Re: [PATCH v7 10/20] gunyah: rsc_mgr: Add resource manager RPC core

From: Elliot Berman <quic_eberman@quicinc.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Bjorn Andersson <quic_bjorande@quicinc.com>,
	Murali Nalajala <quic_mnalajal@quicinc.com>,
	Trilok Soni <quic_tsoni@quicinc.com>,
	"Srivatsa Vaddagiri" <quic_svaddagi@quicinc.com>,
	Carl van Schaik <quic_cvanscha@quicinc.com>,
	Prakruthi Deepak Heragu <quic_pheragu@quicinc.com>,
	Arnd Bergmann <arnd@arndb.de>, Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Jassi Brar <jassisinghbrar@gmail.com>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Lorenzo Pieralisi <lpieralisi@kernel.org>,
	<linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-doc@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-acpi@vger.kernel.org>
Subject: Re: [PATCH v7 10/20] gunyah: rsc_mgr: Add resource manager RPC core
Date: Mon, 12 Dec 2022 15:46:58 -0800	[thread overview]
Message-ID: <a5c7089c-9880-e22a-ae33-eba91dc47f0e@quicinc.com> (raw)
In-Reply-To: <Y3uX9ywOVLubxYkW@kroah.com>

On 11/21/2022 7:23 AM, Greg Kroah-Hartman wrote:
> On Mon, Nov 21, 2022 at 05:59:59AM -0800, Elliot Berman wrote:
>> The resource manager is a special virtual machine which is always
>> running on a Gunyah system. It provides APIs for creating and destroying
>> VMs, secure memory management, sharing/lending of memory between VMs,
>> and setup of inter-VM communication. Calls to the resource manager are
>> made via message queues.
>>
>> This patch implements the basic probing and RPC mechanism to make those
>> API calls. Request/response calls can be made with gh_rm_call.
>> Drivers can also register to notifications pushed by RM via
>> gh_rm_register_notifier
>>
>> Specific API calls that resource manager supports will be implemented in
>> subsequent patches.
>>
>> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
>> ---
>>   MAINTAINERS                          |   2 +-
>>   drivers/virt/gunyah/Kconfig          |   7 +
>>   drivers/virt/gunyah/Makefile         |   2 +
>>   drivers/virt/gunyah/gunyah_rm_rpc.c  | 570 +++++++++++++++++++++++++++
>>   drivers/virt/gunyah/gunyah_rsc_mgr.c |  50 +++
>>   drivers/virt/gunyah/rsc_mgr.h        |  37 ++
>>   include/linux/gunyah_rsc_mgr.h       |  18 +
>>   7 files changed, 685 insertions(+), 1 deletion(-)
>>   create mode 100644 drivers/virt/gunyah/gunyah_rm_rpc.c
>>   create mode 100644 drivers/virt/gunyah/gunyah_rsc_mgr.c
>>   create mode 100644 drivers/virt/gunyah/rsc_mgr.h
>>   create mode 100644 include/linux/gunyah_rsc_mgr.h
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 502798197b80..b65f7ff444e5 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -8948,7 +8948,7 @@ F:	Documentation/virt/gunyah/
>>   F:	arch/arm64/gunyah/
>>   F:	drivers/mailbox/gunyah-msgq.c
>>   F:	drivers/virt/gunyah/
>> -F:	include/linux/gunyah.h
>> +F:	include/linux/gunyah*.h
>>   
>>   HABANALABS PCI DRIVER
>>   M:	Oded Gabbay <ogabbay@kernel.org>
>> diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
>> index 127156a678a6..0bb497372d4e 100644
>> --- a/drivers/virt/gunyah/Kconfig
>> +++ b/drivers/virt/gunyah/Kconfig
>> @@ -10,3 +10,10 @@ config GUNYAH
>>   
>>   	  Say Y/M here to enable the drivers needed to interact in a Gunyah
>>   	  virtual environment.
>> +
>> +if GUNYAH
>> +config GUNYAH_RESOURCE_MANAGER
>> +	tristate
>> +	depends on MAILBOX
>> +	select GUNYAH_MESSAGE_QUEUES
>> +endif
>> diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
>> index 2ac4ee64b89d..b62ac4045621 100644
>> --- a/drivers/virt/gunyah/Makefile
>> +++ b/drivers/virt/gunyah/Makefile
>> @@ -1 +1,3 @@
>>   obj-$(CONFIG_GUNYAH) += gunyah.o
>> +
>> +obj-$(CONFIG_GUNYAH_RESOURCE_MANAGER) += gunyah_rsc_mgr.o gunyah_rm_rpc.o
>> diff --git a/drivers/virt/gunyah/gunyah_rm_rpc.c b/drivers/virt/gunyah/gunyah_rm_rpc.c
>> new file mode 100644
>> index 000000000000..45b1a8691982
>> --- /dev/null
>> +++ b/drivers/virt/gunyah/gunyah_rm_rpc.c
>> @@ -0,0 +1,570 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#include <linux/of.h>
>> +#include <linux/slab.h>
>> +#include <linux/mutex.h>
>> +#include <linux/sched.h>
>> +#include <linux/gunyah.h>
>> +#include <linux/module.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/kthread.h>
>> +#include <linux/notifier.h>
>> +#include <linux/workqueue.h>
>> +#include <linux/completion.h>
>> +#include <linux/gunyah_rsc_mgr.h>
>> +#include <linux/platform_device.h>
> 
> This should not have anything to do with a platform device, please see
> below.
> 
>> +#include <linux/gunyah_rsc_mgr.h>
>> +#include <linux/platform_device.h>
>> +
>> +#include "rsc_mgr.h"
>> +
>> +static int gh_rm_drv_probe(struct platform_device *pdev)
> 
> Why is this tied to a platformm device?
> 
> I don't understand the relationship here, sorry.
> >> +{
>> +	struct gh_rm_rpc *rsc_mgr;
>> +
>> +	rsc_mgr = gh_rm_rpc_init(pdev);
> 
> Shouldn't this be creating a new one that is just a child passed in?
> Shouldn't this call just take a 'struct device *'?
> 

I'm following the suggestion from Arnd to have small core module that 
calls into initialization routines for the other parts of the driver, 
rather than creating bus for a few (2) devices.

https://lore.kernel.org/all/a3754259-9989-495e-a6bd-5501daff06a2@app.fastmail.com/

Thanks,
Elliot