Add an initial implementation of a proper (i.e. an ELF shared library)
VDSO. With this commit it does not export any symbols, it only replaces
the current signal return trampoline page. A later commit will add user
implementations of gettimeofday()/clock_gettime().

To support both new toolchains and old ones which don't generate ABI
flags section, we define its content manually and then use a tool
(genvdso) to patch up the section to have the correct name and type.
genvdso also extracts symbol offsets ({,rt_}sigreturn) needed by the
kernel, and generates a C file containing a "struct mips_vdso_image"
containing both the VDSO data and these offsets. This C file is
compiled into the kernel.

On 64-bit kernels we require a different VDSO for each supported ABI,
so we may build up to 3 different VDSOs. The VDSO to use is selected by
the mips_abi structure.

A kernel/user shared data page is created and mapped below the VDSO
image. This is currently empty, but will be used by the user time
function implementations which are added later.

[markos.chandras@imgtec.com:
- Add more comments
- Move abi detection in genvdso.h since it's the get_symbol function
that needs it.
- Add an R6 specific way to calculate the base address of VDSO in order
to avoid the branch instruction which affects performance.
- Do not patch .gnu.attributes since it's not needed for dynamic linking.
- Simplify Makefile a little bit.
- checkpatch fixes
- Restrict VDSO support for binutils < 2.25 for pre-R6
- Include atomic64.h for O32 variant on MIPS64]
Signed-off-by: NAlex Smith <alex.smith@imgtec.com>
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11337/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This adds initial support for BPF-JIT on MIPS

Tested on mips32 LE/BE and mips64 BE/n64 using
dhcp, ping and various tcpdump filters.

Benchmarking:

Assuming the remote MIPS target uses 192.168.154.181
as its IP address, and the local host uses 192.168.154.136,
the following results can be obtained using the following
tcpdump filter (catches no frames) and a simple
'time ping -f -c 1000000' command.

[root@(none) ~]# tcpdump -p -n -s 0 -i eth0 net 10.0.0.0/24 -d
(000) ldh      [12]
(001) jeq      #0x800           jt 2	jf 8
(002) ld       [26]
(003) and      #0xffffff00
(004) jeq      #0xa000000       jt 16	jf 5
(005) ld       [30]
(006) and      #0xffffff00
(007) jeq      #0xa000000       jt 16	jf 17
(008) jeq      #0x806           jt 10	jf 9
(009) jeq      #0x8035          jt 10	jf 17
(010) ld       [28]
(011) and      #0xffffff00
(012) jeq      #0xa000000       jt 16	jf 13
(013) ld       [38]
(014) and      #0xffffff00
(015) jeq      #0xa000000       jt 16	jf 17
(016) ret      #65535

- BPF-JIT Disabled

real    1m38.005s
user    0m1.510s
sys     0m6.710s

- BPF-JIT Enabled

real    1m35.215s
user    0m1.200s
sys     0m4.140s

[ralf@linux-mips.org: Resolved conflict.]
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

ieee754d.o contains only debug code and dp_sqrt.o and sp_sqrt.o contain
code which for MIPS I/II/III systems we don't want to link.  Again the
savings can be considerable for some systems:

$ mips-linux-size --totals ieee754d.o dp_sqrt.o sp_sqrt.o
   text	   data	    bss	    dec	    hex	filename
   1624	      0	      0	   1624	    658	ieee754d.o
   2016	      0	      0	   2016	    7e0	dp_sqrt.o
    736	      0	      0	    736	    2e0	sp_sqrt.o
   4376	      0	      0	   4376	   1118	(TOTALS)
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

- Add the KVM option to MIPS build files.
- Add default config files for KVM host/guest kernels.
- Change the link address for the Malta KVM Guest kernel to UM (0x40100000).
- Add KVM Kconfig file with KVM/MIPS specific options
Signed-off-by: NSanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When running make clean, Kbuild doesn't process the .config file, so nothing
generates a platform-y variable.  We can get it to descend into the platform
directories by setting $(obj-).

The dec Platform file was unconditionally setting platform-, obliterating
its previous contents and preventing some directories from being cleaned.
This is change to an append operation '+=' to allow cavium-octeon to be
cleaned.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Patchwork: https://patchwork.linux-mips.org/patch/1718/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Move platform specific definitions to the platfrom directories.

Each platform shall do the following:
1) include an entry in arch/mips/Kbuild.platforms
2) add relevant definitions to arch/mips/<platform>/Platform

This commits changes ar7 to the new scheme as an example.

Introducing a platform speecific Platfrom file has following advantages:
1) decentralization of platfrom definitions
2) simplification af arch/mips/Makefile
3) force all platfrom to build with -Werror (done in arch/mips/Kbuild)

[Ralf: Remove forgotten -Werror from AR7 Makefile]
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
To: linux-mips <linux-mips@linux-mips.org>
To: Wu Zhangjin <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1302/
Patchwork: http://patchwork.linux-mips.org/patch/1308/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Adding subdirs-ccflags-y := -Werror to arch/mips/Kbuild
let us in one go cover all files with -Werror.

In addition this allows us to remove the
individual -Werror definition in various Makefile.

Adding the definition to Kbuild as a recursive
option help us not to forget to do so.

With this change we now compile arch/mips/kernel/cpufreq with -Werror

One drawback:
When specifying a subdirectory covered by the Kbuild file like this:

    make arch/mips/kernel/

then kbuild fails to pick up the -Werror definition.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
To: linux-mips <linux-mips@linux-mips.org>
To: Wu Zhangjin <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1301/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
To: linux-mips <linux-mips@linux-mips.org>
To: Wu Zhangjin <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1300/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>