s390/vmalloc: have separate modules area
Add a special module area on top of the vmalloc area, which may be only
used for modules and bpf jit generated code.
This makes sure that inter module branches will always happen without a
trampoline and in addition having all the code within a 2GB frame is
branch prediction unit friendly.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
index 46412b1..4610dea 100644
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -44,6 +44,17 @@
#define PLT_ENTRY_SIZE 20
#endif /* CONFIG_64BIT */
+#ifdef CONFIG_64BIT
+void *module_alloc(unsigned long size)
+{
+ if (PAGE_ALIGN(size) > MODULES_LEN)
+ return NULL;
+ return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
+ GFP_KERNEL, PAGE_KERNEL, -1,
+ __builtin_return_address(0));
+}
+#endif
+
/* Free memory returned from module_alloc */
void module_free(struct module *mod, void *module_region)
{
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index bfb48f1..b1f2be9 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -105,6 +105,11 @@
struct page *vmemmap;
EXPORT_SYMBOL(vmemmap);
+#ifdef CONFIG_64BIT
+unsigned long MODULES_VADDR;
+unsigned long MODULES_END;
+#endif
+
/* An array with a pointer to the lowcore of every CPU. */
struct _lowcore *lowcore_ptr[NR_CPUS];
EXPORT_SYMBOL(lowcore_ptr);
@@ -544,19 +549,23 @@
/* Choose kernel address space layout: 2, 3, or 4 levels. */
#ifdef CONFIG_64BIT
- vmalloc_size = VMALLOC_END ?: 128UL << 30;
+ vmalloc_size = VMALLOC_END ?: (128UL << 30) - MODULES_LEN;
tmp = (memory_end ?: real_memory_size) / PAGE_SIZE;
tmp = tmp * (sizeof(struct page) + PAGE_SIZE) + vmalloc_size;
if (tmp <= (1UL << 42))
vmax = 1UL << 42; /* 3-level kernel page table */
else
vmax = 1UL << 53; /* 4-level kernel page table */
+ /* module area is at the end of the kernel address space. */
+ MODULES_END = vmax;
+ MODULES_VADDR = MODULES_END - MODULES_LEN;
+ VMALLOC_END = MODULES_VADDR;
#else
vmalloc_size = VMALLOC_END ?: 96UL << 20;
vmax = 1UL << 31; /* 2-level kernel page table */
-#endif
/* vmalloc area is at the end of the kernel address space. */
VMALLOC_END = vmax;
+#endif
VMALLOC_START = vmax - vmalloc_size;
/* Split remaining virtual space between 1:1 mapping & vmemmap array */