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From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Darren Hart <dvhart@infradead.org>,
	Lee Jones <lee.jones@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H . Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, Zha Qipeng <qipeng.zha@intel.com>,
	"David E . Box" <david.e.box@linux.intel.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	Wim Van Sebroeck <wim@linux-watchdog.org>,
	Mark Brown <broonie@kernel.org>,
	platform-driver-x86@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 14/38] platform/x86: intel_scu_ipc: Introduce new SCU IPC API
Date: Wed, 22 Jan 2020 16:40:48 +0200	[thread overview]
Message-ID: <20200122144048.GV2665@lahna.fi.intel.com> (raw)
In-Reply-To: <20200122134359.GE4963@kroah.com>

On Wed, Jan 22, 2020 at 02:43:59PM +0100, Greg Kroah-Hartman wrote:
> On Tue, Jan 21, 2020 at 07:00:50PM +0300, Mika Westerberg wrote:
> > The current SCU IPC API has been operating on a single instance and
> > there has been no way to pin the providing module in place when the SCU
> > IPC is in use.
> > 
> > This implements a new API that takes the SCU IPC instance as first
> > parameter (NULL means the single instance is being used). The SCU IPC
> > instance can be retrieved by calling new function
> > intel_scu_ipc_dev_get() that take care of pinning the providing module
> > in place as long as intel_scu_ipc_dev_put() is not called.
> > 
> > The old API is left there to support existing users which cannot be
> > converted easily but it is put to a separate header that is subject to
> > be removed eventually. Subsequent patches will convert most of the users
> > to the new API.
> > 
> > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > ---
> >  arch/x86/include/asm/intel_scu_ipc.h        |  74 +++----
> >  arch/x86/include/asm/intel_scu_ipc_legacy.h |  76 +++++++
> >  drivers/platform/x86/intel_scu_ipc.c        | 219 ++++++++++++++++----
> >  drivers/platform/x86/intel_scu_pcidrv.c     |   7 +-
> >  4 files changed, 287 insertions(+), 89 deletions(-)
> >  create mode 100644 arch/x86/include/asm/intel_scu_ipc_legacy.h
> > 
> > diff --git a/arch/x86/include/asm/intel_scu_ipc.h b/arch/x86/include/asm/intel_scu_ipc.h
> > index 252ea0046f16..ce2ad516f0f9 100644
> > --- a/arch/x86/include/asm/intel_scu_ipc.h
> > +++ b/arch/x86/include/asm/intel_scu_ipc.h
> > @@ -1,9 +1,8 @@
> >  /* SPDX-License-Identifier: GPL-2.0 */
> >  #ifndef _ASM_X86_INTEL_SCU_IPC_H_
> > -#define  _ASM_X86_INTEL_SCU_IPC_H_
> > +#define _ASM_X86_INTEL_SCU_IPC_H_
> 
> gratuitous change :(

Oops.

> >  #include <linux/ioport.h>
> > -#include <linux/notifier.h>
> >  
> >  #define IPCMSG_INDIRECT_READ	0x02
> >  #define IPCMSG_INDIRECT_WRITE	0x05
> > @@ -21,6 +20,7 @@
> >  	#define IPC_CMD_VRTC_SETALARM     2 /* Set alarm */
> >  
> >  struct device;
> > +struct intel_scu_ipc_dev;
> >  
> >  /**
> >   * struct intel_scu_ipc_pdata - Platform data for SCU IPC
> > @@ -32,47 +32,39 @@ struct intel_scu_ipc_pdata {
> >  	int irq;
> >  };
> >  
> > -int intel_scu_ipc_register(struct device *dev,
> > -			   const struct intel_scu_ipc_pdata *pdata);
> > -
> > -/* Read single register */
> > -int intel_scu_ipc_ioread8(u16 addr, u8 *data);
> > -
> > -/* Read a vector */
> > -int intel_scu_ipc_readv(u16 *addr, u8 *data, int len);
> > -
> > -/* Write single register */
> > -int intel_scu_ipc_iowrite8(u16 addr, u8 data);
> > -
> > -/* Write a vector */
> > -int intel_scu_ipc_writev(u16 *addr, u8 *data, int len);
> > -
> > -/* Update single register based on the mask */
> > -int intel_scu_ipc_update_register(u16 addr, u8 data, u8 mask);
> > -
> > -/* Issue commands to the SCU with or without data */
> > -int intel_scu_ipc_simple_command(int cmd, int sub);
> > -int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
> > -			  u32 *out, int outlen);
> > -
> > -extern struct blocking_notifier_head intel_scu_notifier;
> > -
> > -static inline void intel_scu_notifier_add(struct notifier_block *nb)
> > -{
> > -	blocking_notifier_chain_register(&intel_scu_notifier, nb);
> > -}
> > -
> > -static inline void intel_scu_notifier_remove(struct notifier_block *nb)
> > -{
> > -	blocking_notifier_chain_unregister(&intel_scu_notifier, nb);
> > -}
> > -
> > -static inline int intel_scu_notifier_post(unsigned long v, void *p)
> > +struct intel_scu_ipc_dev *
> > +intel_scu_ipc_register(struct device *dev, const struct intel_scu_ipc_pdata *pdata);
> > +
> > +struct intel_scu_ipc_dev *intel_scu_ipc_dev_get(void);
> > +void intel_scu_ipc_dev_put(struct intel_scu_ipc_dev *scu);
> > +struct intel_scu_ipc_dev *devm_intel_scu_ipc_dev_get(struct device *dev);
> > +
> > +int intel_scu_ipc_dev_ioread8(struct intel_scu_ipc_dev *scu, u16 addr,
> > +			      u8 *data);
> > +int intel_scu_ipc_dev_iowrite8(struct intel_scu_ipc_dev *scu, u16 addr,
> > +			       u8 data);
> > +int intel_scu_ipc_dev_readv(struct intel_scu_ipc_dev *scu, u16 *addr,
> > +			    u8 *data, size_t len);
> > +int intel_scu_ipc_dev_writev(struct intel_scu_ipc_dev *scu, u16 *addr,
> > +			     u8 *data, size_t len);
> > +
> > +int intel_scu_ipc_dev_update(struct intel_scu_ipc_dev *scu, u16 addr,
> > +			     u8 data, u8 mask);
> > +
> > +int intel_scu_ipc_dev_simple_command(struct intel_scu_ipc_dev *scu, int cmd,
> > +				     int sub);
> > +int intel_scu_ipc_dev_command_with_size(struct intel_scu_ipc_dev *scu, int cmd,
> > +					int sub, const void *in, size_t inlen,
> > +					size_t size, void *out, size_t outlen);
> > +
> > +static inline int intel_scu_ipc_dev_command(struct intel_scu_ipc_dev *scu, int cmd,
> > +					    int sub, const void *in, size_t inlen,
> > +					    void *out, size_t outlen)
> >  {
> > -	return blocking_notifier_call_chain(&intel_scu_notifier, v, p);
> > +	return intel_scu_ipc_dev_command_with_size(scu, cmd, sub, in, inlen,
> > +						   inlen, out, outlen);
> >  }
> >  
> > -#define		SCU_AVAILABLE		1
> > -#define		SCU_DOWN		2
> > +#include <asm/intel_scu_ipc_legacy.h>
> >  
> >  #endif
> > diff --git a/arch/x86/include/asm/intel_scu_ipc_legacy.h b/arch/x86/include/asm/intel_scu_ipc_legacy.h
> > new file mode 100644
> > index 000000000000..3399ea8eea48
> > --- /dev/null
> > +++ b/arch/x86/include/asm/intel_scu_ipc_legacy.h
> > @@ -0,0 +1,76 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef _ASM_X86_INTEL_SCU_IPC_LEGACY_H_
> > +#define _ASM_X86_INTEL_SCU_IPC_LEGACY_H_
> > +
> > +#include <linux/notifier.h>
> > +
> > +/* Don't call these in new code - they will be removed eventually */
> > +
> > +/* Read single register */
> > +static inline int intel_scu_ipc_ioread8(u16 addr, u8 *data)
> > +{
> > +	return intel_scu_ipc_dev_ioread8(NULL, addr, data);
> > +}
> > +
> > +/* Read a vector */
> > +static inline int intel_scu_ipc_readv(u16 *addr, u8 *data, int len)
> > +{
> > +	return intel_scu_ipc_dev_readv(NULL, addr, data, len);
> > +}
> > +
> > +/* Write single register */
> > +static inline int intel_scu_ipc_iowrite8(u16 addr, u8 data)
> > +{
> > +	return intel_scu_ipc_dev_iowrite8(NULL, addr, data);
> > +}
> > +
> > +/* Write a vector */
> > +static inline int intel_scu_ipc_writev(u16 *addr, u8 *data, int len)
> > +{
> > +	return intel_scu_ipc_dev_writev(NULL, addr, data, len);
> > +}
> > +
> > +/* Update single register based on the mask */
> > +static inline int intel_scu_ipc_update_register(u16 addr, u8 data, u8 mask)
> > +{
> > +	return intel_scu_ipc_dev_update(NULL, addr, data, mask);
> > +}
> > +
> > +/* Issue commands to the SCU with or without data */
> > +static inline int intel_scu_ipc_simple_command(int cmd, int sub)
> > +{
> > +	return intel_scu_ipc_dev_simple_command(NULL, cmd, sub);
> > +}
> > +
> > +static inline int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
> > +					u32 *out, int outlen)
> > +{
> > +	/* New API takes both inlen and outlen as bytes so convert here */
> > +	size_t inbytes = inlen * sizeof(u32);
> > +	size_t outbytes = outlen * sizeof(u32);
> > +
> > +	return intel_scu_ipc_dev_command_with_size(NULL, cmd, sub, in, inbytes,
> > +						   inlen, out, outbytes);
> > +}
> > +
> > +extern struct blocking_notifier_head intel_scu_notifier;
> > +
> > +static inline void intel_scu_notifier_add(struct notifier_block *nb)
> > +{
> > +	blocking_notifier_chain_register(&intel_scu_notifier, nb);
> > +}
> > +
> > +static inline void intel_scu_notifier_remove(struct notifier_block *nb)
> > +{
> > +	blocking_notifier_chain_unregister(&intel_scu_notifier, nb);
> > +}
> > +
> > +static inline int intel_scu_notifier_post(unsigned long v, void *p)
> > +{
> > +	return blocking_notifier_call_chain(&intel_scu_notifier, v, p);
> > +}
> > +
> > +#define		SCU_AVAILABLE		1
> > +#define		SCU_DOWN		2
> > +
> > +#endif
> > diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
> > index 518b044d8ecb..391b65a4789e 100644
> > --- a/drivers/platform/x86/intel_scu_ipc.c
> > +++ b/drivers/platform/x86/intel_scu_ipc.c
> > @@ -19,6 +19,7 @@
> >  #include <linux/init.h>
> >  #include <linux/interrupt.h>
> >  #include <linux/io.h>
> > +#include <linux/module.h>
> >  
> >  #include <asm/intel_scu_ipc.h>
> >  
> > @@ -78,6 +79,99 @@ static struct intel_scu_ipc_dev  ipcdev; /* Only one for now */
> >  
> >  static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
> >  
> > +/**
> > + * intel_scu_ipc_dev_get() - Get SCU IPC instance
> > + *
> > + * The recommended new API takes SCU IPC instance as parameter and this
> > + * function can be called by driver to get the instance. This also makes
> > + * sure the driver providing the IPC functionality cannot be unloaded
> > + * while the caller has the intance.
> > + *
> > + * Call intel_scu_ipc_dev_put() to release the instance.
> > + *
> > + * Returns %NULL if SCU IPC is not currently available.
> > + */
> > +struct intel_scu_ipc_dev *intel_scu_ipc_dev_get(void)
> > +{
> > +	struct intel_scu_ipc_dev *scu = &ipcdev;
> > +
> > +	mutex_lock(&ipclock);
> > +	if (!scu->dev)
> > +		goto err_unlock;
> > +	if (!try_module_get(scu->dev->driver->owner))
> > +		goto err_unlock;
> > +	mutex_unlock(&ipclock);
> > +	return scu;
> 
> NO REFERENCE COUNT INCREMENT???

You mean increment the scu->dev reference count? I kind of thought that
the try_module_get() should make sure the thing stays there as long as
the caller has not called _put() but now when I think about it bit more
we would need to do device_get() here as well.

Sorry about this.

> You owe me 5 recitations of the "Data Structures" of
> Documentation/process/coding-style.rst
> 
> And some whisky to get me through the next round of code reviews of this
> mess...

Sure :)

  reply	other threads:[~2020-01-22 14:40 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-21 16:00 [PATCH v4 00/38] platform/x86: Rework intel_scu_ipc and intel_pmc_ipc drivers Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 01/38] platform/x86: intel_mid_powerbtn: Take a copy of ddata Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 02/38] platform/x86: intel_scu_ipcutil: Remove default y from Kconfig Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 03/38] platform/x86: intel_scu_ipc: Add constants for register offsets Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 04/38] platform/x86: intel_scu_ipc: Remove Lincroft support Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 05/38] platform/x86: intel_scu_ipc: Drop intel_scu_ipc_i2c_cntrl() Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 06/38] platform/x86: intel_scu_ipc: Fix interrupt support Mika Westerberg
2020-01-22 13:34   ` Greg Kroah-Hartman
2020-01-22 14:30     ` Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 07/38] platform/x86: intel_scu_ipc: Sleeping is fine when polling Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 08/38] platform/x86: intel_scu_ipc: Drop unused prototype intel_scu_ipc_fw_update() Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 09/38] platform/x86: intel_scu_ipc: Drop unused macros Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 10/38] platform/x86: intel_scu_ipc: Drop intel_scu_ipc_io[read|write][8|16]() Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 11/38] platform/x86: intel_scu_ipc: Drop intel_scu_ipc_raw_command() Mika Westerberg
2020-01-22 13:36   ` Greg Kroah-Hartman
2020-01-22 14:33     ` Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 12/38] platform/x86: intel_scu_ipc: Split out SCU IPC functionality from the SCU driver Mika Westerberg
2020-01-22 13:40   ` Greg Kroah-Hartman
2020-01-22 14:35     ` Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 13/38] platform/x86: intel_scu_ipc: Reformat kernel-doc comments of exported functions Mika Westerberg
2020-01-22 13:40   ` Greg Kroah-Hartman
2020-01-22 14:36     ` Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 14/38] platform/x86: intel_scu_ipc: Introduce new SCU IPC API Mika Westerberg
2020-01-22 13:43   ` Greg Kroah-Hartman
2020-01-22 14:40     ` Mika Westerberg [this message]
2020-01-22 14:49       ` Greg Kroah-Hartman
2020-01-22 15:04         ` Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 15/38] platform/x86: intel_mid_powerbtn: Convert to use " Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 16/38] watchdog: intel-mid_wdt: " Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 17/38] platform/x86: intel_scu_ipcutil: " Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 18/38] platform/x86: intel_pmc_ipc: Make intel_pmc_gcr_update() static Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 19/38] platform/x86: intel_pmc_ipc: Make intel_pmc_ipc_simple_command() static Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 20/38] platform/x86: intel_pmc_ipc: Make intel_pmc_ipc_raw_cmd() static Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 21/38] platform/x86: intel_pmc_ipc: Drop intel_pmc_gcr_read() and intel_pmc_gcr_write() Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 22/38] platform/x86: intel_pmc_ipc: Drop ipc_data_readb() Mika Westerberg
2020-01-21 16:00 ` [PATCH v4 23/38] platform/x86: intel_pmc_ipc: Get rid of unnecessary includes Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 24/38] platform/x86: intel_scu_ipc: Add managed function to register SCU IPC Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 25/38] platform/x86: intel_pmc_ipc: Start using " Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 26/38] mfd: intel_soc_pmic: Add SCU IPC member to struct intel_soc_pmic Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 27/38] mfd: intel_soc_pmic_bxtwc: Convert to use new SCU IPC API Mika Westerberg
2020-01-22 13:46   ` Greg Kroah-Hartman
2020-01-22 14:41     ` Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 28/38] mfd: intel_soc_pmic_mrfld: " Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 29/38] platform/x86: intel_telemetry: " Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 30/38] platform/x86: intel_pmc_ipc: Drop intel_pmc_ipc_command() Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 31/38] x86/platform/intel-mid: Add empty stubs for intel_scu_devices_[create|destroy]() Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 32/38] platform/x86: intel_pmc_ipc: Move PCI IDs to intel_scu_pcidrv.c Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 33/38] platform/x86: intel_pmc_ipc: Use octal permissions in sysfs attributes Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 34/38] platform/x86: intel_pmc_ipc: Propagate error from kstrtoul() Mika Westerberg
2020-01-21 17:51   ` Andy Shevchenko
2020-01-21 16:01 ` [PATCH v4 35/38] platform/x86: intel_pmc_ipc: Switch to use driver->dev_groups Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 36/38] platform/x86: intel_telemetry: Add telemetry_get_pltdata() Mika Westerberg
2020-01-21 18:00   ` Andy Shevchenko
2020-01-21 16:01 ` [PATCH v4 37/38] platform/x86: intel_pmc_ipc: Convert to MFD Mika Westerberg
2020-01-21 18:26   ` Andy Shevchenko
2020-01-22 10:55     ` Mika Westerberg
2020-01-22 12:34   ` Lee Jones
2020-01-22 12:53     ` Mika Westerberg
2020-01-22 13:27       ` Lee Jones
2020-01-22 14:45         ` Mika Westerberg
2020-01-23  8:01           ` Lee Jones
2020-01-23  8:56             ` Mika Westerberg
2020-01-21 16:01 ` [PATCH v4 38/38] MAINTAINERS: Update entry for Intel Broxton PMC driver Mika Westerberg
2020-01-21 16:21 ` [PATCH v4 00/38] platform/x86: Rework intel_scu_ipc and intel_pmc_ipc drivers Mark Brown
2020-01-21 16:33   ` Mika Westerberg
2020-01-21 16:45     ` Mark Brown
2020-01-21 17:00       ` Mika Westerberg
2020-01-21 17:06         ` Mark Brown
2020-01-21 17:21           ` Mika Westerberg

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