From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> To: Bjorn Helgaas <helgaas@kernel.org> Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ashok.raj@intel.com, keith.busch@intel.com Subject: Re: [PATCH v5 1/7] PCI/ATS: Fix pci_prg_resp_pasid_required() dependency issues Date: Fri, 16 Aug 2019 11:06:38 -0700 Message-ID: <20190816180638.GA28404@skuppusw-desk.amr.corp.intel.com> (raw) In-Reply-To: <20190813035148.GI7302@google.com> On Mon, Aug 12, 2019 at 10:51:48PM -0500, Bjorn Helgaas wrote: > On Mon, Aug 12, 2019 at 01:20:55PM -0700, sathyanarayanan kuppuswamy wrote: > > On 8/12/19 1:04 PM, Bjorn Helgaas wrote: > > > On Thu, Aug 01, 2019 at 05:05:58PM -0700, sathyanarayanan.kuppuswamy@linux.intel.com wrote: > > > > From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> > > > > > > > > Since pci_prg_resp_pasid_required() function has dependency on both > > > > PASID and PRI, define it only if both CONFIG_PCI_PRI and > > > > CONFIG_PCI_PASID config options are enabled. > > > > I don't really like this. It makes the #ifdefs more complicated and I > > > don't think it really buys us anything. Will anything break if we > > > just drop this patch? > > > Yes, this function uses "pri_lock" mutex which is only defined if > > CONFIG_PCI_PRI is enabled. So not protecting this function within > > CONFIG_PCI_PRI will lead to compilation issues. > > Ah, OK. That helps a lot. "pri_lock" doesn't exist at this point in > the series, so the patch makes no sense without knowing that. > > I'm still not convinced this is the right thing because I'm not sure > the lock is necessary. I'll respond to the patch that adds the lock. Its not only pri_lock. This function also uses "pri_cap" which is also only defined for CONFIG_PCI_PRI. "pri_cap" is added by next patch in the series which adds caching support for PRI capability check. So this patch is still required even if we remove use of pri_lock in this function. > > > > > Fixes: e5567f5f6762 ("PCI/ATS: Add pci_prg_resp_pasid_required() > > > > interface.") > > > > Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> > > > > --- > > > > drivers/pci/ats.c | 10 ++++++---- > > > > include/linux/pci-ats.h | 12 +++++++++--- > > > > 2 files changed, 15 insertions(+), 7 deletions(-) > > > > > > > > diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c > > > > index e18499243f84..cdd936d10f68 100644 > > > > --- a/drivers/pci/ats.c > > > > +++ b/drivers/pci/ats.c > > > > @@ -395,6 +395,8 @@ int pci_pasid_features(struct pci_dev *pdev) > > > > } > > > > EXPORT_SYMBOL_GPL(pci_pasid_features); > > > > +#ifdef CONFIG_PCI_PRI > > > > + > > > > /** > > > > * pci_prg_resp_pasid_required - Return PRG Response PASID Required bit > > > > * status. > > > > @@ -402,10 +404,8 @@ EXPORT_SYMBOL_GPL(pci_pasid_features); > > > > * > > > > * Returns 1 if PASID is required in PRG Response Message, 0 otherwise. > > > > * > > > > - * Even though the PRG response PASID status is read from PRI Status > > > > - * Register, since this API will mainly be used by PASID users, this > > > > - * function is defined within #ifdef CONFIG_PCI_PASID instead of > > > > - * CONFIG_PCI_PRI. > > > > + * Since this API has dependency on both PRI and PASID, protect it > > > > + * with both CONFIG_PCI_PRI and CONFIG_PCI_PASID. > > > > */ > > > > int pci_prg_resp_pasid_required(struct pci_dev *pdev) > > > > { > > > > @@ -425,6 +425,8 @@ int pci_prg_resp_pasid_required(struct pci_dev *pdev) > > > > } > > > > EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required); > > > > +#endif > > > > + > > > > #define PASID_NUMBER_SHIFT 8 > > > > #define PASID_NUMBER_MASK (0x1f << PASID_NUMBER_SHIFT) > > > > /** > > > > diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h > > > > index 1ebb88e7c184..1a0bdaee2f32 100644 > > > > --- a/include/linux/pci-ats.h > > > > +++ b/include/linux/pci-ats.h > > > > @@ -40,7 +40,6 @@ void pci_disable_pasid(struct pci_dev *pdev); > > > > void pci_restore_pasid_state(struct pci_dev *pdev); > > > > int pci_pasid_features(struct pci_dev *pdev); > > > > int pci_max_pasids(struct pci_dev *pdev); > > > > -int pci_prg_resp_pasid_required(struct pci_dev *pdev); > > > > #else /* CONFIG_PCI_PASID */ > > > > @@ -67,11 +66,18 @@ static inline int pci_max_pasids(struct pci_dev *pdev) > > > > return -EINVAL; > > > > } > > > > +#endif /* CONFIG_PCI_PASID */ > > > > + > > > > +#if defined(CONFIG_PCI_PRI) && defined(CONFIG_PCI_PASID) > > > > + > > > > +int pci_prg_resp_pasid_required(struct pci_dev *pdev); > > > > + > > > > +#else /* CONFIG_PCI_PASID && CONFIG_PCI_PRI */ > > > > + > > > > static inline int pci_prg_resp_pasid_required(struct pci_dev *pdev) > > > > { > > > > return 0; > > > > } > > > > -#endif /* CONFIG_PCI_PASID */ > > > > - > > > > +#endif > > > > #endif /* LINUX_PCI_ATS_H*/ > > > > -- > > > > 2.21.0 > > > > > > -- > > Sathyanarayanan Kuppuswamy > > Linux kernel developer > > -- -- Sathyanarayanan Kuppuswamy Linux kernel developer
next prev parent reply index Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-08-02 0:05 [PATCH v5 0/7] Fix PF/VF dependency issue sathyanarayanan.kuppuswamy 2019-08-02 0:05 ` [PATCH v5 1/7] PCI/ATS: Fix pci_prg_resp_pasid_required() dependency issues sathyanarayanan.kuppuswamy 2019-08-12 20:04 ` Bjorn Helgaas 2019-08-12 20:20 ` sathyanarayanan kuppuswamy 2019-08-13 3:51 ` Bjorn Helgaas 2019-08-16 18:06 ` Kuppuswamy Sathyanarayanan [this message] 2019-08-02 0:05 ` [PATCH v5 2/7] PCI/ATS: Initialize PRI in pci_ats_init() sathyanarayanan.kuppuswamy 2019-08-12 20:04 ` Bjorn Helgaas 2019-08-12 21:35 ` sathyanarayanan kuppuswamy 2019-08-13 4:10 ` Bjorn Helgaas 2019-08-15 4:46 ` Bjorn Helgaas 2019-08-15 17:30 ` Kuppuswamy Sathyanarayanan 2019-08-16 17:31 ` Bjorn Helgaas 2019-08-02 0:06 ` [PATCH v5 3/7] PCI/ATS: Initialize PASID " sathyanarayanan.kuppuswamy 2019-08-12 20:04 ` Bjorn Helgaas 2019-08-15 4:48 ` Bjorn Helgaas 2019-08-15 4:56 ` Bjorn Helgaas 2019-08-15 17:31 ` Kuppuswamy Sathyanarayanan 2019-08-02 0:06 ` [PATCH v5 4/7] PCI/ATS: Add PRI support for PCIe VF devices sathyanarayanan.kuppuswamy 2019-08-12 20:04 ` Bjorn Helgaas 2019-08-12 21:40 ` sathyanarayanan kuppuswamy 2019-08-13 4:16 ` Bjorn Helgaas 2019-08-15 22:20 ` Bjorn Helgaas 2019-08-15 22:39 ` Kuppuswamy Sathyanarayanan 2019-08-19 14:15 ` Bjorn Helgaas 2019-08-19 22:53 ` Kuppuswamy Sathyanarayanan 2019-08-19 23:19 ` Bjorn Helgaas 2019-08-28 18:21 ` Kuppuswamy Sathyanarayanan 2019-08-28 18:57 ` Bjorn Helgaas 2019-08-02 0:06 ` [PATCH v5 5/7] PCI/ATS: Add PASID " sathyanarayanan.kuppuswamy 2019-08-12 20:05 ` Bjorn Helgaas 2019-08-13 22:19 ` Kuppuswamy Sathyanarayanan 2019-08-15 5:04 ` Bjorn Helgaas 2019-08-16 1:21 ` Kuppuswamy Sathyanarayanan 2019-08-02 0:06 ` [PATCH v5 6/7] PCI/ATS: Disable PF/VF ATS service independently sathyanarayanan.kuppuswamy 2019-08-02 0:06 ` [PATCH v5 7/7] PCI: Skip Enhanced Allocation (EA) initialization for VF device sathyanarayanan.kuppuswamy
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20190816180638.GA28404@skuppusw-desk.amr.corp.intel.com \ --to=sathyanarayanan.kuppuswamy@linux.intel.com \ --cc=ashok.raj@intel.com \ --cc=helgaas@kernel.org \ --cc=keith.busch@intel.com \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-pci@vger.kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Linux-PCI Archive on lore.kernel.org Archives are clonable: git clone --mirror https://lore.kernel.org/linux-pci/0 linux-pci/git/0.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 linux-pci linux-pci/ https://lore.kernel.org/linux-pci \ linux-pci@vger.kernel.org public-inbox-index linux-pci Example config snippet for mirrors Newsgroup available over NNTP: nntp://nntp.lore.kernel.org/org.kernel.vger.linux-pci AGPL code for this site: git clone https://public-inbox.org/public-inbox.git