Re: [discuss] What will be in the x86-64/x86 2.6.21 merge

Muli Ben-Yehuda
2007-02-10T13:43:52Z

On Sat, Feb 10, 2007 at 12:42:48PM +0100, Andi Kleen wrote:
>
> I will post the existing patches in batches for closer review.
>
> Can be already all viewed at
> ftp://ftp.firstfloor.org/pub/ak/x86_64/quilt/patches/

Andi, please make sure to also include this Calgary patch I sent on
Feb 6th.

Thanks,
Muli

Subject: x86-64 Calgary: robustify bad_dma_address handling
From: Muli Ben-Yehuda <muli@il.ibm.com>

- 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>
Cc: Leo Duran <leo.duran@amd.com>
Cc: Job Mason <jdmason@kudzu.us>
---
arch/x86_64/kernel/pci-calgary.c | 17 +++++++++++++++--
1 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/x86_64/kernel/pci-calgary.c b/arch/x86_64/kernel/pci-calgary.c
index 3d65b1d..04480c3 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_off

#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_ta
{
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_regio
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;
--
1.4.1