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author | Jia Hongtao <B38951@freescale.com> | 2012-02-17 10:49:03 +0800 |
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committer | Kumar Gala <galak@kernel.crashing.org> | 2012-03-16 16:15:28 -0500 |
commit | 8626816e905e8e131663dfcae27d307df8c220d0 (patch) | |
tree | 53d6eeed360ce02a075d8adba5b399352ddcf2c6 /arch/powerpc/include/asm/mpic_msgr.h | |
parent | da3b6c0534c76bc08ce5524342586138687fd106 (diff) | |
download | linux-stable-8626816e905e8e131663dfcae27d307df8c220d0.tar.gz linux-stable-8626816e905e8e131663dfcae27d307df8c220d0.tar.bz2 linux-stable-8626816e905e8e131663dfcae27d307df8c220d0.zip |
powerpc: add support for MPIC message register API
Some MPIC implementations contain one or more blocks of message registers
that are used to send messages between cores via IPIs. A simple API has
been added to access (get/put, read, write, etc ...) these message registers.
The available message registers are initially discovered via nodes in the
device tree. A separate commit contains a binding for the message register
nodes.
Signed-off-by: Meador Inge <meador_inge@mentor.com>
Signed-off-by: Jia Hongtao <B38951@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include/asm/mpic_msgr.h')
-rw-r--r-- | arch/powerpc/include/asm/mpic_msgr.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/mpic_msgr.h b/arch/powerpc/include/asm/mpic_msgr.h new file mode 100644 index 000000000000..3ec37dc9003e --- /dev/null +++ b/arch/powerpc/include/asm/mpic_msgr.h @@ -0,0 +1,132 @@ +/* + * Copyright 2011-2012, Meador Inge, Mentor Graphics Corporation. + * + * 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; version 2 of the + * License. + * + */ + +#ifndef _ASM_MPIC_MSGR_H +#define _ASM_MPIC_MSGR_H + +#include <linux/types.h> +#include <linux/spinlock.h> + +struct mpic_msgr { + u32 __iomem *base; + u32 __iomem *mer; + int irq; + unsigned char in_use; + raw_spinlock_t lock; + int num; +}; + +/* Get a message register + * + * @reg_num: the MPIC message register to get + * + * A pointer to the message register is returned. If + * the message register asked for is already in use, then + * EBUSY is returned. If the number given is not associated + * with an actual message register, then ENODEV is returned. + * Successfully getting the register marks it as in use. + */ +extern struct mpic_msgr *mpic_msgr_get(unsigned int reg_num); + +/* Relinquish a message register + * + * @msgr: the message register to return + * + * Disables the given message register and marks it as free. + * After this call has completed successully the message + * register is available to be acquired by a call to + * mpic_msgr_get. + */ +extern void mpic_msgr_put(struct mpic_msgr *msgr); + +/* Enable a message register + * + * @msgr: the message register to enable + * + * The given message register is enabled for sending + * messages. + */ +extern void mpic_msgr_enable(struct mpic_msgr *msgr); + +/* Disable a message register + * + * @msgr: the message register to disable + * + * The given message register is disabled for sending + * messages. + */ +extern void mpic_msgr_disable(struct mpic_msgr *msgr); + +/* Write a message to a message register + * + * @msgr: the message register to write to + * @message: the message to write + * + * The given 32-bit message is written to the given message + * register. Writing to an enabled message registers fires + * an interrupt. + */ +static inline void mpic_msgr_write(struct mpic_msgr *msgr, u32 message) +{ + out_be32(msgr->base, message); +} + +/* Read a message from a message register + * + * @msgr: the message register to read from + * + * Returns the 32-bit value currently in the given message register. + * Upon reading the register any interrupts for that register are + * cleared. + */ +static inline u32 mpic_msgr_read(struct mpic_msgr *msgr) +{ + return in_be32(msgr->base); +} + +/* Clear a message register + * + * @msgr: the message register to clear + * + * Clears any interrupts associated with the given message register. + */ +static inline void mpic_msgr_clear(struct mpic_msgr *msgr) +{ + (void) mpic_msgr_read(msgr); +} + +/* Set the destination CPU for the message register + * + * @msgr: the message register whose destination is to be set + * @cpu_num: the Linux CPU number to bind the message register to + * + * Note that the CPU number given is the CPU number used by the kernel + * and *not* the actual hardware CPU number. + */ +static inline void mpic_msgr_set_destination(struct mpic_msgr *msgr, + u32 cpu_num) +{ + out_be32(msgr->base, 1 << get_hard_smp_processor_id(cpu_num)); +} + +/* Get the IRQ number for the message register + * @msgr: the message register whose IRQ is to be returned + * + * Returns the IRQ number associated with the given message register. + * NO_IRQ is returned if this message register is not capable of + * receiving interrupts. What message register can and cannot receive + * interrupts is specified in the device tree for the system. + */ +static inline int mpic_msgr_get_irq(struct mpic_msgr *msgr) +{ + return msgr->irq; +} + +#endif |