Re: [PATCH v10 6/6] ACPI/IORT: Stub out ACS functions when CONFIG_PCI is not set

[Lorenzo Pieralisi]

On Sat, Dec 15, 2018 at 01:02:47AM +0000, Sinan Kaya wrote:
> Remove PCI dependent code out of iort.c when CONFIG_PCI is not defined.
> 
> Signed-off-by: Sinan Kaya <ok...@kernel.org>
> ---
>  drivers/acpi/arm64/iort.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 70f4e80b9246..d0f68607efe6 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -1437,6 +1437,7 @@ static int __init iort_add_platform_device(struct 
> acpi_iort_node *node,
>  
>  static bool __init iort_enable_acs(struct acpi_iort_node *iort_node)
>  {
> +#ifdef CONFIG_PCI
>       if (iort_node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
>               struct acpi_iort_node *parent;
>               struct acpi_iort_id_mapping *map;
> @@ -1462,6 +1463,7 @@ static bool __init iort_enable_acs(struct 
> acpi_iort_node *iort_node)
>                       }
>               }
>       }
> +#endif
>  
>       return false;
>  }
> -- 
> 2.19.0

I would prefer the ifdef to wrap the function rather than in the
function.

Anyway, as an alternative, what about this:

-- >8 --
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 70f4e80b9246..06d4cc888df6 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -1435,8 +1435,14 @@ static int __init iort_add_platform_device(struct 
acpi_iort_node *node,
        return ret;
 }
 
-static bool __init iort_enable_acs(struct acpi_iort_node *iort_node)
+#ifdef CONFIG_PCI
+static void __init iort_enable_acs(struct acpi_iort_node *iort_node)
 {
+       static bool acs_enabled __initdata = false;
+
+       if (acs_enabled)
+               return;
+
        if (iort_node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
                struct acpi_iort_node *parent;
                struct acpi_iort_id_mapping *map;
@@ -1458,13 +1464,15 @@ static bool __init iort_enable_acs(struct 
acpi_iort_node *iort_node)
                        if ((parent->type == ACPI_IORT_NODE_SMMU) ||
                                (parent->type == ACPI_IORT_NODE_SMMU_V3)) {
                                pci_request_acs();
-                               return true;
+                               acs_enabled = true;
+                               return;
                        }
                }
        }
-
-       return false;
 }
+#else
+static inline void iort_enable_acs(struct acpi_iort_node *iort_node) { }
+#endif
 
 static void __init iort_init_platform_devices(void)
 {
@@ -1472,7 +1480,6 @@ static void __init iort_init_platform_devices(void)
        struct acpi_table_iort *iort;
        struct fwnode_handle *fwnode;
        int i, ret;
-       bool acs_enabled = false;
        const struct iort_dev_config *ops;
 
        /*
@@ -1493,8 +1500,7 @@ static void __init iort_init_platform_devices(void)
                        return;
                }
 
-               if (!acs_enabled)
-                       acs_enabled = iort_enable_acs(iort_node);
+               iort_enable_acs(iort_node);
 
                ops = iort_get_dev_cfg(iort_node);
                if (ops) {