[mirror_ubuntu-hirsute-kernel.git] / arch / x86 / mm / pgtable_32.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/nmi.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/spinlock.h>

#include <asm/cpu_entry_area.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/fixmap.h>
#include <asm/e820/api.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/io.h>
#include <linux/vmalloc.h>

unsigned int __VMALLOC_RESERVE = 128 << 20;

/*
 * Associate a virtual page frame with a given physical page frame 
 * and protection flags for that frame.
 */ 
void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
{
	pgd_t *pgd;
	p4d_t *p4d;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;

	pgd = swapper_pg_dir + pgd_index(vaddr);
	if (pgd_none(*pgd)) {
		BUG();
		return;
	}
	p4d = p4d_offset(pgd, vaddr);
	if (p4d_none(*p4d)) {
		BUG();
		return;
	}
	pud = pud_offset(p4d, vaddr);
	if (pud_none(*pud)) {
		BUG();
		return;
	}
	pmd = pmd_offset(pud, vaddr);
	if (pmd_none(*pmd)) {
		BUG();
		return;
	}
	pte = pte_offset_kernel(pmd, vaddr);
	if (!pte_none(pteval))
		set_pte_at(&init_mm, vaddr, pte, pteval);
	else
		pte_clear(&init_mm, vaddr, pte);

	/*
	 * It's enough to flush this one mapping.
	 * (PGE mappings get flushed as well)
	 */
	__flush_tlb_one_kernel(vaddr);
}

unsigned long __FIXADDR_TOP = 0xfffff000;
EXPORT_SYMBOL(__FIXADDR_TOP);

/*
 * vmalloc=size forces the vmalloc area to be exactly 'size'
 * bytes. This can be used to increase (or decrease) the
 * vmalloc area - the default is 128m.
 */
static int __init parse_vmalloc(char *arg)
{
	if (!arg)
		return -EINVAL;

	/* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/
	__VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET;
	return 0;
}
early_param("vmalloc", parse_vmalloc);

/*
 * reservetop=size reserves a hole at the top of the kernel address space which
 * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
 * so relocating the fixmap can be done before paging initialization.
 */
static int __init parse_reservetop(char *arg)
{
	unsigned long address;

	if (!arg)
		return -EINVAL;

	address = memparse(arg, &arg);
	reserve_top_address(address);
	early_ioremap_init();
	return 0;
}
early_param("reservetop", parse_reservetop);
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	#include <linux/sched.h>
	3	#include <linux/kernel.h>
	4	#include <linux/errno.h>
	5	#include <linux/mm.h>
27eb0b28	6	#include <linux/nmi.h>
1da177e4 LT	7	#include <linux/swap.h>
	8	#include <linux/smp.h>
	9	#include <linux/highmem.h>
1da177e4 LT	10	#include <linux/pagemap.h>
	11	#include <linux/spinlock.h>
	12
92a0f81d	13	#include <asm/cpu_entry_area.h>
1da177e4 LT	14	#include <asm/pgtable.h>
	15	#include <asm/pgalloc.h>
	16	#include <asm/fixmap.h>
66441bd3	17	#include <asm/e820/api.h>
1da177e4 LT	18	#include <asm/tlb.h>
1da177e4 LT	19	#include <asm/tlbflush.h>
56f0e74c	20	#include <asm/io.h>
186525bd	21	#include <linux/vmalloc.h>
1da177e4	22
2b688dfd PE	23	unsigned int __VMALLOC_RESERVE = 128 << 20;
2b688dfd PE	24
1da177e4 LT	25	/*
	26	* Associate a virtual page frame with a given physical page frame
	27	* and protection flags for that frame.
	28	*/
d494a961	29	void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
1da177e4 LT	30	{
1da177e4 LT	31	pgd_t *pgd;
e0c4f675	32	p4d_t *p4d;
1da177e4 LT	33	pud_t *pud;
	34	pmd_t *pmd;
	35	pte_t *pte;
	36
	37	pgd = swapper_pg_dir + pgd_index(vaddr);
	38	if (pgd_none(*pgd)) {
	39	BUG();
	40	return;
	41	}
e0c4f675 KS	42	p4d = p4d_offset(pgd, vaddr);
	43	if (p4d_none(*p4d)) {
	44	BUG();
	45	return;
	46	}
	47	pud = pud_offset(p4d, vaddr);
1da177e4 LT	48	if (pud_none(*pud)) {
	49	BUG();
	50	return;
	51	}
	52	pmd = pmd_offset(pud, vaddr);
	53	if (pmd_none(*pmd)) {
	54	BUG();
	55	return;
	56	}
	57	pte = pte_offset_kernel(pmd, vaddr);
dcb32d99	58	if (!pte_none(pteval))
b40c7579	59	set_pte_at(&init_mm, vaddr, pte, pteval);
b0bfece4 JB	60	else
b0bfece4 JB	61	pte_clear(&init_mm, vaddr, pte);
1da177e4 LT	62
	63	/*
	64	* It's enough to flush this one mapping.
	65	* (PGE mappings get flushed as well)
1da177e4	66	*/
1299ef1d	67	__flush_tlb_one_kernel(vaddr);
1da177e4 LT	68	}
1da177e4 LT	69
052e7994 JF	70	unsigned long __FIXADDR_TOP = 0xfffff000;
052e7994 JF	71	EXPORT_SYMBOL(__FIXADDR_TOP);
052e7994	72
bef1568d YL	73	/*
	74	* vmalloc=size forces the vmalloc area to be exactly 'size'
	75	* bytes. This can be used to increase (or decrease) the
	76	* vmalloc area - the default is 128m.
	77	*/
	78	static int __init parse_vmalloc(char *arg)
	79	{
	80	if (!arg)
	81	return -EINVAL;
	82
e621bd18 DY	83	/* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/
e621bd18 DY	84	__VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET;
bef1568d YL	85	return 0;
	86	}
	87	early_param("vmalloc", parse_vmalloc);
	88
	89	/*
	90	* reservetop=size reserves a hole at the top of the kernel address space which
	91	* a hypervisor can load into later. Needed for dynamically loaded hypervisors,
	92	* so relocating the fixmap can be done before paging initialization.
	93	*/
	94	static int __init parse_reservetop(char *arg)
	95	{
	96	unsigned long address;
	97
	98	if (!arg)
	99	return -EINVAL;
	100
	101	address = memparse(arg, &arg);
	102	reserve_top_address(address);
5b7c73e0	103	early_ioremap_init();
bef1568d YL	104	return 0;
	105	}
	106	early_param("reservetop", parse_reservetop);