[PATCH v3 0/7] iommu/dma-iommu: Split iommu_dma_map_msi_msg in two parts

Julien Grall
2019-05-01T13:58:17Z

Hi all,

On RT, the function iommu_dma_map_msi_msg expects to be called from preemptible
context. However, this is not always the case resulting a splat with
!CONFIG_DEBUG_ATOMIC_SLEEP:

[ 48.875777] BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:974
[ 48.875779] in_atomic(): 1, irqs_disabled(): 128, pid: 2103, name: ip
[ 48.875782] INFO: lockdep is turned off.
[ 48.875784] irq event stamp: 10684
[ 48.875786] hardirqs last enabled at (10683): [<ffff0000110c8d70>] _raw_spin_unlock_irqrestore+0x88/0x90
[ 48.875791] hardirqs last disabled at (10684): [<ffff0000110c8b2c>] _raw_spin_lock_irqsave+0x24/0x68
[ 48.875796] softirqs last enabled at (0): [<ffff0000100ec590>] copy_process.isra.1.part.2+0x8d8/0x1970
[ 48.875801] softirqs last disabled at (0): [<0000000000000000>] (null)
[ 48.875805] Preemption disabled at:
[ 48.875805] [<ffff000010189ae8>] __setup_irq+0xd8/0x6c0
[ 48.875811] CPU: 2 PID: 2103 Comm: ip Not tainted 5.0.3-rt1-00007-g42ede9a0fed6 #45
[ 48.875815] Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Jan 23 2017
[ 48.875817] Call trace:
[ 48.875818] dump_backtrace+0x0/0x140
[ 48.875821] show_stack+0x14/0x20
[ 48.875823] dump_stack+0xa0/0xd4
[ 48.875827] ___might_sleep+0x16c/0x1f8
[ 48.875831] rt_spin_lock+0x5c/0x70
[ 48.875835] iommu_dma_map_msi_msg+0x5c/0x1d8
[ 48.875839] gicv2m_compose_msi_msg+0x3c/0x48
[ 48.875843] irq_chip_compose_msi_msg+0x40/0x58
[ 48.875846] msi_domain_activate+0x38/0x98
[ 48.875849] __irq_domain_activate_irq+0x58/0xa0
[ 48.875852] irq_domain_activate_irq+0x34/0x58
[ 48.875855] irq_activate+0x28/0x30
[ 48.875858] __setup_irq+0x2b0/0x6c0
[ 48.875861] request_threaded_irq+0xdc/0x188
[ 48.875865] sky2_setup_irq+0x44/0xf8
[ 48.875868] sky2_open+0x1a4/0x240
[ 48.875871] __dev_open+0xd8/0x188
[ 48.875874] __dev_change_flags+0x164/0x1f0
[ 48.875877] dev_change_flags+0x20/0x60
[ 48.875879] do_setlink+0x2a0/0xd30
[ 48.875882] __rtnl_newlink+0x5b4/0x6d8
[ 48.875885] rtnl_newlink+0x50/0x78
[ 48.875888] rtnetlink_rcv_msg+0x178/0x640
[ 48.875891] netlink_rcv_skb+0x58/0x118
[ 48.875893] rtnetlink_rcv+0x14/0x20
[ 48.875896] netlink_unicast+0x188/0x200
[ 48.875898] netlink_sendmsg+0x248/0x3d8
[ 48.875900] sock_sendmsg+0x18/0x40
[ 48.875904] ___sys_sendmsg+0x294/0x2d0
[ 48.875908] __sys_sendmsg+0x68/0xb8
[ 48.875911] __arm64_sys_sendmsg+0x20/0x28
[ 48.875914] el0_svc_common+0x90/0x118
[ 48.875918] el0_svc_handler+0x2c/0x80
[ 48.875922] el0_svc+0x8/0xc

Most of the patches have now been acked (missing a couple of ack from Joerg).

I was able to test the changes in GICv2m and GICv3 ITS. I don't have
hardware for the other interrupt controllers.

Cheers,

Julien Grall (7):
genirq/msi: Add a new field in msi_desc to store an IOMMU cookie
iommu/dma-iommu: Split iommu_dma_map_msi_msg() in two parts
irqchip/gicv2m: Don't map the MSI page in gicv2m_compose_msi_msg()
irqchip/gic-v3-its: Don't map the MSI page in
its_irq_compose_msi_msg()
irqchip/ls-scfg-msi: Don't map the MSI page in
ls_scfg_msi_compose_msg()
irqchip/gic-v3-mbi: Don't map the MSI page in mbi_compose_m{b,
s}i_msg()
iommu/dma-iommu: Remove iommu_dma_map_msi_msg()

drivers/iommu/Kconfig | 1 +
drivers/iommu/dma-iommu.c | 48 +++++++++++++++++++++++----------------
drivers/irqchip/irq-gic-v2m.c | 8 ++++++-
drivers/irqchip/irq-gic-v3-its.c | 7 +++++-
drivers/irqchip/irq-gic-v3-mbi.c | 15 ++++++++++--
drivers/irqchip/irq-ls-scfg-msi.c | 7 +++++-
include/linux/dma-iommu.h | 24 ++++++++++++++++++--
include/linux/msi.h | 26 +++++++++++++++++++++
kernel/irq/Kconfig | 3 +++
9 files changed, 112 insertions(+), 27 deletions(-)

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2.11.0