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-rw-r--r--arch/arm/vfp/vfp.h4
-rw-r--r--arch/arm/vfp/vfphw.S60
-rw-r--r--arch/arm/vfp/vfpinstr.h6
-rw-r--r--arch/arm/vfp/vfpmodule.c98
4 files changed, 99 insertions, 69 deletions
diff --git a/arch/arm/vfp/vfp.h b/arch/arm/vfp/vfp.h
index 791d0238c68f..c85860bad585 100644
--- a/arch/arm/vfp/vfp.h
+++ b/arch/arm/vfp/vfp.h
@@ -265,7 +265,11 @@ struct vfp_double {
* which returns (double)0.0. This is useful for the compare with
* zero instructions.
*/
+#ifdef CONFIG_VFPv3
+#define VFP_REG_ZERO 32
+#else
#define VFP_REG_ZERO 16
+#endif
extern u64 vfp_get_double(unsigned int reg);
extern void vfp_put_double(u64 val, unsigned int reg);
diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S
index 0ac022f800a1..353f9e5c7919 100644
--- a/arch/arm/vfp/vfphw.S
+++ b/arch/arm/vfp/vfphw.S
@@ -99,12 +99,12 @@ vfp_support_entry:
DBGSTR1 "save old state %p", r4
cmp r4, #0
beq no_old_VFP_process
+ VFPFSTMIA r4, r5 @ save the working registers
VFPFMRX r5, FPSCR @ current status
- VFPFMRX r6, FPINST @ FPINST (always there, rev0 onwards)
- tst r1, #FPEXC_FPV2 @ is there an FPINST2 to read?
- VFPFMRX r8, FPINST2, NE @ FPINST2 if needed - avoids reading
- @ nonexistant reg on rev0
- VFPFSTMIA r4 @ save the working registers
+ tst r1, #FPEXC_EX @ is there additional state to save?
+ VFPFMRX r6, FPINST, NE @ FPINST (only if FPEXC.EX is set)
+ tstne r1, #FPEXC_FP2V @ is there an FPINST2 to read?
+ VFPFMRX r8, FPINST2, NE @ FPINST2 if needed (and present)
stmia r4, {r1, r5, r6, r8} @ save FPEXC, FPSCR, FPINST, FPINST2
@ and point r4 at the word at the
@ start of the register dump
@@ -114,13 +114,13 @@ no_old_VFP_process:
DBGSTR1 "load state %p", r10
str r10, [r3, r11, lsl #2] @ update the last_VFP_context pointer
@ Load the saved state back into the VFP
- VFPFLDMIA r10 @ reload the working registers while
+ VFPFLDMIA r10, r5 @ reload the working registers while
@ FPEXC is in a safe state
ldmia r10, {r1, r5, r6, r8} @ load FPEXC, FPSCR, FPINST, FPINST2
- tst r1, #FPEXC_FPV2 @ is there an FPINST2 to write?
- VFPFMXR FPINST2, r8, NE @ FPINST2 if needed - avoids writing
- @ nonexistant reg on rev0
- VFPFMXR FPINST, r6
+ tst r1, #FPEXC_EX @ is there additional state to restore?
+ VFPFMXR FPINST, r6, NE @ restore FPINST (only if FPEXC.EX is set)
+ tstne r1, #FPEXC_FP2V @ is there an FPINST2 to write?
+ VFPFMXR FPINST2, r8, NE @ FPINST2 if needed (and present)
VFPFMXR FPSCR, r5 @ restore status
check_for_exception:
@@ -136,10 +136,14 @@ check_for_exception:
look_for_VFP_exceptions:
- tst r1, #FPEXC_EX
+ @ Check for synchronous or asynchronous exception
+ tst r1, #FPEXC_EX | FPEXC_DEX
bne process_exception
+ @ On some implementations of the VFP subarch 1, setting FPSCR.IXE
+ @ causes all the CDP instructions to be bounced synchronously without
+ @ setting the FPEXC.EX bit
VFPFMRX r5, FPSCR
- tst r5, #FPSCR_IXE @ IXE doesn't set FPEXC_EX !
+ tst r5, #FPSCR_IXE
bne process_exception
@ Fall into hand on to next handler - appropriate coproc instr
@@ -150,10 +154,6 @@ look_for_VFP_exceptions:
process_exception:
DBGSTR "bounce"
- sub r2, r2, #4
- str r2, [sp, #S_PC] @ retry the instruction on exit from
- @ the imprecise exception handling in
- @ the support code
mov r2, sp @ nothing stacked - regdump is at TOS
mov lr, r9 @ setup for a return to the user code.
@@ -161,7 +161,7 @@ process_exception:
@ r0 holds the trigger instruction
@ r1 holds the FPEXC value
@ r2 pointer to register dump
- b VFP9_bounce @ we have handled this - the support
+ b VFP_bounce @ we have handled this - the support
@ code will raise an exception if
@ required. If not, the user code will
@ retry the faulted instruction
@@ -174,12 +174,12 @@ vfp_save_state:
@ r0 - save location
@ r1 - FPEXC
DBGSTR1 "save VFP state %p", r0
+ VFPFSTMIA r0, r2 @ save the working registers
VFPFMRX r2, FPSCR @ current status
- VFPFMRX r3, FPINST @ FPINST (always there, rev0 onwards)
- tst r1, #FPEXC_FPV2 @ is there an FPINST2 to read?
- VFPFMRX r12, FPINST2, NE @ FPINST2 if needed - avoids reading
- @ nonexistant reg on rev0
- VFPFSTMIA r0 @ save the working registers
+ tst r1, #FPEXC_EX @ is there additional state to save?
+ VFPFMRX r3, FPINST, NE @ FPINST (only if FPEXC.EX is set)
+ tstne r1, #FPEXC_FP2V @ is there an FPINST2 to read?
+ VFPFMRX r12, FPINST2, NE @ FPINST2 if needed (and present)
stmia r0, {r1, r2, r3, r12} @ save FPEXC, FPSCR, FPINST, FPINST2
mov pc, lr
#endif
@@ -217,8 +217,15 @@ vfp_get_double:
fmrrd r0, r1, d\dr
mov pc, lr
.endr
+#ifdef CONFIG_VFPv3
+ @ d16 - d31 registers
+ .irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
+ mrrc p11, 3, r0, r1, c\dr @ fmrrd r0, r1, d\dr
+ mov pc, lr
+ .endr
+#endif
- @ virtual register 16 for compare with zero
+ @ virtual register 16 (or 32 if VFPv3) for compare with zero
mov r0, #0
mov r1, #0
mov pc, lr
@@ -231,3 +238,10 @@ vfp_put_double:
fmdrr d\dr, r0, r1
mov pc, lr
.endr
+#ifdef CONFIG_VFPv3
+ @ d16 - d31 registers
+ .irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
+ mcrr p11, 3, r1, r2, c\dr @ fmdrr r1, r2, d\dr
+ mov pc, lr
+ .endr
+#endif
diff --git a/arch/arm/vfp/vfpinstr.h b/arch/arm/vfp/vfpinstr.h
index 7f343a4beca0..15b95b5ab97e 100644
--- a/arch/arm/vfp/vfpinstr.h
+++ b/arch/arm/vfp/vfpinstr.h
@@ -52,11 +52,11 @@
#define FEXT_TO_IDX(inst) ((inst & 0x000f0000) >> 15 | (inst & (1 << 7)) >> 7)
#define vfp_get_sd(inst) ((inst & 0x0000f000) >> 11 | (inst & (1 << 22)) >> 22)
-#define vfp_get_dd(inst) ((inst & 0x0000f000) >> 12)
+#define vfp_get_dd(inst) ((inst & 0x0000f000) >> 12 | (inst & (1 << 22)) >> 18)
#define vfp_get_sm(inst) ((inst & 0x0000000f) << 1 | (inst & (1 << 5)) >> 5)
-#define vfp_get_dm(inst) ((inst & 0x0000000f))
+#define vfp_get_dm(inst) ((inst & 0x0000000f) | (inst & (1 << 5)) >> 1)
#define vfp_get_sn(inst) ((inst & 0x000f0000) >> 15 | (inst & (1 << 7)) >> 7)
-#define vfp_get_dn(inst) ((inst & 0x000f0000) >> 16)
+#define vfp_get_dn(inst) ((inst & 0x000f0000) >> 16 | (inst & (1 << 7)) >> 3)
#define vfp_single(inst) (((inst) & 0x0000f00) == 0xa00)
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index b4e210df92f2..32455c633f1c 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -125,13 +125,13 @@ void vfp_raise_sigfpe(unsigned int sicode, struct pt_regs *regs)
send_sig_info(SIGFPE, &info, current);
}
-static void vfp_panic(char *reason)
+static void vfp_panic(char *reason, u32 inst)
{
int i;
printk(KERN_ERR "VFP: Error: %s\n", reason);
printk(KERN_ERR "VFP: EXC 0x%08x SCR 0x%08x INST 0x%08x\n",
- fmrx(FPEXC), fmrx(FPSCR), fmrx(FPINST));
+ fmrx(FPEXC), fmrx(FPSCR), inst);
for (i = 0; i < 32; i += 2)
printk(KERN_ERR "VFP: s%2u: 0x%08x s%2u: 0x%08x\n",
i, vfp_get_float(i), i+1, vfp_get_float(i+1));
@@ -147,19 +147,16 @@ static void vfp_raise_exceptions(u32 exceptions, u32 inst, u32 fpscr, struct pt_
pr_debug("VFP: raising exceptions %08x\n", exceptions);
if (exceptions == VFP_EXCEPTION_ERROR) {
- vfp_panic("unhandled bounce");
+ vfp_panic("unhandled bounce", inst);
vfp_raise_sigfpe(0, regs);
return;
}
/*
- * If any of the status flags are set, update the FPSCR.
+ * Update the FPSCR with the additional exception flags.
* Comparison instructions always return at least one of
* these flags set.
*/
- if (exceptions & (FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V))
- fpscr &= ~(FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V);
-
fpscr |= exceptions;
fmxr(FPSCR, fpscr);
@@ -220,35 +217,64 @@ static u32 vfp_emulate_instruction(u32 inst, u32 fpscr, struct pt_regs *regs)
/*
* Package up a bounce condition.
*/
-void VFP9_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs)
+void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs)
{
- u32 fpscr, orig_fpscr, exceptions, inst;
+ u32 fpscr, orig_fpscr, fpsid, exceptions;
pr_debug("VFP: bounce: trigger %08x fpexc %08x\n", trigger, fpexc);
/*
- * Enable access to the VFP so we can handle the bounce.
+ * At this point, FPEXC can have the following configuration:
+ *
+ * EX DEX IXE
+ * 0 1 x - synchronous exception
+ * 1 x 0 - asynchronous exception
+ * 1 x 1 - sychronous on VFP subarch 1 and asynchronous on later
+ * 0 0 1 - synchronous on VFP9 (non-standard subarch 1
+ * implementation), undefined otherwise
+ *
+ * Clear various bits and enable access to the VFP so we can
+ * handle the bounce.
*/
- fmxr(FPEXC, fpexc & ~(FPEXC_EX|FPEXC_FPV2|FPEXC_INV|FPEXC_UFC|FPEXC_OFC|FPEXC_IOC));
+ fmxr(FPEXC, fpexc & ~(FPEXC_EX|FPEXC_DEX|FPEXC_FP2V|FPEXC_VV|FPEXC_TRAP_MASK));
+ fpsid = fmrx(FPSID);
orig_fpscr = fpscr = fmrx(FPSCR);
/*
- * If we are running with inexact exceptions enabled, we need to
- * emulate the trigger instruction. Note that as we're emulating
- * the trigger instruction, we need to increment PC.
+ * Check for the special VFP subarch 1 and FPSCR.IXE bit case
*/
- if (fpscr & FPSCR_IXE) {
- regs->ARM_pc += 4;
+ if ((fpsid & FPSID_ARCH_MASK) == (1 << FPSID_ARCH_BIT)
+ && (fpscr & FPSCR_IXE)) {
+ /*
+ * Synchronous exception, emulate the trigger instruction
+ */
goto emulate;
}
- barrier();
+ if (fpexc & FPEXC_EX) {
+ /*
+ * Asynchronous exception. The instruction is read from FPINST
+ * and the interrupted instruction has to be restarted.
+ */
+ trigger = fmrx(FPINST);
+ regs->ARM_pc -= 4;
+ } else if (!(fpexc & FPEXC_DEX)) {
+ /*
+ * Illegal combination of bits. It can be caused by an
+ * unallocated VFP instruction but with FPSCR.IXE set and not
+ * on VFP subarch 1.
+ */
+ vfp_raise_exceptions(VFP_EXCEPTION_ERROR, trigger, fpscr, regs);
+ return;
+ }
/*
- * Modify fpscr to indicate the number of iterations remaining
+ * Modify fpscr to indicate the number of iterations remaining.
+ * If FPEXC.EX is 0, FPEXC.DEX is 1 and the FPEXC.VV bit indicates
+ * whether FPEXC.VECITR or FPSCR.LEN is used.
*/
- if (fpexc & FPEXC_EX) {
+ if (fpexc & (FPEXC_EX | FPEXC_VV)) {
u32 len;
len = fpexc + (1 << FPEXC_LENGTH_BIT);
@@ -262,15 +288,15 @@ void VFP9_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs)
* FPEXC bounce reason, but this appears to be unreliable.
* Emulate the bounced instruction instead.
*/
- inst = fmrx(FPINST);
- exceptions = vfp_emulate_instruction(inst, fpscr, regs);
+ exceptions = vfp_emulate_instruction(trigger, fpscr, regs);
if (exceptions)
- vfp_raise_exceptions(exceptions, inst, orig_fpscr, regs);
+ vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs);
/*
- * If there isn't a second FP instruction, exit now.
+ * If there isn't a second FP instruction, exit now. Note that
+ * the FPEXC.FP2V bit is valid only if FPEXC.EX is 1.
*/
- if (!(fpexc & FPEXC_FPV2))
+ if (fpexc ^ (FPEXC_EX | FPEXC_FP2V))
return;
/*
@@ -279,10 +305,9 @@ void VFP9_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs)
*/
barrier();
trigger = fmrx(FPINST2);
- orig_fpscr = fpscr = fmrx(FPSCR);
emulate:
- exceptions = vfp_emulate_instruction(trigger, fpscr, regs);
+ exceptions = vfp_emulate_instruction(trigger, orig_fpscr, regs);
if (exceptions)
vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs);
}
@@ -306,16 +331,9 @@ static int __init vfp_init(void)
{
unsigned int vfpsid;
unsigned int cpu_arch = cpu_architecture();
- u32 access = 0;
- if (cpu_arch >= CPU_ARCH_ARMv6) {
- access = get_copro_access();
-
- /*
- * Enable full access to VFP (cp10 and cp11)
- */
- set_copro_access(access | CPACC_FULL(10) | CPACC_FULL(11));
- }
+ if (cpu_arch >= CPU_ARCH_ARMv6)
+ vfp_enable(NULL);
/*
* First check that there is a VFP that we can use.
@@ -329,15 +347,9 @@ static int __init vfp_init(void)
vfp_vector = vfp_null_entry;
printk(KERN_INFO "VFP support v0.3: ");
- if (VFP_arch) {
+ if (VFP_arch)
printk("not present\n");
-
- /*
- * Restore the copro access register.
- */
- if (cpu_arch >= CPU_ARCH_ARMv6)
- set_copro_access(access);
- } else if (vfpsid & FPSID_NODOUBLE) {
+ else if (vfpsid & FPSID_NODOUBLE) {
printk("no double precision support\n");
} else {
smp_call_function(vfp_enable, NULL, 1, 1);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.