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In cases where we have an issue in the device interrupt path with IOMMU
interrupt remapping enabled, dumping valid IRT table entries for the device
is very useful and good input for debugging the issue.
eg.
-> To dump irte entries for a particular device
#echo "c4:00.0" > /sys/kernel/debug/iommu/amd/devid
#cat /sys/kernel/debug/iommu/amd/irqtbl | less
or
#echo "0000:c4:00.0" > /sys/kernel/debug/iommu/amd/devid
#cat /sys/kernel/debug/iommu/amd/irqtbl | less
Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20250702093804.849-8-dheerajkumar.srivastava@amd.com
Signed-off-by: Will Deacon <will@kernel.org>
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IOMMU uses device table data structure to get per-device information for
DMA remapping, interrupt remapping, and other functionalities. It's a
valuable data structure to visualize for debugging issues related to
IOMMU.
eg.
-> To dump device table entry for a particular device
#echo 0000:c4:00.0 > /sys/kernel/debug/iommu/amd/devid
#cat /sys/kernel/debug/iommu/amd/devtbl
or
#echo c4:00.0 > /sys/kernel/debug/iommu/amd/devid
#cat /sys/kernel/debug/iommu/amd/devtbl
Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20250702093804.849-7-dheerajkumar.srivastava@amd.com
Signed-off-by: Will Deacon <will@kernel.org>
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Dumping IOMMU data structures like device table, IRT, etc., for all devices
on the system will be a lot of data dumped in a file. Also, user may want
to dump and analyze these data structures just for one or few devices. So
dumping IOMMU data structures like device table, IRT etc for all devices
is not a good approach.
Add "device id" user input to be used for dumping IOMMU data structures
like device table, IRT etc in AMD IOMMU debugfs.
eg.
1. # echo 0000:01:00.0 > /sys/kernel/debug/iommu/amd/devid
# cat /sys/kernel/debug/iommu/amd/devid
Output : 0000:01:00.0
2. # echo 01:00.0 > /sys/kernel/debug/iommu/amd/devid
# cat /sys/kernel/debug/iommu/amd/devid
Output : 0000:01:00.0
Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20250702093804.849-6-dheerajkumar.srivastava@amd.com
Signed-off-by: Will Deacon <will@kernel.org>
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IOMMU driver sends command to IOMMU hardware via command buffer. In cases
where IOMMU hardware fails to process commands in command buffer, dumping
it is a valuable input to debug the issue.
IOMMU hardware processes command buffer entry at offset equals to the head
pointer. Dumping just the entry at the head pointer may not always be
useful. The current head may not be pointing to the entry of the command
buffer which is causing the issue. IOMMU Hardware may have processed the
entry and updated the head pointer. So dumping the entire command buffer
gives a broad understanding of what hardware was/is doing. The command
buffer dump will have all entries from start to end of the command buffer.
Along with that, it will have a head and tail command buffer pointer
register dump to facilitate where the IOMMU driver and hardware are in
the command buffer for injecting and processing the entries respectively.
Command buffer is a per IOMMU data structure. So dumping on per IOMMU
basis.
eg.
-> To get command buffer dump for iommu<x> (say, iommu00)
#cat /sys/kernel/debug/iommu/amd/iommu00/cmdbuf
Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20250702093804.849-5-dheerajkumar.srivastava@amd.com
Signed-off-by: Will Deacon <will@kernel.org>
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IOMMU Capability registers defines capabilities of IOMMU and information
needed for initialising MMIO registers and device table. This is useful
to dump these registers for debugging IOMMU related issues.
e.g.
-> To get capability registers value at offset 0x10 for iommu<x> (say,
iommu00)
# echo "0x10" > /sys/kernel/debug/iommu/amd/iommu00/capability
# cat /sys/kernel/debug/iommu/amd/iommu00/capability
Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20250702093804.849-4-dheerajkumar.srivastava@amd.com
Signed-off-by: Will Deacon <will@kernel.org>
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Analyzing IOMMU MMIO registers gives a view of what IOMMU is
configured with on the system and is helpful to debug issues
with IOMMU.
eg.
-> To get mmio registers value at offset 0x18 for iommu<x> (say, iommu00)
# echo "0x18" > /sys/kernel/debug/iommu/amd/iommu00/mmio
# cat /sys/kernel/debug/iommu/amd/iommu00/mmio
Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20250702093804.849-3-dheerajkumar.srivastava@amd.com
Signed-off-by: Will Deacon <will@kernel.org>
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Rearrange initial setup of AMD IOMMU debugfs to segregate per IOMMU
setup and setup which is common for all IOMMUs. This ensures that common
debugfs paths (introduced in subsequent patches) are created only once
instead of being created for each IOMMU.
With the change, there is no need to use lock as amd_iommu_debugfs_setup()
will be called only once during AMD IOMMU initialization. So remove lock
acquisition in amd_iommu_debugfs_setup().
Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20250702093804.849-2-dheerajkumar.srivastava@amd.com
Signed-off-by: Will Deacon <will@kernel.org>
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Move all files related to the AMD IOMMU driver into its own
subdirectory.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20200609130303.26974-2-joro@8bytes.org
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