[AMD Official Use Only - AMD Internal Distribution Only] Hi, Bjorn and pci driver maintainers Could you review the VF resizable BAR patch? Thanks, HaiJun -----Original Message----- From: Lianjie Shi <Lianjie.Shi@xxxxxxx> Sent: Thursday, May 23, 2024 3:11 PM To: linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Chang, HaiJun <HaiJun.Chang@xxxxxxx>; Jiang, Jerry (SW) <Jerry.Jiang@xxxxxxx>; Zhang, Andy <Andy.Zhang@xxxxxxx>; Shi, Lianjie <Lianjie.Shi@xxxxxxx> Subject: [PATCH 1/1][v2] PCI: Support VF resizable BAR Add support for VF resizable BAR PCI extended cap. Similar to regular BAR, drivers can use pci_resize_resource() to resize an IOV BAR. For each VF, dev->sriov->barsz of the IOV BAR is resized, but the total resource size of the IOV resource should not exceed its original size upon init. Based on following patch series: Link: https://lore.kernel.org/lkml/YbqGplTKl5i%2F1%2FkY@rocinante/T/ Signed-off-by: Lianjie Shi <Lianjie.Shi@xxxxxxx> --- drivers/pci/pci.c | 47 ++++++++++++++++++++++++++++++++++- drivers/pci/setup-res.c | 45 +++++++++++++++++++++++++++------ include/uapi/linux/pci_regs.h | 1 + 3 files changed, 85 insertions(+), 8 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e5f243dd4..12f86e00a 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1867,6 +1867,42 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) } } +static void pci_restore_vf_rebar_state(struct pci_dev *pdev) { #ifdef +CONFIG_PCI_IOV + unsigned int pos, nbars, i; + u32 ctrl; + u16 total; + + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_VF_REBAR); + if (!pos) + return; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + nbars = FIELD_GET(PCI_REBAR_CTRL_NBAR_MASK, ctrl); + + for (i = 0; i < nbars; i++, pos += 8) { + struct resource *res; + int bar_idx, size; + u64 tmp; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; + total = pdev->sriov->total_VFs; + if (!total) + return; + + res = pdev->resource + bar_idx + PCI_IOV_RESOURCES; + tmp = resource_size(res); + do_div(tmp, total); + size = pci_rebar_bytes_to_size(tmp); + ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; + ctrl |= FIELD_PREP(PCI_REBAR_CTRL_BAR_SIZE, size); + pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); + } +#endif +} + /** * pci_restore_state - Restore the saved state of a PCI device * @dev: PCI device that we're dealing with @@ -1882,6 +1918,7 @@ void pci_restore_state(struct pci_dev *dev) pci_restore_ats_state(dev); pci_restore_vc_state(dev); pci_restore_rebar_state(dev); + pci_restore_vf_rebar_state(dev); pci_restore_dpc_state(dev); pci_restore_ptm_state(dev); @@ -3677,10 +3714,18 @@ 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 c6d933ddf..d978a2ccf 100644 --- a/drivers/pci/setup-res.c +++ b/drivers/pci/setup-res.c @@ -427,13 +427,32 @@ void pci_release_resource(struct pci_dev *dev, int resno) } EXPORT_SYMBOL(pci_release_resource); +static int pci_memory_decoding(struct pci_dev *dev, int resno) { + u16 cmd; + +#ifdef CONFIG_PCI_IOV + if (resno >= PCI_IOV_RESOURCES) { + pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_CTRL, &cmd); + if (cmd & PCI_SRIOV_CTRL_MSE) + return -EBUSY; + else + return 0; + } +#endif + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (cmd & PCI_COMMAND_MEMORY) + return -EBUSY; + + return 0; +} + 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); @@ -444,9 +463,9 @@ 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; + ret = pci_memory_decoding(dev, resno); + if (ret) + return ret; sizes = pci_rebar_get_possible_sizes(dev, resno); if (!sizes) @@ -463,19 +482,31 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size) if (ret) return ret; - 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); + else +#endif + res->end = res->start + pci_rebar_size_to_bytes(size) - 1; /* 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); - if (ret) + if (ret && ret != -ENOENT) goto error_resize; } return 0; 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); + else +#endif + res->end = res->start + pci_rebar_size_to_bytes(old) - 1; + return ret; } EXPORT_SYMBOL(pci_resize_resource); diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index a39193213..a66b90982 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -738,6 +738,7 @@ #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_PL_32GT 0x2A /* Physical Layer 32.0 GT/s */ -- 2.34.1
