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linux-next/arch/x86/include/asm/fixmap.h
Thomas Gleixner 14df326702 x86: Support kmap_local() forced debugging
kmap_local() and related interfaces are NOOPs on 64bit and only create
temporary fixmaps for highmem pages on 32bit. That means the test coverage
for this code is pretty small.

CONFIG_KMAP_LOCAL can be enabled independent from CONFIG_HIGHMEM, which
allows to provide support for enforced kmap_local() debugging even on
64bit.

For 32bit the support is unconditional, for 64bit it's only supported when
CONFIG_NR_CPUS <= 4096 as supporting it for 8192 CPUs would require to set
up yet another fixmap PGT.

If CONFIG_KMAP_LOCAL_FORCE_DEBUG is enabled then kmap_local()/kmap_atomic()
will use the temporary fixmap mapping path.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20201118204007.169209557@linutronix.de
2020-11-24 14:42:09 +01:00

204 lines
6.0 KiB
C

/*
* fixmap.h: compile-time virtual memory allocation
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1998 Ingo Molnar
*
* Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
* x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009
*/
#ifndef _ASM_X86_FIXMAP_H
#define _ASM_X86_FIXMAP_H
#include <asm/kmap_size.h>
/*
* Exposed to assembly code for setting up initial page tables. Cannot be
* calculated in assembly code (fixmap entries are an enum), but is sanity
* checked in the actual fixmap C code to make sure that the fixmap is
* covered fully.
*/
#ifndef CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
# define FIXMAP_PMD_NUM 2
#else
# define KM_PMDS (KM_MAX_IDX * ((CONFIG_NR_CPUS + 511) / 512))
# define FIXMAP_PMD_NUM (KM_PMDS + 2)
#endif
/* fixmap starts downwards from the 507th entry in level2_fixmap_pgt */
#define FIXMAP_PMD_TOP 507
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
#include <asm/apicdef.h>
#include <asm/page.h>
#include <asm/pgtable_types.h>
#ifdef CONFIG_X86_32
#include <linux/threads.h>
#else
#include <uapi/asm/vsyscall.h>
#endif
/*
* We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
* uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
* Because of this, FIXADDR_TOP x86 integration was left as later work.
*/
#ifdef CONFIG_X86_32
/*
* Leave one empty page between vmalloc'ed areas and
* the start of the fixmap.
*/
extern unsigned long __FIXADDR_TOP;
#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
#else
#define FIXADDR_TOP (round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
PAGE_SIZE)
#endif
/*
* Here we define all the compile-time 'special' virtual
* addresses. The point is to have a constant address at
* compile time, but to set the physical address only
* in the boot process.
* for x86_32: We allocate these special addresses
* from the end of virtual memory (0xfffff000) backwards.
* Also this lets us do fail-safe vmalloc(), we
* can guarantee that these special addresses and
* vmalloc()-ed addresses never overlap.
*
* These 'compile-time allocated' memory buffers are
* fixed-size 4k pages (or larger if used with an increment
* higher than 1). Use set_fixmap(idx,phys) to associate
* physical memory with fixmap indices.
*
* TLB entries of such buffers will not be flushed across
* task switches.
*/
enum fixed_addresses {
#ifdef CONFIG_X86_32
FIX_HOLE,
#else
#ifdef CONFIG_X86_VSYSCALL_EMULATION
VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
#endif
#endif
FIX_DBGP_BASE,
FIX_EARLYCON_MEM_BASE,
#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
FIX_OHCI1394_BASE,
#endif
#ifdef CONFIG_X86_LOCAL_APIC
FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
#endif
#ifdef CONFIG_X86_IO_APIC
FIX_IO_APIC_BASE_0,
FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
#endif
#ifdef CONFIG_KMAP_LOCAL
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#ifdef CONFIG_PCI_MMCONFIG
FIX_PCIE_MCFG,
#endif
#endif
#ifdef CONFIG_PARAVIRT_XXL
FIX_PARAVIRT_BOOTMAP,
#endif
#ifdef CONFIG_X86_INTEL_MID
FIX_LNW_VRTC,
#endif
#ifdef CONFIG_ACPI_APEI_GHES
/* Used for GHES mapping from assorted contexts */
FIX_APEI_GHES_IRQ,
FIX_APEI_GHES_NMI,
#endif
__end_of_permanent_fixed_addresses,
/*
* 512 temporary boot-time mappings, used by early_ioremap(),
* before ioremap() is functional.
*
* If necessary we round it up to the next 512 pages boundary so
* that we can have a single pmd entry and a single pte table:
*/
#define NR_FIX_BTMAPS 64
#define FIX_BTMAPS_SLOTS 8
#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
FIX_BTMAP_END =
(__end_of_permanent_fixed_addresses ^
(__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
-PTRS_PER_PTE
? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
(__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
: __end_of_permanent_fixed_addresses,
FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
#ifdef CONFIG_X86_32
FIX_WP_TEST,
#endif
#ifdef CONFIG_INTEL_TXT
FIX_TBOOT_BASE,
#endif
__end_of_fixed_addresses
};
extern void reserve_top_address(unsigned long reserve);
#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
#define FIXADDR_TOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_TOT_START (FIXADDR_TOP - FIXADDR_TOT_SIZE)
extern int fixmaps_set;
extern pte_t *pkmap_page_table;
void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
phys_addr_t phys, pgprot_t flags);
#ifndef CONFIG_PARAVIRT_XXL
static inline void __set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags)
{
native_set_fixmap(idx, phys, flags);
}
#endif
/*
* FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not
* supported for MMIO addresses, so make sure that the memory encryption
* mask is not part of the page attributes.
*/
#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE
/*
* Early memremap routines used for in-place encryption. The mappings created
* by these routines are intended to be used as temporary mappings.
*/
void __init *early_memremap_encrypted(resource_size_t phys_addr,
unsigned long size);
void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
unsigned long size);
void __init *early_memremap_decrypted(resource_size_t phys_addr,
unsigned long size);
void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
unsigned long size);
#include <asm-generic/fixmap.h>
#define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
#define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
void __early_set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags);
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_X86_FIXMAP_H */