Commit 5bfc4a3a authored by Tiwei Bie's avatar Tiwei Bie Committed by Johannes Berg
Browse files

um: Remove obsolete fixmap support 



It was added to support highmem. But since the highmem support has
been removed by commit a98a6d86 ("um: Remove broken highmem
support"), it is no longer needed. Remove it to simplify the code.

Signed-off-by: default avatarTiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241128081939.2216246-3-tiwei.btw@antgroup.com


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent aa36314c

arch/um/include/asm/fixmap.h

deleted100644 → 0
+0 −56
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __UM_FIXMAP_H

#define __UM_FIXMAP_H



#include <asm/processor.h>

#include <asm/archparam.h>

#include <asm/page.h>

#include <linux/threads.h>



/*

 * 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. 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

 * highger than 1) use fixmap_set(idx,phys) to associate

 * physical memory with fixmap indices.

 *

 * TLB entries of such buffers will not be flushed across

 * task switches.

 */



/*

 * on UP currently we will have no trace of the fixmap mechanizm,

 * no page table allocations, etc. This might change in the

 * future, say framebuffers for the console driver(s) could be

 * fix-mapped?

 */

enum fixed_addresses {

	__end_of_fixed_addresses

};



extern void __set_fixmap (enum fixed_addresses idx,

			  unsigned long phys, pgprot_t flags);



/*

 * used by vmalloc.c.

 *

 * Leave one empty page between vmalloc'ed areas and

 * the start of the fixmap, and leave one page empty

 * at the top of mem..

 */



#define FIXADDR_TOP	(TASK_SIZE - 2 * PAGE_SIZE)

#define FIXADDR_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)

#define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)



#include <asm-generic/fixmap.h>



#endif

arch/um/include/asm/pgtable.h

+1 −4
Original line number Diff line number Diff line
@@ -8,8 +8,6 @@ 
#ifndef __UM_PGTABLE_H

#define __UM_PGTABLE_H



#include <asm/fixmap.h>



#define _PAGE_PRESENT	0x001

#define _PAGE_NEEDSYNC	0x002

#define _PAGE_RW	0x020
@@ -48,8 +46,7 @@ extern unsigned long end_iomem; 


#define VMALLOC_OFFSET	(__va_space)

#define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))

#define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)

#define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)

#define VMALLOC_END	(TASK_SIZE-2*PAGE_SIZE)

#define MODULES_VADDR	VMALLOC_START

#define MODULES_END	VMALLOC_END

arch/um/kernel/mem.c

+4 −11
Original line number Diff line number Diff line
@@ -9,7 +9,6 @@ 
#include <linux/mm.h>

#include <linux/swap.h>

#include <linux/slab.h>

#include <asm/fixmap.h>

#include <asm/page.h>

#include <asm/pgalloc.h>

#include <as-layout.h>
@@ -74,6 +73,7 @@ void __init mem_init(void) 
	kmalloc_ok = 1;

}



#if IS_ENABLED(CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA)

/*

 * Create a page table and place a pointer to it in a middle page

 * directory entry.
@@ -152,7 +152,6 @@ static void __init fixrange_init(unsigned long start, unsigned long end, 


static void __init fixaddr_user_init( void)

{

#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA

	long size = FIXADDR_USER_END - FIXADDR_USER_START;

	pte_t *pte;

	phys_t p;
@@ -174,13 +173,12 @@ static void __init fixaddr_user_init( void) 
		pte = virt_to_kpte(vaddr);

		pte_set_val(*pte, p, PAGE_READONLY);

	}

#endif

}

#endif



void __init paging_init(void)

{

	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };

	unsigned long vaddr;



	empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,

							       PAGE_SIZE);
@@ -191,14 +189,9 @@ void __init paging_init(void) 
	max_zone_pfn[ZONE_NORMAL] = end_iomem >> PAGE_SHIFT;

	free_area_init(max_zone_pfn);



	/*

	 * Fixed mappings, only the page table structure has to be

	 * created - mappings will be set by set_fixmap():

	 */

	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;

	fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);



#if IS_ENABLED(CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA)

	fixaddr_user_init();

#endif

}



/*