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Diffstat (limited to 'arch/mips/include/asm/mach-pmcs-msp71xx/msp_regops.h')
| -rw-r--r-- | arch/mips/include/asm/mach-pmcs-msp71xx/msp_regops.h | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/arch/mips/include/asm/mach-pmcs-msp71xx/msp_regops.h b/arch/mips/include/asm/mach-pmcs-msp71xx/msp_regops.h new file mode 100644 index 000000000..90dbe43c8 --- /dev/null +++ b/arch/mips/include/asm/mach-pmcs-msp71xx/msp_regops.h @@ -0,0 +1,237 @@ +/* + * 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__ */ |