[PATCH] sparc: Add assembly workaround for LEON3FT B2BST errata
Daniel Cederman
cederman at gaisler.com
Thu Jul 13 07:26:50 UTC 2017
This patch adds NOP instructions to prevent instruction sequences
that are sensitive to the LEON3FT B2BST errata. See GRLIB-TN-0009:
"LEON3FT Stale Cache Entry After Store with Data Tag Parity Error"
for more information.
The sequences are only modified if __FIX_LEON3FT_B2BST is defined.
The patch works in conjunction with the -mfix-ut700, -mfix-gr712rc,
and -mfix-ut699 GCC flags that prevents the sensitive sequences from
being generated.
See also https://devel.rtems.org/ticket/3057
---
c/src/lib/libbsp/sparc/shared/irq_asm.S | 47 +++++++++++++++++++++++++
c/src/lib/libcpu/sparc/access/access.S | 28 +++++++++++++++
c/src/lib/libcpu/sparc/reg_win/window.S | 12 +++++++
cpukit/score/cpu/sparc/cpu_asm.S | 22 ++++++++++++
cpukit/score/cpu/sparc/rtems/score/sparc.h | 10 ++++++
cpukit/score/cpu/sparc/sparc-context-validate.S | 1 +
6 files changed, 120 insertions(+)
diff --git a/c/src/lib/libbsp/sparc/shared/irq_asm.S b/c/src/lib/libbsp/sparc/shared/irq_asm.S
index 075c780..b4374c3 100644
--- a/c/src/lib/libbsp/sparc/shared/irq_asm.S
+++ b/c/src/lib/libbsp/sparc/shared/irq_asm.S
@@ -66,14 +66,22 @@ SYM(_CPU_Context_switch):
*/
std %l0, [%o0 + L0_OFFSET] ! save the local registers
+ SPARC_LEON3FT_B2BST_NOP
std %l2, [%o0 + L2_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l4, [%o0 + L4_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l6, [%o0 + L6_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i0, [%o0 + I0_OFFSET] ! save the input registers
+ SPARC_LEON3FT_B2BST_NOP
std %i2, [%o0 + I2_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i4, [%o0 + I4_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i6, [%o0 + I6_FP_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %o6, [%o0 + O6_SP_OFFSET] ! save the output registers
@@ -158,14 +166,22 @@ save_frame_loop:
*/
std %l0, [%sp + CPU_STACK_FRAME_L0_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l2, [%sp + CPU_STACK_FRAME_L2_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l4, [%sp + CPU_STACK_FRAME_L4_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l6, [%sp + CPU_STACK_FRAME_L6_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i0, [%sp + CPU_STACK_FRAME_I0_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i2, [%sp + CPU_STACK_FRAME_I2_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i4, [%sp + CPU_STACK_FRAME_I4_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i6, [%sp + CPU_STACK_FRAME_I6_FP_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
ba save_frame_loop
nop
@@ -375,13 +391,20 @@ win_ovflow:
*/
std %l0, [%sp + CPU_STACK_FRAME_L0_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l2, [%sp + CPU_STACK_FRAME_L2_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l4, [%sp + CPU_STACK_FRAME_L4_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l6, [%sp + CPU_STACK_FRAME_L6_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i0, [%sp + CPU_STACK_FRAME_I0_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i2, [%sp + CPU_STACK_FRAME_I2_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i4, [%sp + CPU_STACK_FRAME_I4_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i6, [%sp + CPU_STACK_FRAME_I6_FP_OFFSET]
restore
@@ -406,15 +429,21 @@ dont_do_the_window:
! make space for ISF
std %l0, [%sp + ISF_PSR_OFFSET] ! save psr, PC
+ SPARC_LEON3FT_B2BST_NOP
st %l2, [%sp + ISF_NPC_OFFSET] ! save nPC
st %g1, [%sp + ISF_G1_OFFSET] ! save g1
std %g2, [%sp + ISF_G2_OFFSET] ! save g2, g3
+ SPARC_LEON3FT_B2BST_NOP
std %l4, [%sp + ISF_G4_OFFSET] ! save g4, g5 -- see above
+ SPARC_LEON3FT_B2BST_NOP
st %g7, [%sp + ISF_G7_OFFSET] ! save g7
std %i0, [%sp + ISF_I0_OFFSET] ! save i0, i1
+ SPARC_LEON3FT_B2BST_NOP
std %i2, [%sp + ISF_I2_OFFSET] ! save i2, i3
+ SPARC_LEON3FT_B2BST_NOP
std %i4, [%sp + ISF_I4_OFFSET] ! save i4, i5
+ SPARC_LEON3FT_B2BST_NOP
std %i6, [%sp + ISF_I6_FP_OFFSET] ! save i6/fp, i7
rd %y, %g1
@@ -440,6 +469,7 @@ dont_do_the_window:
add %l7, 1, %l7
st %l7, [%g6 + PER_CPU_ISR_NEST_LEVEL]
+ SPARC_LEON3FT_B2BST_NOP
add %l6, 1, %l6
st %l6, [%g6 + PER_CPU_THREAD_DISPATCH_DISABLE_LEVEL]
@@ -587,6 +617,7 @@ profiling_not_outer_most_exit:
ldub [%g6 + PER_CPU_DISPATCH_NEEDED], %o2
ld [%g6 + PER_CPU_ISR_DISPATCH_DISABLE], %o3
st %l7, [%g6 + PER_CPU_ISR_NEST_LEVEL]
+ SPARC_LEON3FT_B2BST_NOP
sub %l6, 1, %l6
st %l6, [%g6 + PER_CPU_THREAD_DISPATCH_DISABLE_LEVEL]
@@ -635,21 +666,37 @@ isr_dispatch:
*/
sub %sp, FP_FRAME_SIZE, %sp
std %f0, [%sp + FP_FRAME_OFFSET_FO_F1]
+ SPARC_LEON3FT_B2BST_NOP
std %f2, [%sp + FP_FRAME_OFFSET_F2_F3]
+ SPARC_LEON3FT_B2BST_NOP
std %f4, [%sp + FP_FRAME_OFFSET_F4_F5]
+ SPARC_LEON3FT_B2BST_NOP
std %f6, [%sp + FP_FRAME_OFFSET_F6_F7]
+ SPARC_LEON3FT_B2BST_NOP
std %f8, [%sp + FP_FRAME_OFFSET_F8_F9]
+ SPARC_LEON3FT_B2BST_NOP
std %f10, [%sp + FP_FRAME_OFFSET_F1O_F11]
+ SPARC_LEON3FT_B2BST_NOP
std %f12, [%sp + FP_FRAME_OFFSET_F12_F13]
+ SPARC_LEON3FT_B2BST_NOP
std %f14, [%sp + FP_FRAME_OFFSET_F14_F15]
+ SPARC_LEON3FT_B2BST_NOP
std %f16, [%sp + FP_FRAME_OFFSET_F16_F17]
+ SPARC_LEON3FT_B2BST_NOP
std %f18, [%sp + FP_FRAME_OFFSET_F18_F19]
+ SPARC_LEON3FT_B2BST_NOP
std %f20, [%sp + FP_FRAME_OFFSET_F2O_F21]
+ SPARC_LEON3FT_B2BST_NOP
std %f22, [%sp + FP_FRAME_OFFSET_F22_F23]
+ SPARC_LEON3FT_B2BST_NOP
std %f24, [%sp + FP_FRAME_OFFSET_F24_F25]
+ SPARC_LEON3FT_B2BST_NOP
std %f26, [%sp + FP_FRAME_OFFSET_F26_F27]
+ SPARC_LEON3FT_B2BST_NOP
std %f28, [%sp + FP_FRAME_OFFSET_F28_F29]
+ SPARC_LEON3FT_B2BST_NOP
std %f30, [%sp + FP_FRAME_OFFSET_F3O_F31]
+ SPARC_LEON3FT_B2BST_NOP
st %fsr, [%sp + FP_FRAME_OFFSET_FSR]
call SYM(_Thread_Do_dispatch)
mov %g6, %o0
diff --git a/c/src/lib/libcpu/sparc/access/access.S b/c/src/lib/libcpu/sparc/access/access.S
index cb8693b..9397cb8 100644
--- a/c/src/lib/libcpu/sparc/access/access.S
+++ b/c/src/lib/libcpu/sparc/access/access.S
@@ -59,6 +59,33 @@ SYM(_ld64):
retl
ldd [%o0], %o0
+#if defined(__FIX_LEON3FT_B2BST)
+
+SYM(_st8):
+ stub %o1, [%o0]
+ retl
+ nop
+
+SYM(_st_be16):
+SYM(_st16):
+ stuh %o1, [%o0]
+ retl
+ nop
+
+SYM(_st_be32):
+SYM(_st32):
+ st %o1, [%o0]
+ retl
+ nop
+
+SYM(_st_be64):
+SYM(_st64):
+ std %o1, [%o0]
+ retl
+ nop
+
+#else
+
SYM(_st8):
retl
stb %o1, [%o0]
@@ -79,3 +106,4 @@ SYM(_st64):
mov %o1, %o2
retl
std %o2, [%o0]
+#endif
diff --git a/c/src/lib/libcpu/sparc/reg_win/window.S b/c/src/lib/libcpu/sparc/reg_win/window.S
index b874559..5a36fd6 100644
--- a/c/src/lib/libcpu/sparc/reg_win/window.S
+++ b/c/src/lib/libcpu/sparc/reg_win/window.S
@@ -51,19 +51,24 @@ SYM(window_overflow_trap_handler):
*/
std %l0, [%sp + 0x00] ! save local register set
+ SPARC_LEON3FT_B2BST_NOP
std %l2, [%sp + 0x08]
mov %wim, %l3
sll %l3, SPARC_NUMBER_OF_REGISTER_WINDOWS-1 , %l2
! l2 = WIM << (Number Windows - 1)
std %l4, [%sp + 0x10]
+ SPARC_LEON3FT_B2BST_NOP
std %l6, [%sp + 0x18]
srl %l3, 1, %l3 ! l3 = WIM >> 1
wr %l3, %l2, %wim ! WIM = (WIM >> 1) ^
! (WIM << (Number Windows - 1))
! 3 instruction delay not needed here
std %i0, [%sp + 0x20] ! save input register set
+ SPARC_LEON3FT_B2BST_NOP
std %i2, [%sp + 0x28]
+ SPARC_LEON3FT_B2BST_NOP
std %i4, [%sp + 0x30]
+ SPARC_LEON3FT_B2BST_NOP
std %i6, [%sp + 0x38]
restore ! Go back to trap window.
jmp %l1 ! Re-execute save.
@@ -206,13 +211,20 @@ save_frame_loop:
*/
std %l0, [%sp + CPU_STACK_FRAME_L0_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l2, [%sp + CPU_STACK_FRAME_L2_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l4, [%sp + CPU_STACK_FRAME_L4_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %l6, [%sp + CPU_STACK_FRAME_L6_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i0, [%sp + CPU_STACK_FRAME_I0_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i2, [%sp + CPU_STACK_FRAME_I2_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i4, [%sp + CPU_STACK_FRAME_I4_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %i6, [%sp + CPU_STACK_FRAME_I6_FP_OFFSET]
ba save_frame_loop
diff --git a/cpukit/score/cpu/sparc/cpu_asm.S b/cpukit/score/cpu/sparc/cpu_asm.S
index 4e683da..399c955 100644
--- a/cpukit/score/cpu/sparc/cpu_asm.S
+++ b/cpukit/score/cpu/sparc/cpu_asm.S
@@ -46,23 +46,45 @@
SYM(_CPU_Context_save_fp):
ld [%o0], %o1
std %f0, [%o1 + FO_F1_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f2, [%o1 + F2_F3_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f4, [%o1 + F4_F5_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f6, [%o1 + F6_F7_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f8, [%o1 + F8_F9_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f10, [%o1 + F1O_F11_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f12, [%o1 + F12_F13_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f14, [%o1 + F14_F15_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f16, [%o1 + F16_F17_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f18, [%o1 + F18_F19_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f20, [%o1 + F2O_F21_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f22, [%o1 + F22_F23_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f24, [%o1 + F24_F25_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f26, [%o1 + F26_F27_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f28, [%o1 + F28_F29_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
std %f30, [%o1 + F3O_F31_OFFSET]
+ SPARC_LEON3FT_B2BST_NOP
+#if defined(__FIX_LEON3FT_B2BST)
+ st %fsr, [%o1 + FSR_OFFSET]
+ jmp %o7 + 8
+ nop
+#else
jmp %o7 + 8
st %fsr, [%o1 + FSR_OFFSET]
+#endif
/*
* void _CPU_Context_restore_fp(
diff --git a/cpukit/score/cpu/sparc/rtems/score/sparc.h b/cpukit/score/cpu/sparc/rtems/score/sparc.h
index 97a59dd..eb69b76 100644
--- a/cpukit/score/cpu/sparc/rtems/score/sparc.h
+++ b/cpukit/score/cpu/sparc/rtems/score/sparc.h
@@ -63,6 +63,16 @@ extern "C" {
#define SPARC_NUMBER_OF_REGISTER_WINDOWS 8
/**
+ * See GRLIB-TN-0009: "LEON3FT Stale Cache Entry After Store with
+ * Data Tag Parity Error"
+ */
+#if defined(__FIX_LEON3FT_B2BST)
+ #define SPARC_LEON3FT_B2BST_NOP nop
+#else
+ #define SPARC_LEON3FT_B2BST_NOP
+#endif
+
+/**
* This macro contains a string describing the multilib variant being
* build.
*/
diff --git a/cpukit/score/cpu/sparc/sparc-context-validate.S b/cpukit/score/cpu/sparc/sparc-context-validate.S
index e0724e0..777f4dd 100644
--- a/cpukit/score/cpu/sparc/sparc-context-validate.S
+++ b/cpukit/score/cpu/sparc/sparc-context-validate.S
@@ -282,6 +282,7 @@ y_checking:
nop
st %o1, [%sp + FRAME_OFFSET_BUFFER_2]
+ SPARC_LEON3FT_B2BST_NOP
/* Check floating point registers */
check_float_register %f31
check_float_register %f30
--
2.9.3
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