Re: git: 3a60869237b8 - main - Add assembly optimized code for OpenSSL on powerpc, powerpc64 and powerpc64le

On 21-11-24 10:34:36, John Baldwin wrote:
> On 11/24/21 10:24 AM, Piotr Kubaj wrote:
> > OK, it looks like ossl uses fpu_kern functions and those are available only an aarch64, amd64 and i386:
> > cc  -O2 -pipe -fno-common  -fno-strict-aliasing -Werror -D_KERNEL -DKLD_MODULE -nostdinc   -include /usr/obj/usr/src/powerpc.powerpc64/sys/modules/ossl/opt_global.h -I. -I/usr/src/sys -I/usr/src/sys/contrib/ck/include -fno-common  -fPIC -mlongcall -fno-omit-frame-pointer -fdebug-prefix-map=./machine=/usr/src/sys/powerpc/include     -MD  -MF.depend.ossl.o -MTossl.o -mno-altivec -msoft-float -mabi=elfv2 -ffreestanding -fwrapv -fstack-protector -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith -Wcast-qual -Wundef -Wno-pointer-sign -D__printf__=__freebsd_kprintf__ -Wmissing-include-dirs -fdiagnostics-show-option -Wno-unknown-pragmas -Wno-error-tautological-compare -Wno-error-empty-body -Wno-error-parentheses-equality -Wno-error-unused-function -Wno-error-pointer-sign -Wno-error-shift-negative-value -Wno-address-of-packed-member -Wno-format-zero-length     -std=iso9899:1999 -c /usr/src/sys/crypto/openssl/ossl.c -o ossl.o
> > /usr/src/sys/crypto/openssl/ossl.c:190:4: error: implicit declaration of function 'fpu_kern_enter' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
> >                          fpu_kern_enter(curthread, NULL, FPU_KERN_NOCTX);
> >                          ^
> > /usr/src/sys/crypto/openssl/ossl.c:190:36: error: use of undeclared identifier 'FPU_KERN_NOCTX'
> >                          fpu_kern_enter(curthread, NULL, FPU_KERN_NOCTX);
> >                                                          ^
> > /usr/src/sys/crypto/openssl/ossl.c:193:4: error: implicit declaration of function 'fpu_kern_leave' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
> >                          fpu_kern_leave(curthread, NULL);
> >                          ^
> > /usr/src/sys/crypto/openssl/ossl.c:193:4: note: did you mean 'fpu_kern_enter'?
> > /usr/src/sys/crypto/openssl/ossl.c:190:4: note: 'fpu_kern_enter' declared here
> >                          fpu_kern_enter(curthread, NULL, FPU_KERN_NOCTX);
> >                          ^
> > /usr/src/sys/crypto/openssl/ossl.c:214:6: error: implicit declaration of function 'is_fpu_kern_thread' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
> >          if (is_fpu_kern_thread(0)) {
> >              ^
> > /usr/src/sys/crypto/openssl/ossl.c:217:3: error: implicit declaration of function 'fpu_kern_enter' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
> >                  fpu_kern_enter(curthread, NULL, FPU_KERN_NOCTX);
> >                  ^
> > /usr/src/sys/crypto/openssl/ossl.c:217:35: error: use of undeclared identifier 'FPU_KERN_NOCTX'
> >                  fpu_kern_enter(curthread, NULL, FPU_KERN_NOCTX);
> >                                                  ^
> > /usr/src/sys/crypto/openssl/ossl.c:263:3: error: implicit declaration of function 'fpu_kern_leave' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
> >                  fpu_kern_leave(curthread, NULL);
> >                  ^
> > 7 errors generated.
> > 
> > AFAIK porting those is not easy and it's certainly above my pay grade.
> 
> Do the powerpc instructions use additional registers that are not part of the normal
> GPRs saved/restored on a context switch?  If so, then, yes, you will need to implement
> something here (though the FPU_KERN_NOCTX variant is a bit simpler as it disables
> context switches and it's sufficient just to init the registers and permit accesses
> without raising a trap until fpu_kern_leave).  If not, then you can make the use of
> those functions conditional on architecture.

I guess bdragon, jhibbits, luporl or adalava would be better source of information.

That said, after looking at https://community.nxp.com/t5/MPC5xxx/Example-code-for-context-switch-for-MPC56XX-PowerPC/m-p/732248/highlight/true, it seems like indeed registers other than GPRs are saved and restored.


I tried looking at https://cgit.freebsd.org/src/diff/?id=6ed982a221e024d64dd0ab776e6197643fa1530e. fpu_kern_enter() and fpu_kern_leave() are quite scary :)

> 
> > On 21-11-24 08:15:26, John Baldwin wrote:
> >> On 11/23/21 2:27 PM, Piotr Kubaj wrote:
> >>> The branch main has been updated by pkubaj (ports committer):
> >>>
> >>> URL: https://cgit.FreeBSD.org/src/commit/?id=3a60869237b8b315fe66497cf5299ec08b688533
> >>>
> >>> commit 3a60869237b8b315fe66497cf5299ec08b688533
> >>> Author:     Piotr Kubaj <pkubaj@FreeBSD.org>
> >>> AuthorDate: 2021-11-22 02:28:46 +0000
> >>> Commit:     Piotr Kubaj <pkubaj@FreeBSD.org>
> >>> CommitDate: 2021-11-23 22:26:53 +0000
> >>>
> >>>       Add assembly optimized code for OpenSSL on powerpc, powerpc64 and powerpc64le
> >>>       
> >>>       Summary:
> >>>       1. https://github.com/openssl/openssl/commit/34ab13b7d8e3e723adb60be8142e38b7c9cd382a
> >>>       needs to be merged for ELFv2 support on big-endian.
> >>>       2. crypto/openssl/crypto/ppccap.c needs to be patched.
> >>>       Same reason as in https://github.com/openssl/openssl/pull/17082.
> >>
> >> Have you looked at adding powerpc support to ossl(4)?  It should be fairly simple
> >> (just adding the right asm files in Makefiles and the powerpc equivalent of
> >> OSSL_cpuid).
> >>
> >> -- 
> >> John Baldwin
> 
> 
> -- 
> John Baldwin

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