This is an experimental (though tested) patch for early ioremap support
on mips, before mem_init runs. Something like this is only needed on
certain SoCs that have all of their I/O on high addresses such that they
can't me ioremapped through kseg1.
I think the CONFIG_64 stuff needs to removed since we don't need it. The
patch was tested on a MIPS32 CPU only. Some of the significant changes:
- trap_init() became early_trap_init() since too much stuff happens
there that is needed to support early ioremap. The old trap_init() is
now empty.
- added plat_setup_late() call. All ports would need to add that call,
or at least a placeholder. Early ioremap is possible only at that point.
However, most of the code in each plat_setup() can be moved to
plat_setup_late()
diff -Naur --exclude=CVS linux-2.6-orig/arch/mips/kernel/setup.c linux-2.6-dev/arch/mips/kernel/setup.c
--- linux-2.6-orig/arch/mips/kernel/setup.c 2005-08-24 17:12:31.000000000 -0700
+++ linux-2.6-dev/arch/mips/kernel/setup.c 2005-08-25 10:56:40.000000000 -0700
@@ -42,7 +42,10 @@
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/system.h>
+#include <asm/traps.h>
+#include <asm/io.h>
+int init_bootmem_done;
struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(cpu_data);
@@ -417,6 +420,8 @@
/* Reserve the bootmap memory. */
reserve_bootmem(PFN_PHYS(first_usable_pfn), bootmap_size);
+
+ init_bootmem_done = 1;
#endif /* CONFIG_SGI_IP27 */
#ifdef CONFIG_BLK_DEV_INITRD
@@ -511,7 +516,23 @@
#undef MAXMEM
#undef MAXMEM_PFN
+void __init early_ioremap_init(void)
+{
+#ifdef CONFIG_64BIT
+ ioremap_base = (VMALLOC_START + PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE);
+#else
+#ifdef CONFIG_HIGHMEM
+ ioremap_base = (PKMAP_BASE-2*PAGE_SIZE);
+#else
+ ioremap_base = (FIXADDR_START-2*PAGE_SIZE);
+#endif
+#endif /* CONFIG_64BIT */
+
+ ioremap_bot = ioremap_base;
+}
+
extern void plat_setup(void);
+extern void plat_setup_late(void);
void __init setup_arch(char **cmdline_p)
{
@@ -540,6 +561,11 @@
sparse_init();
paging_init();
resource_init();
+
+ early_trap_init();
+ early_ioremap_init();
+
+ plat_setup_late(); /* safe to do early ioremap */
}
int __init fpu_disable(char *s)
diff -Naur --exclude=CVS linux-2.6-orig/arch/mips/kernel/traps.c linux-2.6-dev/arch/mips/kernel/traps.c
--- linux-2.6-orig/arch/mips/kernel/traps.c 2005-08-24 17:12:32.000000000 -0700
+++ linux-2.6-dev/arch/mips/kernel/traps.c 2005-08-25 00:39:39.000000000 -0700
@@ -1239,6 +1238,10 @@
void __init trap_init(void)
{
+}
+
+void __init early_trap_init(void)
+{
extern char except_vec3_generic, except_vec3_r4000;
extern char except_vec4;
unsigned long i;
diff -Naur --exclude=CVS linux-2.6-orig/arch/mips/mm/init.c linux-2.6-dev/arch/mips/mm/init.c
--- linux-2.6-orig/arch/mips/mm/init.c 2005-08-10 18:15:55.000000000 -0700
+++ linux-2.6-dev/arch/mips/mm/init.c 2005-08-25 00:39:40.000000000 -0700
@@ -47,6 +47,8 @@
* don't have to care about aliases on other CPUs.
*/
unsigned long empty_zero_page, zero_page_mask;
+int mem_init_done;
+extern int init_bootmem_done;
/*
* Not static inline because used by IP27 special magic initialization code
@@ -200,6 +202,17 @@
return 0;
}
+void __init *early_get_page(void)
+{
+ void *p;
+ if (init_bootmem_done) {
+ p = alloc_bootmem_pages(PAGE_SIZE);
+ } else {
+ p = NULL;
+ }
+ return p;
+}
+
void __init mem_init(void)
{
unsigned long codesize, reservedpages, datasize, initsize;
@@ -258,6 +271,8 @@
datasize >> 10,
initsize >> 10,
(unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
+
+ mem_init_done = 1;
}
#endif /* !CONFIG_NEED_MULTIPLE_NODES */
diff -Naur --exclude=CVS linux-2.6-orig/arch/mips/mm/ioremap.c linux-2.6-dev/arch/mips/mm/ioremap.c
--- linux-2.6-orig/arch/mips/mm/ioremap.c 2005-08-10 18:15:55.000000000 -0700
+++ linux-2.6-dev/arch/mips/mm/ioremap.c 2005-08-25 13:35:25.045624752 -0700
@@ -15,6 +15,8 @@
#include <asm/io.h>
#include <asm/tlbflush.h>
+extern int mem_init_done;
+
static inline void remap_area_pte(pte_t * pte, unsigned long address,
phys_t size, phys_t phys_addr, unsigned long flags)
{
@@ -141,8 +143,9 @@
/*
* Don't allow anybody to remap normal RAM that we're using..
+ * mem_init() sets high_memory so only do the check after that.
*/
- if (phys_addr < virt_to_phys(high_memory)) {
+ if (mem_init_done && (phys_addr < virt_to_phys(high_memory))) {
char *t_addr, *t_end;
struct page *page;
@@ -164,12 +167,18 @@
/*
* Ok, go for it..
*/
- area = get_vm_area(size, VM_IOREMAP);
- if (!area)
- return NULL;
- addr = area->addr;
+ if (mem_init_done) {
+ area = get_vm_area(size, VM_IOREMAP);
+ if (!area)
+ return NULL;
+ addr = area->addr;
+ }
+ else {
+ addr = (void *)(ioremap_bot -= size);
+ }
if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
- vunmap(addr);
+ if (mem_init_done)
+ vunmap(addr);
return NULL;
}
@@ -185,13 +194,15 @@
if (IS_KSEG1(addr))
return;
- p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
- if (!p) {
- printk(KERN_ERR "iounmap: bad address %p\n", addr);
- return;
- }
+ if ((unsigned long) addr < ioremap_bot) {
+ p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
+ if (!p) {
+ printk(KERN_ERR "iounmap: bad address %p\n", addr);
+ return;
+ }
- kfree(p);
+ kfree(p);
+ }
}
EXPORT_SYMBOL(__ioremap);
diff -Naur --exclude=CVS linux-2.6-orig/arch/mips/mm/pgtable-32.c linux-2.6-dev/arch/mips/mm/pgtable-32.c
--- linux-2.6-orig/arch/mips/mm/pgtable-32.c 2005-08-10 18:15:56.000000000 -0700
+++ linux-2.6-dev/arch/mips/mm/pgtable-32.c 2005-08-23 00:46:14.000000000 -0700
@@ -13,6 +13,9 @@
#include <asm/fixmap.h>
#include <asm/pgtable.h>
+unsigned long ioremap_base;
+unsigned long ioremap_bot;
+
void pgd_init(unsigned long page)
{
unsigned long *p = (unsigned long *) page;
diff -Naur --exclude=CVS linux-2.6-orig/include/asm-mips/io.h linux-2.6-dev/include/asm-mips/io.h
--- linux-2.6-orig/include/asm-mips/io.h 2005-08-10 18:22:04.000000000 -0700
+++ linux-2.6-dev/include/asm-mips/io.h 2005-08-25 13:35:31.000000000 -0700
@@ -637,4 +637,6 @@
*/
#define xlate_dev_kmem_ptr(p) p
+extern void early_ioremap_init(void);
+
#endif /* _ASM_IO_H */
diff -Naur --exclude=CVS linux-2.6-orig/include/asm-mips/pgalloc.h linux-2.6-dev/include/asm-mips/pgalloc.h
--- linux-2.6-orig/include/asm-mips/pgalloc.h 2005-08-10 18:22:02.000000000 -0700
+++ linux-2.6-dev/include/asm-mips/pgalloc.h 2005-08-25 01:49:04.000000000 -0700
@@ -67,8 +67,17 @@
unsigned long address)
{
pte_t *pte;
+ extern int mem_init_done;
+ extern void *early_get_page(void);
- pte = (pte_t *) __get_free_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, PTE_ORDER);
+ if (mem_init_done) {
+ pte = (pte_t *) __get_free_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, PTE_ORDER);
+ } else {
+ pte = (pte_t *)early_get_page();
+ if (pte) {
+ clear_page(pte);
+ }
+ }
return pte;
}
diff -Naur --exclude=CVS linux-2.6-orig/include/asm-mips/pgtable-32.h linux-2.6-dev/include/asm-mips/pgtable-32.h
--- linux-2.6-orig/include/asm-mips/pgtable-32.h 2005-08-25 13:02:30.000000000 -0700
+++ linux-2.6-dev/include/asm-mips/pgtable-32.h 2005-08-25 01:49:04.000000000 -0700
@@ -19,6 +19,8 @@
#include <asm-generic/pgtable-nopmd.h>
+extern unsigned long ioremap_bot, ioremap_base;
+
/*
* - add_wired_entry() add a fixed TLB entry, and move wired register
*/
@@ -74,13 +76,9 @@
#define USER_PTRS_PER_PGD (0x80000000UL/PGDIR_SIZE)
#define FIRST_USER_ADDRESS 0
-#define VMALLOC_START MAP_BASE
+#define VMALLOC_START MAP_BASE
-#ifdef CONFIG_HIGHMEM
-# define VMALLOC_END (PKMAP_BASE-2*PAGE_SIZE)
-#else
-# define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE)
-#endif
+#define VMALLOC_END ioremap_bot
#ifdef CONFIG_64BIT_PHYS_ADDR
#define pte_ERROR(e) \
diff -Naur --exclude=CVS linux-2.6-orig/include/asm-mips/traps.h linux-2.6-dev/include/asm-mips/traps.h
--- linux-2.6-orig/include/asm-mips/traps.h 2005-08-10 18:22:04.000000000 -0700
+++ linux-2.6-dev/include/asm-mips/traps.h 2005-08-25 10:56:01.000000000 -0700
@@ -24,4 +24,6 @@
extern void (*board_nmi_handler_setup)(void);
extern void (*board_ejtag_handler_setup)(void);
+extern void early_trap_init(void);
+
#endif /* _ASM_TRAPS_H */
