Fix mis-uses of 'cc-option' for warning disablement

This was triggered by one of my mis-uses causing odd build warnings on
sparc in linux-next, but while figuring out why the "obviously correct"
use

Fix mis-uses of 'cc-option' for warning disablement

This was triggered by one of my mis-uses causing odd build warnings on
sparc in linux-next, but while figuring out why the "obviously correct"
use of cc-option caused such odd breakage, I found eight other cases of
the same thing in the tree.

The root cause is that 'cc-option' doesn't work for checking negative
warning options (ie things like '-Wno-stringop-overflow') because gcc
will silently accept options it doesn't recognize, and so 'cc-option'
ends up thinking they are perfectly fine.

And it all works, until you have a situation where _another_ warning is
emitted. At that point the compiler will go "Hmm, maybe the user
intended to disable this warning but used that wrong option that I
didn't recognize", and generate a warning for the unrecognized negative
option.

Which explains why we have several cases of this in the tree: the
'cc-option' test really doesn't work for this situation, but most of the
time it simply doesn't matter that ity doesn't work.

The reason my recently added case caused problems on sparc was pointed
out by Thomas Weißschuh: the sparc build had a previous explicit warning
that then triggered the new one.

I think the best fix for this would be to make 'cc-option' a bit smarter
about this sitation, possibly by adding an intentional warning to the
test case that then triggers the unrecognized option warning reliably.

But the short-term fix is to replace 'cc-option' with an existing helper
designed for this exact case: 'cc-disable-warning', which picks the
negative warning but uses the positive form for testing the compiler
support.

Reported-by: Stephen Rothwell <[email protected]>
Link: https://lore.kernel.org/all/[email protected]/
Explained-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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LoongArch: KVM: Remove unnecessary header include path

arch/loongarch/kvm/ includes local headers with the double-quote form
(#include "..."). Also, TRACE_INCLUDE_PATH in arch/loongarch/kvm/trace.h

LoongArch: KVM: Remove unnecessary header include path

arch/loongarch/kvm/ includes local headers with the double-quote form
(#include "..."). Also, TRACE_INCLUDE_PATH in arch/loongarch/kvm/trace.h
is relative to include/trace/.

Hence, the local header search path is unneeded.

Reviewed-by: Bibo Mao <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: KVM: Add irqfd support

Enable the KVM_IRQ_ROUTING/KVM_IRQCHIP/KVM_MSI configuration items,
add the KVM_CAP_IRQCHIP capability, and implement the query interface
of the in-kernel irqchip.

LoongArch: KVM: Add irqfd support

Enable the KVM_IRQ_ROUTING/KVM_IRQCHIP/KVM_MSI configuration items,
add the KVM_CAP_IRQCHIP capability, and implement the query interface
of the in-kernel irqchip.

Signed-off-by: Xianglai Li <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: KVM: Add PCHPIC device support

Add device model for PCHPIC interrupt controller, implemente basic
create & destroy interface, and register device model to kvm device
table.

Signed-off-by

LoongArch: KVM: Add PCHPIC device support

Add device model for PCHPIC interrupt controller, implemente basic
create & destroy interface, and register device model to kvm device
table.

Signed-off-by: Tianrui Zhao <[email protected]>
Signed-off-by: Xianglai Li <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: KVM: Add EIOINTC device support

Add device model for EIOINTC interrupt controller, implement basic
create & destroy interfaces, and register device model to kvm device
table.

Signed-off-

LoongArch: KVM: Add EIOINTC device support

Add device model for EIOINTC interrupt controller, implement basic
create & destroy interfaces, and register device model to kvm device
table.

Signed-off-by: Tianrui Zhao <[email protected]>
Signed-off-by: Xianglai Li <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: KVM: Add IPI device support

Add device model for IPI interrupt controller, implement basic create &
destroy interfaces, and register device model to kvm device table.

Signed-off-by: Tian

LoongArch: KVM: Add IPI device support

Add device model for IPI interrupt controller, implement basic create &
destroy interfaces, and register device model to kvm device table.

Signed-off-by: Tianrui Zhao <[email protected]>
Signed-off-by: Xianglai Li <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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kbuild: use $(src) instead of $(srctree)/$(src) for source directory

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention withou

kbuild: use $(src) instead of $(srctree)/$(src) for source directory

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

$(obj) - directory in the object tree
$(src) - directory in the source tree (changed by this commit)
$(objtree) - the top of the kernel object tree
$(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Nicolas Schier <[email protected]>

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LoongArch: KVM: Enable kvm config and add the makefile

Enable LoongArch kvm config and add the makefile to support build kvm
module.

Reviewed-by: Bibo Mao <[email protected]>
Tested-by: Huacai Ch

LoongArch: KVM: Enable kvm config and add the makefile

Enable LoongArch kvm config and add the makefile to support build kvm
module.

Reviewed-by: Bibo Mao <[email protected]>
Tested-by: Huacai Chen <[email protected]>
Signed-off-by: Tianrui Zhao <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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