linux_dsm_epyc7002/arch/arm/mm
Laurent Pinchart a93a121a96 ARM: dma-mapping: Don't tear down third-party mappings
arch_setup_dma_ops() is used in device probe code paths to create an
IOMMU mapping and attach it to the device. The function assumes that the
device is attached to a device-specific IOMMU instance (or at least a
device-specific TLB in a shared IOMMU instance) and thus creates a
separate mapping for every device.

On several systems (Renesas R-Car Gen2 being one of them), that
assumption is not true, and IOMMU mappings must be shared between
multiple devices. In those cases the IOMMU driver knows better than the
generic ARM dma-mapping layer and attaches mapping to devices manually
with arm_iommu_attach_device(), which sets the DMA ops for the device.

The arch_setup_dma_ops() function takes this into account and bails out
immediately if the device already has DMA ops assigned. However, the
corresponding arch_teardown_dma_ops() function, called from driver
unbind code paths (including probe deferral), will tear the mapping down
regardless of who created it. When the device is reprobed
arch_setup_dma_ops() will be called again but won't perform any
operation as the DMA ops will still be set.

We need to reset the DMA ops in arch_teardown_dma_ops() to fix this.
However, we can't do so unconditionally, as then a new mapping would be
created by arch_setup_dma_ops() when the device is reprobed, regardless
of whether the device needs to share a mapping or not. We must thus keep
track of whether arch_setup_dma_ops() created the mapping, and only in
that case tear it down in arch_teardown_dma_ops().

Keep track of that information in the dev_archdata structure. As the
structure is embedded in all instances of struct device let's not grow
it, but turn the existing dma_coherent bool field into a bitfield that
can be used for other purposes.

Fixes: 09515ef5dd ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices")
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-05-30 11:31:33 +02:00
..
abort-ev4.S
abort-ev4t.S
abort-ev5t.S
abort-ev5tj.S
abort-ev6.S
abort-ev7.S
abort-lv4t.S ARM: fix oops when using older ARMv4T CPUs 2016-10-19 10:18:43 +01:00
abort-macro.S
abort-nommu.S
alignment.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h> 2017-03-02 08:42:34 +01:00
cache-aurora-l2.h
cache-fa.S
cache-feroceon-l2.c
cache-l2x0-pmu.c cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
cache-l2x0.c ARM: 8659/1: l2c: allow CA9 optimizations to be disabled 2017-03-17 10:01:26 +00:00
cache-nop.S
cache-tauros2.c
cache-tauros3.h
cache-uniphier.c ARM: 8652/1: cache-uniphier: clean up active way setup code 2017-02-28 11:06:17 +00:00
cache-v4.S
cache-v4wb.S
cache-v4wt.S
cache-v6.S
cache-v7.S scripts/spelling.txt: add "swith" pattern and fix typo instances 2017-02-27 18:43:46 -08:00
cache-v7m.S scripts/spelling.txt: add "swith" pattern and fix typo instances 2017-02-27 18:43:46 -08:00
cache-xsc3l2.c
context.c
copypage-fa.c
copypage-feroceon.c
copypage-v4mc.c
copypage-v4wb.c
copypage-v4wt.c
copypage-v6.c
copypage-xsc3.c
copypage-xscale.c
dma-mapping.c ARM: dma-mapping: Don't tear down third-party mappings 2017-05-30 11:31:33 +02:00
dma.h
dump.c ARM: 8666/1: mm: dump: Add domain to output 2017-03-29 17:39:17 +01:00
extable.c arm: migrate exception table users off module.h and onto extable.h 2017-01-24 12:41:46 -05:00
fault-armv.c
fault.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h> 2017-03-02 08:42:34 +01:00
fault.h ARM: 8642/1: LPAE: catch pending imprecise abort on unmask 2017-01-30 12:04:12 +00:00
flush.c ARM: 8627/1: avoid cache flushing in flush_dcache_page() 2017-01-10 23:31:30 +00:00
fsr-2level.c
fsr-3level.c
highmem.c
hugetlbpage.c
idmap.c sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
init.c ARM: 8672/1: mm: remove tasklist locking from update_sections_early() 2017-04-26 10:59:36 +01:00
iomap.c
ioremap.c ARM: Implement pci_remap_cfgspace() interface 2017-04-24 13:53:13 -05:00
Kconfig Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-02-28 11:50:53 -08:00
l2c-common.c
l2c-l2x0-resume.S
Makefile ARM: 8640/1: Add support for CONFIG_DEBUG_VIRTUAL 2017-02-28 11:06:09 +00:00
mm.h
mmap.c sched/headers: Prepare for new header dependencies before moving more code to <linux/sched/mm.h> 2017-03-02 08:42:30 +01:00
mmu.c * ARM: HYP mode stub supports kexec/kdump on 32-bit; improved PMU 2017-05-08 12:37:56 -07:00
nommu.c pci-v4.12-changes 2017-05-08 19:03:25 -07:00
pabort-legacy.S
pabort-v6.S
pabort-v7.S
pageattr.c arm: use set_memory.h header 2017-05-08 17:15:13 -07:00
pgd.c
physaddr.c ARM: 8640/1: Add support for CONFIG_DEBUG_VIRTUAL 2017-02-28 11:06:09 +00:00
proc-arm7tdmi.S
proc-arm9tdmi.S
proc-arm720.S
proc-arm740.S
proc-arm920.S
proc-arm922.S
proc-arm925.S
proc-arm926.S
proc-arm940.S
proc-arm946.S
proc-arm1020.S
proc-arm1020e.S
proc-arm1022.S
proc-arm1026.S
proc-fa526.S
proc-feroceon.S
proc-macros.S
proc-mohawk.S
proc-sa110.S
proc-sa1100.S
proc-syms.c
proc-v6.S
proc-v7-2level.S
proc-v7-3level.S
proc-v7.S ARM: Update cpu_v7_reset documentation 2017-04-09 07:49:25 -07:00
proc-v7m.S Merge branches 'fixes' and 'misc' into for-next 2017-04-26 10:59:49 +01:00
proc-xsc3.S
proc-xscale.S
pv-fixup-asm.S
tcm.h
tlb-fa.S
tlb-v4.S
tlb-v4wb.S
tlb-v4wbi.S
tlb-v6.S
tlb-v7.S