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authorLinus Torvalds <torvalds@linux-foundation.org>2023-05-01 11:52:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-05-01 11:52:32 -0700
commitd75439d64a1e2b35e0f08906205b00279753cbed (patch)
treea1dbe1281ef228f7999cd21ca3380931eacd8dd5 /arch/openrisc/kernel/entry.S
parent3f2a1903af06672f416efd506f029066b9243cbd (diff)
parentc91b4a07655d5ba67962a08dfac8bd7f45ad049c (diff)
Merge tag 'for-linus' of https://github.com/openrisc/linux
Pull OpenRISC updates from Stafford Horne: "Two things for OpenRISC this cycle: - Small cleanup for device tree cpu iteration from Rob Herring - Add support for storing, restoring and accessing user space FPU state, to allow for libc to support the FPU on OpenRISC" * tag 'for-linus' of https://github.com/openrisc/linux: openrisc: Add floating point regset openrisc: Support floating point user api openrisc: Support storing and restoring fpu state openrisc: Properly store r31 to pt_regs on unhandled exceptions openrisc: Use common of_get_cpu_node() instead of open-coding
Diffstat (limited to 'arch/openrisc/kernel/entry.S')
-rw-r--r--arch/openrisc/kernel/entry.S31
1 files changed, 25 insertions, 6 deletions
diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
index 54a87bba35ca..c9f48e750b72 100644
--- a/arch/openrisc/kernel/entry.S
+++ b/arch/openrisc/kernel/entry.S
@@ -106,6 +106,8 @@
l.mtspr r0,r3,SPR_EPCR_BASE ;\
l.lwz r3,PT_SR(r1) ;\
l.mtspr r0,r3,SPR_ESR_BASE ;\
+ l.lwz r3,PT_FPCSR(r1) ;\
+ l.mtspr r0,r3,SPR_FPCSR ;\
l.lwz r2,PT_GPR2(r1) ;\
l.lwz r3,PT_GPR3(r1) ;\
l.lwz r4,PT_GPR4(r1) ;\
@@ -173,9 +175,10 @@ handler: ;\
l.sw PT_GPR28(r1),r28 ;\
l.sw PT_GPR29(r1),r29 ;\
/* r30 already save */ ;\
-/* l.sw PT_GPR30(r1),r30*/ ;\
l.sw PT_GPR31(r1),r31 ;\
TRACE_IRQS_OFF_ENTRY ;\
+ l.mfspr r30,r0,SPR_FPCSR ;\
+ l.sw PT_FPCSR(r1),r30 ;\
/* Store -1 in orig_gpr11 for non-syscall exceptions */ ;\
l.addi r30,r0,-1 ;\
l.sw PT_ORIG_GPR11(r1),r30
@@ -211,12 +214,13 @@ handler: ;\
l.sw PT_GPR27(r1),r27 ;\
l.sw PT_GPR28(r1),r28 ;\
l.sw PT_GPR29(r1),r29 ;\
- /* r31 already saved */ ;\
- l.sw PT_GPR30(r1),r30 ;\
-/* l.sw PT_GPR31(r1),r31 */ ;\
+ /* r30 already saved */ ;\
+ l.sw PT_GPR31(r1),r31 ;\
/* Store -1 in orig_gpr11 for non-syscall exceptions */ ;\
l.addi r30,r0,-1 ;\
l.sw PT_ORIG_GPR11(r1),r30 ;\
+ l.mfspr r30,r0,SPR_FPCSR ;\
+ l.sw PT_FPCSR(r1),r30 ;\
l.addi r3,r1,0 ;\
/* r4 is exception EA */ ;\
l.addi r5,r0,vector ;\
@@ -844,9 +848,16 @@ _syscall_badsys:
/******* END SYSCALL HANDLING *******/
-/* ---[ 0xd00: Trap exception ]------------------------------------------ */
+/* ---[ 0xd00: Floating Point exception ]-------------------------------- */
-UNHANDLED_EXCEPTION(_vector_0xd00,0xd00)
+EXCEPTION_ENTRY(_fpe_trap_handler)
+ CLEAR_LWA_FLAG(r3)
+ /* r4: EA of fault (set by EXCEPTION_HANDLE) */
+ l.jal do_fpe_trap
+ l.addi r3,r1,0 /* pt_regs */
+
+ l.j _ret_from_exception
+ l.nop
/* ---[ 0xe00: Trap exception ]------------------------------------------ */
@@ -1089,6 +1100,10 @@ ENTRY(_switch)
l.sw PT_GPR28(r1),r28
l.sw PT_GPR30(r1),r30
+ /* Store the old FPU state to new pt_regs */
+ l.mfspr r29,r0,SPR_FPCSR
+ l.sw PT_FPCSR(r1),r29
+
l.addi r11,r10,0 /* Save old 'current' to 'last' return value*/
/* We use thread_info->ksp for storing the address of the above
@@ -1111,6 +1126,10 @@ ENTRY(_switch)
l.lwz r29,PT_SP(r1)
l.sw TI_KSP(r10),r29
+ /* Restore the old value of FPCSR */
+ l.lwz r29,PT_FPCSR(r1)
+ l.mtspr r0,r29,SPR_FPCSR
+
/* ...and restore the registers, except r11 because the return value
* has already been set above.
*/