Commit 8e9205d2 authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Heiko Carstens
Browse files

s390/mm: allocate Real Memory Copy Area in decompressor 



Move Real Memory Copy Area allocation to the decompressor.
As result, memcpy_real() and memcpy_real_iter() movers
become usable since the very moment the kernel starts.

Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent e0e0a87b

arch/s390/boot/startup.c

+2 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#include <linux/elf.h>

#include <asm/boot_data.h>

#include <asm/sections.h>

#include <asm/maccess.h>

#include <asm/cpu_mf.h>

#include <asm/setup.h>

#include <asm/kasan.h>
@@ -19,6 +20,7 @@ 
unsigned long __bootdata_preserved(__kaslr_offset);

unsigned long __bootdata_preserved(__abs_lowcore);

unsigned long __bootdata_preserved(__memcpy_real_area);

pte_t *__bootdata_preserved(memcpy_real_ptep);

unsigned long __bootdata(__amode31_base);

unsigned long __bootdata_preserved(VMALLOC_START);

unsigned long __bootdata_preserved(VMALLOC_END);

arch/s390/boot/vmem.c

+15 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <asm/facility.h>

#include <asm/sections.h>

#include <asm/mem_detect.h>

#include <asm/maccess.h>

#include "decompressor.h"

#include "boot.h"
@@ -12,12 +13,21 @@ 
#define swapper_pg_dir		vmlinux.swapper_pg_dir_off

#define invalid_pg_dir		vmlinux.invalid_pg_dir_off



/*

 * Mimic virt_to_kpte() in lack of init_mm symbol. Skip pmd NULL check though.

 */

static inline pte_t *__virt_to_kpte(unsigned long va)

{

	return pte_offset_kernel(pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va), va);

}



unsigned long __bootdata_preserved(s390_invalid_asce);

unsigned long __bootdata(pgalloc_pos);

unsigned long __bootdata(pgalloc_end);

unsigned long __bootdata(pgalloc_low);



enum populate_mode {

	POPULATE_NONE,

	POPULATE_ONE2ONE,

};
@@ -88,6 +98,8 @@ static pte_t *boot_pte_alloc(void) 
static unsigned long _pa(unsigned long addr, enum populate_mode mode)

{

	switch (mode) {

	case POPULATE_NONE:

		return -1;

	case POPULATE_ONE2ONE:

		return addr;

	default:
@@ -259,6 +271,9 @@ void setup_vmem(unsigned long online_end, unsigned long asce_limit) 
	pgtable_populate_begin(online_end);

	pgtable_populate(0, sizeof(struct lowcore), POPULATE_ONE2ONE);

	pgtable_populate(0, online_end, POPULATE_ONE2ONE);

	pgtable_populate(__memcpy_real_area, __memcpy_real_area + PAGE_SIZE,

			 POPULATE_NONE);

	memcpy_real_ptep = __virt_to_kpte(__memcpy_real_area);

	pgtable_populate_end();



	S390_lowcore.kernel_asce = swapper_pg_dir | asce_bits;

arch/s390/include/asm/maccess.h

+1 −1
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ 
struct iov_iter;



extern unsigned long __memcpy_real_area;

void memcpy_real_init(void);

extern pte_t *memcpy_real_ptep;

size_t memcpy_real_iter(struct iov_iter *iter, unsigned long src, size_t count);

int memcpy_real(void *dest, unsigned long src, size_t count);

#ifdef CONFIG_CRASH_DUMP

arch/s390/kernel/setup.c

+1 −1
Original line number Diff line number Diff line
@@ -1046,7 +1046,7 @@ void __init setup_arch(char **cmdline_p) 
	 * Create kernel page tables.

	 */

        paging_init();

	memcpy_real_init();



	/*

	 * After paging_init created the kernel page table, the new PSWs

	 * in lowcore can now run with DAT enabled.

arch/s390/mm/maccess.c

+1 −8
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ 
#include <asm/maccess.h>



unsigned long __bootdata_preserved(__memcpy_real_area);

static __ro_after_init pte_t *memcpy_real_ptep;

pte_t *__bootdata_preserved(memcpy_real_ptep);

static DEFINE_MUTEX(memcpy_real_mutex);



static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t size)
@@ -79,13 +79,6 @@ notrace void *s390_kernel_write(void *dst, const void *src, size_t size) 
	return dst;

}



void __init memcpy_real_init(void)

{

	memcpy_real_ptep = vmem_get_alloc_pte(__memcpy_real_area, true);

	if (!memcpy_real_ptep)

		panic("Couldn't setup memcpy real area");

}



size_t memcpy_real_iter(struct iov_iter *iter, unsigned long src, size_t count)

{

	size_t len, copied, res = 0;