diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 2 | ||||
| -rw-r--r-- | arch/powerpc/platforms/powernv/pci-ioda.c | 26 |
2 files changed, 27 insertions, 1 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4df73da11adc..7dedfe56c3f3 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1493,6 +1493,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. forcesac soft pt [x86, IA-64] + nobypass [PPC/POWERNV] + Disable IOMMU bypass, using IOMMU for PCI devices. io7= [HW] IO7 for Marvel based alpha systems diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index 4f1e43c05e84..85b473823fda 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -75,6 +75,28 @@ static void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level, #define pe_info(pe, fmt, ...) \ pe_level_printk(pe, KERN_INFO, fmt, ##__VA_ARGS__) +static bool pnv_iommu_bypass_disabled __read_mostly; + +static int __init iommu_setup(char *str) +{ + if (!str) + return -EINVAL; + + while (*str) { + if (!strncmp(str, "nobypass", 8)) { + pnv_iommu_bypass_disabled = true; + pr_info("PowerNV: IOMMU bypass window disabled.\n"); + break; + } + str += strcspn(str, ","); + if (*str == ',') + str++; + } + + return 0; +} +early_param("iommu", iommu_setup); + /* * stdcix is only supposed to be used in hypervisor real mode as per * the architecture spec @@ -1351,7 +1373,9 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb, pnv_ioda_setup_bus_dma(pe, pe->pbus, true); /* Also create a bypass window */ - pnv_pci_ioda2_setup_bypass_pe(phb, pe); + if (!pnv_iommu_bypass_disabled) + pnv_pci_ioda2_setup_bypass_pe(phb, pe); + return; fail: if (pe->tce32_seg >= 0) |