/* * Firmware replacement code. * * Work around broken BIOSes that don't set an aperture or only set the * aperture in the AGP bridge. * If all fails map the aperture over some low memory. This is cheaper than * doing bounce buffering. The memory is lost. This is done at early boot * because only the bootmem allocator can allocate 32+MB. * * Copyright 2002 Andi Kleen, SuSE Labs. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include int gart_iommu_aperture; int gart_iommu_aperture_disabled __initdata; int gart_iommu_aperture_allowed __initdata; int fallback_aper_order __initdata = 1; /* 64MB */ int fallback_aper_force __initdata; int fix_aperture __initdata = 1; static struct resource gart_resource = { .name = "GART", .flags = IORESOURCE_MEM, }; static void __init insert_aperture_resource(u32 aper_base, u32 aper_size) { gart_resource.start = aper_base; gart_resource.end = aper_base + aper_size - 1; insert_resource(&iomem_resource, &gart_resource); } /* This code runs before the PCI subsystem is initialized, so just access the northbridge directly. */ static u32 __init allocate_aperture(void) { u32 aper_size; void *p; if (fallback_aper_order > 7) fallback_aper_order = 7; aper_size = (32 * 1024 * 1024) << fallback_aper_order; /* * Aperture has to be naturally aligned. This means a 2GB aperture * won't have much chance of finding a place in the lower 4GB of * memory. Unfortunately we cannot move it up because that would * make the IOMMU useless. */ p = __alloc_bootmem_nopanic(aper_size, aper_size, 0); if (!p || __pa(p)+aper_size > 0xffffffff) { printk(KERN_ERR "Cannot allocate aperture memory hole (%p,%uK)\n", p, aper_size>>10); if (p) free_bootmem(__pa(p), aper_size); return 0; } printk(KERN_INFO "Mapping aperture over %d KB of RAM @ %lx\n", aper_size >> 10, __pa(p)); insert_aperture_resource((u32)__pa(p), aper_size); register_nosave_region((u32)__pa(p) >> PAGE_SHIFT, (u32)__pa(p+aper_size) >> PAGE_SHIFT); return (u32)__pa(p); } static int __init aperture_valid(u64 aper_base, u32 aper_size) { if (!aper_base) return 0; if (aper_base + aper_size > 0x100000000UL) { printk(KERN_ERR "Aperture beyond 4GB. Ignoring.\n"); return 0; } if (e820_any_mapped(aper_base, aper_base + aper_size, E820_RAM)) { printk(KERN_ERR "Aperture pointing to e820 RAM. Ignoring.\n"); return 0; } if (aper_size < 64*1024*1024) { printk(KERN_ERR "Aperture too small (%d MB)\n", aper_size>>20); return 0; } return 1; } /* Find a PCI capability */ static __u32 __init find_cap(int num, int slot, int func, int cap) { int bytes; u8 pos; if (!(read_pci_config_16(num, slot, func, PCI_STATUS) & PCI_STATUS_CAP_LIST)) return 0; pos = read_pci_config_byte(num, slot, func, PCI_CAPABILITY_LIST); for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) { u8 id; pos &= ~3; id = read_pci_config_byte(num, slot, func, pos+PCI_CAP_LIST_ID); if (id == 0xff) break; if (id == cap) return pos; pos = read_pci_config_byte(num, slot, func, pos+PCI_CAP_LIST_NEXT); } return 0; } /* Read a standard AGPv3 bridge header */ static __u32 __init read_agp(int num, int slot, int func, int cap, u32 *order) { u32 apsize; u32 apsizereg; int nbits; u32 aper_low, aper_hi; u64 aper; printk(KERN_INFO "AGP bridge at %02x:%02x:%02x\n", num, slot, func); apsizereg = read_pci_config_16(num, slot, func, cap + 0x14); if (apsizereg == 0xffffffff) { printk(KERN_ERR "APSIZE in AGP bridge unreadable\n"); return 0; } apsize = apsizereg & 0xfff; /* Some BIOS use weird encodings not in the AGPv3 table. */ if (apsize & 0xff) apsize |= 0xf00; nbits = hweight16(apsize); *order = 7 - nbits; if ((int)*order < 0) /* < 32MB */ *order = 0; aper_low = read_pci_config(num, slot, func, 0x10); aper_hi = read_pci_config(num, slot, func, 0x14); aper = (aper_low & ~((1<<22)-1)) | ((u64)aper_hi << 32); printk(KERN_INFO "Aperture from AGP @ %Lx size %u MB (APSIZE %x)\n", aper, 32 << *order, apsizereg); if (!aperture_valid(aper, (32*1024*1024) << *order)) return 0; return (u32)aper; } /* * Look for an AGP bridge. Windows only expects the aperture in the * AGP bridge and some BIOS forget to initialize the Northbridge too. * Work around this here. * * Do an PCI bus scan by hand because we're running before the PCI * subsystem. * * All K8 AGP bridges are AGPv3 compliant, so we can do this scan * generically. It's probably overkill to always scan all slots because * the AGP bridges should be always an own bus on the HT hierarchy, * but do it here for future safety. */ static __u32 __init search_agp_bridge(u32 *order, int *valid_agp) { int num, slot, func; /* Poor man's PCI discovery */ for (num = 0; num < 256; num++) { for (slot = 0; slot < 32; slot++) { for (func = 0; func < 8; func++) { u32 class, cap; u8 type; class = read_pci_config(num, slot, func, PCI_CLASS_REVISION); if (class == 0xffffffff) break; switch (class >> 16) { case PCI_CLASS_BRIDGE_HOST: case PCI_CLASS_BRIDGE_OTHER: /* needed? */ /* AGP bridge? */ cap = find_cap(num, slot, func, PCI_CAP_ID_AGP); if (!cap) break; *valid_agp = 1; return read_agp(num, slot, func, cap, order); } /* No multi-function device? */ type = read_pci_config_byte(num, slot, func, PCI_HEADER_TYPE); if (!(type & 0x80)) break; } } } printk(KERN_INFO "No AGP bridge found\n"); return 0; } static int gart_fix_e820 __initdata = 1; static int __init parse_gart_mem(char *p) { if (!p) return -EINVAL; if (!strncmp(p, "off", 3)) gart_fix_e820 = 0; else if (!strncmp(p, "on", 2)) gart_fix_e820 = 1; return 0; } early_param("gart_fix_e820", parse_gart_mem); void __init early_gart_iommu_check(void) { /* * in case it is enabled before, esp for kexec/kdump, * previous kernel already enable that. memset called * by allocate_aperture/__alloc_bootmem_nopanic cause restart. * or second kernel have different position for GART hole. and new * kernel could use hole as RAM that is still used by GART set by * first kernel * or BIOS forget to put that in reserved. * try to update e820 to make that region as reserved. */ int fix, num; u32 ctl; u32 aper_size = 0, aper_order = 0, last_aper_order = 0; u64 aper_base = 0, last_aper_base = 0; int aper_enabled = 0, last_aper_enabled = 0; if (!early_pci_allowed()) return; fix = 0; for (num = 24; num < 32; num++) { if (!early_is_k8_nb(read_pci_config(0, num, 3, 0x00))) continue; ctl = read_pci_config(0, num, 3, 0x90); aper_enabled = ctl & 1; aper_order = (ctl >> 1) & 7; aper_size = (32 * 1024 * 1024) << aper_order; aper_base = read_pci_config(0, num, 3, 0x94) & 0x7fff; aper_base <<= 25; if ((last_aper_order && aper_order != last_aper_order) || (last_aper_base && aper_base != last_aper_base) || (last_aper_enabled && aper_enabled != last_aper_enabled)) { fix = 1; break; } last_aper_order = aper_order; last_aper_base = aper_base; last_aper_enabled = aper_enabled; } if (!fix && !aper_enabled) return; if (!aper_base || !aper_size || aper_base + aper_size > 0x100000000UL) fix = 1; if (gart_fix_e820 && !fix && aper_enabled) { if (e820_any_mapped(aper_base, aper_base + aper_size, E820_RAM)) { /* reserved it, so we can resuse it in second kernel */ printk(KERN_INFO "update e820 for GART\n"); e820_add_region(aper_base, aper_size, E820_RESERVED); update_e820(); } return; } /* different nodes have different setting, disable them all at first*/ for (num = 24; num < 32; num++) { if (!early_is_k8_nb(read_pci_config(0, num, 3, 0x00))) continue; ctl = read_pci_config(0, num, 3, 0x90); ctl &= ~1; write_pci_config(0, num, 3, 0x90, ctl); } } void __init gart_iommu_hole_init(void) { u32 aper_size, aper_alloc = 0, aper_order = 0, last_aper_order = 0; u64 aper_base, last_aper_base = 0; int fix, num, valid_agp = 0; int node; if (gart_iommu_aperture_disabled || !fix_aperture || !early_pci_allowed()) return; printk(KERN_INFO "Checking aperture...\n"); fix = 0; node = 0; for (num = 24; num < 32; num++) { if (!early_is_k8_nb(read_pci_config(0, num, 3, 0x00))) continue; iommu_detected = 1; gart_iommu_aperture = 1; aper_order = (read_pci_config(0, num, 3, 0x90) >> 1) & 7; aper_size = (32 * 1024 * 1024) << aper_order; aper_base = read_pci_config(0, num, 3, 0x94) & 0x7fff; aper_base <<= 25; printk(KERN_INFO "Node %d: aperture @ %Lx size %u MB\n", node, aper_base, aper_size >> 20); node++; if (!aperture_valid(aper_base, aper_size)) { fix = 1; break; } if ((last_aper_order && aper_order != last_aper_order) || (last_aper_base && aper_base != last_aper_base)) { fix = 1; break; } last_aper_order = aper_order; last_aper_base = aper_base; } if (!fix && !fallback_aper_force) { if (last_aper_base) { unsigned long n = (32 * 1024 * 1024) << last_aper_order; insert_aperture_resource((u32)last_aper_base, n); } return; } if (!fallback_aper_force) aper_alloc = search_agp_bridge(&aper_order, &valid_agp); if (aper_alloc) { /* Got the aperture from the AGP bridge */ } else if (swiotlb && !valid_agp) { /* Do nothing */ } else if ((!no_iommu && end_pfn > MAX_DMA32_PFN) || force_iommu || valid_agp || fallback_aper_force) { printk(KERN_ERR "Your BIOS doesn't leave a aperture memory hole\n"); printk(KERN_ERR "Please enable the IOMMU option in the BIOS setup\n"); printk(KERN_ERR "This costs you %d MB of RAM\n", 32 << fallback_aper_order); aper_order = fallback_aper_order; aper_alloc = allocate_aperture(); if (!aper_alloc) { /* * Could disable AGP and IOMMU here, but it's * probably not worth it. But the later users * cannot deal with bad apertures and turning * on the aperture over memory causes very * strange problems, so it's better to panic * early. */ panic("Not enough memory for aperture"); } } else { return; } /* Fix up the north bridges */ for (num = 24; num < 32; num++) { if (!early_is_k8_nb(read_pci_config(0, num, 3, 0x00))) continue; /* * Don't enable translation yet. That is done later. * Assume this BIOS didn't initialise the GART so * just overwrite all previous bits */ write_pci_config(0, num, 3, 0x90, aper_order<<1); write_pci_config(0, num, 3, 0x94, aper_alloc>>25); } }