s390/boot: allocate amode31 section in decompressor

[platform/kernel/linux-rpi.git] / arch / s390 / boot / startup.c

diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 6dc8d0a..1aa11a8 100644 (file)
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -15,6 +15,7 @@
 #include "uv.h"
 
 unsigned long __bootdata_preserved(__kaslr_offset);
+unsigned long __bootdata(__amode31_base);
 unsigned long __bootdata_preserved(VMALLOC_START);
 unsigned long __bootdata_preserved(VMALLOC_END);
 struct page *__bootdata_preserved(vmemmap);
@@ -148,82 +149,56 @@ static void setup_ident_map_size(unsigned long max_physmem_end)
 
 static void setup_kernel_memory_layout(void)
 {
-       bool vmalloc_size_verified = false;
-       unsigned long vmemmap_off;
-       unsigned long vspace_left;
+       unsigned long vmemmap_start;
        unsigned long rte_size;
        unsigned long pages;
-       unsigned long vmax;
 
        pages = ident_map_size / PAGE_SIZE;
        /* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
        vmemmap_size = SECTION_ALIGN_UP(pages) * sizeof(struct page);
 
        /* choose kernel address space layout: 4 or 3 levels. */
-       vmemmap_off = round_up(ident_map_size, _REGION3_SIZE);
+       vmemmap_start = round_up(ident_map_size, _REGION3_SIZE);
        if (IS_ENABLED(CONFIG_KASAN) ||
            vmalloc_size > _REGION2_SIZE ||
-           vmemmap_off + vmemmap_size + vmalloc_size + MODULES_LEN > _REGION2_SIZE)
-               vmax = _REGION1_SIZE;
-       else
-               vmax = _REGION2_SIZE;
-
-       /* keep vmemmap_off aligned to a top level region table entry */
-       rte_size = vmax == _REGION1_SIZE ? _REGION2_SIZE : _REGION3_SIZE;
-       MODULES_END = vmax;
-       if (is_prot_virt_host()) {
-               /*
-                * forcing modules and vmalloc area under the ultravisor
-                * secure storage limit, so that any vmalloc allocation
-                * we do could be used to back secure guest storage.
-                */
-               adjust_to_uv_max(&MODULES_END);
-       }
-
-#ifdef CONFIG_KASAN
-       if (MODULES_END < vmax) {
-               /* force vmalloc and modules below kasan shadow */
-               MODULES_END = min(MODULES_END, KASAN_SHADOW_START);
+           vmemmap_start + vmemmap_size + vmalloc_size + MODULES_LEN >
+                   _REGION2_SIZE) {
+               MODULES_END = _REGION1_SIZE;
+               rte_size = _REGION2_SIZE;
        } else {
-               /*
-                * leave vmalloc and modules above kasan shadow but make
-                * sure they don't overlap with it
-                */
-               vmalloc_size = min(vmalloc_size, vmax - KASAN_SHADOW_END - MODULES_LEN);
-               vmalloc_size_verified = true;
-               vspace_left = KASAN_SHADOW_START;
+               MODULES_END = _REGION2_SIZE;
+               rte_size = _REGION3_SIZE;
        }
+       /*
+        * forcing modules and vmalloc area under the ultravisor
+        * secure storage limit, so that any vmalloc allocation
+        * we do could be used to back secure guest storage.
+        */
+       adjust_to_uv_max(&MODULES_END);
+#ifdef CONFIG_KASAN
+       /* force vmalloc and modules below kasan shadow */
+       MODULES_END = min(MODULES_END, KASAN_SHADOW_START);
 #endif
        MODULES_VADDR = MODULES_END - MODULES_LEN;
        VMALLOC_END = MODULES_VADDR;
 
-       if (vmalloc_size_verified) {
-               VMALLOC_START = VMALLOC_END - vmalloc_size;
-       } else {
-               vmemmap_off = round_up(ident_map_size, rte_size);
+       /* allow vmalloc area to occupy up to about 1/2 of the rest virtual space left */
+       vmalloc_size = min(vmalloc_size, round_down(VMALLOC_END / 2, _REGION3_SIZE));
+       VMALLOC_START = VMALLOC_END - vmalloc_size;
 
-               if (vmemmap_off + vmemmap_size > VMALLOC_END ||
-                   vmalloc_size > VMALLOC_END - vmemmap_off - vmemmap_size) {
-                       /*
-                        * allow vmalloc area to occupy up to 1/2 of
-                        * the rest virtual space left.
-                        */
-                       vmalloc_size = min(vmalloc_size, VMALLOC_END / 2);
-               }
-               VMALLOC_START = VMALLOC_END - vmalloc_size;
-               vspace_left = VMALLOC_START;
-       }
-
-       pages = vspace_left / (PAGE_SIZE + sizeof(struct page));
+       /* split remaining virtual space between 1:1 mapping & vmemmap array */
+       pages = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
        pages = SECTION_ALIGN_UP(pages);
-       vmemmap_off = round_up(vspace_left - pages * sizeof(struct page), rte_size);
-       /* keep vmemmap left most starting from a fresh region table entry */
-       vmemmap_off = min(vmemmap_off, round_up(ident_map_size, rte_size));
-       /* take care that identity map is lower then vmemmap */
-       ident_map_size = min(ident_map_size, vmemmap_off);
+       /* 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);
        vmemmap_size = SECTION_ALIGN_UP(ident_map_size / PAGE_SIZE) * sizeof(struct page);
-       VMALLOC_START = max(vmemmap_off + vmemmap_size, VMALLOC_START);
-       vmemmap = (struct page *)vmemmap_off;
+       /* make sure vmemmap doesn't overlay with vmalloc area */
+       VMALLOC_START = max(vmemmap_start + vmemmap_size, VMALLOC_START);
+       vmemmap = (struct page *)vmemmap_start;
 }
 
 /*
@@ -259,6 +234,12 @@ static void offset_vmlinux_info(unsigned long offset)
        vmlinux.dynsym_start += offset;
 }
 
+static unsigned long reserve_amode31(unsigned long safe_addr)
+{
+       __amode31_base = PAGE_ALIGN(safe_addr);
+       return safe_addr + vmlinux.amode31_size;
+}
+
 void startup_kernel(void)
 {
        unsigned long random_lma;
@@ -273,6 +254,7 @@ void startup_kernel(void)
        setup_lpp();
        store_ipl_parmblock();
        safe_addr = mem_safe_offset();
+       safe_addr = reserve_amode31(safe_addr);
        safe_addr = read_ipl_report(safe_addr);
        uv_query_info();
        rescue_initrd(safe_addr);