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