diff mbox

[v2] sh: Add fixed ioremap support

Message ID 1257887162-2721-1-git-send-email-matt@console-pimps.org (mailing list archive)
State Superseded
Headers show

Commit Message

Matt Fleming Nov. 10, 2009, 9:06 p.m. UTC
None
diff mbox

Patch

diff --git a/arch/sh/include/asm/fixmap.h b/arch/sh/include/asm/fixmap.h
index 76c5a30..0038881 100644
--- a/arch/sh/include/asm/fixmap.h
+++ b/arch/sh/include/asm/fixmap.h
@@ -54,19 +54,30 @@  enum fixed_addresses {
 	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */
 	FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
 #endif
+	/*
+	 * FIX_IOREMAP entries are useful for mapping physical address
+	 * space before ioremap() is useable, e.g. really early in boot
+	 * before kmalloc() is working.
+	 */
+#define FIX_N_IOREMAPS	32
+	FIX_IOREMAP_BEGIN,
+	FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS,
 	__end_of_fixed_addresses
 };
 
+#define FIXMAP_UPDATE_TLB	0x0001	/* Load the fixmap's pte into TLB */
+#define FIXMAP_CLEAR		0x0002	/* Clear (zero) the pte for fixmap */
+
 extern void __set_fixmap(enum fixed_addresses idx,
-			 unsigned long phys, pgprot_t flags);
+			 unsigned long phys, pgprot_t prot, int flags);
 
 #define set_fixmap(idx, phys) \
-		__set_fixmap(idx, phys, PAGE_KERNEL)
+		__set_fixmap(idx, phys, PAGE_KERNEL, 0)
 /*
  * Some hardware wants to get fixmapped without caching.
  */
 #define set_fixmap_nocache(idx, phys) \
-		__set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
+		__set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE, 0)
 /*
  * used by vmalloc.c.
  *
diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h
index 0cf2a57..1f11da7 100644
--- a/arch/sh/include/asm/io.h
+++ b/arch/sh/include/asm/io.h
@@ -294,6 +294,10 @@  __ioremap_mode(unsigned long offset, unsigned long size, unsigned long flags)
 #define iounmap(addr)					\
 	__iounmap((addr))
 
+extern void __iomem *ioremap_fixed(resource_size_t, unsigned long, pgprot_t);
+extern void iounmap_fixed(void __iomem *);
+extern void ioremap_fixed_init(void);
+
 #define maybebadio(port) \
 	printk(KERN_ERR "bad PC-like io %s:%u for port 0x%lx at 0x%08x\n", \
 	       __func__, __LINE__, (port), (u32)__builtin_return_address(0))
diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index 5a947a2..dd0c86a 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -443,6 +443,10 @@  void __init setup_arch(char **cmdline_p)
 	setup_memory();
 	sparse_init();
 
+	paging_init();
+
+	ioremap_fixed_init();
+
 #ifdef CONFIG_DUMMY_CONSOLE
 	conswitchp = &dummy_con;
 #endif
@@ -451,8 +455,6 @@  void __init setup_arch(char **cmdline_p)
 	if (likely(sh_mv.mv_setup))
 		sh_mv.mv_setup(cmdline_p);
 
-	paging_init();
-
 #ifdef CONFIG_PMB_ENABLE
 	pmb_init();
 #endif
diff --git a/arch/sh/mm/Makefile b/arch/sh/mm/Makefile
index 8a70535..f554730 100644
--- a/arch/sh/mm/Makefile
+++ b/arch/sh/mm/Makefile
@@ -15,7 +15,8 @@  obj-y			+= $(cacheops-y)
 
 mmu-y			:= nommu.o extable_32.o
 mmu-$(CONFIG_MMU)	:= extable_$(BITS).o fault_$(BITS).o \
-			   ioremap_$(BITS).o kmap.o tlbflush_$(BITS).o
+			   ioremap_$(BITS).o ioremap_fixed.o kmap.o \
+			   tlbflush_$(BITS).o
 
 obj-y			+= $(mmu-y)
 obj-$(CONFIG_DEBUG_FS)	+= asids-debugfs.o
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 432acd0..513fa39 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -39,7 +39,8 @@  unsigned long cached_to_uncached = P2SEG - P1SEG;
 #endif
 
 #ifdef CONFIG_MMU
-static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
+static void set_pte_phys(unsigned long addr, unsigned long phys,
+			 pgprot_t prot, int flags)
 {
 	pgd_t *pgd;
 	pud_t *pud;
@@ -65,13 +66,16 @@  static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
 	}
 
 	pte = pte_offset_kernel(pmd, addr);
-	if (!pte_none(*pte)) {
+	if ((flags & FIXMAP_CLEAR) && !pte_none(*pte)) {
 		pte_ERROR(*pte);
 		return;
 	}
 
 	set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
 	local_flush_tlb_one(get_asid(), addr);
+
+	if (flags & FIXMAP_UPDATE_TLB)
+		__update_tlb(NULL, addr, *pte);
 }
 
 /*
@@ -89,7 +93,8 @@  static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
  *
  *					 -- PFM.
  */
-void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
+void __set_fixmap(enum fixed_addresses idx, unsigned long phys,
+		  pgprot_t prot, int flags)
 {
 	unsigned long address = __fix_to_virt(idx);
 
@@ -98,7 +103,7 @@  void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
 		return;
 	}
 
-	set_pte_phys(address, phys, prot);
+	set_pte_phys(address, phys, prot, flags);
 }
 
 void __init page_table_range_init(unsigned long start, unsigned long end,
diff --git a/arch/sh/mm/ioremap_fixed.c b/arch/sh/mm/ioremap_fixed.c
new file mode 100644
index 0000000..2f4800e
--- /dev/null
+++ b/arch/sh/mm/ioremap_fixed.c
@@ -0,0 +1,141 @@ 
+/*
+ * Re-map IO memory to kernel address space so that we can access it.
+ *
+ * These functions should only be used when it is necessary to map a
+ * physical address space into the kernel address space before ioremap()
+ * can be used, e.g. early in boot before paging_init().
+ *
+ * Copyright (C) 2009  Matt Fleming
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <linux/bootmem.h>
+#include <linux/proc_fs.h>
+#include <linux/slab.h>
+#include <asm/fixmap.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/addrspace.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu.h>
+#include <asm/mmu_context.h>
+
+struct ioremap_map {
+	void __iomem *addr;
+	unsigned long size;
+	unsigned long fixmap_addr;
+};
+
+static struct ioremap_map ioremap_maps[FIX_N_IOREMAPS];
+
+void __init ioremap_fixed_init(void)
+{
+	struct ioremap_map *map;
+	int i;
+
+	for (i = 0; i < FIX_N_IOREMAPS; i++) {
+		map = &ioremap_maps[i];
+		map->fixmap_addr = __fix_to_virt(FIX_IOREMAP_BEGIN + i);
+	}
+}
+
+void __init __iomem *
+ioremap_fixed(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
+{
+	enum fixed_addresses idx0, idx;
+	resource_size_t last_addr;
+	struct ioremap_map *map;
+	unsigned long offset;
+	unsigned int nrpages;
+	int i, slot;
+
+	slot = -1;
+	for (i = 0; i < FIX_N_IOREMAPS; i++) {
+		map = &ioremap_maps[i];
+		if (!map->addr) {
+			map->size = size;
+			slot = i;
+			break;
+		}
+	}
+
+	if (slot < 0)
+		return NULL;
+
+	/* Don't allow wraparound or zero size */
+	last_addr = phys_addr + size - 1;
+	if (!size || last_addr < phys_addr)
+		return NULL;
+
+	/*
+	 * Fixmap mappings have to be page-aligned
+	 */
+	offset = phys_addr & ~PAGE_MASK;
+	phys_addr &= PAGE_MASK;
+	size = PAGE_ALIGN(last_addr + 1) - phys_addr;
+
+	/*
+	 * Mappings have to fit in the FIX_IOREMAP area.
+	 */
+	nrpages = size >> PAGE_SHIFT;
+	if (nrpages > FIX_N_IOREMAPS)
+		return NULL;
+
+	/*
+	 * Ok, go for it..
+	 */
+	idx0 = FIX_IOREMAP_BEGIN + slot;
+	idx = idx0;
+	while (nrpages > 0) {
+
+		__set_fixmap(idx, phys_addr, prot, FIXMAP_TLB_LOAD);
+		phys_addr += PAGE_SIZE;
+		idx++;
+		--nrpages;
+	}
+
+	map->addr = (void __iomem *)(offset + map->fixmap_addr);
+	return map->addr;
+}
+
+void __init iounmap_fixed(void __iomem *addr)
+{
+	enum fixed_addresses idx;
+	unsigned long virt_addr;
+	struct ioremap_map *map;
+	unsigned long offset;
+	unsigned int nrpages;
+	int i, slot;
+
+	slot = -1;
+	for (i = 0; i < FIX_N_IOREMAPS; i++) {
+		map = &ioremap_maps[i];
+		if (map->addr == addr) {
+			slot = i;
+			break;
+		}
+	}
+
+	if (slot < 0)
+		return;
+
+	virt_addr = (unsigned long)addr;
+
+	offset = virt_addr & ~PAGE_MASK;
+	nrpages = PAGE_ALIGN(offset + map->size - 1) >> PAGE_SHIFT;
+
+	idx = FIX_IOREMAP_BEGIN + slot;
+	while (nrpages > 0) {
+		__set_fixmap(idx, 0, __pgprot(0), 0);
+		idx++;
+		--nrpages;
+	}
+
+	map->size = 0;
+	map->addr = NULL;
+}
diff --git a/arch/sh/mm/nommu.c b/arch/sh/mm/nommu.c
index ac16c05..4b4eb50 100644
--- a/arch/sh/mm/nommu.c
+++ b/arch/sh/mm/nommu.c
@@ -91,6 +91,7 @@  void __init page_table_range_init(unsigned long start, unsigned long end,
 {
 }
 
-void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
+void __set_fixmap(enum fixed_addresses idx, unsigned long phys,
+		  pgprot_t prot, int flags)
 {
 }