From 23fa18eaa71266feff7ba8d83022d9e1cc83c65a Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 07:42:03 +0000
Subject: [PATCH] disable pwm7
---
kernel/arch/arm64/kernel/efi.c | 90 ++++++++++++++++++++++++++++++++-------------
1 files changed, 64 insertions(+), 26 deletions(-)
diff --git a/kernel/arch/arm64/kernel/efi.c b/kernel/arch/arm64/kernel/efi.c
index 4f9acb5..3ee3b3d 100644
--- a/kernel/arch/arm64/kernel/efi.c
+++ b/kernel/arch/arm64/kernel/efi.c
@@ -1,20 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Extensible Firmware Interface
*
* Based on Extensible Firmware Interface Specification version 2.4
*
* Copyright (C) 2013, 2014 Linaro Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
*/
#include <linux/efi.h>
#include <linux/init.h>
#include <asm/efi.h>
+
+static bool region_is_misaligned(const efi_memory_desc_t *md)
+{
+ if (PAGE_SIZE == EFI_PAGE_SIZE)
+ return false;
+ return !PAGE_ALIGNED(md->phys_addr) ||
+ !PAGE_ALIGNED(md->num_pages << EFI_PAGE_SHIFT);
+}
/*
* Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
@@ -29,14 +33,22 @@
if (type == EFI_MEMORY_MAPPED_IO)
return PROT_DEVICE_nGnRE;
- if (WARN_ONCE(!PAGE_ALIGNED(md->phys_addr),
- "UEFI Runtime regions are not aligned to 64 KB -- buggy firmware?"))
+ if (region_is_misaligned(md)) {
+ static bool __initdata code_is_misaligned;
+
/*
- * If the region is not aligned to the page size of the OS, we
- * can not use strict permissions, since that would also affect
- * the mapping attributes of the adjacent regions.
+ * Regions that are not aligned to the OS page size cannot be
+ * mapped with strict permissions, as those might interfere
+ * with the permissions that are needed by the adjacent
+ * region's mapping. However, if we haven't encountered any
+ * misaligned runtime code regions so far, we can safely use
+ * non-executable permissions for non-code regions.
*/
- return pgprot_val(PAGE_KERNEL_EXEC);
+ code_is_misaligned |= (type == EFI_RUNTIME_SERVICES_CODE);
+
+ return code_is_misaligned ? pgprot_val(PAGE_KERNEL_EXEC)
+ : pgprot_val(PAGE_KERNEL);
+ }
/* R-- */
if ((attr & (EFI_MEMORY_XP | EFI_MEMORY_RO)) ==
@@ -58,7 +70,7 @@
}
/* we will fill this structure from the stub, so don't put it in .bss */
-struct screen_info screen_info __section(.data);
+struct screen_info screen_info __section(".data");
int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
{
@@ -66,19 +78,16 @@
bool page_mappings_only = (md->type == EFI_RUNTIME_SERVICES_CODE ||
md->type == EFI_RUNTIME_SERVICES_DATA);
- if (!PAGE_ALIGNED(md->phys_addr) ||
- !PAGE_ALIGNED(md->num_pages << EFI_PAGE_SHIFT)) {
- /*
- * If the end address of this region is not aligned to page
- * size, the mapping is rounded up, and may end up sharing a
- * page frame with the next UEFI memory region. If we create
- * a block entry now, we may need to split it again when mapping
- * the next region, and support for that is going to be removed
- * from the MMU routines. So avoid block mappings altogether in
- * that case.
- */
+ /*
+ * If this region is not aligned to the page size used by the OS, the
+ * mapping will be rounded outwards, and may end up sharing a page
+ * frame with an adjacent runtime memory region. Given that the page
+ * table descriptor covering the shared page will be rewritten when the
+ * adjacent region gets mapped, we must avoid block mappings here so we
+ * don't have to worry about splitting them when that happens.
+ */
+ if (region_is_misaligned(md))
page_mappings_only = true;
- }
create_pgd_mapping(mm, md->phys_addr, md->virt_addr,
md->num_pages << EFI_PAGE_SHIFT,
@@ -86,8 +95,7 @@
return 0;
}
-static int __init set_permissions(pte_t *ptep, pgtable_t token,
- unsigned long addr, void *data)
+static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
{
efi_memory_desc_t *md = data;
pte_t pte = READ_ONCE(*ptep);
@@ -105,6 +113,9 @@
{
BUG_ON(md->type != EFI_RUNTIME_SERVICES_CODE &&
md->type != EFI_RUNTIME_SERVICES_DATA);
+
+ if (region_is_misaligned(md))
+ return 0;
/*
* Calling apply_to_page_range() is only safe on regions that are
@@ -132,3 +143,30 @@
pr_err_ratelimited(FW_BUG "register x18 corrupted by EFI %s\n", f);
return s;
}
+
+DEFINE_RAW_SPINLOCK(efi_rt_lock);
+
+asmlinkage u64 *efi_rt_stack_top __ro_after_init;
+
+/* EFI requires 8 KiB of stack space for runtime services */
+static_assert(THREAD_SIZE >= SZ_8K);
+
+static int __init arm64_efi_rt_init(void)
+{
+ void *p;
+
+ if (!efi_enabled(EFI_RUNTIME_SERVICES))
+ return 0;
+
+ p = __vmalloc_node(THREAD_SIZE, THREAD_ALIGN, GFP_KERNEL,
+ NUMA_NO_NODE, &&l);
+l: if (!p) {
+ pr_warn("Failed to allocate EFI runtime stack\n");
+ clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+ return -ENOMEM;
+ }
+
+ efi_rt_stack_top = p + THREAD_SIZE;
+ return 0;
+}
+core_initcall(arm64_efi_rt_init);
--
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