| Message ID | 20250327114604.118030-2-selvakumar.kalimuthu@in.bosch.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | *** export interface for custom UPIU transfer *** | expand |
On 3/27/25 7:46 AM, Selvakumar Kalimuthu wrote: > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c > index 78b57e946cdf..226cc90c74b0 100644 > --- a/drivers/ufs/core/ufshcd.c > +++ b/drivers/ufs/core/ufshcd.c > @@ -7360,6 +7360,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba, > > return err; > } > +EXPORT_SYMBOL_GPL(ufshcd_exec_raw_upiu_cmd); As I already mentioned off-list, please do not export functions without adding a caller that needs the export. Thanks, Bart.
Hi Bart, Thanks for your feedback. The caller for this exported function resides in an OEM/vendor-specific module, which is not part of the standard Linux kernel. The intent of this patch is to provide an interface that allows vendors to send raw UPIU commands from their external modules to retrieve device-specific information or execute proprietary commands. Since vendor modules cannot modify the UFS core driver directly, exporting ufshcd_exec_raw_upiu_cmd is necessary to enable controlled access without modifying the mainline kernel further. Would you prefer that we also provide an example of a vendor module using this export, even though it won’t be part of the upstream kernel? Or is there a preferred approach to enable vendor-specific extensions without modifying the standard kernel UFS driver? Looking forward to your guidance. Mit freundlichen Grüßen / Best regards Selvakumar Kalimuthu responsible for Platform 1 projects (MS/ECF1-XC) Robert Bosch GmbH | Postfach 10 60 50 | 70049 Stuttgart | GERMANY | www.bosch.com Fax +91 422 667-1208 | Selvakumar.Kalimuthu@in.bosch.com Registered Office: Stuttgart, Registration Court: Amtsgericht Stuttgart, HRB 14000; Chairman of the Supervisory Board: Prof. Dr. Stefan Asenkerschbaumer; Managing Directors: Dr. Stefan Hartung, Dr. Christian Fischer, Dr. Markus Forschner, Stefan Grosch, Dr. Markus Heyn, Dr. Frank Meyer, Katja von Raven, Dr. Tanja Rückert -----Original Message----- From: Bart Van Assche <bvanassche@acm.org> Sent: Thursday, March 27, 2025 5:28 PM To: Selvakumar Kalimuthu (MS/ECC-CF3-XC) <selvakumar.kalimuthu@in.bosch.com>; Alim Akhtar <alim.akhtar@samsung.com>; Avri Altman <avri.altman@wdc.com>; James E.J. Bottomley <jejb@linux.ibm.com>; Martin K. Petersen <martin.petersen@oracle.com>; Peter Wang <peter.wang@mediatek.com>; Manjunatha Madana <quic_c_mamanj@quicinc.com> Cc: Antony A (MS/ECC-CF-EP2-XC) <Antony.Ambrose@in.bosch.com>; linux-scsi@vger.kernel.org Subject: Re: [PATCH v1 1/1] ufs: core: Export interface for sending raw UPIU commands On 3/27/25 7:46 AM, Selvakumar Kalimuthu wrote: > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c > index 78b57e946cdf..226cc90c74b0 100644 > --- a/drivers/ufs/core/ufshcd.c > +++ b/drivers/ufs/core/ufshcd.c > @@ -7360,6 +7360,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba > *hba, > > return err; > } > +EXPORT_SYMBOL_GPL(ufshcd_exec_raw_upiu_cmd); As I already mentioned off-list, please do not export functions without adding a caller that needs the export. Thanks, Bart.
> Hi Bart, > > Thanks for your feedback. > > The caller for this exported function resides in an OEM/vendor-specific > module, which is not part of the standard Linux kernel. The intent of this patch > is to provide an interface that allows vendors to send raw UPIU commands > from their external modules to retrieve device-specific information or execute > proprietary commands. The ufs spec defines a wide range of vendor specific query commands: 0x40-0x7F, and 0xC0-0xFF. For those you can use the current caller, e.g. ufs-bsg module? Thanks, Avri > Since vendor modules cannot modify the UFS core > driver directly, exporting ufshcd_exec_raw_upiu_cmd is necessary to enable > controlled access without modifying the mainline kernel further. > > Would you prefer that we also provide an example of a vendor module using > this export, even though it won’t be part of the upstream kernel? Or is there a > preferred approach to enable vendor-specific extensions without modifying > the standard kernel UFS driver? > > Looking forward to your guidance. > > Mit freundlichen Grüßen / Best regards > > Selvakumar Kalimuthu > > responsible for Platform 1 projects (MS/ECF1-XC) Robert Bosch GmbH | > Postfach 10 60 50 | 70049 Stuttgart | GERMANY | www.bosch.com Fax +91 > 422 667-1208 | Selvakumar.Kalimuthu@in.bosch.com > > Registered Office: Stuttgart, Registration Court: Amtsgericht Stuttgart, HRB > 14000; Chairman of the Supervisory Board: Prof. Dr. Stefan > Asenkerschbaumer; Managing Directors: Dr. Stefan Hartung, Dr. Christian > Fischer, Dr. Markus Forschner, Stefan Grosch, Dr. Markus Heyn, Dr. Frank > Meyer, Katja von Raven, Dr. Tanja Rückert > > -----Original Message----- > From: Bart Van Assche <bvanassche@acm.org> > Sent: Thursday, March 27, 2025 5:28 PM > To: Selvakumar Kalimuthu (MS/ECC-CF3-XC) > <selvakumar.kalimuthu@in.bosch.com>; Alim Akhtar > <alim.akhtar@samsung.com>; Avri Altman <avri.altman@wdc.com>; James > E.J. Bottomley <jejb@linux.ibm.com>; Martin K. Petersen > <martin.petersen@oracle.com>; Peter Wang <peter.wang@mediatek.com>; > Manjunatha Madana <quic_c_mamanj@quicinc.com> > Cc: Antony A (MS/ECC-CF-EP2-XC) <Antony.Ambrose@in.bosch.com>; linux- > scsi@vger.kernel.org > Subject: Re: [PATCH v1 1/1] ufs: core: Export interface for sending raw UPIU > commands > > On 3/27/25 7:46 AM, Selvakumar Kalimuthu wrote: > > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c > > index 78b57e946cdf..226cc90c74b0 100644 > > --- a/drivers/ufs/core/ufshcd.c > > +++ b/drivers/ufs/core/ufshcd.c > > @@ -7360,6 +7360,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba > > *hba, > > > > return err; > > } > > +EXPORT_SYMBOL_GPL(ufshcd_exec_raw_upiu_cmd); > > As I already mentioned off-list, please do not export functions without adding > a caller that needs the export. > > Thanks, > > Bart.
Hi Avri, Thank you for your insights. We understand that vendor-specific query commands can be sent using the ufs-bsg module. However, there are a couple of challenges: * Some vendor-specific commands use unique msgcode values that may not be handled efficiently through the existing ufs-bsg framework. * In the Android system, access to ufs-bsg is restricted, and not all processes can communicate with it, making it difficult to use for vendor-specific extensions. Given these constraints, exporting ufshcd_exec_raw_upiu_cmd provides a more flexible solution for vendor modules to execute necessary commands without modifying the mainline kernel. Looking forward to your thoughts. Mit freundlichen Grüßen / Best regards Selvakumar Kalimuthu responsible for Platform 1 projects (MS/ECF1-XC) Robert Bosch GmbH | Postfach 10 60 50 | 70049 Stuttgart | GERMANY | www.bosch.com Fax +91 422 667-1208 | Selvakumar.Kalimuthu@in.bosch.com Registered Office: Stuttgart, Registration Court: Amtsgericht Stuttgart, HRB 14000; Chairman of the Supervisory Board: Prof. Dr. Stefan Asenkerschbaumer; Managing Directors: Dr. Stefan Hartung, Dr. Christian Fischer, Dr. Markus Forschner, Stefan Grosch, Dr. Markus Heyn, Dr. Frank Meyer, Katja von Raven, Dr. Tanja Rückert -----Original Message----- From: Avri Altman <Avri.Altman@sandisk.com> Sent: Friday, March 28, 2025 12:36 PM To: Selvakumar Kalimuthu (MS/ECC-CF3-XC) <selvakumar.kalimuthu@in.bosch.com>; Bart Van Assche <bvanassche@acm.org>; Alim Akhtar <alim.akhtar@samsung.com>; Avri Altman <avri.altman@wdc.com>; James E.J. Bottomley <jejb@linux.ibm.com>; Martin K. Petersen <martin.petersen@oracle.com>; Peter Wang <peter.wang@mediatek.com>; Manjunatha Madana <quic_c_mamanj@quicinc.com> Cc: Antony A (MS/ECC-CF-EP2-XC) <Antony.Ambrose@in.bosch.com>; linux-scsi@vger.kernel.org Subject: RE: [PATCH v1 1/1] ufs: core: Export interface for sending raw UPIU commands > Hi Bart, > > Thanks for your feedback. > > The caller for this exported function resides in an > OEM/vendor-specific module, which is not part of the standard Linux > kernel. The intent of this patch is to provide an interface that > allows vendors to send raw UPIU commands from their external modules > to retrieve device-specific information or execute proprietary commands. The ufs spec defines a wide range of vendor specific query commands: 0x40-0x7F, and 0xC0-0xFF. For those you can use the current caller, e.g. ufs-bsg module? Thanks, Avri > Since vendor modules cannot modify the UFS core driver directly, > exporting ufshcd_exec_raw_upiu_cmd is necessary to enable controlled > access without modifying the mainline kernel further. > > Would you prefer that we also provide an example of a vendor module > using this export, even though it won't be part of the upstream > kernel? Or is there a preferred approach to enable vendor-specific > extensions without modifying the standard kernel UFS driver? > > Looking forward to your guidance. > > Mit freundlichen Grüßen / Best regards > > Selvakumar Kalimuthu > > responsible for Platform 1 projects (MS/ECF1-XC) Robert Bosch GmbH | > Postfach 10 60 50 | 70049 Stuttgart | GERMANY | www.bosch.com Fax +91 > 422 667-1208 | Selvakumar.Kalimuthu@in.bosch.com > > Registered Office: Stuttgart, Registration Court: Amtsgericht > Stuttgart, HRB 14000; Chairman of the Supervisory Board: Prof. Dr. > Stefan Asenkerschbaumer; Managing Directors: Dr. Stefan Hartung, Dr. > Christian Fischer, Dr. Markus Forschner, Stefan Grosch, Dr. Markus > Heyn, Dr. Frank Meyer, Katja von Raven, Dr. Tanja Rückert > > -----Original Message----- > From: Bart Van Assche <bvanassche@acm.org> > Sent: Thursday, March 27, 2025 5:28 PM > To: Selvakumar Kalimuthu (MS/ECC-CF3-XC) > <selvakumar.kalimuthu@in.bosch.com>; Alim Akhtar > <alim.akhtar@samsung.com>; Avri Altman <avri.altman@wdc.com>; James > E.J. Bottomley <jejb@linux.ibm.com>; Martin K. Petersen > <martin.petersen@oracle.com>; Peter Wang <peter.wang@mediatek.com>; > Manjunatha Madana <quic_c_mamanj@quicinc.com> > Cc: Antony A (MS/ECC-CF-EP2-XC) <Antony.Ambrose@in.bosch.com>; linux- > scsi@vger.kernel.org > Subject: Re: [PATCH v1 1/1] ufs: core: Export interface for sending > raw UPIU commands > > On 3/27/25 7:46 AM, Selvakumar Kalimuthu wrote: > > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c > > index 78b57e946cdf..226cc90c74b0 100644 > > --- a/drivers/ufs/core/ufshcd.c > > +++ b/drivers/ufs/core/ufshcd.c > > @@ -7360,6 +7360,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba > > *hba, > > > > return err; > > } > > +EXPORT_SYMBOL_GPL(ufshcd_exec_raw_upiu_cmd); > > As I already mentioned off-list, please do not export functions > without adding a caller that needs the export. > > Thanks, > > Bart.
> Hi Avri, > > Thank you for your insights. > > We understand that vendor-specific query commands can be sent using the > ufs-bsg module. However, there are a couple of challenges: > > * Some vendor-specific commands use unique msgcode values that may not > be handled efficiently through the existing ufs-bsg framework. ufshcd_exec_raw_upiu_cmd only supports a subset of the message codes supported by ufs-bsg. > * In the Android system, access to ufs-bsg is restricted, and not all processes > can communicate with it, making it difficult to use for vendor-specific > extensions. by 'restricted' you mean privileged? I don't think that allowing non-privileged access is a good idea. Thanks, Avri > > Given these constraints, exporting ufshcd_exec_raw_upiu_cmd provides a > more flexible solution for vendor modules to execute necessary commands > without modifying the mainline kernel. > > Looking forward to your thoughts. > > Mit freundlichen Grüßen / Best regards > > Selvakumar Kalimuthu > > responsible for Platform 1 projects (MS/ECF1-XC) Robert Bosch GmbH | > Postfach 10 60 50 | 70049 Stuttgart | GERMANY | www.bosch.com Fax +91 > 422 667-1208 | Selvakumar.Kalimuthu@in.bosch.com > > Registered Office: Stuttgart, Registration Court: Amtsgericht Stuttgart, HRB > 14000; Chairman of the Supervisory Board: Prof. Dr. Stefan > Asenkerschbaumer; Managing Directors: Dr. Stefan Hartung, Dr. Christian > Fischer, Dr. Markus Forschner, Stefan Grosch, Dr. Markus Heyn, Dr. Frank > Meyer, Katja von Raven, Dr. Tanja Rückert > > -----Original Message----- > From: Avri Altman <Avri.Altman@sandisk.com> > Sent: Friday, March 28, 2025 12:36 PM > To: Selvakumar Kalimuthu (MS/ECC-CF3-XC) > <selvakumar.kalimuthu@in.bosch.com>; Bart Van Assche > <bvanassche@acm.org>; Alim Akhtar <alim.akhtar@samsung.com>; Avri > Altman <avri.altman@wdc.com>; James E.J. Bottomley > <jejb@linux.ibm.com>; Martin K. Petersen <martin.petersen@oracle.com>; > Peter Wang <peter.wang@mediatek.com>; Manjunatha Madana > <quic_c_mamanj@quicinc.com> > Cc: Antony A (MS/ECC-CF-EP2-XC) <Antony.Ambrose@in.bosch.com>; linux- > scsi@vger.kernel.org > Subject: RE: [PATCH v1 1/1] ufs: core: Export interface for sending raw UPIU > commands > > > Hi Bart, > > > > Thanks for your feedback. > > > > The caller for this exported function resides in an > > OEM/vendor-specific module, which is not part of the standard Linux > > kernel. The intent of this patch is to provide an interface that > > allows vendors to send raw UPIU commands from their external modules > > to retrieve device-specific information or execute proprietary commands. > The ufs spec defines a wide range of vendor specific query commands: 0x40- > 0x7F, and 0xC0-0xFF. > For those you can use the current caller, e.g. ufs-bsg module? > > Thanks, > Avri > > > Since vendor modules cannot modify the UFS core driver directly, > > exporting ufshcd_exec_raw_upiu_cmd is necessary to enable controlled > > access without modifying the mainline kernel further. > > > > Would you prefer that we also provide an example of a vendor module > > using this export, even though it won't be part of the upstream > > kernel? Or is there a preferred approach to enable vendor-specific > > extensions without modifying the standard kernel UFS driver? > > > > Looking forward to your guidance. > > > > Mit freundlichen Grüßen / Best regards > > > > Selvakumar Kalimuthu > > > > responsible for Platform 1 projects (MS/ECF1-XC) Robert Bosch GmbH | > > Postfach 10 60 50 | 70049 Stuttgart | GERMANY | www.bosch.com Fax +91 > > 422 667-1208 | Selvakumar.Kalimuthu@in.bosch.com > > > > Registered Office: Stuttgart, Registration Court: Amtsgericht > > Stuttgart, HRB 14000; Chairman of the Supervisory Board: Prof. Dr. > > Stefan Asenkerschbaumer; Managing Directors: Dr. Stefan Hartung, Dr. > > Christian Fischer, Dr. Markus Forschner, Stefan Grosch, Dr. Markus > > Heyn, Dr. Frank Meyer, Katja von Raven, Dr. Tanja Rückert > > > > -----Original Message----- > > From: Bart Van Assche <bvanassche@acm.org> > > Sent: Thursday, March 27, 2025 5:28 PM > > To: Selvakumar Kalimuthu (MS/ECC-CF3-XC) > > <selvakumar.kalimuthu@in.bosch.com>; Alim Akhtar > > <alim.akhtar@samsung.com>; Avri Altman <avri.altman@wdc.com>; James > > E.J. Bottomley <jejb@linux.ibm.com>; Martin K. Petersen > > <martin.petersen@oracle.com>; Peter Wang <peter.wang@mediatek.com>; > > Manjunatha Madana <quic_c_mamanj@quicinc.com> > > Cc: Antony A (MS/ECC-CF-EP2-XC) <Antony.Ambrose@in.bosch.com>; > linux- > > scsi@vger.kernel.org > > Subject: Re: [PATCH v1 1/1] ufs: core: Export interface for sending > > raw UPIU commands > > > > On 3/27/25 7:46 AM, Selvakumar Kalimuthu wrote: > > > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c > > > index 78b57e946cdf..226cc90c74b0 100644 > > > --- a/drivers/ufs/core/ufshcd.c > > > +++ b/drivers/ufs/core/ufshcd.c > > > @@ -7360,6 +7360,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba > > > *hba, > > > > > > return err; > > > } > > > +EXPORT_SYMBOL_GPL(ufshcd_exec_raw_upiu_cmd); > > > > As I already mentioned off-list, please do not export functions > > without adding a caller that needs the export. > > > > Thanks, > > > > Bart.
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 78b57e946cdf..226cc90c74b0 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -7360,6 +7360,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba, return err; } +EXPORT_SYMBOL_GPL(ufshcd_exec_raw_upiu_cmd); /** * ufshcd_advanced_rpmb_req_handler - handle advanced RPMB request
Expose an interface for external vendor modules to send raw UPIU commands to the UFS device. This allows vendors can create own module to issue custom commands and retrieve device-specific information. Exporting this symbol enables OEMs to develop vendor modules that can send raw UPIU commands from their processes, facilitating access to necessary device information. Signed-off-by: Selvakumar Kalimuthu <selvakumar.kalimuthu@in.bosch.com> --- drivers/ufs/core/ufshcd.c | 1 + 1 file changed, 1 insertion(+)