| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <stdint.h> |
| |
| #include <device/pci_ops.h> |
| #include <device/pci_def.h> |
| |
| #include "gm45.h" |
| |
| void init_iommu(void) |
| { |
| /* FIXME: proper test? */ |
| int me_active = pci_read_config8(PCI_DEV(0, 3, 0), PCI_CLASS_REVISION) != 0xff; |
| int stepping = pci_read_config8(PCI_DEV(0, 0, 0), PCI_CLASS_REVISION); |
| |
| mchbar_write32(0x28, IOMMU_BASE1 | 1); /* HDA @ 0:1b.0 */ |
| if (stepping != STEPPING_B2) { |
| /* The official workaround is to run SMM every 64ms. |
| The only winning move is not to play. */ |
| mchbar_write32(0x18, IOMMU_BASE2 | 1); /* IGD @ 0:2.0-1 */ |
| } else { |
| /* write-once, so lock it down */ |
| mchbar_write32(0x18, 0); /* disable IOMMU for IGD @ 0:2.0-1 */ |
| } |
| if (me_active) { |
| mchbar_write32(0x10, IOMMU_BASE3 | 1); /* ME @ 0:3.0-3 */ |
| } else { |
| mchbar_write32(0x10, 0); /* disable IOMMU for ME */ |
| } |
| mchbar_write32(0x20, IOMMU_BASE4 | 1); /* all other DMA sources */ |
| |
| if (stepping == STEPPING_B3) { |
| mchbar_setbits8(0xffc, 1 << 4); |
| const pci_devfn_t peg = PCI_DEV(0, 1, 0); |
| |
| /* FIXME: proper test? */ |
| if (pci_read_config8(peg, PCI_CLASS_REVISION) != 0xff) |
| pci_or_config32(peg, 0xfc, 1 << 15); |
| } |
| |
| /* final */ |
| mchbar_setbits8(0x94, 1 << 3); |
| } |