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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org>4 */5#include <linux/efi.h>6#include <asm/efi.h>7 8#include "efistub.h"9 10static efi_guid_t cpu_state_guid = LINUX_EFI_ARM_CPU_STATE_TABLE_GUID;11 12struct efi_arm_entry_state *efi_entry_state;13 14static void get_cpu_state(u32 *cpsr, u32 *sctlr)15{16 asm("mrs %0, cpsr" : "=r"(*cpsr));17 if ((*cpsr & MODE_MASK) == HYP_MODE)18 asm("mrc p15, 4, %0, c1, c0, 0" : "=r"(*sctlr));19 else20 asm("mrc p15, 0, %0, c1, c0, 0" : "=r"(*sctlr));21}22 23efi_status_t check_platform_features(void)24{25 efi_status_t status;26 u32 cpsr, sctlr;27 int block;28 29 get_cpu_state(&cpsr, &sctlr);30 31 efi_info("Entering in %s mode with MMU %sabled\n",32 ((cpsr & MODE_MASK) == HYP_MODE) ? "HYP" : "SVC",33 (sctlr & 1) ? "en" : "dis");34 35 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,36 sizeof(*efi_entry_state),37 (void **)&efi_entry_state);38 if (status != EFI_SUCCESS) {39 efi_err("allocate_pool() failed\n");40 return status;41 }42 43 efi_entry_state->cpsr_before_ebs = cpsr;44 efi_entry_state->sctlr_before_ebs = sctlr;45 46 status = efi_bs_call(install_configuration_table, &cpu_state_guid,47 efi_entry_state);48 if (status != EFI_SUCCESS) {49 efi_err("install_configuration_table() failed\n");50 goto free_state;51 }52 53 /* non-LPAE kernels can run anywhere */54 if (!IS_ENABLED(CONFIG_ARM_LPAE))55 return EFI_SUCCESS;56 57 /* LPAE kernels need compatible hardware */58 block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);59 if (block < 5) {60 efi_err("This LPAE kernel is not supported by your CPU\n");61 status = EFI_UNSUPPORTED;62 goto drop_table;63 }64 return EFI_SUCCESS;65 66drop_table:67 efi_bs_call(install_configuration_table, &cpu_state_guid, NULL);68free_state:69 efi_bs_call(free_pool, efi_entry_state);70 return status;71}72 73void efi_handle_post_ebs_state(void)74{75 get_cpu_state(&efi_entry_state->cpsr_after_ebs,76 &efi_entry_state->sctlr_after_ebs);77}78 79efi_status_t handle_kernel_image(unsigned long *image_addr,80 unsigned long *image_size,81 unsigned long *reserve_addr,82 unsigned long *reserve_size,83 efi_loaded_image_t *image,84 efi_handle_t image_handle)85{86 const int slack = TEXT_OFFSET - 5 * PAGE_SIZE;87 int alloc_size = MAX_UNCOMP_KERNEL_SIZE + EFI_PHYS_ALIGN;88 unsigned long alloc_base, kernel_base;89 efi_status_t status;90 91 /*92 * Allocate space for the decompressed kernel as low as possible.93 * The region should be 16 MiB aligned, but the first 'slack' bytes94 * are not used by Linux, so we allow those to be occupied by the95 * firmware.96 */97 status = efi_low_alloc_above(alloc_size, EFI_PAGE_SIZE, &alloc_base, 0x0);98 if (status != EFI_SUCCESS) {99 efi_err("Unable to allocate memory for uncompressed kernel.\n");100 return status;101 }102 103 if ((alloc_base % EFI_PHYS_ALIGN) > slack) {104 /*105 * More than 'slack' bytes are already occupied at the base of106 * the allocation, so we need to advance to the next 16 MiB block.107 */108 kernel_base = round_up(alloc_base, EFI_PHYS_ALIGN);109 efi_info("Free memory starts at 0x%lx, setting kernel_base to 0x%lx\n",110 alloc_base, kernel_base);111 } else {112 kernel_base = round_down(alloc_base, EFI_PHYS_ALIGN);113 }114 115 *reserve_addr = kernel_base + slack;116 *reserve_size = MAX_UNCOMP_KERNEL_SIZE;117 118 /* now free the parts that we will not use */119 if (*reserve_addr > alloc_base) {120 efi_bs_call(free_pages, alloc_base,121 (*reserve_addr - alloc_base) / EFI_PAGE_SIZE);122 alloc_size -= *reserve_addr - alloc_base;123 }124 efi_bs_call(free_pages, *reserve_addr + MAX_UNCOMP_KERNEL_SIZE,125 (alloc_size - MAX_UNCOMP_KERNEL_SIZE) / EFI_PAGE_SIZE);126 127 *image_addr = kernel_base + TEXT_OFFSET;128 *image_size = 0;129 130 efi_debug("image addr == 0x%lx, reserve_addr == 0x%lx\n",131 *image_addr, *reserve_addr);132 133 return EFI_SUCCESS;134}135