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