diff options
| author | cinap_lenrek <cinap_lenrek@felloff.net> | 2017-11-04 20:08:22 +0100 |
|---|---|---|
| committer | cinap_lenrek <cinap_lenrek@felloff.net> | 2017-11-04 20:08:22 +0100 |
| commit | 24057fd4f494a00573d34adeaa7042721c1a06a0 (patch) | |
| tree | ca69cfd03461c148c60ba0137d20b93976f61b61 /sys/src/9/teg2 | |
| parent | 04ce485f1b4453335db70b4a1b5d2c96458db3c1 (diff) | |
kernel: introduce per process FPU struct (PFPU) for more flexible machine specific fpu handling
introducing the PFPU structue which allows the machine specific
code some flexibility on how to handle the FPU process state.
for example, in the pc and pc64 kernel, the FPsave structure is
arround 512 bytes. with avx512, it could grow up to 2K. instead
of embedding that into the Proc strucutre, it is more effective
to allocate it on first use of the fpu, as most processes do not
use simd or floating point in the first place. also, the FPsave
structure has special 16 byte alignment constraint, which further
favours dynamic allocation.
this gets rid of the memmoves in pc/pc64 kernels for the aligment.
there is also devproc, which is now checking if the fpsave area
is actually valid before reading it, avoiding debuggers to see
garbage data.
the Notsave structure is gone now, as it was not used on any
machine.
Diffstat (limited to 'sys/src/9/teg2')
| -rw-r--r-- | sys/src/9/teg2/dat.h | 24 | ||||
| -rw-r--r-- | sys/src/9/teg2/fpiarm.c | 2 |
2 files changed, 11 insertions, 15 deletions
diff --git a/sys/src/9/teg2/dat.h b/sys/src/9/teg2/dat.h index 0aa54a7d0..30dd4b5eb 100644 --- a/sys/src/9/teg2/dat.h +++ b/sys/src/9/teg2/dat.h @@ -24,6 +24,7 @@ enum { typedef struct Conf Conf; typedef struct Confmem Confmem; typedef struct FPsave FPsave; +typedef struct PFPU PFPU; typedef struct ISAConf ISAConf; typedef struct Isolated Isolated; typedef struct Label Label; @@ -33,7 +34,6 @@ typedef struct Memcache Memcache; typedef struct MMMU MMMU; typedef struct Mach Mach; typedef u32int Mreg; /* Msr - bloody UART */ -typedef struct Notsave Notsave; typedef struct Page Page; typedef struct Pcisiz Pcisiz; typedef struct Pcidev Pcidev; @@ -72,14 +72,14 @@ struct Label uintptr pc; }; +/* + * emulated or vfp3 floating point + */ enum { Maxfpregs = 32, /* could be 16 or 32, see Mach.fpnregs */ Nfpctlregs = 16, }; -/* - * emulated or vfp3 floating point - */ struct FPsave { ulong status; @@ -94,9 +94,12 @@ struct FPsave uintptr pc; /* of failed fp instr. */ }; -/* - * FPsave.fpstate - */ +struct PFPU +{ + int fpstate; + FPsave fpsave[1]; +}; + enum { FPinit, @@ -136,13 +139,6 @@ struct Conf }; /* - * things saved in the Proc structure during a notify - */ -struct Notsave { - int emptiness; -}; - -/* * MMU stuff in Mach. */ struct MMMU diff --git a/sys/src/9/teg2/fpiarm.c b/sys/src/9/teg2/fpiarm.c index d92455328..cefddc3e5 100644 --- a/sys/src/9/teg2/fpiarm.c +++ b/sys/src/9/teg2/fpiarm.c @@ -650,7 +650,7 @@ fpiarm(Ureg *ur) if(up == nil) panic("fpiarm not in a process"); - ufp = &up->fpsave; + ufp = up->fpsave; /* * because all the emulated fp state is in the proc structure, * it need not be saved/restored |