Messages in this thread Patch in this message | | | Subject | Re: [PATCH 1/2] PCI: Add support for VF Resizable Bar extended cap | From | Christian König <> | Date | Thu, 16 Dec 2021 08:50:35 +0100 |
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Am 15.12.21 um 15:16 schrieb Michał Winiarski: > Similar to regular resizable BAR, VF BAR can also be resized. > The structures are very similar, which means we can reuse most of the > implementation. See PCIe r4.0, sec 9.3.7.4. > > Signed-off-by: Michał Winiarski <michal.winiarski@intel.com> > --- > drivers/pci/pci.c | 25 +++++++++++++++-- > drivers/pci/setup-res.c | 53 ++++++++++++++++++++++++++++++++--- > include/uapi/linux/pci_regs.h | 1 + > 3 files changed, 72 insertions(+), 7 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 3d2fb394986a4..89448c5104e46 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -1682,12 +1682,15 @@ static void pci_restore_config_space(struct pci_dev *pdev) > } > } > > -static void pci_restore_rebar_state(struct pci_dev *pdev) > +static void __pci_restore_rebar_state(struct pci_dev *pdev, int cap) > { > unsigned int pos, nbars, i; > u32 ctrl; > > - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR); > + if (WARN_ON(cap != PCI_EXT_CAP_ID_REBAR && cap != PCI_EXT_CAP_ID_VF_REBAR)) > + return; > + > + pos = pci_find_ext_capability(pdev, cap); > if (!pos) > return; > > @@ -1709,6 +1712,14 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) > } > } > > +static void pci_restore_rebar_state(struct pci_dev *pdev) > +{ > + __pci_restore_rebar_state(pdev, PCI_EXT_CAP_ID_REBAR); > +#ifdef CONFIG_PCI_IOV > + __pci_restore_rebar_state(pdev, PCI_EXT_CAP_ID_VF_REBAR); > +#endif > +} > +
It's probably cleaner to let the caller specify the capability to restore directly.
> /** > * pci_restore_state - Restore the saved state of a PCI device > * @dev: PCI device that we're dealing with > @@ -3639,10 +3650,18 @@ void pci_acs_init(struct pci_dev *dev) > */ > static int pci_rebar_find_pos(struct pci_dev *pdev, int bar) > { > + int cap = PCI_EXT_CAP_ID_REBAR; > unsigned int pos, nbars, i; > u32 ctrl; > > - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR); > +#ifdef CONFIG_PCI_IOV > + if (bar >= PCI_IOV_RESOURCES) { > + cap = PCI_EXT_CAP_ID_VF_REBAR; > + bar -= PCI_IOV_RESOURCES; > + } > +#endif > + > + pos = pci_find_ext_capability(pdev, cap); > if (!pos) > return -ENOTSUPP; > > diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c > index 7f1acb3918d0c..1946e52e7678a 100644 > --- a/drivers/pci/setup-res.c > +++ b/drivers/pci/setup-res.c > @@ -407,13 +407,36 @@ void pci_release_resource(struct pci_dev *dev, int resno) > } > EXPORT_SYMBOL(pci_release_resource); > > +static int pci_memory_decoding(struct pci_dev *dev) > +{ > + u16 cmd; > + > + pci_read_config_word(dev, PCI_COMMAND, &cmd); > + if (cmd & PCI_COMMAND_MEMORY) > + return -EBUSY; > + > + return 0; > +} > + > +#ifdef CONFIG_PCI_IOV > +static int pci_vf_memory_decoding(struct pci_dev *dev) > +{ > + u16 cmd; > + > + pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_CTRL, &cmd); > + if (cmd & PCI_SRIOV_CTRL_MSE) > + return -EBUSY; > + > + return 0; > +} > +#endif > + > int pci_resize_resource(struct pci_dev *dev, int resno, int size) > { > struct resource *res = dev->resource + resno; > struct pci_host_bridge *host; > int old, ret; > u32 sizes; > - u16 cmd; > > /* Check if we must preserve the firmware's resource assignment */ > host = pci_find_host_bridge(dev->bus); > @@ -424,9 +447,14 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size) > if (!(res->flags & IORESOURCE_UNSET)) > return -EBUSY; > > - pci_read_config_word(dev, PCI_COMMAND, &cmd); > - if (cmd & PCI_COMMAND_MEMORY) > - return -EBUSY; > +#ifdef CONFIG_PCI_IOV > + if (resno >= PCI_IOV_RESOURCES) > + ret = pci_vf_memory_decoding(dev); > + else > +#endif > + ret = pci_memory_decoding(dev); > + if (ret) > + return ret;
Way to many #ifdef spread around inside the code, please restructure that.
For example concentrating the logic in a single function should help:
static int pci_check_decoding_disabled(..., inr resno) {
#ifdef CONFIG_PCI_IOV if (resno... return -EBUSY; else return 0; #endif
if (...) return -EBUSY; return 0;
}
> > sizes = pci_rebar_get_possible_sizes(dev, resno); > if (!sizes) > @@ -445,6 +473,14 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size) > > res->end = res->start + pci_rebar_size_to_bytes(size) - 1; > > +#ifdef CONFIG_PCI_IOV > + if (resno >= PCI_IOV_RESOURCES) { > + dev->sriov->barsz[resno - PCI_IOV_RESOURCES] = pci_rebar_size_to_bytes(size); > + res->end = res->start + > + resource_size(res) * pci_sriov_get_totalvfs(dev) - 1; > + } > +#endif > + > /* Check if the new config works by trying to assign everything. */ > if (dev->bus->self) { > ret = pci_reassign_bridge_resources(dev->bus->self, res->flags); > @@ -456,6 +492,15 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size) > error_resize: > pci_rebar_set_size(dev, resno, old); > res->end = res->start + pci_rebar_size_to_bytes(old) - 1; > + > +#ifdef CONFIG_PCI_IOV > + if (resno >= PCI_IOV_RESOURCES) { > + dev->sriov->barsz[resno - PCI_IOV_RESOURCES] = pci_rebar_size_to_bytes(old); > + res->end = res->start + > + pci_rebar_size_to_bytes(old) * pci_sriov_get_totalvfs(dev) - 1; > + } > +#endif > +
Looks like this deserves it's own function.
Regards, Christian.
> return ret; > } > EXPORT_SYMBOL(pci_resize_resource); > diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h > index ff6ccbc6efe96..7f5726d23b038 100644 > --- a/include/uapi/linux/pci_regs.h > +++ b/include/uapi/linux/pci_regs.h > @@ -734,6 +734,7 @@ > #define PCI_EXT_CAP_ID_L1SS 0x1E /* L1 PM Substates */ > #define PCI_EXT_CAP_ID_PTM 0x1F /* Precision Time Measurement */ > #define PCI_EXT_CAP_ID_DVSEC 0x23 /* Designated Vendor-Specific */ > +#define PCI_EXT_CAP_ID_VF_REBAR 0x24 /* VF Resizable BAR */ > #define PCI_EXT_CAP_ID_DLF 0x25 /* Data Link Feature */ > #define PCI_EXT_CAP_ID_PL_16GT 0x26 /* Physical Layer 16.0 GT/s */ > #define PCI_EXT_CAP_ID_MAX PCI_EXT_CAP_ID_PL_16GT
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