[PATCH 08/10] iommu: Set default domain type at runtime

From: Joerg Roedel
Date: Wed Aug 14 2019 - 09:39:09 EST


From: Joerg Roedel <jroedel@xxxxxxx>

Set the default domain-type at runtime, not at compile-time.
This keeps default domain type setting in one place when we
have to change it at runtime.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
drivers/iommu/iommu.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 233bc22b487e..96cc7cc8ab21 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -26,11 +26,8 @@

static struct kset *iommu_group_kset;
static DEFINE_IDA(iommu_group_ida);
-#ifdef CONFIG_IOMMU_DEFAULT_PASSTHROUGH
-static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY;
-#else
-static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA;
-#endif
+
+static unsigned int iommu_def_domain_type __read_mostly;
static bool iommu_dma_strict __read_mostly = true;
static u32 iommu_cmd_line __read_mostly;

@@ -76,7 +73,7 @@ static void iommu_set_cmd_line_dma_api(void)
iommu_cmd_line |= IOMMU_CMD_LINE_DMA_API;
}

-static bool __maybe_unused iommu_cmd_line_dma_api(void)
+static bool iommu_cmd_line_dma_api(void)
{
return !!(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API);
}
@@ -115,8 +112,18 @@ static const char *iommu_domain_type_str(unsigned int t)

static int __init iommu_subsys_init(void)
{
- pr_info("Default domain type: %s\n",
- iommu_domain_type_str(iommu_def_domain_type));
+ bool cmd_line = iommu_cmd_line_dma_api();
+
+ if (!cmd_line) {
+ if (IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH))
+ iommu_set_default_passthrough();
+ else
+ iommu_set_default_translated();
+ }
+
+ pr_info("Default domain type: %s %s\n",
+ iommu_domain_type_str(iommu_def_domain_type),
+ cmd_line ? "(set via kernel command line)" : "");

return 0;
}
--
2.17.1