1 /* 2 * (C) Copyright 2016 Beniamino Galvani <b.galvani@gmail.com> 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 * 6 * Secure monitor calls. 7 */ 8 9 #include <common.h> 10 #include <asm/arch/gxbb.h> 11 #include <linux/kernel.h> 12 13 #define FN_GET_SHARE_MEM_INPUT_BASE 0x82000020 14 #define FN_GET_SHARE_MEM_OUTPUT_BASE 0x82000021 15 #define FN_EFUSE_READ 0x82000030 16 #define FN_EFUSE_WRITE 0x82000031 17 18 static void *shmem_input; 19 static void *shmem_output; 20 21 static void meson_init_shmem(void) 22 { 23 struct pt_regs regs; 24 25 if (shmem_input && shmem_output) 26 return; 27 28 regs.regs[0] = FN_GET_SHARE_MEM_INPUT_BASE; 29 smc_call(®s); 30 shmem_input = (void *)regs.regs[0]; 31 32 regs.regs[0] = FN_GET_SHARE_MEM_OUTPUT_BASE; 33 smc_call(®s); 34 shmem_output = (void *)regs.regs[0]; 35 36 debug("Secure Monitor shmem: 0x%p 0x%p\n", shmem_input, shmem_output); 37 } 38 39 ssize_t meson_sm_read_efuse(uintptr_t offset, void *buffer, size_t size) 40 { 41 struct pt_regs regs; 42 43 meson_init_shmem(); 44 45 regs.regs[0] = FN_EFUSE_READ; 46 regs.regs[1] = offset; 47 regs.regs[2] = size; 48 49 smc_call(®s); 50 51 if (regs.regs[0] == 0) 52 return -1; 53 54 memcpy(buffer, shmem_output, min(size, regs.regs[0])); 55 56 return regs.regs[0]; 57 } 58