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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
* Copyright 2014 Broadcom Corporation
*/
#include <common.h>
/*
* Macro to force the compiler to *populate* memory (for an array or struct)
* before passing the pointer to an inline assembly call.
*/
#define USE_PTR(ptr) *(const char (*)[]) (ptr)
#if defined(CONFIG_ARM64)
#define SMH_TRAP "hlt #0xf000"
#elif defined(CONFIG_CPU_V7M)
#define SMH_TRAP "bkpt #0xAB"
#elif defined(CONFIG_SYS_THUMB_BUILD)
#define SMH_TRAP "svc #0xab"
#else
#define SMH_TRAP "svc #0x123456"
#endif
/*
* Call the handler
*/
long smh_trap(unsigned int sysnum, void *addr)
{
register long result asm("r0");
register void *_addr asm("r1") = addr;
/*
* We need a memory clobber (aka compiler barrier) for two reasons:
* - The compiler needs to populate any data structures pointed to
* by "addr" *before* the trap instruction is called.
* - At least the SYSREAD function puts the result into memory pointed
* to by "addr", so the compiler must not use a cached version of
* the previous content, after the call has finished.
*/
asm volatile (SMH_TRAP
: "=r" (result)
: "0"(sysnum), "r"(USE_PTR(_addr))
: "memory");
return result;
}
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