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Jia Hongtaokumargala
Jia Hongtao
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kumargala
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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 <[email protected]> Signed-off-by: Jia Hongtao <[email protected]> Signed-off-by: Li Yang <[email protected]> Signed-off-by: Kumar Gala <[email protected]>
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‎arch/powerpc/include/asm/mpic_msgr.h

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/*
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* Copyright 2011-2012, Meador Inge, Mentor Graphics Corporation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; version 2 of the
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* License.
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*
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*/
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#ifndef _ASM_MPIC_MSGR_H
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#define _ASM_MPIC_MSGR_H
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#include <linux/types.h>
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#include <linux/spinlock.h>
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struct mpic_msgr {
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u32 __iomem *base;
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u32 __iomem *mer;
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int irq;
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unsigned char in_use;
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raw_spinlock_t lock;
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int num;
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};
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/* Get a message register
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*
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* @reg_num: the MPIC message register to get
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*
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* A pointer to the message register is returned. If
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* the message register asked for is already in use, then
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* EBUSY is returned. If the number given is not associated
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* with an actual message register, then ENODEV is returned.
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* Successfully getting the register marks it as in use.
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*/
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extern struct mpic_msgr *mpic_msgr_get(unsigned int reg_num);
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/* Relinquish a message register
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*
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* @msgr: the message register to return
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*
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* Disables the given message register and marks it as free.
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* After this call has completed successully the message
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* register is available to be acquired by a call to
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* mpic_msgr_get.
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*/
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extern void mpic_msgr_put(struct mpic_msgr *msgr);
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/* Enable a message register
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*
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* @msgr: the message register to enable
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*
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* The given message register is enabled for sending
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* messages.
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*/
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extern void mpic_msgr_enable(struct mpic_msgr *msgr);
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/* Disable a message register
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*
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* @msgr: the message register to disable
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*
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* The given message register is disabled for sending
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* messages.
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*/
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extern void mpic_msgr_disable(struct mpic_msgr *msgr);
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/* Write a message to a message register
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*
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* @msgr: the message register to write to
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* @message: the message to write
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*
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* The given 32-bit message is written to the given message
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* register. Writing to an enabled message registers fires
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* an interrupt.
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*/
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static inline void mpic_msgr_write(struct mpic_msgr *msgr, u32 message)
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{
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out_be32(msgr->base, message);
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}
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/* Read a message from a message register
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*
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* @msgr: the message register to read from
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*
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* Returns the 32-bit value currently in the given message register.
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* Upon reading the register any interrupts for that register are
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* cleared.
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*/
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static inline u32 mpic_msgr_read(struct mpic_msgr *msgr)
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{
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return in_be32(msgr->base);
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}
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/* Clear a message register
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*
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* @msgr: the message register to clear
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*
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* Clears any interrupts associated with the given message register.
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*/
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static inline void mpic_msgr_clear(struct mpic_msgr *msgr)
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{
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(void) mpic_msgr_read(msgr);
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}
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/* Set the destination CPU for the message register
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*
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* @msgr: the message register whose destination is to be set
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* @cpu_num: the Linux CPU number to bind the message register to
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*
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* Note that the CPU number given is the CPU number used by the kernel
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* and *not* the actual hardware CPU number.
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*/
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static inline void mpic_msgr_set_destination(struct mpic_msgr *msgr,
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u32 cpu_num)
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{
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out_be32(msgr->base, 1 << get_hard_smp_processor_id(cpu_num));
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}
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/* Get the IRQ number for the message register
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* @msgr: the message register whose IRQ is to be returned
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*
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* Returns the IRQ number associated with the given message register.
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* NO_IRQ is returned if this message register is not capable of
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* receiving interrupts. What message register can and cannot receive
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* interrupts is specified in the device tree for the system.
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*/
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static inline int mpic_msgr_get_irq(struct mpic_msgr *msgr)
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{
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return msgr->irq;
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}
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#endif

‎arch/powerpc/platforms/Kconfig

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bool
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default n
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config MPIC_MSGR
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bool "MPIC message register support"
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depends on MPIC
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default n
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help
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Enables support for the MPIC message registers. These
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registers are used for inter-processor communication.
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config PPC_I8259
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bool
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default n

‎arch/powerpc/sysdev/Makefile

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mpic-msi-obj-$(CONFIG_PCI_MSI) += mpic_msi.o mpic_u3msi.o mpic_pasemi_msi.o
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obj-$(CONFIG_MPIC) += mpic.o $(mpic-msi-obj-y)
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mpic-msgr-obj-$(CONFIG_MPIC_MSGR) += mpic_msgr.o
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obj-$(CONFIG_MPIC) += mpic.o $(mpic-msi-obj-y) $(mpic-msgr-obj-y)
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obj-$(CONFIG_PPC_EPAPR_HV_PIC) += ehv_pic.o
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fsl-msi-obj-$(CONFIG_PCI_MSI) += fsl_msi.o
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obj-$(CONFIG_PPC_MSI_BITMAP) += msi_bitmap.o

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