Fix-up SMC to better follow the ARM CC

Changed the SMC interface to better follow ARM's SMC calling convention.

Signed-off-by: Greg Bellows <greg.bellows@linaro.org>

9 files changed, 79 insertions, 96 deletions

diff --git a/aarch64/common/arm_builtins.h b/aarch64/common/arm_builtins.h
index 1ca14f9..4e4417e 100644
--- a/aarch64/common/arm_builtins.h
+++ b/aarch64/common/arm_builtins.h
@@ -1,36 +1,6 @@
 #ifndef _ARM_BUILTINS_H
 #define _ARM_BUILTINS_H
 
-extern void __smc(void *);
-extern void __svc(void *);
-/*
-#define __smc(_op)                       \
-    asm volatile (                              \
-        "mov x0, %0\n"                       \
-        "smc 0\n"                               \
-        "mov %0, x0\n"                       \
-        : "+r" (_op)   \
-    )
-
-#define __smc(_imm, _desc) \
-    asm volatile ("mov x0, %1\n" \
-                  "smc #%0\n" \
-                  ::[imm] "+I" (_imm), "r" (_desc))
-*/
-
-    /*
-#define __svc(_op)                       \
-    asm volatile (                              \
-        "mov x0, %0\n"                       \
-        "svc 0\n"                               \
-        "mov %0, x0\n"                       \
-        : "+r" (_op)   \
-    )
-#define __svc(_imm, _desc) \
-    asm volatile ("mov x0, %1\n" \
-                  "svc #%0\n" \
-                  ::[imm] "I" (_imm), "r" (_desc))
-    */
 #define __exception_return(_x0) asm volatile ("eret\n")
 #define __set_exception_return(_elr) \
     asm volatile("msr elr_el1, %[elr]\n"::[elr] "r" (_elr))
diff --git a/aarch64/common/armv8_exception.h b/aarch64/common/armv8_exception.h
index da2b75f..85b2604 100644
--- a/aarch64/common/armv8_exception.h
+++ b/aarch64/common/armv8_exception.h
@@ -1,6 +1,19 @@
 #ifndef _EXCEPTION_H
 #define _EXCEPTION_H
 
+#define EC_UNKNOWN 0x00
+#define EC_SIMD 0x07
+#define EC_ILLEGAL_STATE 0x0E
+#define EC_SVC32 0x11
+#define EC_SMC32 0x13
+#define EC_SVC64 0x15
+#define EC_SMC64 0x17
+#define EC_IABORT_LOWER 0x20
+#define EC_IABORT 0x21
+#define EC_DABORT_LOWER 0x24
+#define EC_DABORT 0x25
+
+#ifndef __ASSEMBLY__
 typedef union {
     struct {
         uint32_t dfsc : 6;
@@ -32,21 +45,6 @@ typedef union {
     };
     uint32_t raw;
 } armv8_inst_abort_iss_t;
-
-typedef enum {
-    EC_UNKNOWN = 0x00,
-    EC_SIMD = 0x07,
-    EC_ILLEGAL_STATE = 0x0E,
-    EC_SVC32 = 0x11,
-    EC_SMC32 = 0x13,
-    EC_SVC64 = 0x15,
-    EC_SMC64 = 0x17,
-    EC_IABORT_LOWER = 0x20,
-    EC_IABORT = 0x21,
-    EC_DABORT_LOWER = 0x24,
-    EC_DABORT = 0x25,
-} armv8_exception_code_t;
-
-
+#endif
 
 #endif
diff --git a/aarch64/common/smc.h b/aarch64/common/smc.h
index c0f9bda..baadb73 100644
--- a/aarch64/common/smc.h
+++ b/aarch64/common/smc.h
@@ -13,21 +13,16 @@
 #ifndef __ASSEMBLY__
 #include "interop.h"
 
-typedef struct {
-    int op;
-    union {
-        op_dispatch_t dispatch;
-        op_map_mem_t map;
-    };
+extern uint32_t __smc(uint32_t, void *);
+
+typedef union {
+    op_dispatch_t dispatch;
+    op_map_mem_t map;
 } smc_op_desc_t;
 
 extern smc_op_desc_t *smc_interop_buf;
 
-#define SMC_NO_DESC(_op)                \
-    do {                                \
-        smc_interop_buf->op = (_op);    \
-        __smc(smc_interop_buf);         \
-    } while(0)
+#define SMC_NO_DESC(_op) __smc((_op), NULL)
 
 #define SMC_EXIT()  SMC_NO_DESC(SMC_OP_EXIT)
 #define SMC_YIELD()  SMC_NO_DESC(SMC_OP_YIELD)
diff --git a/aarch64/common/svc.h b/aarch64/common/svc.h
index 8f31ee6..255af5a 100644
--- a/aarch64/common/svc.h
+++ b/aarch64/common/svc.h
@@ -15,6 +15,8 @@
 #define SVC_YIELD 9
 
 #ifndef __ASSEMBLY__
+extern void __svc(void *);
+
 typedef struct {
     int op;
     union {
diff --git a/aarch64/el0_ns/tztest.c b/aarch64/el0_ns/tztest.c
index 1287c17..59efb35 100644
--- a/aarch64/el0_ns/tztest.c
+++ b/aarch64/el0_ns/tztest.c
@@ -1,5 +1,4 @@
 #include "libcflat.h"
-#include "arm_builtins.h"
 #include "svc.h"
 
 typedef struct {
diff --git a/aarch64/el1_common/el1.c b/aarch64/el1_common/el1.c
index 1a240d4..3a1f11a 100644
--- a/aarch64/el1_common/el1.c
+++ b/aarch64/el1_common/el1.c
@@ -156,12 +156,11 @@ void el1_map_secure(op_map_mem_t *map)
 {
     smc_op_desc_t *desc = (smc_op_desc_t *)smc_interop_buf;
 
-    memcpy(&desc->map, map, sizeof(op_map_mem_t));
+    memcpy(desc, map, sizeof(op_map_mem_t));
 
-    desc->op = SMC_OP_MAP;
     desc->map.pa = el1_lookup_pa(desc->map.va);
 
-    __smc(desc);
+    __smc(SMC_OP_MAP, desc);
 }
 
 void el1_handle_exception(uint64_t ec, uint64_t iss, svc_op_desc_t *desc)
diff --git a/aarch64/el1_s/el1_sec.c b/aarch64/el1_s/el1_sec.c
index 43b828d..09cc9f9 100644
--- a/aarch64/el1_s/el1_sec.c
+++ b/aarch64/el1_s/el1_sec.c
@@ -8,10 +8,12 @@ extern void el1_map_pa(uintptr_t vaddr, uintptr_t paddr);
 void el1_sec_smc_loop()
 {
     smc_op_desc_t *desc = smc_interop_buf;
+    uint32_t op = SMC_OP_YIELD;
+
     printf("EL1_S: In loop\n");
 
-    while (desc->op != SMC_OP_EXIT) {
-        switch (desc->op) {
+    while (op != SMC_OP_EXIT) {
+        switch (op) {
         case SMC_OP_MAP:
             printf("EL1_S: Doing a MAP desc = %p\n", desc);
             el1_map_pa((uintptr_t)(desc->map.va), (uintptr_t)(desc->map.pa));
@@ -20,12 +22,12 @@ void el1_sec_smc_loop()
             printf("EL1_S: Doing a YIELD desc = %p\n", desc);
             break;
         default:
-            printf("Unrecognized SMC opcode %d.  Exiting ...\n", desc->op);
+            printf("Unrecognized SMC opcode %d.  Exiting ...\n", op);
             SMC_EXIT();
             break;
         }
 
-        SMC_YIELD();
+        op = __smc(op, desc);
     }
 
     SMC_EXIT();
@@ -33,7 +35,5 @@ void el1_sec_smc_loop()
 
 void el1_init_el0()
 {
-    SMC_YIELD();
-
     el1_sec_smc_loop();
 }
diff --git a/aarch64/el3/el3.c b/aarch64/el3/el3.c
index 5a3d1cb..4ee1b4e 100644
--- a/aarch64/el3/el3.c
+++ b/aarch64/el3/el3.c
@@ -183,7 +183,39 @@ void el3_map_mem(op_map_mem_t *map)
 */
 }
 
-int el3_handle_exception(uint64_t ec, uint64_t iss, smc_op_desc_t *desc)
+int el3_handle_smc(uint64_t ec, uint64_t op, smc_op_desc_t *desc)
+{
+    assert(ec == EC_SMC64);
+
+    switch (op) {
+    case SMC_OP_YIELD:
+        DEBUG_MSG("took an SMC(SMC_YIELD) exception\n");
+        return 1;
+        break;
+    case SMC_OP_DISPATCH_MONITOR:
+        DEBUG_MSG("took an smc(SMC_OP_DSPATCH_MONITOR) exception\n");
+        el3_dispatch((op_dispatch_t *)&desc->dispatch);
+        break;
+    case SMC_OP_MAP:
+        DEBUG_MSG("took an smc(SMC_OP_MAP) exception\n");
+        el3_map_mem((op_map_mem_t *)&desc->map);
+        return 1;
+        break;
+    case SMC_OP_NOOP:
+        DEBUG_MSG("took an smc(SMC_OP_NOOP) exception\n");
+        break;
+    case SMC_OP_EXIT:
+        el3_shutdown();
+        break;
+    default:
+        printf("Unrecognized AArch64 SMC opcode: iss = %d\n", op);
+        break;
+    }
+
+    return 0;
+}
+
+int el3_handle_exception(uint64_t ec, uint64_t iss)
 {
     armv8_data_abort_iss_t dai = {.raw = iss};
     uint64_t elr, far;
@@ -193,31 +225,6 @@ int el3_handle_exception(uint64_t ec, uint64_t iss, smc_op_desc_t *desc)
 
     switch (ec) {
     case EC_SMC64:      /* SMC from aarch64 */
-        switch (desc->op) {
-        case SMC_OP_YIELD:
-            DEBUG_MSG("took an SMC(SMC_YIELD) exception\n");
-            return 1;
-            break;
-        case SMC_OP_DISPATCH_MONITOR:
-            DEBUG_MSG("took an smc(SMC_OP_DSPATCH_MONITOR) exception\n");
-            el3_dispatch((op_dispatch_t *)&desc->dispatch);
-            break;
-        case SMC_OP_MAP:
-            DEBUG_MSG("took an smc(SMC_OP_MAP) exception\n");
-            el3_map_mem((op_map_mem_t *)&desc->map);
-            return 1;
-            break;
-        case SMC_OP_NOOP:
-            DEBUG_MSG("took an smc(SMC_OP_NOOP) exception\n");
-            break;
-        case SMC_OP_EXIT:
-            el3_shutdown();
-            break;
-        default:
-            printf("Unrecognized AArch64 SMC opcode: iss = %d\n", iss);
-            break;
-        }
-        break;
     case EC_IABORT_LOWER:
         printf("Instruction abort at lower level: far = %0lx\n", far);
         break;
diff --git a/aarch64/el3/el3_exception.S b/aarch64/el3/el3_exception.S
index 03397b7..cbed1a7 100644
--- a/aarch64/el3/el3_exception.S
+++ b/aarch64/el3/el3_exception.S
@@ -1,3 +1,7 @@
+#define __ASSEMBLY__
+#include "armv8_exception.h"
+#undef __ASSEMBLY__
+
 .section .vectors
 .align 12                   // Align to vector table size (0x800)
 .globl el3_vectors
@@ -25,12 +29,21 @@ el3_sync_exception_lower64:
     mov x1, #0xffffff
     and x1, x1, x0
     lsr x0, x0, #26
+    cmp x0, #EC_SMC64
+    b.eq el3_sync_exception_lower64_smc
+    cmp x0, #EC_SMC32
+    b.eq el3_sync_exception_lower64_smc
     bl el3_handle_exception
-    mov x3, x0
     ldp x0, x1, [sp], #16
     ldp x30, x2, [sp], #16
-    cbz x3, el3_sync_exception_lower64_done
-    b monitor_switch
+    b el3_sync_exception_lower64_done
+el3_sync_exception_lower64_smc:
+    ldp x1, x2, [sp]        /* Fetch our inputs as SMC args */
+    bl el3_handle_smc
+    cbz x0, el3_sync_exception_lower64_done
+    ldp x0, x1, [sp], #16
+    ldp x30, x2, [sp], #16
+    b monitor_switch        /* This never returns, erets */
 el3_sync_exception_lower64_done:
     eret
 .align 7