Hi, I have no comments about coding and architecture. It looks fine.
Only have a query about its use case.. "Any application intended to use message interrupt requires to know reg_num because of struct mpic_msgr* mpic_msgr_get(unsigned int reg_num) API" It will be good to search available unit internally and provide its pointer. It will make application more flexible. Regards, Prabhakar > -----Original Message----- > From: devicetree-discuss-bounces+b32579=freescale....@lists.ozlabs.org > [mailto:devicetree-discuss-bounces+b32579=freescale....@lists.ozlabs.org] > On Behalf Of Meador Inge > Sent: Tuesday, April 19, 2011 10:30 PM > To: linuxppc-dev@lists.ozlabs.org > Cc: openmcapi-...@googlegroups.com; devicetree-disc...@lists.ozlabs.org; > Hollis Blanchard > Subject: [PATCH 2/2] 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_i...@mentor.com> > Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> > Cc: Hollis Blanchard <hollis_blanch...@mentor.com> > --- > arch/powerpc/include/asm/mpic_msgr.h | 35 +++++ > arch/powerpc/platforms/Kconfig | 8 + > arch/powerpc/sysdev/Makefile | 3 +- > arch/powerpc/sysdev/mpic_msgr.c | 279 > ++++++++++++++++++++++++++++++++++ > 4 files changed, 324 insertions(+), 1 deletions(-) create mode 100644 > arch/powerpc/include/asm/mpic_msgr.h > create mode 100644 arch/powerpc/sysdev/mpic_msgr.c > > diff --git a/arch/powerpc/include/asm/mpic_msgr.h > b/arch/powerpc/include/asm/mpic_msgr.h > new file mode 100644 > index 0000000..370dcb4 > --- /dev/null > +++ b/arch/powerpc/include/asm/mpic_msgr.h > @@ -0,0 +1,35 @@ > +/* > + * 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> > + > +struct mpic_msgr { > + u32 __iomem *addr; > + u32 __iomem *mer; > + u32 __iomem *msr; > + int irq; > + atomic_t in_use; > + int num; > +}; > + > +extern struct mpic_msgr* mpic_msgr_get(unsigned int reg_num); extern > +void mpic_msgr_put(struct mpic_msgr* msgr); extern void > +mpic_msgr_enable(struct mpic_msgr *msgr); extern void > +mpic_msgr_disable(struct mpic_msgr *msgr); extern void > +mpic_msgr_write(struct mpic_msgr *msgr, u32 message); extern u32 > +mpic_msgr_read(struct mpic_msgr *msgr); extern void > +mpic_msgr_clear(struct mpic_msgr *msgr); extern void > +mpic_msgr_set_destination(struct mpic_msgr *msgr, u32 cpu_num); extern > +int mpic_msgr_get_irq(struct mpic_msgr *msgr); > + > +#endif > diff --git a/arch/powerpc/platforms/Kconfig > b/arch/powerpc/platforms/Kconfig index f7b0772..4d65593 100644 > --- a/arch/powerpc/platforms/Kconfig > +++ b/arch/powerpc/platforms/Kconfig > @@ -78,6 +78,14 @@ config MPIC_WEIRD > bool > default n > > +config MPIC_MSGR > + bool "MPIC message register support" > + depends on MPIC > + default n > + help > + Enables support for the MPIC message registers. These > + registers are used for inter-processor communication. > + > config PPC_I8259 > bool > default n > diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile > index 1e0c933..6d40185 100644 > --- a/arch/powerpc/sysdev/Makefile > +++ b/arch/powerpc/sysdev/Makefile > @@ -3,7 +3,8 @@ subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror > ccflags-$(CONFIG_PPC64) := -mno-minimal-toc > > mpic-msi-obj-$(CONFIG_PCI_MSI) += mpic_msi.o mpic_u3msi.o > mpic_pasemi_msi.o > -obj-$(CONFIG_MPIC) += mpic.o $(mpic-msi-obj-y) > +mpic-msgr-obj-$(CONFIG_MPIC_MSGR) += mpic_msgr.o > +obj-$(CONFIG_MPIC) += mpic.o $(mpic-msi-obj-y) $(mpic-msgr- > obj-y) > fsl-msi-obj-$(CONFIG_PCI_MSI) += fsl_msi.o > obj-$(CONFIG_PPC_MSI_BITMAP) += msi_bitmap.o > > diff --git a/arch/powerpc/sysdev/mpic_msgr.c > b/arch/powerpc/sysdev/mpic_msgr.c new file mode 100644 index > 0000000..352bfa6 > --- /dev/null > +++ b/arch/powerpc/sysdev/mpic_msgr.c > @@ -0,0 +1,279 @@ > +/* > + * Copyright 2011-2012, Meador Inge, Mentor Graphics Corporation. > + * > + * Some ideas based on un-pushed work done by Vivek Mahajan, Jason Jin, > +and > + * Mingkai Hu from Freescale Semiconductor, 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; version 2 of the > + * License. > + * > + */ > + > +#include <linux/list.h> > +#include <linux/of_platform.h> > +#include <linux/errno.h> > +#include <asm/prom.h> > +#include <asm/hw_irq.h> > +#include <asm/ppc-pci.h> > +#include <asm/mpic_msgr.h> > + > +#define MPIC_MSGR_REGISTERS_PER_BLOCK 4 #define MSGR_INUSE 0 #define > +MSGR_FREE 1 > + > +/* Internal structure used *only* for IO mapping register blocks. */ > +struct mpic_msgr_block { > + struct msgr { > + u32 msgr; > + u8 res[12]; > + } msgrs[MPIC_MSGR_REGISTERS_PER_BLOCK]; > + u8 res0[192]; > + u32 mer; > + u8 res1[12]; > + u32 msr; > +}; > + > +static struct mpic_msgr **mpic_msgrs = 0; static unsigned int > +mpic_msgr_count = 0; > + > +struct mpic_msgr* mpic_msgr_get(unsigned int reg_num) { > + struct mpic_msgr* msgr; > + > + if (reg_num >= mpic_msgr_count) > + return ERR_PTR(-ENODEV); > + > + msgr = mpic_msgrs[reg_num]; > + > + if (atomic_cmpxchg(&msgr->in_use, MSGR_FREE, MSGR_INUSE) == > MSGR_FREE) > + return msgr; > + > + return ERR_PTR(-EBUSY); > +} > +EXPORT_SYMBOL(mpic_msgr_get); > + > +void mpic_msgr_put(struct mpic_msgr* msgr) { > + atomic_set(&msgr->in_use, MSGR_FREE); > +} > +EXPORT_SYMBOL(mpic_msgr_put); > + > +void mpic_msgr_enable(struct mpic_msgr *msgr) { > + out_be32(msgr->mer, in_be32(msgr->mer) | (1 << msgr->num)); } > +EXPORT_SYMBOL(mpic_msgr_enable); > + > +void mpic_msgr_disable(struct mpic_msgr *msgr) { > + out_be32(msgr->mer, in_be32(msgr->mer) & ~(1 << msgr->num)); } > +EXPORT_SYMBOL(mpic_msgr_disable); > + > +void mpic_msgr_write(struct mpic_msgr *msgr, u32 message) { > + out_be32(msgr->addr, message); > +} > +EXPORT_SYMBOL(mpic_msgr_write); > + > +u32 mpic_msgr_read(struct mpic_msgr *msgr) { > + return in_be32(msgr->addr); > +} > +EXPORT_SYMBOL(mpic_msgr_read); > + > +void mpic_msgr_clear(struct mpic_msgr *msgr) { > + (void) mpic_msgr_read(msgr); > +} > +EXPORT_SYMBOL(mpic_msgr_clear); > + > +void mpic_msgr_set_destination(struct mpic_msgr *msgr, u32 cpu_num) { > + out_be32(msgr->addr, 1 << cpu_num); > +} > +EXPORT_SYMBOL(mpic_msgr_set_destination); > + > +int mpic_msgr_get_irq(struct mpic_msgr *msgr) { > + return msgr->irq; > +} > +EXPORT_SYMBOL(mpic_msgr_get_irq); > + > +/* The following three functions are used to compute the order and > +number of > + * the message register blocks. They are clearly very inefficent. > +However, > + * they are called *only* a few times during device initialization. > + */ > +static unsigned int mpic_msgr_number_of_blocks(void) { > + unsigned int count; > + struct device_node *aliases; > + > + count = 0; > + aliases = of_find_node_by_name(NULL, "aliases"); > + > + if (aliases) { > + char buf[32]; > + > + for (;;) { > + snprintf(buf, sizeof(buf), "msgr-block%d", count); > + if (!of_find_property(aliases, buf, NULL)) > + break; > + > + count += 1; > + } > + } > + > + return count; > +} > + > +static unsigned int mpic_msgr_number_of_registers(void) > +{ > + return mpic_msgr_number_of_blocks() * > MPIC_MSGR_REGISTERS_PER_BLOCK; } > + > +static int mpic_msgr_block_number(struct device_node *node) { > + struct device_node *aliases; > + unsigned int index, number_of_blocks; > + char buf[64]; > + > + number_of_blocks = mpic_msgr_number_of_blocks(); > + aliases = of_find_node_by_name(NULL, "aliases"); > + if (!aliases) > + return -1; > + > + for (index = 0; index < number_of_blocks; ++index) { > + struct property *prop; > + > + snprintf(buf, sizeof(buf), "msgr-block%d", index); > + prop = of_find_property(aliases, buf, NULL); > + if (node == of_find_node_by_path(prop->value)) > + break; > + } > + > + return index == number_of_blocks ? -1 : index; } > + > +/* The probe function for a single message register block. > + */ > +static __devinit int mpic_msgr_probe(struct platform_device *dev) { > + struct mpic_msgr_block __iomem *msgr_block; > + int block_number; > + struct resource rsrc; > + unsigned int i; > + unsigned int irq_index; > + struct device_node *np = dev->dev.of_node; > + unsigned int receive_mask; > + const unsigned int *prop; > + > + if (!np) { > + dev_err(&dev->dev, "Device OF-Node is NULL"); > + return -EFAULT; > + } > + > + /* Allocate the message register array upon the first device > + * registered. > + */ > + if (!mpic_msgrs) { > + mpic_msgr_count = mpic_msgr_number_of_registers(); > + dev_info(&dev->dev, "Found %d message registers\n", > mpic_msgr_count); > + > + mpic_msgrs = kzalloc(sizeof(struct mpic_msgr) * > mpic_msgr_count, > + GFP_KERNEL); > + if (!mpic_msgrs) { > + dev_err(&dev->dev, "No memory for message register > blocks\n"); > + return -ENOMEM; > + } > + } > + dev_info(&dev->dev, "Of-device full name %s\n", np->full_name); > + > + /* IO map the message register block. */ > + of_address_to_resource(np, 0, &rsrc); > + msgr_block = ioremap(rsrc.start, rsrc.end - rsrc.start); > + if (!msgr_block) { > + dev_err(&dev->dev, "Failed to iomap MPIC message registers"); > + return -EFAULT; > + } > + > + /* Ensure the block has a defined order. */ > + block_number = mpic_msgr_block_number(np); > + if (block_number < 0) { > + dev_err(&dev->dev, "Failed to find message register block > alias\n"); > + return -ENODEV; > + } > + dev_info(&dev->dev, "Setting up message register block %d\n", > +block_number); > + > + /* Grab the receive mask which specifies what registers can receive > + * interrupts. > + */ > + prop = of_get_property(np, "msg-receive-mask", NULL); > + receive_mask = (prop) ? *prop : 0xF; > + > + /* Build up the appropriate message register data structures. */ > + for (i = 0, irq_index = 0; i < MPIC_MSGR_REGISTERS_PER_BLOCK; ++i) > { > + struct mpic_msgr *msgr; > + unsigned int reg_number; > + > + msgr = kzalloc(sizeof(struct mpic_msgr), GFP_KERNEL); > + if (!msgr) { > + dev_err(&dev->dev, "No memory for message register\n"); > + return -ENOMEM; > + } > + > + reg_number = block_number * MPIC_MSGR_REGISTERS_PER_BLOCK + > i; > + msgr->addr = &msgr_block->msgrs[i].msgr; > + msgr->mer = &msgr_block->mer; > + msgr->msr = &msgr_block->msr; > + atomic_set(&msgr->in_use, MSGR_FREE); > + msgr->num = reg_number; > + > + if (receive_mask & (1 << i)) { > + struct resource irq; > + > + if (of_irq_to_resource(np, irq_index, &irq) == NO_IRQ) > { > + dev_err(&dev->dev, "Missing interrupt > specifier"); > + kfree(msgr); > + return -EFAULT; > + } > + msgr->irq = irq.start; > + irq_index += 1; > + } else { > + msgr->irq = NO_IRQ; > + } > + > + mpic_msgrs[reg_number] = msgr; > + mpic_msgr_disable(msgr); > + dev_info(&dev->dev, "Register %d initialized: irq %d\n", > + msgr->num, msgr->irq); > + > + } > + > + return 0; > +} > + > +static const struct of_device_id mpic_msgr_ids[] = { > + { > + .compatible = "fsl,mpic-v3.1-msgr", > + .data = NULL, > + }, > + {} > +}; > + > +static struct platform_driver mpic_msgr_driver = { > + .driver = { > + .name = "mpic-msgr", > + .owner = THIS_MODULE, > + .of_match_table = mpic_msgr_ids, > + }, > + .probe = mpic_msgr_probe, > +}; > + > +static __init int mpic_msgr_init(void) > +{ > + return platform_driver_register(&mpic_msgr_driver); > +} > +subsys_initcall(mpic_msgr_init); > -- > 1.6.3.3 > > _______________________________________________ > devicetree-discuss mailing list > devicetree-disc...@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/devicetree-discuss _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
