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-rw-r--r--include/arch/aarch32/smccc_helpers.h159
1 files changed, 159 insertions, 0 deletions
diff --git a/include/arch/aarch32/smccc_helpers.h b/include/arch/aarch32/smccc_helpers.h
new file mode 100644
index 0000000000..67952ec509
--- /dev/null
+++ b/include/arch/aarch32/smccc_helpers.h
@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef SMCCC_HELPERS_H
+#define SMCCC_HELPERS_H
+
+#include <smccc.h>
+
+/* These are offsets to registers in smc_ctx_t */
+#define SMC_CTX_GPREG_R0 U(0x0)
+#define SMC_CTX_GPREG_R1 U(0x4)
+#define SMC_CTX_GPREG_R2 U(0x8)
+#define SMC_CTX_GPREG_R3 U(0xC)
+#define SMC_CTX_GPREG_R4 U(0x10)
+#define SMC_CTX_GPREG_R5 U(0x14)
+#define SMC_CTX_SP_USR U(0x34)
+#define SMC_CTX_SPSR_MON U(0x78)
+#define SMC_CTX_SP_MON U(0x7C)
+#define SMC_CTX_LR_MON U(0x80)
+#define SMC_CTX_SCR U(0x84)
+#define SMC_CTX_PMCR U(0x88)
+#define SMC_CTX_SIZE U(0x90)
+
+#ifndef __ASSEMBLY__
+#include <cassert.h>
+#include <stdint.h>
+
+/*
+ * The generic structure to save arguments and callee saved registers during
+ * an SMC. Also this structure is used to store the result return values after
+ * the completion of SMC service.
+ */
+typedef struct smc_ctx {
+ u_register_t r0;
+ u_register_t r1;
+ u_register_t r2;
+ u_register_t r3;
+ u_register_t r4;
+ u_register_t r5;
+ u_register_t r6;
+ u_register_t r7;
+ u_register_t r8;
+ u_register_t r9;
+ u_register_t r10;
+ u_register_t r11;
+ u_register_t r12;
+ /* spsr_usr doesn't exist */
+ u_register_t sp_usr;
+ u_register_t lr_usr;
+ u_register_t spsr_irq;
+ u_register_t sp_irq;
+ u_register_t lr_irq;
+ u_register_t spsr_fiq;
+ u_register_t sp_fiq;
+ u_register_t lr_fiq;
+ u_register_t spsr_svc;
+ u_register_t sp_svc;
+ u_register_t lr_svc;
+ u_register_t spsr_abt;
+ u_register_t sp_abt;
+ u_register_t lr_abt;
+ u_register_t spsr_und;
+ u_register_t sp_und;
+ u_register_t lr_und;
+ u_register_t spsr_mon;
+ /*
+ * `sp_mon` will point to the C runtime stack in monitor mode. But prior
+ * to exit from SMC, this will point to the `smc_ctx_t` so that
+ * on next entry due to SMC, the `smc_ctx_t` can be easily accessed.
+ */
+ u_register_t sp_mon;
+ u_register_t lr_mon;
+ u_register_t scr;
+ u_register_t pmcr;
+ /*
+ * The workaround for CVE-2017-5715 requires storing information in
+ * the bottom 3 bits of the stack pointer. Add a padding field to
+ * force the size of the struct to be a multiple of 8.
+ */
+ u_register_t pad;
+} smc_ctx_t __aligned(8);
+
+/*
+ * Compile time assertions related to the 'smc_context' structure to
+ * ensure that the assembler and the compiler view of the offsets of
+ * the structure members is the same.
+ */
+CASSERT(SMC_CTX_GPREG_R0 == __builtin_offsetof(smc_ctx_t, r0), \
+ assert_smc_ctx_greg_r0_offset_mismatch);
+CASSERT(SMC_CTX_GPREG_R1 == __builtin_offsetof(smc_ctx_t, r1), \
+ assert_smc_ctx_greg_r1_offset_mismatch);
+CASSERT(SMC_CTX_GPREG_R2 == __builtin_offsetof(smc_ctx_t, r2), \
+ assert_smc_ctx_greg_r2_offset_mismatch);
+CASSERT(SMC_CTX_GPREG_R3 == __builtin_offsetof(smc_ctx_t, r3), \
+ assert_smc_ctx_greg_r3_offset_mismatch);
+CASSERT(SMC_CTX_GPREG_R4 == __builtin_offsetof(smc_ctx_t, r4), \
+ assert_smc_ctx_greg_r4_offset_mismatch);
+CASSERT(SMC_CTX_SP_USR == __builtin_offsetof(smc_ctx_t, sp_usr), \
+ assert_smc_ctx_sp_usr_offset_mismatch);
+CASSERT(SMC_CTX_LR_MON == __builtin_offsetof(smc_ctx_t, lr_mon), \
+ assert_smc_ctx_lr_mon_offset_mismatch);
+CASSERT(SMC_CTX_SPSR_MON == __builtin_offsetof(smc_ctx_t, spsr_mon), \
+ assert_smc_ctx_spsr_mon_offset_mismatch);
+
+CASSERT((sizeof(smc_ctx_t) & 0x7U) == 0U, assert_smc_ctx_not_aligned);
+CASSERT(SMC_CTX_SIZE == sizeof(smc_ctx_t), assert_smc_ctx_size_mismatch);
+
+/* Convenience macros to return from SMC handler */
+#define SMC_RET0(_h) { \
+ return (uintptr_t)(_h); \
+}
+#define SMC_RET1(_h, _r0) { \
+ ((smc_ctx_t *)(_h))->r0 = (_r0); \
+ SMC_RET0(_h); \
+}
+#define SMC_RET2(_h, _r0, _r1) { \
+ ((smc_ctx_t *)(_h))->r1 = (_r1); \
+ SMC_RET1(_h, (_r0)); \
+}
+#define SMC_RET3(_h, _r0, _r1, _r2) { \
+ ((smc_ctx_t *)(_h))->r2 = (_r2); \
+ SMC_RET2(_h, (_r0), (_r1)); \
+}
+#define SMC_RET4(_h, _r0, _r1, _r2, _r3) { \
+ ((smc_ctx_t *)(_h))->r3 = (_r3); \
+ SMC_RET3(_h, (_r0), (_r1), (_r2)); \
+}
+
+/*
+ * Helper macro to retrieve the SMC parameters from smc_ctx_t.
+ */
+#define get_smc_params_from_ctx(_hdl, _r1, _r2, _r3, _r4) { \
+ _r1 = ((smc_ctx_t *)_hdl)->r1; \
+ _r2 = ((smc_ctx_t *)_hdl)->r2; \
+ _r3 = ((smc_ctx_t *)_hdl)->r3; \
+ _r4 = ((smc_ctx_t *)_hdl)->r4; \
+ }
+
+/* ------------------------------------------------------------------------
+ * Helper APIs for setting and retrieving appropriate `smc_ctx_t`.
+ * These functions need to implemented by the BL including this library.
+ * ------------------------------------------------------------------------
+ */
+
+/* Get the pointer to `smc_ctx_t` corresponding to the security state. */
+void *smc_get_ctx(unsigned int security_state);
+
+/* Set the next `smc_ctx_t` corresponding to the security state. */
+void smc_set_next_ctx(unsigned int security_state);
+
+/* Get the pointer to next `smc_ctx_t` already set by `smc_set_next_ctx()`. */
+void *smc_get_next_ctx(void);
+
+#endif /*__ASSEMBLY__*/
+
+#endif /* SMCCC_HELPERS_H */