[PATCH v5 5/6] powernv/iommu: add support for generic boot option iommu.dma_mode

From: Zhen Lei
Date: Tue Apr 09 2019 - 08:57:27 EST


iommu=nobypass can be replaced with iommu.dma_mode=strict.

Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 2 +-
arch/powerpc/platforms/powernv/pci-ioda.c | 5 ++---
drivers/iommu/Kconfig | 1 +
3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index ab8e3c4798c0a2a..176f96032d9d62a 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1815,7 +1815,7 @@
options(such as CONFIG_IOMMU_DEFAULT_PASSTHROUGH) to
choose which mode to be used.
Note: For historical reasons, ARM64/S390/PPC/X86 have
- their specific options. Currently, only ARM64/S390
+ their specific options. Currently, only ARM64/S390/PPC
support this boot option, and hope other ARCHs to use
this as generic boot option.
passthrough
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 3ead4c237ed0ec9..8862885d866418f 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -85,7 +85,6 @@ void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level,
va_end(args);
}

-static bool pnv_iommu_bypass_disabled __read_mostly;
static bool pci_reset_phbs __read_mostly;

static int __init iommu_setup(char *str)
@@ -95,7 +94,7 @@ static int __init iommu_setup(char *str)

while (*str) {
if (!strncmp(str, "nobypass", 8)) {
- pnv_iommu_bypass_disabled = true;
+ iommu_default_dma_mode_set(IOMMU_DMA_MODE_STRICT);
pr_info("PowerNV: IOMMU bypass window disabled.\n");
break;
}
@@ -2456,7 +2455,7 @@ static long pnv_pci_ioda2_setup_default_config(struct pnv_ioda_pe *pe)
return rc;
}

- if (!pnv_iommu_bypass_disabled)
+ if (IOMMU_DMA_MODE_IS_PASSTHROUGH())
pnv_pci_ioda2_set_bypass(pe, true);

return 0;
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index b7173b106cd816a..5dca666b22e6cd5 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -77,6 +77,7 @@ config IOMMU_DEBUGFS
choice
prompt "IOMMU dma mode"
depends on IOMMU_API
+ default IOMMU_DEFAULT_PASSTHROUGH if (PPC_POWERNV && PCI)
default IOMMU_DEFAULT_LAZY if S390_IOMMU
default IOMMU_DEFAULT_STRICT
help
--
1.8.3