Currently, the test allocates BAR sizes according to fixed table
bar_size[] = { 512, 512, 1024, 16384, 131072, 1048576 } . This
does not work with controllers which have fixed size BARs, like
Renesas R-Car V4H PCIe controller, which has BAR4 size limited
to 256 Bytes, which is much less than 131072 currently requested
by this test.

Adjust the test such, that in case a fixed size BAR is detected
on a controller, minimum of requested size and fixed size BAR
size is used during the test instead.

This helps with test failures reported as follows:
"
pci_epf_test pci_epf_test.0: requested BAR size is larger than fixed size
pci_epf_test pci_epf_test.0: Failed to allocate space for BAR4
"

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Frank Li <Frank.Li@nxp.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Kishon Vijay Abraham I <kishon@kernel.org>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Niklas Cassel <cassel@kernel.org>
Cc: Wang Jiang <jiangwang@kylinos.cn>
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
V2: Simplify the conditional to always use fixed size BAR size for test
---
 drivers/pci/endpoint/functions/pci-epf-test.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index e091193bd8a8a..2418add64104a 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -1050,7 +1050,12 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
 		if (bar == test_reg_bar)
 			continue;
 
-		base = pci_epf_alloc_space(epf, bar_size[bar], bar,
+		if (epc_features->bar[bar].type == BAR_FIXED)
+			test_reg_size = epc_features->bar[bar].fixed_size;
+		else
+			test_reg_size = bar_size[bar];
+
+		base = pci_epf_alloc_space(epf, test_reg_size, bar,
 					   epc_features, PRIMARY_INTERFACE);
 		if (!base)
 			dev_err(dev, "Failed to allocate space for BAR%d\n",
-- 
2.50.1

On Fri, Sep 05, 2025 at 02:12:43PM +0200, Marek Vasut wrote:
> Currently, the test allocates BAR sizes according to fixed table
> bar_size[] = { 512, 512, 1024, 16384, 131072, 1048576 } . This
> does not work with controllers which have fixed size BARs, like
> Renesas R-Car V4H PCIe controller, which has BAR4 size limited
> to 256 Bytes, which is much less than 131072 currently requested
> by this test.

Perhaps rephase this to more clearly state that:
This does not work with controllers with have fixed size BARs that is
smaller than the requested BAR size.

(Since a lot of controllers drivers in-tree have fixed size BARs,
and they do work perfectly fine, but it is only because their fixed
size is larger than the size requested by pci-epf-test.c)


> 
> Adjust the test such, that in case a fixed size BAR is detected
> on a controller, minimum of requested size and fixed size BAR
> size is used during the test instead.

This sentence needs to be updated, since you no longer take the minimum
of requested size and fixed size BAR.

Perhaps simply:
"Adjust the test such that in case a fixed size BAR is detected,
the fixed BAR size is used, as that is the only possibly option."


With that:
Reviewed-by: Niklas Cassel <cassel@kernel.org>


> ---
>  drivers/pci/endpoint/functions/pci-epf-test.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index e091193bd8a8a..2418add64104a 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -1050,7 +1050,12 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
>  		if (bar == test_reg_bar)
>  			continue;
>  
> -		base = pci_epf_alloc_space(epf, bar_size[bar], bar,
> +		if (epc_features->bar[bar].type == BAR_FIXED)
> +			test_reg_size = epc_features->bar[bar].fixed_size;
> +		else
> +			test_reg_size = bar_size[bar];
> +
> +		base = pci_epf_alloc_space(epf, test_reg_size, bar,
>  					   epc_features, PRIMARY_INTERFACE);
>  		if (!base)
>  			dev_err(dev, "Failed to allocate space for BAR%d\n",
> -- 
> 2.50.1
>

On 9/5/25 2:27 PM, Niklas Cassel wrote:
> On Fri, Sep 05, 2025 at 02:12:43PM +0200, Marek Vasut wrote:
>> Currently, the test allocates BAR sizes according to fixed table
>> bar_size[] = { 512, 512, 1024, 16384, 131072, 1048576 } . This
>> does not work with controllers which have fixed size BARs, like
>> Renesas R-Car V4H PCIe controller, which has BAR4 size limited
>> to 256 Bytes, which is much less than 131072 currently requested
>> by this test.
> 
> Perhaps rephase this to more clearly state that:
> This does not work with controllers with have fixed size BARs that is
> smaller than the requested BAR size.
> 
> (Since a lot of controllers drivers in-tree have fixed size BARs,
> and they do work perfectly fine, but it is only because their fixed
> size is larger than the size requested by pci-epf-test.c)
> 
> 
>>
>> Adjust the test such, that in case a fixed size BAR is detected
>> on a controller, minimum of requested size and fixed size BAR
>> size is used during the test instead.
> 
> This sentence needs to be updated, since you no longer take the minimum
> of requested size and fixed size BAR.
> 
> Perhaps simply:
> "Adjust the test such that in case a fixed size BAR is detected,
> the fixed BAR size is used, as that is the only possibly option."
> 
> 
> With that:
> Reviewed-by: Niklas Cassel <cassel@kernel.org>
All done in V3, which I will send shortly.

Thank you