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

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

[Philippe Bergheaud]

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>
---
 drivers/misc/cxl/pci.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 83f1d08058fc..3beff9188446 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1742,6 +1742,9 @@ 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 ((rc = pnv_pci_set_tunnel_bar(dev, 0x00020000E0000000ull, 1)))
+		goto err;
+
 	if ((rc = pnv_phb_to_cxl_mode(dev, adapter->native->sl_ops->capi_mode)))
 		goto err;
 
@@ -1768,6 +1771,7 @@ static void cxl_deconfigure_adapter(struct cxl *adapter)
 {
 	struct pci_dev *pdev = to_pci_dev(adapter->dev.parent);
 
+	pnv_pci_set_tunnel_bar(pdev, 0x00020000E0000000ull, 0);
 	cxl_native_release_psl_err_irq(adapter);
 	cxl_unmap_adapter_regs(adapter);
 
-- 
2.16.2

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

[Frederic Barrat]

Le 12/04/2018 à 13:06, 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>
> ---
>   drivers/misc/cxl/pci.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
> index 83f1d08058fc..3beff9188446 100644
> --- a/drivers/misc/cxl/pci.c
> +++ b/drivers/misc/cxl/pci.c
> @@ -1742,6 +1742,9 @@ 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 ((rc = pnv_pci_set_tunnel_bar(dev, 0x00020000E0000000ull, 1)))
> +		goto err;
> +


Isn't that call going to fail on older skiboot which don't support 
OPAL_PCI_SET_PBCQ_TUNNEL_BAR, i.e. on p8?

   Fred


>   	if ((rc = pnv_phb_to_cxl_mode(dev, adapter->native->sl_ops->capi_mode)))
>   		goto err;
>   
> @@ -1768,6 +1771,7 @@ static void cxl_deconfigure_adapter(struct cxl *adapter)
>   {
>   	struct pci_dev *pdev = to_pci_dev(adapter->dev.parent);
>   
> +	pnv_pci_set_tunnel_bar(pdev, 0x00020000E0000000ull, 0);
>   	cxl_native_release_psl_err_irq(adapter);
>   	cxl_unmap_adapter_regs(adapter);
>   
>