[PATCH 0/3] Remove x86-specific code from generic headers

[Thiago Jung Bauermann]

Hello,

This version mostly changes patch 2/3, removing dma_check_mask() from
kernel/dma/mapping.c as suggested by Christoph Hellwig, and also adapting
s390's <asm/mem_encrypt.h>. There's also a small change in patch 1/3 as
mentioned in the changelog below.

Patch 3/3 may or may not need to change s390 code depending on how Tom
Lendacky's patch is fixed to avoid breaking that architecture, so I haven't
made any changes for now.

These patches are applied on top of today's master which at the time was at
commit 9787aed57dd3 ("coresight: Make the coresight_device_fwnode_match
declaration's fwnode parameter const"), plus a cherry-pick of commit
e67a5ed1f86f ("dma-direct: Force unencrypted DMA under SME for certain DMA
masks"), which is in dma-mapping/for-next and comes from this patch:

https://lore.kernel.org/linux-iommu/10b83d9ff31bca88e94da2ff34e30619eb396078.1562785123.git.thomas.lendacky@amd.com/

I don't have a way to test SME, SEV, nor s390's PEF so the patches have only
been build tested.

Original cover letter below:

Both powerpc¹ and s390² are adding <asm/mem_encrypt.h> headers. Currently,
they have to supply definitions for functions and macros which only have a
meaning on x86: sme_me_mask, sme_active() and sev_active().

Christoph Hellwig made a suggestion to "clean up the Kconfig and generic
headers bits for memory encryption so that we don't need all this
boilerplate code", and this is what this patch does.

After this patch set, this is powerpc's <asm/mem_encrypt.h>:

    #ifndef _ASM_POWERPC_MEM_ENCRYPT_H
    #define _ASM_POWERPC_MEM_ENCRYPT_H

    #include <asm/svm.h>

    static inline bool mem_encrypt_active(void)
    {
	    return is_secure_guest();
    }

    static inline bool force_dma_unencrypted(struct device *dev)
    {
	    return is_secure_guest();
    }

    int set_memory_encrypted(unsigned long addr, int numpages);
    int set_memory_decrypted(unsigned long addr, int numpages);

    #endif /* _ASM_POWERPC_MEM_ENCRYPT_H */

Changelog

Since v1:

- Patch "x86,s390: Move ARCH_HAS_MEM_ENCRYPT definition to arch/Kconfig"
  - Remove definition of ARCH_HAS_MEM_ENCRYPT from s390/Kconfig as well.
  - Reworded patch title and message a little bit.

- Patch "DMA mapping: Move SME handling to x86-specific files"
  - Adapt s390's <asm/mem_encrypt.h> as well.
  - Remove dma_check_mask() from kernel/dma/mapping.c. Suggested by
    Christoph Hellwig.

-- 

¹ https://lore.kernel.org/linuxppc-dev/20190521044912.1375-12-bauerman@linux.ibm.com/
² https://lore.kernel.org/kvm/20190612111236.99538-2-pasic@linux.ibm.com/

Thiago Jung Bauermann (3):
  x86,s390: Move ARCH_HAS_MEM_ENCRYPT definition to arch/Kconfig
  DMA mapping: Move SME handling to x86-specific files
  fs/core/vmcore: Move sev_active() reference to x86 arch code

 arch/Kconfig                        |  3 +++
 arch/s390/Kconfig                   |  3 ---
 arch/s390/include/asm/mem_encrypt.h |  4 +---
 arch/x86/Kconfig                    |  4 +---
 arch/x86/include/asm/mem_encrypt.h  | 10 ++++++++++
 arch/x86/kernel/crash_dump_64.c     |  5 +++++
 fs/proc/vmcore.c                    |  8 ++++----
 include/linux/crash_dump.h          | 14 ++++++++++++++
 include/linux/mem_encrypt.h         | 15 +--------------
 kernel/dma/mapping.c                |  8 --------
 kernel/dma/swiotlb.c                |  3 +--
 11 files changed, 40 insertions(+), 37 deletions(-)