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Fix the vfp code to work with the 16 register variants of the VFP unit. We

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check which variant we are on, and if it is a VFPv3 or v4, and has 32
double registers we save these. This fixes VFP support on Raspberry Pi.

While here clean fmrx and fmxr up to use the register names from vfp.h
as opposed to the raw register names.
This commit is contained in:
Andrew Turner 2013-06-13 21:31:33 +00:00
parent ef72505e6d
commit 93ef7ecb75
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=251712
2 changed files with 46 additions and 35 deletions
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77
sys/arm/arm/vfp.c
View File

@ -49,16 +49,18 @@ void set_coprocessorACR(u_int);
extern int vfp_exists;
static struct undefined_handler vfp10_uh, vfp11_uh;
/* If true the VFP unit has 32 double registers, otherwise it has 16 */
static int is_d32;
/* The VFMXR command using coprocessor commands */
#define fmxr(reg, val) \
__asm __volatile("mcr p10, 7, %0, " #reg " , c0, 0" :: "r" (val));
__asm __volatile("mcr p10, 7, %0, " __STRING(reg) " , c0, 0" :: "r"(val));
/* The VFMRX command using coprocessor commands */
#define fmrx(reg) \
({ u_int val = 0;\
__asm __volatile("mrc p10, 7, %0, " #reg " , c0, 0" : "=r" (val));\
val; \
__asm __volatile("mrc p10, 7, %0, " __STRING(reg) " , c0, 0" : "=r"(val));\
val; \
})
u_int
@ -83,24 +85,34 @@ void
vfp_init(void)
{
u_int fpsid, fpexc, tmp;
u_int coproc;
u_int coproc, vfp_arch;
coproc = get_coprocessorACR();
coproc |= COPROC10 | COPROC11;
set_coprocessorACR(coproc);
fpsid = fmrx(cr0); /* read the vfp system id */
fpexc = fmrx(cr8); /* read the vfp exception reg */
fpsid = fmrx(VFPSID); /* read the vfp system id */
fpexc = fmrx(VFPEXC); /* read the vfp exception reg */
if (!(fpsid & VFPSID_HARDSOFT_IMP)) {
vfp_exists = 1;
is_d32 = 0;
PCPU_SET(vfpsid, fpsid); /* save the VFPSID */
if ((fpsid & VFPSID_SUBVERSION2_MASK) == VFP_ARCH3) {
tmp = fmrx(cr7); /* extended registers */
vfp_arch =
(fpsid & VFPSID_SUBVERSION2_MASK) >> VFPSID_SUBVERSION_OFF;
if (vfp_arch >= VFP_ARCH3) {
tmp = fmrx(VMVFR0);
PCPU_SET(vfpmvfr0, tmp);
tmp = fmrx(cr6); /* extended registers */
if ((tmp & VMVFR0_RB_MASK) == 2)
is_d32 = 1;
tmp = fmrx(VMVFR1);
PCPU_SET(vfpmvfr1, tmp);
}
/* initialize the coprocess 10 and 11 calls
* These are called to restore the registers and enable
* the VFP hardware.
@ -129,7 +141,7 @@ vfp_bounce(u_int addr, u_int insn, struct trapframe *frame, int code)
if (!vfp_exists)
return 1; /* vfp does not exist */
fpexc = fmrx(cr8); /* read the vfp exception reg */
fpexc = fmrx(VFPEXC); /* read the vfp exception reg */
if (fpexc & VFPEXC_EN) {
vfptd = PCPU_GET(vfpcthread);
/* did the kernel call the vfp or exception that expect us
@ -147,7 +159,7 @@ vfp_bounce(u_int addr, u_int insn, struct trapframe *frame, int code)
vfp_store(&vfptd->td_pcb->pcb_vfpstate);
fpexc &= ~VFPEXC_EN;
fmxr(cr8, fpexc); /* turn vfp hardware off */
fmxr(VFPEXC, fpexc); /* turn vfp hardware off */
if (vfptd == curthread) {
/* kill the process - we do not handle emulation */
killproc(curthread->td_proc, "vfp emulation");
@ -158,7 +170,7 @@ vfp_bounce(u_int addr, u_int insn, struct trapframe *frame, int code)
vfptd, curthread);
}
fpexc |= VFPEXC_EN;
fmxr(cr8, fpexc); /* enable the vfp and repeat command */
fmxr(VFPEXC, fpexc); /* enable the vfp and repeat command */
curpcb = PCPU_GET(curpcb);
/* If we were the last process to use the VFP, the process did not
* use a VFP on another processor, then the registers in the VFP
@ -184,15 +196,14 @@ vfp_restore(struct vfp_state *vfpsave)
u_int vfpscr = 0;
if (vfpsave) {
__asm __volatile("ldc p10, c0, [%0], #128\n" /* d0-d31 */
#ifndef VFPv2
"ldcl p11, c0, [%0], #128\n" /* d16-d31 */
#else
"add %0, %0, #128\n" /* slip missing regs */
#endif
__asm __volatile("ldc p10, c0, [%0], #128\n" /* d0-d15 */
"cmp %0, 0\n" /* -D16 or -D32? */
"ldcleq p11, c0, [%0], #128\n" /* d16-d31 */
"addne %0, %0, #128\n" /* skip missing regs */
"ldr %1, [%0]\n" /* set old vfpscr */
"mcr p10, 7, %1, cr1, c0, 0\n"
:: "r" (vfpsave), "r" (vfpscr));
:: "r" (vfpsave), "r" (vfpscr), "r" (is_d32)
: "cc");
PCPU_SET(vfpcthread, PCPU_GET(curthread));
}
}
@ -211,24 +222,22 @@ vfp_store(struct vfp_state *vfpsave)
{
u_int tmp, vfpscr = 0;
tmp = fmrx(cr8); /* Is the vfp enabled? */
tmp = fmrx(VFPEXC); /* Is the vfp enabled? */
if (vfpsave && tmp & VFPEXC_EN) {
__asm __volatile("stc p11, c0, [%1], #128\n" /* d0-d31 */
#ifndef VFPv2
"stcl p11, c0, [%1], #128\n"
#else
"add %1, %1, #128\n"
#endif
"mrc p10, 7, %0, cr1, c0, 0\n"
"str %0, [%1]\n"
: "=&r" (vfpscr) : "r" (vfpsave));
__asm __volatile("stc p11, c0, [%1], #128\n" /* d0-d15 */
"cmp %0, 0\n" /* -D16 or -D32? */
"stcleq p11, c0, [%1], #128\n" /* d16-d31 */
"addne %1, %1, #128\n" /* skip missing regs */
"mrc p10, 7, %0, cr1, c0, 0\n" /* fmxr(VFPSCR) */
"str %0, [%1]\n" /* save vfpscr */
: "=&r" (vfpscr) : "r" (vfpsave), "r" (is_d32) : "cc");
}
#ifndef SMP
/* eventually we will use this information for UP also */
PCPU_SET(vfpcthread, 0);
#endif
tmp &= ~VFPEXC_EN; /* disable the vfp hardware */
fmxr(cr8 , tmp);
fmxr(VFPEXC , tmp);
}
/* discard the registers at cpu_thread_free() when fpcurthread == td.
@ -240,9 +249,9 @@ vfp_discard()
u_int tmp = 0;
PCPU_SET(vfpcthread, 0); /* permanent forget about reg */
tmp = fmrx(cr8);
tmp = fmrx(VFPEXC);
tmp &= ~VFPEXC_EN; /* turn off VFP hardware */
fmxr(cr8, tmp);
fmxr(VFPEXC, tmp);
}
/* Enable the VFP hardware without restoring registers.
@ -253,7 +262,7 @@ vfp_enable()
{
u_int tmp = 0;
tmp = fmrx(cr8);
tmp = fmrx(VFPEXC);
tmp |= VFPEXC_EN;
fmxr(cr8 , tmp);
fmxr(VFPEXC, tmp);
}

4
sys/arm/include/vfp.h
View File

@ -47,7 +47,9 @@
#define VFPSID_SUBVERSION_OFF 16
#define VFPSID_SUBVERSION2_MASK (0x000f0000) /* version 1 and 2 */
#define VFPSID_SUBVERSION3_MASK (0x007f0000) /* version 3 */
#define VFP_ARCH3 (0x00030000)
#define VFP_ARCH1 0x0
#define VFP_ARCH2 0x1
#define VFP_ARCH3 0x2
#define VFPSID_PARTNUMBER_OFF 8
#define VFPSID_PARTNUMBER_MASK (0x0000ff00)
#define VFPSID_VARIANT_OFF 4