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Commit a7eb08c2 authored by mark gross's avatar mark gross Committed by Jesse Barnes
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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: default avatarMark Gross <mgross@linux.intel.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 34a65055

drivers/pci/intel-iommu.c

+3 −3
Original line number Diff line number Diff line
@@ -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();\

	}\