freebsd-dev/sys/powerpc/include/slb.h
Nathan Whitehorn 3b4b38304e Improve hash coverage for kernel page table entries by modifying the kernel
ESID -> VSID map function. This makes ZFS run stably on PowerPC under
heavy loads (repeated simultaneous SVN checkouts and updates).
2010-07-31 21:35:15 +00:00

71 lines
2.8 KiB
C

/*-
* Copyright (C) 2009 Nathan Whitehorn
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _MACHINE_SLB_H_
#define _MACHINE_SLB_H_
/*
* Bit definitions for segment lookaside buffer entries.
*
* PowerPC Microprocessor Family: The Programming Environments for 64-bit
* Microprocessors, section 7.4.2.1
*
* Note that these bitmasks are relative to the values for one of the two
* values for slbmte, slbmfee, and slbmfev, not the internal SLB
* representation.
*/
#define SLBV_KS 0x0000000000000800UL /* Supervisor-state prot key */
#define SLBV_KP 0x0000000000000400UL /* User-state prot key */
#define SLBV_N 0x0000000000000200UL /* No-execute protection */
#define SLBV_L 0x0000000000000100UL /* Large page selector */
#define SLBV_CLASS 0x0000000000000080UL /* Class selector */
#define SLBV_VSID_MASK 0xfffffffffffff000UL /* Virtual segment ID mask */
#define SLBV_VSID_SHIFT 12
/*
* Make a predictable 1:1 map from ESIDs to VSIDs for the kernel. Hash table
* coverage is increased by swizzling the ESID and multiplying by a prime
* number (0x13bb).
*/
#define KERNEL_VSID_BIT 0x0000001000000000UL /* Bit set in all kernel VSIDs */
#define KERNEL_VSID(esid) ((((((uint64_t)esid << 8) | ((uint64_t)esid >> 28)) \
* 0x13bbUL) & (KERNEL_VSID_BIT - 1)) | \
KERNEL_VSID_BIT)
#define SLBE_VALID 0x0000000008000000UL /* SLB entry valid */
#define SLBE_INDEX_MASK 0x0000000000000fffUL /* SLB index mask*/
#define SLBE_ESID_MASK 0xfffffffff0000000UL /* Effective segment ID mask */
#define SLBE_ESID_SHIFT 28
struct slb {
uint64_t slbv;
uint64_t slbe;
};
#endif /* !_MACHINE_SLB_H_ */