diff mbox series

[1/1] PCI: Support VF resizable BAR

Message ID 20240516093334.2266599-2-Lianjie.Shi@amd.com
State New
Headers show
Series PCI: VF resizable BAR | expand

Commit Message

Lianjie Shi May 16, 2024, 9:33 a.m. UTC
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@amd.com>
---
 drivers/pci/pci.c             | 44 +++++++++++++++++++++++++++++++++-
 drivers/pci/setup-res.c       | 45 +++++++++++++++++++++++++++++------
 include/uapi/linux/pci_regs.h |  1 +
 3 files changed, 82 insertions(+), 8 deletions(-)

Comments

kernel test robot May 18, 2024, 2:06 a.m. UTC | #1
Hi Lianjie,

kernel test robot noticed the following build errors:

[auto build test ERROR on cf87f46fd34d6c19283d9625a7822f20d90b64a4]

url:    https://github.com/intel-lab-lkp/linux/commits/Lianjie-Shi/PCI-Support-VF-resizable-BAR/20240516-173624
base:   cf87f46fd34d6c19283d9625a7822f20d90b64a4
patch link:    https://lore.kernel.org/r/20240516093334.2266599-2-Lianjie.Shi%40amd.com
patch subject: [PATCH 1/1] PCI: Support VF resizable BAR
config: i386-randconfig-014-20240518 (https://download.01.org/0day-ci/archive/20240518/202405180954.pffoQtM9-lkp@intel.com/config)
compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240518/202405180954.pffoQtM9-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202405180954.pffoQtM9-lkp@intel.com/

All errors (new ones prefixed by >>):

   ld: drivers/pci/pci.o: in function `pci_restore_vf_rebar_state':
>> drivers/pci/pci.c:1895:(.text+0x3bff): undefined reference to `__udivdi3'


vim +1895 drivers/pci/pci.c

  1869	
  1870	static void pci_restore_vf_rebar_state(struct pci_dev *pdev)
  1871	{
  1872	#ifdef CONFIG_PCI_IOV
  1873		unsigned int pos, nbars, i;
  1874		u32 ctrl;
  1875		u16 total;
  1876	
  1877		pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_VF_REBAR);
  1878		if (!pos)
  1879			return;
  1880	
  1881		pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
  1882		nbars = FIELD_GET(PCI_REBAR_CTRL_NBAR_MASK, ctrl);
  1883	
  1884		for (i = 0; i < nbars; i++, pos += 8) {
  1885			struct resource *res;
  1886			int bar_idx, size;
  1887	
  1888			pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
  1889			bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
  1890			total = pdev->sriov->total_VFs;
  1891			if (!total)
  1892				return;
  1893	
  1894			res = pdev->resource + bar_idx + PCI_IOV_RESOURCES;
> 1895			size = pci_rebar_bytes_to_size(resource_size(res) / total);
  1896			ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
  1897			ctrl |= FIELD_PREP(PCI_REBAR_CTRL_BAR_SIZE, size);
  1898			pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
  1899		}
  1900	#endif
  1901	}
  1902
diff mbox series

Patch

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e5f243dd4..bb9a2f322 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1867,6 +1867,39 @@  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;
+
+		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;
+		size = pci_rebar_bytes_to_size(resource_size(res) / total);
+		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 +1915,7 @@  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 +3711,18 @@  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 */