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Commit a19bd79e authored by Ian Munsie's avatar Ian Munsie Committed by Michael Ellerman
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cxl: Allow a default context to be associated with an external pci_dev 



The cxl kernel API has a concept of a default context associated with
each PCI device under the virtual PHB. The Mellanox CX4 will also use
the cxl kernel API, but it does not use a virtual PHB - rather, the AFU
appears as a physical function as a peer to the networking functions.

In order to allow the kernel API to work with those networking
functions, we will need to associate a default context with them as
well. To this end, refactor the corresponding code to do this in vphb.c
and export it so that it can be called from the PHB code.

Signed-off-by: default avatarIan Munsie <imunsie@au1.ibm.com>
Reviewed-by: default avatarFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: default avatarAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 62ccf2d2

drivers/misc/cxl/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -3,7 +3,7 @@ ccflags-$(CONFIG_PPC_WERROR) += -Werror 


cxl-y				+= main.o file.o irq.o fault.o native.o

cxl-y				+= context.o sysfs.o debugfs.o pci.o trace.o

cxl-y				+= vphb.o api.o

cxl-y				+= vphb.o phb.o api.o

cxl-$(CONFIG_PPC_PSERIES)	+= flash.o guest.o of.o hcalls.o

obj-$(CONFIG_CXL)		+= cxl.o

obj-$(CONFIG_CXL_BASE)		+= base.o

drivers/misc/cxl/base.c

+35 −0
Original line number Diff line number Diff line
@@ -106,6 +106,41 @@ int cxl_update_properties(struct device_node *dn, 
}

EXPORT_SYMBOL_GPL(cxl_update_properties);



/*

 * API calls into the driver that may be called from the PHB code and must be

 * built in.

 */

bool cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu)

{

	bool ret;

	struct cxl_calls *calls;



	calls = cxl_calls_get();

	if (!calls)

		return false;



	ret = calls->cxl_pci_associate_default_context(dev, afu);



	cxl_calls_put(calls);



	return ret;

}

EXPORT_SYMBOL_GPL(cxl_pci_associate_default_context);



void cxl_pci_disable_device(struct pci_dev *dev)

{

	struct cxl_calls *calls;



	calls = cxl_calls_get();

	if (!calls)

		return;



	calls->cxl_pci_disable_device(dev);



	cxl_calls_put(calls);

}

EXPORT_SYMBOL_GPL(cxl_pci_disable_device);



static int __init cxl_base_init(void)

{

	struct device_node *np;

drivers/misc/cxl/cxl.h

+6 −0
Original line number Diff line number Diff line
@@ -719,9 +719,15 @@ static inline u64 cxl_p2n_read(struct cxl_afu *afu, cxl_p2n_reg_t reg) 
ssize_t cxl_pci_afu_read_err_buffer(struct cxl_afu *afu, char *buf,

				loff_t off, size_t count);



/* Internal functions wrapped in cxl_base to allow PHB to call them */

bool _cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu);

void _cxl_pci_disable_device(struct pci_dev *dev);



struct cxl_calls {

	void (*cxl_slbia)(struct mm_struct *mm);

	bool (*cxl_pci_associate_default_context)(struct pci_dev *dev, struct cxl_afu *afu);

	void (*cxl_pci_disable_device)(struct pci_dev *dev);



	struct module *owner;

};

int register_cxl_calls(struct cxl_calls *calls);

drivers/misc/cxl/main.c

+2 −0
Original line number Diff line number Diff line
@@ -110,6 +110,8 @@ static inline void cxl_slbia_core(struct mm_struct *mm) 


static struct cxl_calls cxl_calls = {

	.cxl_slbia = cxl_slbia_core,

	.cxl_pci_associate_default_context = _cxl_pci_associate_default_context,

	.cxl_pci_disable_device = _cxl_pci_disable_device,

	.owner = THIS_MODULE,

};

drivers/misc/cxl/phb.c

0 → 100644
+44 −0
Original line number Diff line number Diff line 
/*

 * Copyright 2014-2016 IBM Corp.

 *

 * 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.

 */



#include <linux/pci.h>

#include "cxl.h"



bool _cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu)

{

	struct cxl_context *ctx;



	/*

	 * Allocate a context to do cxl things to. This is used for interrupts

	 * in the peer model using a real phb, and if we eventually do DMA ops

	 * in the virtual phb, we'll need a default context to attach them to.

	 */

	ctx = cxl_dev_context_init(dev);

	if (!ctx)

		return false;

	dev->dev.archdata.cxl_ctx = ctx;



	return (cxl_ops->afu_check_and_enable(afu) == 0);

}

/* exported via cxl_base */



void _cxl_pci_disable_device(struct pci_dev *dev)

{

	struct cxl_context *ctx = cxl_get_context(dev);



	if (ctx) {

		if (ctx->status == STARTED) {

			dev_err(&dev->dev, "Default context started\n");

			return;

		}

		dev->dev.archdata.cxl_ctx = NULL;

		cxl_release_context(ctx);

	}

}

/* exported via cxl_base */