linux.git/arch/x86/kernel/fpu/init.c, branch v5.17

x86/fpu: Add fpu_state_config::legacy_features

2021-10-26T08:18:09+00:00

The upcoming prctl() which is required to request the permission for a
dynamically enabled feature will also provide an option to retrieve the
supported features. If the CPU does not support XSAVE, the supported
features would be 0 even when the CPU supports FP and SSE.

Provide separate storage for the legacy feature set to avoid that and fill
in the bits in the legacy init function.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Chang S. Bae 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211021225527.10184-6-chang.seok.bae@intel.com

x86/fpu: Move xstate feature masks to fpu_*_cfg

2021-10-21T18:36:58+00:00

Move the feature mask storage to the kernel and user config
structs. Default and maximum feature set are the same for now.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211014230739.352041752@linutronix.de

x86/fpu: Move xstate size to fpu_*_cfg

2021-10-21T17:38:55+00:00

Use the new kernel and user space config storage to store and retrieve the
XSTATE buffer sizes. The default and the maximum size are the same for now,
but will change when support for dynamically enabled features is added.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211014230739.296830097@linutronix.de

x86/fpu: Cleanup fpu__init_system_xstate_size_legacy()

2021-10-21T17:18:43+00:00

Clean the function up before making changes.

No functional change.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211014230739.184014242@linutronix.de

x86/fpu: Add size and mask information to fpstate

2021-10-21T11:51:42+00:00

Add state size and feature mask information to the fpstate container. This
will be used for runtime checks with the upcoming support for dynamically
enabled features and dynamically sized buffers. That avoids conditionals
all over the place as the required information is accessible for both
default and extended buffers.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211013145322.921388806@linutronix.de

x86/fpu: Remove fpu::state

2021-10-20T21:58:29+00:00

All users converted. Remove it along with the sanity checks.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211013145322.765063318@linutronix.de

x86/fpu/core: Convert to fpstate

2021-10-20T21:54:26+00:00

Convert the rest of the core code to the new register storage mechanism in
preparation for dynamically sized buffers.

No functional change.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211013145322.659456185@linutronix.de

x86/fpu: Provide struct fpstate

2021-10-20T20:26:24+00:00

New xfeatures will not longer be automatically stored in the regular XSAVE
buffer in thread_struct::fpu.

The kernel will provide the default sized buffer for storing the regular
features up to AVX512 in thread_struct::fpu and if a task requests to use
one of the new features then the register storage has to be extended.

The state will be accessed via a pointer in thread_struct::fpu which
defaults to the builtin storage and can be switched when extended storage
is required.

To avoid conditionals all over the code, create a new container for the
register storage which will gain other information, e.g. size, feature
masks etc., later. For now it just contains the register storage, which
gives it exactly the same layout as the exiting fpu::state.

Stick fpu::state and the new fpu::__fpstate into an anonymous union and
initialize the pointer. Add build time checks to validate that both are
at the same place and have the same size.

This allows step by step conversion of all users.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211013145322.234458659@linutronix.de

x86/fpu: Replace the includes of fpu/internal.h

2021-10-20T13:27:29+00:00

Now that the file is empty, fixup all references with the proper includes
and delete the former kitchen sink.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211015011540.001197214@linutronix.de

x86/fpu: Mop up the internal.h leftovers

2021-10-20T13:27:29+00:00

Move the global interfaces to api.h and the rest into the core.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211015011539.948837194@linutronix.de