
#define _PAGE_KERNEL_ROX _PAGE_EXEC
|
||
|
|
#define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW)
|
||
|
|
#define _PAGE_KERNEL_RWX (_PAGE_DIRTY | _PAGE_RW | _PAGE_EXEC)
|
||
|
|
|
||
|
|
#define _PMD_PRESENT 0x400 /* PMD points to page of PTEs */
|
||
|
|
#define _PMD_PRESENT_MASK _PMD_PRESENT
|
||
|
|
#define _PMD_BAD 0x802
|
||
|
|
#define _PMD_SIZE_4M 0x0c0
|
||
|
|
#define _PMD_SIZE_16M 0x0e0
|
||
|
|
#define _PMD_USER 0
|
||
|
|
|
||
|
|
#define _PTE_NONE_MASK 0
|
||
|
|
|
||
|
|
/* Until my rework is finished, 40x still needs atomic PTE updates */
|
||
|
|
#define PTE_ATOMIC_UPDATES 1
|
||
|
|
|
||
|
|
#define _PAGE_BASE_NC (_PAGE_PRESENT | _PAGE_ACCESSED)
|
||
|
|
#define _PAGE_BASE (_PAGE_BASE_NC)
|
||
|
|
|
||
|
|
/* Permission masks used to generate the __P and __S table */
|
||
|
|
#define PAGE_NONE __pgprot(_PAGE_BASE)
|
||
|
|
#define PAGE_SHARED __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
|
||
|
|
#define PAGE_SHARED_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
|
||
|
|
#define PAGE_COPY __pgprot(_PAGE_BASE | _PAGE_USER)
|
||
|
|
#define PAGE_COPY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
|
||
|
|
#define PAGE_READONLY __pgprot(_PAGE_BASE | _PAGE_USER)
|
||
|
|
#define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
|
||
|
|
|
||
|
|
#endif /* __KERNEL__ */
|
||
|
|
#endif /* _ASM_POWERPC_NOHASH_32_PTE_40x_H */
|