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| author |  Alexander Gordeev <agordeev@linux.ibm.com>
| 2024-03-01 07:03:49 +0100 |
|---|---|---|
| committer | Alexander Gordeev <agordeev@linux.ibm.com>
| 2024-04-17 13:37:59 +0200 |
| commit | b2b15f079c4c19e3a73a8b0cf4f901186f12098f (patch) | |
| tree | d00cb0bad807dd98414097e445ffddb654ef7acf | |
| parent | s390/boot: Do not force vmemmap to start at MAX_PHYSMEM_BITS (diff) | |
| download | linux-b2b15f079c4c19e3a73a8b0cf4f901186f12098f.tar.gz linux-b2b15f079c4c19e3a73a8b0cf4f901186f12098f.tar.bz2 linux-b2b15f079c4c19e3a73a8b0cf4f901186f12098f.zip | |
s390/boot: Consider DCSS segments on memory layout setup
The maximum mappable physical address (as returned by
arch_get_mappable_range() callback) is limited by the
value of (1UL << MAX_PHYSMEM_BITS).
The maximum physical address available to a DCSS segment
is 512GB.
In case the available online or offline memory size is less
than the DCSS limit arch_get_mappable_range() would include
never used [512GB..(1UL << MAX_PHYSMEM_BITS)] range.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
| -rw-r--r-- | arch/s390/boot/startup.c | 7 | ||||
| -rw-r--r-- | arch/s390/include/asm/extmem.h | 7 |
2 files changed, 12 insertions, 2 deletions
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index bb5d26f0ff41..eee742b88cc8 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -3,6 +3,7 @@ #include <linux/elf.h> #include <asm/page-states.h> #include <asm/boot_data.h> +#include <asm/extmem.h> #include <asm/sections.h> #include <asm/maccess.h> #include <asm/cpu_mf.h> @@ -313,14 +314,16 @@ 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); - /* maximum address for which linear mapping could be created (DCSS, memory) */ - max_mappable = 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); vmemmap_size = SECTION_ALIGN_UP(ident_map_size / PAGE_SIZE) * sizeof(struct page); /* make sure vmemmap doesn't overlay with vmalloc area */ VMALLOC_START = max(vmemmap_start + vmemmap_size, VMALLOC_START); vmemmap = (struct page *)vmemmap_start; + /* maximum address for which linear mapping could be created (DCSS, memory) */ + BUILD_BUG_ON(MAX_DCSS_ADDR > (1UL << MAX_PHYSMEM_BITS)); + max_mappable = max(ident_map_size, MAX_DCSS_ADDR); + max_mappable = min(max_mappable, vmemmap_start); return asce_limit; } diff --git a/arch/s390/include/asm/extmem.h b/arch/s390/include/asm/extmem.h index 568fd81bb77b..e0a06060afdd 100644 --- a/arch/s390/include/asm/extmem.h +++ b/arch/s390/include/asm/extmem.h @@ -8,6 +8,13 @@ #define _ASM_S390X_DCSS_H #ifndef __ASSEMBLY__ +/* + * DCSS segment is defined as a contiguous range of pages using DEFSEG command. + * The range start and end is a page number with a value less than or equal to + * 0x7ffffff (see CP Commands and Utilities Reference). + */ +#define MAX_DCSS_ADDR (512UL * SZ_1G) + /* possible values for segment type as returned by segment_info */ #define SEG_TYPE_SW 0 #define SEG_TYPE_EW 1 |