From f0aa6617903648077dffe5cfcf7c4458f4610fa7 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 20 Feb 2009 16:29:08 +0900 Subject: [PATCH] vmalloc: implement vm_area_register_early() Impact: allow multiple early vm areas There are places where kernel VM area needs to be allocated before vmalloc is initialized. This is done by allocating static vm_struct, initializing several fields and linking it to vmlist and later vmalloc initialization picking up these from vmlist. This is currently done manually and if there's more than one such areas, there's no defined way to arbitrate who gets which address. This patch implements vm_area_register_early(), which takes vm_area struct with flags and size initialized, assigns address to it and puts it on the vmlist. This way, multiple early vm areas can determine which addresses they should use. The only current user - alpha mm init - is converted to use it. Signed-off-by: Tejun Heo --- arch/alpha/mm/init.c | 20 +++++++++++++------- include/linux/vmalloc.h | 1 + mm/vmalloc.c | 24 ++++++++++++++++++++++++ 3 files changed, 38 insertions(+), 7 deletions(-) diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c index 5d7a16eab312..df6df025ded4 100644 --- a/arch/alpha/mm/init.c +++ b/arch/alpha/mm/init.c @@ -189,9 +189,21 @@ callback_init(void * kernel_end) if (alpha_using_srm) { static struct vm_struct console_remap_vm; - unsigned long vaddr = VMALLOC_START; + unsigned long nr_pages = 0; + unsigned long vaddr; unsigned long i, j; + /* calculate needed size */ + for (i = 0; i < crb->map_entries; ++i) + nr_pages += crb->map[i].count; + + /* register the vm area */ + console_remap_vm.flags = VM_ALLOC; + console_remap_vm.size = nr_pages << PAGE_SHIFT; + vm_area_register_early(&console_remap_vm); + + vaddr = (unsigned long)consle_remap_vm.addr; + /* Set up the third level PTEs and update the virtual addresses of the CRB entries. */ for (i = 0; i < crb->map_entries; ++i) { @@ -213,12 +225,6 @@ callback_init(void * kernel_end) vaddr += PAGE_SIZE; } } - - /* Let vmalloc know that we've allocated some space. */ - console_remap_vm.flags = VM_ALLOC; - console_remap_vm.addr = (void *) VMALLOC_START; - console_remap_vm.size = vaddr - VMALLOC_START; - vmlist = &console_remap_vm; } callback_init_done = 1; diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 506e7620a986..bbc051392298 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -106,5 +106,6 @@ extern long vwrite(char *buf, char *addr, unsigned long count); */ extern rwlock_t vmlist_lock; extern struct vm_struct *vmlist; +extern __init void vm_area_register_early(struct vm_struct *vm); #endif /* _LINUX_VMALLOC_H */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index c37924a2ee36..d206261ad9ef 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -982,6 +983,29 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t pro } EXPORT_SYMBOL(vm_map_ram); +/** + * vm_area_register_early - register vmap area early during boot + * @vm: vm_struct to register + * @size: size of area to register + * + * This function is used to register kernel vm area before + * vmalloc_init() is called. @vm->size and @vm->flags should contain + * proper values on entry and other fields should be zero. On return, + * vm->addr contains the allocated address. + * + * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. + */ +void __init vm_area_register_early(struct vm_struct *vm) +{ + static size_t vm_init_off __initdata; + + vm->addr = (void *)VMALLOC_START + vm_init_off; + vm_init_off = PFN_ALIGN(vm_init_off + vm->size); + + vm->next = vmlist; + vmlist = vm; +} + void __init vmalloc_init(void) { struct vmap_area *va; -- GitLab