From 310adfdd9153f6ae818981a38a48dd2330990d8d Mon Sep 17 00:00:00 2001
From: Muli Ben-Yehuda <muli@il.ibm.com>
Date: Tue, 13 Feb 2007 13:26:24 +0100
Subject: [PATCH] [PATCH] x86-64: robustify bad_dma_address handling
- set bad_dma_address explicitly to 0x0
- reserve 32 pages from bad_dma_address and up
- WARN_ON() a driver feeding us bad_dma_address
Thanks to Leo Duran <leo.duran@amd.com> for the suggestion.
Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Leo Duran <leo.duran@amd.com>
Cc: Job Mason <jdmason@kudzu.us>
---
arch/x86_64/kernel/pci-calgary.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/arch/x86_64/kernel/pci-calgary.c b/arch/x86_64/kernel/pci-calgary.c
index 3d65b1d4c2b39..04480c3b68f5d 100644
--- a/arch/x86_64/kernel/pci-calgary.c
+++ b/arch/x86_64/kernel/pci-calgary.c
@@ -138,6 +138,8 @@ static const unsigned long phb_debug_offsets[] = {
#define PHB_DEBUG_STUFF_OFFSET 0x0020
+#define EMERGENCY_PAGES 32 /* = 128KB */
+
unsigned int specified_table_size = TCE_TABLE_SIZE_UNSPECIFIED;
static int translate_empty_slots __read_mostly = 0;
static int calgary_detected __read_mostly = 0;
@@ -296,6 +298,16 @@ static void __iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
{
unsigned long entry;
unsigned long badbit;
+ unsigned long badend;
+
+ /* were we called with bad_dma_address? */
+ badend = bad_dma_address + (EMERGENCY_PAGES * PAGE_SIZE);
+ if (unlikely((dma_addr >= bad_dma_address) && (dma_addr < badend))) {
+ printk(KERN_ERR "Calgary: driver tried unmapping bad DMA "
+ "address 0x%Lx\n", dma_addr);
+ WARN_ON(1);
+ return;
+ }
entry = dma_addr >> PAGE_SHIFT;
@@ -656,8 +668,8 @@ static void __init calgary_reserve_regions(struct pci_dev *dev)
u64 start;
struct iommu_table *tbl = dev->sysdata;
- /* reserve bad_dma_address in case it's a legal address */
- iommu_range_reserve(tbl, bad_dma_address, 1);
+ /* reserve EMERGENCY_PAGES from bad_dma_address and up */
+ iommu_range_reserve(tbl, bad_dma_address, EMERGENCY_PAGES);
/* avoid the BIOS/VGA first 640KB-1MB region */
start = (640 * 1024);
@@ -1176,6 +1188,7 @@ int __init calgary_iommu_init(void)
}
force_iommu = 1;
+ bad_dma_address = 0x0;
dma_ops = &calgary_dma_ops;
return 0;
--
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