From eb740ca8e40e53720b0911603471a5883278109a Mon Sep 17 00:00:00 2001
From: Felipe Neves <felipe.neves@espressif.com>
Date: Fri, 11 Oct 2019 11:08:32 -0300
Subject: [PATCH] freertos/xtensa_context: modification of interrupt handler is
 workin, needs stabilization

---
 components/freertos/xtensa_context.S | 71 +++++++++++++---------------
 1 file changed, 33 insertions(+), 38 deletions(-)

diff --git a/components/freertos/xtensa_context.S b/components/freertos/xtensa_context.S
index f5192e25a7..4ef7365e51 100644
--- a/components/freertos/xtensa_context.S
+++ b/components/freertos/xtensa_context.S
@@ -144,53 +144,15 @@ _xt_context_save:
     mov     a9,  a0                     /* preserve ret addr */
     #endif
 
-    #ifdef CONFIG_FREERTOS_PORT_OPTIMIZE_INTERRUPT_HANDLING
-    SPILL_ALL_WINDOWS /* add the optimized spill reg */   
-    #else
-    #ifndef __XTENSA_CALL0_ABI__
-    /*
-    To spill the reg windows, temp. need pre-interrupt stack ptr and a4-15.
-    Need to save a9,12,13 temporarily (in frame temps) and recover originals.
-    Interrupts need to be disabled below XCHAL_EXCM_LEVEL and window overflow
-    and underflow exceptions disabled (assured by PS.EXCM == 1).
-    */
     s32i    a12, sp, XT_STK_TMP0        /* temp. save stuff in stack frame */
     s32i    a13, sp, XT_STK_TMP1    
     s32i    a9,  sp, XT_STK_TMP2    
 
-    /*
-    Save the overlay state if we are supporting overlays. Since we just saved
-    three registers, we can conveniently use them here. Note that as of now,
-    overlays only work for windowed calling ABI.
-    */
-    #ifdef XT_USE_OVLY
-    l32i    a9,  sp, XT_STK_PC          /* recover saved PC */
-    _xt_overlay_get_state    a9, a12, a13
-    s32i    a9,  sp, XT_STK_OVLY        /* save overlay state */
-    #endif
-
     l32i    a12, sp, XT_STK_A12         /* recover original a9,12,13 */
     l32i    a13, sp, XT_STK_A13
     l32i    a9,  sp, XT_STK_A9
-    addi    sp,  sp, XT_STK_FRMSZ       /* restore the interruptee's SP */
-    call0   xthal_window_spill_nw       /* preserves only a4,5,8,9,12,13 */
-    addi    sp,  sp, -XT_STK_FRMSZ
-    l32i    a12, sp, XT_STK_TMP0        /* recover stuff from stack frame */
-    l32i    a13, sp, XT_STK_TMP1    
-    l32i    a9,  sp, XT_STK_TMP2    
-    #endif
-    #endif
 
     #if XCHAL_EXTRA_SA_SIZE > 0
-    /*  
-    NOTE: Normally the xthal_save_extra_nw macro only affects address
-    registers a2-a5. It is theoretically possible for Xtensa processor
-    designers to write TIE that causes more address registers to be
-    affected, but it is generally unlikely. If that ever happens,
-    more registers need to be saved/restored around this macro invocation.
-    Here we assume a9,12,13 are preserved.
-    Future Xtensa tools releases might limit the regs that can be affected.
-    */
     addi    a2,  sp, XT_STK_EXTRA       /* where to save it */
     # if XCHAL_EXTRA_SA_ALIGN > 16
     movi    a3, -XCHAL_EXTRA_SA_ALIGN
@@ -199,6 +161,39 @@ _xt_context_save:
     call0   xthal_save_extra_nw         /* destroys a0,2,3,4,5 */
     #endif
 
+
+    #ifndef __XTENSA_CALL0_ABI__
+    #ifdef XT_USE_OVLY
+    l32i    a9,  sp, XT_STK_PC          /* recover saved PC */
+    _xt_overlay_get_state    a9, a12, a13
+    s32i    a9,  sp, XT_STK_OVLY        /* save overlay state */
+    #endif
+
+	rsr     a2, PS
+	movi    a3, PS_INTLEVEL_MASK
+	and     a2, a2, a3
+	bnez    a2, _not_l1
+	rsr     a2, PS
+	movi    a3, PS_INTLEVEL(1)
+	or      a2, a2, a3
+	wsr     a2, PS
+_not_l1:
+
+	rsr     a2, PS
+	movi    a3, ~(PS_EXCM_MASK)
+	and     a2, a2, a3
+	wsr     a2, PS
+    rsync
+
+    addi    sp,  sp, XT_STK_FRMSZ      /* restore the interruptee's SP */
+    SPILL_ALL_WINDOWS
+    addi    sp,  sp, -XT_STK_FRMSZ
+    #endif
+
+    l32i    a12, sp, XT_STK_TMP0        /* temp. save stuff in stack frame */
+    l32i    a13, sp, XT_STK_TMP1    
+    l32i    a9,  sp, XT_STK_TMP2  
+
     #if XCHAL_EXTRA_SA_SIZE > 0 || !defined(__XTENSA_CALL0_ABI__)
     mov     a0, a9                      /* retrieve ret addr */
     #endif