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authorYinghai Lu <yhlu.kernel@gmail.com>2008-03-07 15:02:50 -0800
committerIngo Molnar <mingo@elte.hu>2008-03-21 17:06:15 +0100
commitf62f1fc9ef94f74fda2b456d935ba2da69fa0a40 (patch)
tree93a1b5d29e516d0c155199b3bab49d40cb1f9cbb /arch/x86
parentfc115bf19b5b2f383614b264569fb48a43bfe56d (diff)
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: [<ffffffff84037c62>] panic+0xb2/0x190 [<ffffffff840381fc>] ? release_console_sem+0x7c/0x250 [<ffffffff847b1628>] ? __alloc_bootmem_nopanic+0x48/0x90 [<ffffffff847b0ac9>] ? free_bootmem+0x29/0x50 [<ffffffff847ac1f7>] gart_iommu_hole_init+0x5e7/0x680 [<ffffffff847b255b>] ? alloc_large_system_hash+0x16b/0x310 [<ffffffff84506a2f>] ? _etext+0x0/0x1 [<ffffffff847a2e8c>] pci_iommu_alloc+0x1c/0x40 [<ffffffff847ac795>] mem_init+0x45/0x1a0 [<ffffffff8479ff35>] start_kernel+0x295/0x380 [<ffffffff8479f1c2>] _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 <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/pci-dma_64.c49
-rw-r--r--arch/x86/kernel/setup_64.c2
2 files changed, 51 insertions, 0 deletions
diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c
index 375cb2bc45b..8bc1e185e55 100644
--- a/arch/x86/kernel/pci-dma_64.c
+++ b/arch/x86/kernel/pci-dma_64.c
@@ -8,6 +8,8 @@
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/dmar.h>
+#include <linux/bootmem.h>
+#include <asm/proto.h>
#include <asm/io.h>
#include <asm/gart.h>
#include <asm/calgary.h>
@@ -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 7637dc91c79..a775fe3de95 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -389,6 +389,8 @@ 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.