diff options
Diffstat (limited to 'arch/s390/boot/startup.c')
| -rw-r--r-- | arch/s390/boot/startup.c | 48 |
1 files changed, 44 insertions, 4 deletions
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index eeda91fcf7cc..05f8eefa3dcf 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/string.h> #include <linux/elf.h> +#include <asm/boot_data.h> #include <asm/sections.h> #include <asm/cpu_mf.h> #include <asm/setup.h> @@ -14,6 +15,7 @@ extern char __boot_data_start[], __boot_data_end[]; extern char __boot_data_preserved_start[], __boot_data_preserved_end[]; unsigned long __bootdata_preserved(__kaslr_offset); +unsigned long __bootdata(ident_map_size); /* * Some code and data needs to stay below 2 GB, even when the kernel would be @@ -128,6 +130,46 @@ static void handle_relocs(unsigned long offset) } /* + * Merge information from several sources into a single ident_map_size value. + * "ident_map_size" represents the upper limit of physical memory we may ever + * reach. It might not be all online memory, but also include standby (offline) + * memory. "ident_map_size" could be lower then actual standby or even online + * memory present, due to limiting factors. We should never go above this limit. + * It is the size of our identity mapping. + * + * Consider the following factors: + * 1. max_physmem_end - end of physical memory online or standby. + * Always <= end of the last online memory block (get_mem_detect_end()). + * 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the + * kernel is able to support. + * 3. "mem=" kernel command line option which limits physical memory usage. + * 4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as + * crash kernel. + * 5. "hsa" size which is a memory limit when the kernel is executed during + * zfcp/nvme dump. + */ +static void setup_ident_map_size(unsigned long max_physmem_end) +{ + unsigned long hsa_size; + + ident_map_size = max_physmem_end; + if (memory_limit) + ident_map_size = min(ident_map_size, memory_limit); + ident_map_size = min(ident_map_size, 1UL << MAX_PHYSMEM_BITS); + +#ifdef CONFIG_CRASH_DUMP + if (OLDMEM_BASE) { + kaslr_enabled = 0; + ident_map_size = min(ident_map_size, OLDMEM_SIZE); + } else if (ipl_block_valid && is_ipl_block_dump()) { + kaslr_enabled = 0; + if (!sclp_early_get_hsa_size(&hsa_size) && hsa_size) + ident_map_size = min(ident_map_size, hsa_size); + } +#endif +} + +/* * This function clears the BSS section of the decompressed Linux kernel and NOT the decompressor's. */ static void clear_bss_section(void) @@ -145,8 +187,7 @@ static void setup_vmalloc_size(void) if (vmalloc_size_set) return; - size = (memory_end ?: max_physmem_end) >> 3; - size = round_up(size, _SEGMENT_SIZE); + size = round_up(ident_map_size / 8, _SEGMENT_SIZE); vmalloc_size = max(size, vmalloc_size); } @@ -165,8 +206,7 @@ void startup_kernel(void) sclp_early_read_info(); setup_boot_command_line(); parse_boot_command_line(); - setup_memory_end(); - detect_memory(); + setup_ident_map_size(detect_memory()); setup_vmalloc_size(); random_lma = __kaslr_offset = 0; |