[v2] cxl: Set the PBCQ Tunnel BAR register when enabling capi mode

Message ID 20180413115939.25269-1-felix@linux.ibm.com
State Superseded
Headers show
Series
  • [v2] cxl: Set the PBCQ Tunnel BAR register when enabling capi mode
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Commit Message

Philippe Bergheaud April 13, 2018, 11:59 a.m.
Skiboot used to set the default Tunnel BAR register value when capi mode
was enabled. This approach was ok for the cxl driver, but prevented other
drivers from choosing different values.

Skiboot versions > 5.11 will not set the default value any longer. This
patch modifies the cxl driver to set/reset the Tunnel BAR register when
entering/exiting the cxl mode, with pnv_pci_set_tunnel_bar().

Signed-off-by: Philippe Bergheaud <felix@linux.ibm.com>
---
Changelog:

v2: Restrict tunnel bar setting to power9.
    Do not fail cxl_configure_adapter() on tunnel bar setting error.
    Log an info message instead, and continue configuring capi mode.
---
 drivers/misc/cxl/pci.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

christophe lombard April 16, 2018, 12:02 p.m. | #1
Le 13/04/2018 à 13:59, Philippe Bergheaud a écrit :
> Skiboot used to set the default Tunnel BAR register value when capi mode
> was enabled. This approach was ok for the cxl driver, but prevented other
> drivers from choosing different values.
> 
> Skiboot versions > 5.11 will not set the default value any longer. This
> patch modifies the cxl driver to set/reset the Tunnel BAR register when
> entering/exiting the cxl mode, with pnv_pci_set_tunnel_bar().
> 
> Signed-off-by: Philippe Bergheaud <felix@linux.ibm.com>
> ---

Thanks

Reviewed-by: Christophe Lombard <clombard@linux.vnet.ibm.com>

Patch

diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 83f1d08058fc..355c789406f7 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1742,6 +1742,10 @@  static int cxl_configure_adapter(struct cxl *adapter, struct pci_dev *dev)
 	/* Required for devices using CAPP DMA mode, harmless for others */
 	pci_set_master(dev);
 
+	if (cxl_is_power9())
+		if (pnv_pci_set_tunnel_bar(dev, 0x00020000E0000000ull, 1))
+			dev_info(&dev->dev, "Tunneled operations unsupported\n");
+
 	if ((rc = pnv_phb_to_cxl_mode(dev, adapter->native->sl_ops->capi_mode)))
 		goto err;
 
@@ -1768,6 +1772,8 @@  static void cxl_deconfigure_adapter(struct cxl *adapter)
 {
 	struct pci_dev *pdev = to_pci_dev(adapter->dev.parent);
 
+	if (cxl_is_power9())
+		pnv_pci_set_tunnel_bar(pdev, 0x00020000E0000000ull, 0);
 	cxl_native_release_psl_err_irq(adapter);
 	cxl_unmap_adapter_regs(adapter);