diff mbox

[v5,10/12] PCI: endpoint: Make sure that BAR_5 does not have 64-bit flag set when clearing

Message ID 20180328115018.31921-11-niklas.cassel@axis.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Niklas Cassel March 28, 2018, 11:50 a.m. UTC
Since a 64-bit BAR consists of a BAR pair, and since there is no
BAR after BAR_5, BAR_5 cannot be 64-bits wide.

This sanity check is done in pci_epc_clear_bar(), so that we don't need
to do this sanity check in all epc->ops->clear_bar() implementations.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
Kishon made a review comment that he wanted this:
https://marc.info/?l=linux-kernel&m=152161168226203

Personally, I don't think that this check is needed,
since pci_epc_set_bar() already does this check,
and no one should modify the flags after pci_epc_set_bar()
has been called.

If everyone agrees, then this patch could be dropped.

 drivers/pci/endpoint/pci-epc-core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Kishon Vijay Abraham I March 29, 2018, 10:02 a.m. UTC | #1
On Wednesday 28 March 2018 05:20 PM, Niklas Cassel wrote:
> Since a 64-bit BAR consists of a BAR pair, and since there is no
> BAR after BAR_5, BAR_5 cannot be 64-bits wide.
> 
> This sanity check is done in pci_epc_clear_bar(), so that we don't need
> to do this sanity check in all epc->ops->clear_bar() implementations.
> 
> Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>

Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
> Kishon made a review comment that he wanted this:
> https://marc.info/?l=linux-kernel&m=152161168226203
> 
> Personally, I don't think that this check is needed,
> since pci_epc_set_bar() already does this check,
> and no one should modify the flags after pci_epc_set_bar()
> has been called.
> 
> If everyone agrees, then this patch could be dropped.
> 
>  drivers/pci/endpoint/pci-epc-core.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index eccc942043cb..b0ee42739c3c 100644
> --- a/drivers/pci/endpoint/pci-epc-core.c
> +++ b/drivers/pci/endpoint/pci-epc-core.c
> @@ -285,7 +285,9 @@ void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no,
>  {
>  	unsigned long flags;
>  
> -	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
> +	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
> +	    (epf_bar->barno == BAR_5 &&
> +	     epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64))
>  		return;
>  
>  	if (!epc->ops->clear_bar)
>
diff mbox

Patch

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index eccc942043cb..b0ee42739c3c 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -285,7 +285,9 @@  void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no,
 {
 	unsigned long flags;
 
-	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
+	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
+	    (epf_bar->barno == BAR_5 &&
+	     epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64))
 		return;
 
 	if (!epc->ops->clear_bar)