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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org>
*/
#include <linux/efi.h>
#include <asm/efi.h>
#include "efistub.h"
static efi_guid_t cpu_state_guid = LINUX_EFI_ARM_CPU_STATE_TABLE_GUID;
struct efi_arm_entry_state *efi_entry_state;
static void get_cpu_state(u32 *cpsr, u32 *sctlr)
{
asm("mrs %0, cpsr" : "=r"(*cpsr));
if ((*cpsr & MODE_MASK) == HYP_MODE)
asm("mrc p15, 4, %0, c1, c0, 0" : "=r"(*sctlr));
else
asm("mrc p15, 0, %0, c1, c0, 0" : "=r"(*sctlr));
}
efi_status_t check_platform_features(void)
{
efi_status_t status;
u32 cpsr, sctlr;
int block;
get_cpu_state(&cpsr, &sctlr);
efi_info("Entering in %s mode with MMU %sabled\n",
((cpsr & MODE_MASK) == HYP_MODE) ? "HYP" : "SVC",
(sctlr & 1) ? "en" : "dis");
status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
sizeof(*efi_entry_state),
(void **)&efi_entry_state);
if (status != EFI_SUCCESS) {
efi_err("allocate_pool() failed\n");
return status;
}
efi_entry_state->cpsr_before_ebs = cpsr;
efi_entry_state->sctlr_before_ebs = sctlr;
status = efi_bs_call(install_configuration_table, &cpu_state_guid,
efi_entry_state);
if (status != EFI_SUCCESS) {
efi_err("install_configuration_table() failed\n");
goto free_state;
}
/* non-LPAE kernels can run anywhere */
if (!IS_ENABLED(CONFIG_ARM_LPAE))
return EFI_SUCCESS;
/* LPAE kernels need compatible hardware */
block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
if (block < 5) {
efi_err("This LPAE kernel is not supported by your CPU\n");
status = EFI_UNSUPPORTED;
goto drop_table;
}
return EFI_SUCCESS;
drop_table:
efi_bs_call(install_configuration_table, &cpu_state_guid, NULL);
free_state:
efi_bs_call(free_pool, efi_entry_state);
return status;
}
void efi_handle_post_ebs_state(void)
{
get_cpu_state(&efi_entry_state->cpsr_after_ebs,
&efi_entry_state->sctlr_after_ebs);
}
static efi_guid_t screen_info_guid = LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID;
struct screen_info *alloc_screen_info(void)
{
struct screen_info *si;
efi_status_t status;
/*
* Unlike on arm64, where we can directly fill out the screen_info
* structure from the stub, we need to allocate a buffer to hold
* its contents while we hand over to the kernel proper from the
* decompressor.
*/
status = efi_bs_call(allocate_pool, EFI_RUNTIME_SERVICES_DATA,
sizeof(*si), (void **)&si);
if (status != EFI_SUCCESS)
return NULL;
status = efi_bs_call(install_configuration_table,
&screen_info_guid, si);
if (status == EFI_SUCCESS)
return si;
efi_bs_call(free_pool, si);
return NULL;
}
void free_screen_info(struct screen_info *si)
{
if (!si)
return;
efi_bs_call(install_configuration_table, &screen_info_guid, NULL);
efi_bs_call(free_pool, si);
}
efi_status_t handle_kernel_image(unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
unsigned long *reserve_size,
efi_loaded_image_t *image,
efi_handle_t image_handle)
{
const int slack = TEXT_OFFSET - 5 * PAGE_SIZE;
int alloc_size = MAX_UNCOMP_KERNEL_SIZE + EFI_PHYS_ALIGN;
unsigned long alloc_base, kernel_base;
efi_status_t status;
/*
* Allocate space for the decompressed kernel as low as possible.
* The region should be 16 MiB aligned, but the first 'slack' bytes
* are not used by Linux, so we allow those to be occupied by the
* firmware.
*/
status = efi_low_alloc_above(alloc_size, EFI_PAGE_SIZE, &alloc_base, 0x0);
if (status != EFI_SUCCESS) {
efi_err("Unable to allocate memory for uncompressed kernel.\n");
return status;
}
if ((alloc_base % EFI_PHYS_ALIGN) > slack) {
/*
* More than 'slack' bytes are already occupied at the base of
* the allocation, so we need to advance to the next 16 MiB block.
*/
kernel_base = round_up(alloc_base, EFI_PHYS_ALIGN);
efi_info("Free memory starts at 0x%lx, setting kernel_base to 0x%lx\n",
alloc_base, kernel_base);
} else {
kernel_base = round_down(alloc_base, EFI_PHYS_ALIGN);
}
*reserve_addr = kernel_base + slack;
*reserve_size = MAX_UNCOMP_KERNEL_SIZE;
/* now free the parts that we will not use */
if (*reserve_addr > alloc_base) {
efi_bs_call(free_pages, alloc_base,
(*reserve_addr - alloc_base) / EFI_PAGE_SIZE);
alloc_size -= *reserve_addr - alloc_base;
}
efi_bs_call(free_pages, *reserve_addr + MAX_UNCOMP_KERNEL_SIZE,
(alloc_size - MAX_UNCOMP_KERNEL_SIZE) / EFI_PAGE_SIZE);
*image_addr = kernel_base + TEXT_OFFSET;
*image_size = 0;
efi_debug("image addr == 0x%lx, reserve_addr == 0x%lx\n",
*image_addr, *reserve_addr);
return EFI_SUCCESS;
}
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