From 752bea4abbff5e3ffef36802b860e80d0b632990 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 7 Mar 2008 15:02:50 -0800 Subject: [PATCH] x86: reserve dma32 early for gart a system with 256 GB of RAM, when NUMA is disabled crashes the following way: Your BIOS doesn't leave a aperture memory hole Please enable the IOMMU option in the BIOS setup This costs you 64 MB of RAM Cannot allocate aperture memory hole (ffff8101c0000000,65536K) Kernel panic - not syncing: Not enough memory for aperture Pid: 0, comm: swapper Not tainted 2.6.25-rc4-x86-latest.git #33 Call Trace: [] panic+0xb2/0x190 [] ? release_console_sem+0x7c/0x250 [] ? __alloc_bootmem_nopanic+0x48/0x90 [] ? free_bootmem+0x29/0x50 [] gart_iommu_hole_init+0x5e7/0x680 [] ? alloc_large_system_hash+0x16b/0x310 [] ? _etext+0x0/0x1 [] pci_iommu_alloc+0x1c/0x40 [] mem_init+0x45/0x1a0 [] start_kernel+0x295/0x380 [] _sinittext+0x1c2/0x230 the root cause is : memmap PMD is too big, [ffffe200e0600000-ffffe200e07fffff] PMD ->ffff81383c000000 on node 0 almost near 4G..., and vmemmap_alloc_block will use up the ram under 4G. solution will be: 1. make memmap allocation get memory above 4G... 2. reserve some dma32 range early before we try to set up memmap for all. and release that before pci_iommu_alloc, so gart or swiotlb could get some range under 4g limit for sure. the patch is using method 2. because method1 may need more code to handle SPARSEMEM and SPASEMEM_VMEMMAP will get Your BIOS doesn't leave a aperture memory hole Please enable the IOMMU option in the BIOS setup This costs you 64 MB of RAM Mapping aperture over 65536 KB of RAM @ 4000000 Memory: 264245736k/268959744k available (8484k kernel code, 4187464k reserved, 4004k data, 724k init) Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/pci-dma_64.c | 49 ++++++++++++++++++++++++++++++++++++ arch/x86/kernel/setup_64.c | 2 ++ include/asm-x86/pci_64.h | 1 + 3 files changed, 52 insertions(+) diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c index ada5a06049..e4fffaabe5 100644 --- a/arch/x86/kernel/pci-dma_64.c +++ b/arch/x86/kernel/pci-dma_64.c @@ -8,6 +8,8 @@ #include #include #include +#include +#include #include #include #include @@ -286,8 +288,55 @@ static __init int iommu_setup(char *p) } early_param("iommu", iommu_setup); +static __initdata void *dma32_bootmem_ptr; +static unsigned long dma32_bootmem_size __initdata = (128ULL<<20); + +static int __init parse_dma32_size_opt(char *p) +{ + if (!p) + return -EINVAL; + dma32_bootmem_size = memparse(p, &p); + return 0; +} +early_param("dma32_size", parse_dma32_size_opt); + +void __init dma32_reserve_bootmem(void) +{ + unsigned long size, align; + if (end_pfn <= MAX_DMA32_PFN) + return; + + align = 64ULL<<20; + size = round_up(dma32_bootmem_size, align); + dma32_bootmem_ptr = __alloc_bootmem_nopanic(size, align, + __pa(MAX_DMA_ADDRESS)); + if (dma32_bootmem_ptr) + dma32_bootmem_size = size; + else + dma32_bootmem_size = 0; +} +static void __init dma32_free_bootmem(void) +{ + int node; + + if (end_pfn <= MAX_DMA32_PFN) + return; + + if (!dma32_bootmem_ptr) + return; + + for_each_online_node(node) + free_bootmem_node(NODE_DATA(node), __pa(dma32_bootmem_ptr), + dma32_bootmem_size); + + dma32_bootmem_ptr = NULL; + dma32_bootmem_size = 0; +} + void __init pci_iommu_alloc(void) { + /* free the range so iommu could get some range less than 4G */ + dma32_free_bootmem(); /* * The order of these functions is important for * fall-back/fail-over reasons diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c index 0aa291bff4..6b8e11f0c1 100644 --- a/arch/x86/kernel/setup_64.c +++ b/arch/x86/kernel/setup_64.c @@ -398,6 +398,8 @@ void __init setup_arch(char **cmdline_p) early_res_to_bootmem(); + dma32_reserve_bootmem(); + #ifdef CONFIG_ACPI_SLEEP /* * Reserve low memory region for sleep support. diff --git a/include/asm-x86/pci_64.h b/include/asm-x86/pci_64.h index df867e5d80..f330234ffa 100644 --- a/include/asm-x86/pci_64.h +++ b/include/asm-x86/pci_64.h @@ -22,6 +22,7 @@ extern int (*pci_config_read)(int seg, int bus, int dev, int fn, extern int (*pci_config_write)(int seg, int bus, int dev, int fn, int reg, int len, u32 value); +extern void dma32_reserve_bootmem(void); extern void pci_iommu_alloc(void); /* The PCI address space does equal the physical memory -- 2.39.5