| /* |
| * SMP/VPE-safe functions to access "registers" (see note). |
| * |
| * NOTES: |
| * - These macros use ll/sc instructions, so it is your responsibility to |
| * ensure these are available on your platform before including this file. |
| * - The MIPS32 spec states that ll/sc results are undefined for uncached |
| * accesses. This means they can't be used on HW registers accessed |
| * through kseg1. Code which requires these macros for this purpose must |
| * front-end the registers with cached memory "registers" and have a single |
| * thread update the actual HW registers. |
| * - A maximum of 2k of code can be inserted between ll and sc. Every |
| * memory accesses between the instructions will increase the chance of |
| * sc failing and having to loop. |
| * - When using custom_read_reg32/custom_write_reg32 only perform the |
| * necessary logical operations on the register value in between these |
| * two calls. All other logic should be performed before the first call. |
| * - There is a bug on the R10000 chips which has a workaround. If you |
| * are affected by this bug, make sure to define the symbol 'R10000_LLSC_WAR' |
| * to be non-zero. If you are using this header from within linux, you may |
| * include <asm/war.h> before including this file to have this defined |
| * appropriately for you. |
| * |
| * Copyright 2005-2007 PMC-Sierra, Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by the |
| * Free Software Foundation; either version 2 of the License, or (at your |
| * option) any later version. |
| * |
| * THIS SOFTWARE IS PROVIDED ``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 THE AUTHOR 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. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., 675 |
| * Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #ifndef __ASM_REGOPS_H__ |
| #define __ASM_REGOPS_H__ |
| |
| #include <linux/types.h> |
| |
| #include <asm/compiler.h> |
| #include <asm/war.h> |
| |
| #ifndef R10000_LLSC_WAR |
| #define R10000_LLSC_WAR 0 |
| #endif |
| |
| #if R10000_LLSC_WAR == 1 |
| #define __beqz "beqzl " |
| #else |
| #define __beqz "beqz " |
| #endif |
| |
| #ifndef _LINUX_TYPES_H |
| typedef unsigned int u32; |
| #endif |
| |
| /* |
| * Sets all the masked bits to the corresponding value bits |
| */ |
| static inline void set_value_reg32(volatile u32 *const addr, |
| u32 const mask, |
| u32 const value) |
| { |
| u32 temp; |
| |
| __asm__ __volatile__( |
| " .set push \n" |
| " .set arch=r4000 \n" |
| "1: ll %0, %1 # set_value_reg32 \n" |
| " and %0, %2 \n" |
| " or %0, %3 \n" |
| " sc %0, %1 \n" |
| " "__beqz"%0, 1b \n" |
| " nop \n" |
| " .set pop \n" |
| : "=&r" (temp), "=" GCC_OFF_SMALL_ASM() (*addr) |
| : "ir" (~mask), "ir" (value), GCC_OFF_SMALL_ASM() (*addr)); |
| } |
| |
| /* |
| * Sets all the masked bits to '1' |
| */ |
| static inline void set_reg32(volatile u32 *const addr, |
| u32 const mask) |
| { |
| u32 temp; |
| |
| __asm__ __volatile__( |
| " .set push \n" |
| " .set arch=r4000 \n" |
| "1: ll %0, %1 # set_reg32 \n" |
| " or %0, %2 \n" |
| " sc %0, %1 \n" |
| " "__beqz"%0, 1b \n" |
| " nop \n" |
| " .set pop \n" |
| : "=&r" (temp), "=" GCC_OFF_SMALL_ASM() (*addr) |
| : "ir" (mask), GCC_OFF_SMALL_ASM() (*addr)); |
| } |
| |
| /* |
| * Sets all the masked bits to '0' |
| */ |
| static inline void clear_reg32(volatile u32 *const addr, |
| u32 const mask) |
| { |
| u32 temp; |
| |
| __asm__ __volatile__( |
| " .set push \n" |
| " .set arch=r4000 \n" |
| "1: ll %0, %1 # clear_reg32 \n" |
| " and %0, %2 \n" |
| " sc %0, %1 \n" |
| " "__beqz"%0, 1b \n" |
| " nop \n" |
| " .set pop \n" |
| : "=&r" (temp), "=" GCC_OFF_SMALL_ASM() (*addr) |
| : "ir" (~mask), GCC_OFF_SMALL_ASM() (*addr)); |
| } |
| |
| /* |
| * Toggles all masked bits from '0' to '1' and '1' to '0' |
| */ |
| static inline void toggle_reg32(volatile u32 *const addr, |
| u32 const mask) |
| { |
| u32 temp; |
| |
| __asm__ __volatile__( |
| " .set push \n" |
| " .set arch=r4000 \n" |
| "1: ll %0, %1 # toggle_reg32 \n" |
| " xor %0, %2 \n" |
| " sc %0, %1 \n" |
| " "__beqz"%0, 1b \n" |
| " nop \n" |
| " .set pop \n" |
| : "=&r" (temp), "=" GCC_OFF_SMALL_ASM() (*addr) |
| : "ir" (mask), GCC_OFF_SMALL_ASM() (*addr)); |
| } |
| |
| /* |
| * Read all masked bits others are returned as '0' |
| */ |
| static inline u32 read_reg32(volatile u32 *const addr, |
| u32 const mask) |
| { |
| u32 temp; |
| |
| __asm__ __volatile__( |
| " .set push \n" |
| " .set noreorder \n" |
| " lw %0, %1 # read \n" |
| " and %0, %2 # mask \n" |
| " .set pop \n" |
| : "=&r" (temp) |
| : "m" (*addr), "ir" (mask)); |
| |
| return temp; |
| } |
| |
| /* |
| * blocking_read_reg32 - Read address with blocking load |
| * |
| * Uncached writes need to be read back to ensure they reach RAM. |
| * The returned value must be 'used' to prevent from becoming a |
| * non-blocking load. |
| */ |
| static inline u32 blocking_read_reg32(volatile u32 *const addr) |
| { |
| u32 temp; |
| |
| __asm__ __volatile__( |
| " .set push \n" |
| " .set noreorder \n" |
| " lw %0, %1 # read \n" |
| " move %0, %0 # block \n" |
| " .set pop \n" |
| : "=&r" (temp) |
| : "m" (*addr)); |
| |
| return temp; |
| } |
| |
| /* |
| * For special strange cases only: |
| * |
| * If you need custom processing within a ll/sc loop, use the following macros |
| * VERY CAREFULLY: |
| * |
| * u32 tmp; <-- Define a variable to hold the data |
| * |
| * custom_read_reg32(address, tmp); <-- Reads the address and put the value |
| * in the 'tmp' variable given |
| * |
| * From here on out, you are (basically) atomic, so don't do anything too |
| * fancy! |
| * Also, this code may loop if the end of this block fails to write |
| * everything back safely due do the other CPU, so do NOT do anything |
| * with side-effects! |
| * |
| * custom_write_reg32(address, tmp); <-- Writes back 'tmp' safely. |
| */ |
| #define custom_read_reg32(address, tmp) \ |
| __asm__ __volatile__( \ |
| " .set push \n" \ |
| " .set arch=r4000 \n" \ |
| "1: ll %0, %1 #custom_read_reg32 \n" \ |
| " .set pop \n" \ |
| : "=r" (tmp), "=" GCC_OFF_SMALL_ASM() (*address) \ |
| : GCC_OFF_SMALL_ASM() (*address)) |
| |
| #define custom_write_reg32(address, tmp) \ |
| __asm__ __volatile__( \ |
| " .set push \n" \ |
| " .set arch=r4000 \n" \ |
| " sc %0, %1 #custom_write_reg32 \n" \ |
| " "__beqz"%0, 1b \n" \ |
| " nop \n" \ |
| " .set pop \n" \ |
| : "=&r" (tmp), "=" GCC_OFF_SMALL_ASM() (*address) \ |
| : "0" (tmp), GCC_OFF_SMALL_ASM() (*address)) |
| |
| #endif /* __ASM_REGOPS_H__ */ |
