From a7eb08c2a14f28cb652ea6ad1a8e2b8efc55fb9a Mon Sep 17 00:00:00 2001 From: mark gross Date: Mon, 12 May 2008 13:41:57 -0700 Subject: [PATCH] PCI: Make the intel-iommu_wait_op macro work when jiffies are not running The following patch changes the intel-iommu.c code to use the TSC instead of jiffies for detecting bad DMAR functionality. Some systems with bad bios's have been seen to hang in early boot spinning in the IOMMU_WAIT_IO macro. This patch will replace the infinite loop with a call to panic. Signed-off-by: Mark Gross Signed-off-by: Jesse Barnes --- drivers/pci/intel-iommu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 1fd8bb76570..66c0fd21894 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -49,7 +49,7 @@ #define DEFAULT_DOMAIN_ADDRESS_WIDTH 48 -#define DMAR_OPERATION_TIMEOUT (HZ*60) /* 1m */ +#define DMAR_OPERATION_TIMEOUT ((cycles_t) tsc_khz*10*1000) /* 10sec */ #define DOMAIN_MAX_ADDR(gaw) ((((u64)1) << gaw) - 1) @@ -490,12 +490,12 @@ static int iommu_alloc_root_entry(struct intel_iommu *iommu) #define IOMMU_WAIT_OP(iommu, offset, op, cond, sts) \ {\ - unsigned long start_time = jiffies;\ + cycles_t start_time = get_cycles();\ while (1) {\ sts = op (iommu->reg + offset);\ if (cond)\ break;\ - if (time_after(jiffies, start_time + DMAR_OPERATION_TIMEOUT))\ + if (DMAR_OPERATION_TIMEOUT < (get_cycles() - start_time))\ panic("DMAR hardware is malfunctioning\n");\ cpu_relax();\ }\ -- 2.41.1