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-rw-r--r--arch/x86/kernel/pci-dma_64.c49
-rw-r--r--arch/x86/kernel/setup_64.c2
-rw-r--r--include/asm-x86/pci_64.h1
3 files changed, 52 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.
diff --git a/include/asm-x86/pci_64.h b/include/asm-x86/pci_64.h
index 37469031453..da8266a0800 100644
--- a/include/asm-x86/pci_64.h
+++ b/include/asm-x86/pci_64.h
@@ -25,6 +25,7 @@ extern int (*pci_config_write)(int seg, int bus, int dev, int fn, int reg, int l
+extern void dma32_reserve_bootmem(void);
extern void pci_iommu_alloc(void);
/* The PCI address space does equal the physical memory