From 250c22777fe1ccd7ac588579a6c16db4c0161cc5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 11 Oct 2007 11:17:24 +0200 Subject: x86_64: move kernel Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/aperture_64.c | 298 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 298 insertions(+) create mode 100644 arch/x86/kernel/aperture_64.c (limited to 'arch/x86/kernel/aperture_64.c') diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c new file mode 100644 index 00000000000..8f681cae7bf --- /dev/null +++ b/arch/x86/kernel/aperture_64.c @@ -0,0 +1,298 @@ +/* + * 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 + +int iommu_aperture; +int iommu_aperture_disabled __initdata = 0; +int iommu_aperture_allowed __initdata = 0; + +int fallback_aper_order __initdata = 1; /* 64MB */ +int fallback_aper_force __initdata = 0; + +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 an 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("Cannot allocate aperture memory hole (%p,%uK)\n", + p, aper_size>>10); + if (p) + free_bootmem(__pa(p), aper_size); + return 0; + } + printk("Mapping aperture over %d KB of RAM @ %lx\n", + aper_size >> 10, __pa(p)); + insert_aperture_resource((u32)__pa(p), aper_size); + return (u32)__pa(p); +} + +static int __init aperture_valid(u64 aper_base, u32 aper_size) +{ + if (!aper_base) + return 0; + if (aper_size < 64*1024*1024) { + printk("Aperture too small (%d MB)\n", aper_size>>20); + return 0; + } + if (aper_base + aper_size > 0x100000000UL) { + printk("Aperture beyond 4GB. Ignoring.\n"); + return 0; + } + if (e820_any_mapped(aper_base, aper_base + aper_size, E820_RAM)) { + printk("Aperture pointing to e820 RAM. Ignoring.\n"); + return 0; + } + return 1; +} + +/* Find a PCI capability */ +static __u32 __init find_cap(int num, int slot, int func, int cap) +{ + u8 pos; + int bytes; + 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("AGP bridge at %02x:%02x:%02x\n", num, slot, func); + apsizereg = read_pci_config_16(num,slot,func, cap + 0x14); + if (apsizereg == 0xffffffff) { + printk("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("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("No AGP bridge found\n"); + return 0; +} + +void __init iommu_hole_init(void) +{ + int fix, num; + u32 aper_size, aper_alloc = 0, aper_order = 0, last_aper_order = 0; + u64 aper_base, last_aper_base = 0; + int valid_agp = 0; + + if (iommu_aperture_disabled || !fix_aperture || !early_pci_allowed()) + return; + + printk(KERN_INFO "Checking aperture...\n"); + + fix = 0; + for (num = 24; num < 32; num++) { + if (!early_is_k8_nb(read_pci_config(0, num, 3, 0x00))) + continue; + + iommu_detected = 1; + 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("CPU %d: aperture @ %Lx size %u MB\n", num-24, + aper_base, aper_size>>20); + + 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("Your BIOS doesn't leave a aperture memory hole\n"); + printk("Please enable the IOMMU option in the BIOS setup\n"); + printk("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); + } +} -- cgit v1.2.3