i386 boot: replace boot_ioremap with enhanced bt_ioremap - enhance bt_ioremap
This patch makes it possible for bt_ioremap() to be used before
paging_init(), via providing an early implementation of set_fixmap()
that can be used before paging_init().
This way boot_ioremap() can be replaced by bt_ioremap().
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/mm/ioremap_32.c b/arch/x86/mm/ioremap_32.c
index ef0f6a45..fd1f5b6 100644
--- a/arch/x86/mm/ioremap_32.c
+++ b/arch/x86/mm/ioremap_32.c
@@ -208,6 +208,89 @@
}
EXPORT_SYMBOL(iounmap);
+static __initdata int after_paging_init;
+static __initdata unsigned long bm_pte[1024]
+ __attribute__((aligned(PAGE_SIZE)));
+
+static inline unsigned long * __init bt_ioremap_pgd(unsigned long addr)
+{
+ return (unsigned long *)swapper_pg_dir + ((addr >> 22) & 1023);
+}
+
+static inline unsigned long * __init bt_ioremap_pte(unsigned long addr)
+{
+ return bm_pte + ((addr >> PAGE_SHIFT) & 1023);
+}
+
+void __init bt_ioremap_init(void)
+{
+ unsigned long *pgd;
+
+ pgd = bt_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
+ *pgd = __pa(bm_pte) | _PAGE_TABLE;
+ memset(bm_pte, 0, sizeof(bm_pte));
+ BUG_ON(pgd != bt_ioremap_pgd(fix_to_virt(FIX_BTMAP_END)));
+}
+
+void __init bt_ioremap_clear(void)
+{
+ unsigned long *pgd;
+
+ pgd = bt_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
+ *pgd = 0;
+ __flush_tlb_all();
+}
+
+void __init bt_ioremap_reset(void)
+{
+ enum fixed_addresses idx;
+ unsigned long *pte, phys, addr;
+
+ after_paging_init = 1;
+ for (idx = FIX_BTMAP_BEGIN; idx <= FIX_BTMAP_END; idx--) {
+ addr = fix_to_virt(idx);
+ pte = bt_ioremap_pte(addr);
+ if (!*pte & _PAGE_PRESENT) {
+ phys = *pte & PAGE_MASK;
+ set_fixmap(idx, phys);
+ }
+ }
+}
+
+static void __init __bt_set_fixmap(enum fixed_addresses idx,
+ unsigned long phys, pgprot_t flags)
+{
+ unsigned long *pte, addr = __fix_to_virt(idx);
+
+ if (idx >= __end_of_fixed_addresses) {
+ BUG();
+ return;
+ }
+ pte = bt_ioremap_pte(addr);
+ if (pgprot_val(flags))
+ *pte = (phys & PAGE_MASK) | pgprot_val(flags);
+ else
+ *pte = 0;
+ __flush_tlb_one(addr);
+}
+
+static inline void __init bt_set_fixmap(enum fixed_addresses idx,
+ unsigned long phys)
+{
+ if (after_paging_init)
+ set_fixmap(idx, phys);
+ else
+ __bt_set_fixmap(idx, phys, PAGE_KERNEL);
+}
+
+static inline void __init bt_clear_fixmap(enum fixed_addresses idx)
+{
+ if (after_paging_init)
+ clear_fixmap(idx);
+ else
+ __bt_set_fixmap(idx, 0, __pgprot(0));
+}
+
void __init *bt_ioremap(unsigned long phys_addr, unsigned long size)
{
unsigned long offset, last_addr;
@@ -244,7 +327,7 @@
*/
idx = FIX_BTMAP_BEGIN;
while (nrpages > 0) {
- set_fixmap(idx, phys_addr);
+ bt_set_fixmap(idx, phys_addr);
phys_addr += PAGE_SIZE;
--idx;
--nrpages;
@@ -267,7 +350,7 @@
idx = FIX_BTMAP_BEGIN;
while (nrpages > 0) {
- clear_fixmap(idx);
+ bt_clear_fixmap(idx);
--idx;
--nrpages;
}