--- /dev/null
+/*
+ * 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__ */
Code Review / kvmfornfv.git / blobdiff