Commit 54372cf0 authored by Alexander Gordeev's avatar Alexander Gordeev
Browse files

Revert "s390/mm: get rid of VMEM_MAX_PHYS macro" 



This reverts commit 456be42a.

The assumption VMEM_MAX_PHYS should match ident_map_size
is wrong. At least discontiguous saved segments (DCSS)
could be loaded at addresses beyond ident_map_size and
dcssblk device driver might fail as result.

Reported-by: default avatarGerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent 6aca56c0

arch/s390/boot/startup.c

+1 −0
Original line number Diff line number Diff line
@@ -220,6 +220,7 @@ static unsigned long setup_kernel_memory_layout(void) 
	pages = SECTION_ALIGN_UP(pages);

	/* keep vmemmap_start aligned to a top level region table entry */

	vmemmap_start = round_down(VMALLOC_START - pages * sizeof(struct page), rte_size);

	/* vmemmap_start is the future VMEM_MAX_PHYS, make sure it is within MAX_PHYSMEM */

	vmemmap_start = min(vmemmap_start, 1UL << MAX_PHYSMEM_BITS);

	/* make sure identity map doesn't overlay with vmemmap */

	ident_map_size = min(ident_map_size, vmemmap_start);

arch/s390/include/asm/pgtable.h

+2 −0
Original line number Diff line number Diff line
@@ -89,6 +89,8 @@ extern unsigned long __bootdata_preserved(VMALLOC_END); 
extern struct page *__bootdata_preserved(vmemmap);

extern unsigned long __bootdata_preserved(vmemmap_size);



#define VMEM_MAX_PHYS ((unsigned long) vmemmap)



extern unsigned long __bootdata_preserved(MODULES_VADDR);

extern unsigned long __bootdata_preserved(MODULES_END);

#define MODULES_VADDR	MODULES_VADDR

arch/s390/mm/extmem.c

+1 −1
Original line number Diff line number Diff line
@@ -642,7 +642,7 @@ void segment_warning(int rc, char *seg_name) 
		break;

	case -ERANGE:

		pr_err("DCSS %s exceeds the kernel mapping range (%lu) "

		       "and cannot be loaded\n", seg_name, ident_map_size);

		       "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS);

		break;

	default:

		break;

arch/s390/mm/vmem.c

+1 −1
Original line number Diff line number Diff line
@@ -531,7 +531,7 @@ struct range arch_get_mappable_range(void) 
	struct range mhp_range;



	mhp_range.start = 0;

	mhp_range.end = ident_map_size - 1;

	mhp_range.end =  VMEM_MAX_PHYS - 1;

	return mhp_range;

}

drivers/s390/char/sclp_cmd.c

+3 −3
Original line number Diff line number Diff line
@@ -392,10 +392,10 @@ static void __init add_memory_merged(u16 rn) 
		goto skip_add;

	start = rn2addr(first_rn);

	size = (unsigned long long) num * sclp.rzm;

	if (start >= ident_map_size)

	if (start >= VMEM_MAX_PHYS)

		goto skip_add;

	if (start + size > ident_map_size)

		size = ident_map_size - start;

	if (start + size > VMEM_MAX_PHYS)

		size = VMEM_MAX_PHYS - start;

	if (start >= ident_map_size)

		goto skip_add;

	if (start + size > ident_map_size)