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732ea9db9d
Currently, arm64, RISC-V and LoongArch rely on the fact that struct screen_info can be accessed directly, due to the fact that the EFI stub and the core kernel are part of the same image. This will change after a future patch, so let's ensure that the screen_info handling is able to deal with this, by adopting the arm32 approach of passing it as a configuration table. While at it, switch to ACPI reclaim memory to hold the screen_info data, which is more appropriate for this kind of allocation. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
134 lines
3.7 KiB
C
134 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org>
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*/
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#include <linux/efi.h>
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#include <asm/efi.h>
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#include "efistub.h"
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static efi_guid_t cpu_state_guid = LINUX_EFI_ARM_CPU_STATE_TABLE_GUID;
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struct efi_arm_entry_state *efi_entry_state;
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static void get_cpu_state(u32 *cpsr, u32 *sctlr)
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{
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asm("mrs %0, cpsr" : "=r"(*cpsr));
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if ((*cpsr & MODE_MASK) == HYP_MODE)
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asm("mrc p15, 4, %0, c1, c0, 0" : "=r"(*sctlr));
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else
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asm("mrc p15, 0, %0, c1, c0, 0" : "=r"(*sctlr));
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}
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efi_status_t check_platform_features(void)
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{
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efi_status_t status;
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u32 cpsr, sctlr;
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int block;
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get_cpu_state(&cpsr, &sctlr);
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efi_info("Entering in %s mode with MMU %sabled\n",
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((cpsr & MODE_MASK) == HYP_MODE) ? "HYP" : "SVC",
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(sctlr & 1) ? "en" : "dis");
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status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
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sizeof(*efi_entry_state),
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(void **)&efi_entry_state);
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if (status != EFI_SUCCESS) {
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efi_err("allocate_pool() failed\n");
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return status;
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}
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efi_entry_state->cpsr_before_ebs = cpsr;
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efi_entry_state->sctlr_before_ebs = sctlr;
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status = efi_bs_call(install_configuration_table, &cpu_state_guid,
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efi_entry_state);
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if (status != EFI_SUCCESS) {
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efi_err("install_configuration_table() failed\n");
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goto free_state;
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}
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/* non-LPAE kernels can run anywhere */
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if (!IS_ENABLED(CONFIG_ARM_LPAE))
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return EFI_SUCCESS;
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/* LPAE kernels need compatible hardware */
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block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
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if (block < 5) {
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efi_err("This LPAE kernel is not supported by your CPU\n");
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status = EFI_UNSUPPORTED;
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goto drop_table;
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}
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return EFI_SUCCESS;
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drop_table:
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efi_bs_call(install_configuration_table, &cpu_state_guid, NULL);
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free_state:
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efi_bs_call(free_pool, efi_entry_state);
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return status;
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}
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void efi_handle_post_ebs_state(void)
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{
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get_cpu_state(&efi_entry_state->cpsr_after_ebs,
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&efi_entry_state->sctlr_after_ebs);
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}
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efi_status_t handle_kernel_image(unsigned long *image_addr,
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unsigned long *image_size,
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unsigned long *reserve_addr,
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unsigned long *reserve_size,
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efi_loaded_image_t *image,
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efi_handle_t image_handle)
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{
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const int slack = TEXT_OFFSET - 5 * PAGE_SIZE;
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int alloc_size = MAX_UNCOMP_KERNEL_SIZE + EFI_PHYS_ALIGN;
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unsigned long alloc_base, kernel_base;
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efi_status_t status;
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/*
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* Allocate space for the decompressed kernel as low as possible.
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* The region should be 16 MiB aligned, but the first 'slack' bytes
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* are not used by Linux, so we allow those to be occupied by the
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* firmware.
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*/
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status = efi_low_alloc_above(alloc_size, EFI_PAGE_SIZE, &alloc_base, 0x0);
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if (status != EFI_SUCCESS) {
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efi_err("Unable to allocate memory for uncompressed kernel.\n");
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return status;
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}
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if ((alloc_base % EFI_PHYS_ALIGN) > slack) {
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/*
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* More than 'slack' bytes are already occupied at the base of
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* the allocation, so we need to advance to the next 16 MiB block.
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*/
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kernel_base = round_up(alloc_base, EFI_PHYS_ALIGN);
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efi_info("Free memory starts at 0x%lx, setting kernel_base to 0x%lx\n",
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alloc_base, kernel_base);
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} else {
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kernel_base = round_down(alloc_base, EFI_PHYS_ALIGN);
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}
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*reserve_addr = kernel_base + slack;
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*reserve_size = MAX_UNCOMP_KERNEL_SIZE;
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/* now free the parts that we will not use */
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if (*reserve_addr > alloc_base) {
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efi_bs_call(free_pages, alloc_base,
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(*reserve_addr - alloc_base) / EFI_PAGE_SIZE);
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alloc_size -= *reserve_addr - alloc_base;
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}
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efi_bs_call(free_pages, *reserve_addr + MAX_UNCOMP_KERNEL_SIZE,
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(alloc_size - MAX_UNCOMP_KERNEL_SIZE) / EFI_PAGE_SIZE);
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*image_addr = kernel_base + TEXT_OFFSET;
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*image_size = 0;
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efi_debug("image addr == 0x%lx, reserve_addr == 0x%lx\n",
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*image_addr, *reserve_addr);
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return EFI_SUCCESS;
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}
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