[PATCH v6 0/3] introduce static_vm for ARM-specific static mapped area

[PATCH v6 0/3] introduce static_vm for ARM-specific static mapped area

[Joonsoo Kim]

In current implementation, we used ARM-specific flag, that is,
VM_ARM_STATIC_MAPPING, for distinguishing ARM specific static mapped area.
The purpose of static mapped area is to re-use static mapped area when
entire physical address range of the ioremap request can be covered
by this area.

This implementation causes needless overhead for some cases.
For example, assume that there is only one static mapped area and
vmlist has 300 areas. Every time we call ioremap, we check 300 areas for
deciding whether it is matched or not. Moreover, even if there is
no static mapped area and vmlist has 300 areas, every time we call
ioremap, we check 300 areas in now.

If we construct a extra list for static mapped area, we can eliminate
above mentioned overhead.
With a extra list, if there is one static mapped area,
we just check only one area and proceed next operation quickly.

In fact, it is not a critical problem, because ioremap is not frequently
used. But reducing overhead is better idea.

Another reason for doing this work is for removing vm_struct list management,
entirely. For more information, look at the following link.
http://lkml.org/lkml/2012/12/6/184

Changelog
v5->v6:
  Add Ack-by, Reviewed-by, Tested-by tags
  [3/3]: Change from Nicolas' suggestion
  	 - remove redundant parenthesis

v4->v5:
  [2/3]: Changes from Nicolas' suggestion
  	 - don't use separate flags for static_vm
  	 - remove a lock
  	 - declare add_static_vm_early() as __init
  [3/3]: Changes from Nicolas' suggestion
  	 - add / leave comments

v3->v4:
  [2/3]: Changes from Nicolas' suggestion
         - embed static_vm code in ioremap.c
         - simplify struct static_vm
         - remove init_static_vm, instead, add_static_vm_early() init static_vm
         Use generic list for list management of static_vm
         Convert spin_lock to rw_lock
         Modify static_vm's flags bits
  [3/3]: Rework according to [2/3] change
  Rebased on v3.8-rc5

v2->v3:
  coverletter: refer a link related to this work
  [2/3]: drop @flags of find_static_vm_vaddr
  Rebased on v3.8-rc4

v1->v2: 
  [2/3]: patch description is improved.
  Rebased on v3.7-rc7

Joonsoo Kim (3):
  ARM: vmregion: remove vmregion code entirely
  ARM: ioremap: introduce an infrastructure for static mapped area
  ARM: mm: use static_vm for managing static mapped areas

 arch/arm/mm/Makefile   |    2 +-
 arch/arm/mm/ioremap.c  |  135 +++++++++++++++++++++----------
 arch/arm/mm/mm.h       |   12 +++
 arch/arm/mm/mmu.c      |   34 ++++----
 arch/arm/mm/vmregion.c |  205 ------------------------------------------------
 arch/arm/mm/vmregion.h |   31 --------
 6 files changed, 123 insertions(+), 296 deletions(-)
 delete mode 100644 arch/arm/mm/vmregion.c
 delete mode 100644 arch/arm/mm/vmregion.h

-- 
1.7.9.5

[PATCH v6 0/3] introduce static_vm for ARM-specific static mapped area

[Joonsoo Kim]

In current implementation, we used ARM-specific flag, that is,
VM_ARM_STATIC_MAPPING, for distinguishing ARM specific static mapped area.
The purpose of static mapped area is to re-use static mapped area when
entire physical address range of the ioremap request can be covered
by this area.

This implementation causes needless overhead for some cases.
For example, assume that there is only one static mapped area and
vmlist has 300 areas. Every time we call ioremap, we check 300 areas for
deciding whether it is matched or not. Moreover, even if there is
no static mapped area and vmlist has 300 areas, every time we call
ioremap, we check 300 areas in now.

If we construct a extra list for static mapped area, we can eliminate
above mentioned overhead.
With a extra list, if there is one static mapped area,
we just check only one area and proceed next operation quickly.

In fact, it is not a critical problem, because ioremap is not frequently
used. But reducing overhead is better idea.

Another reason for doing this work is for removing vm_struct list management,
entirely. For more information, look at the following link.
http://lkml.org/lkml/2012/12/6/184

Changelog
v5->v6:
  Add Ack-by, Reviewed-by, Tested-by tags
  [3/3]: Change from Nicolas' suggestion
  	 - remove redundant parenthesis

v4->v5:
  [2/3]: Changes from Nicolas' suggestion
  	 - don't use separate flags for static_vm
  	 - remove a lock
  	 - declare add_static_vm_early() as __init
  [3/3]: Changes from Nicolas' suggestion
  	 - add / leave comments

v3->v4:
  [2/3]: Changes from Nicolas' suggestion
         - embed static_vm code in ioremap.c
         - simplify struct static_vm
         - remove init_static_vm, instead, add_static_vm_early() init static_vm
         Use generic list for list management of static_vm
         Convert spin_lock to rw_lock
         Modify static_vm's flags bits
  [3/3]: Rework according to [2/3] change
  Rebased on v3.8-rc5

v2->v3:
  coverletter: refer a link related to this work
  [2/3]: drop @flags of find_static_vm_vaddr
  Rebased on v3.8-rc4

v1->v2: 
  [2/3]: patch description is improved.
  Rebased on v3.7-rc7

Joonsoo Kim (3):
  ARM: vmregion: remove vmregion code entirely
  ARM: ioremap: introduce an infrastructure for static mapped area
  ARM: mm: use static_vm for managing static mapped areas

 arch/arm/mm/Makefile   |    2 +-
 arch/arm/mm/ioremap.c  |  135 +++++++++++++++++++++----------
 arch/arm/mm/mm.h       |   12 +++
 arch/arm/mm/mmu.c      |   34 ++++----
 arch/arm/mm/vmregion.c |  205 ------------------------------------------------
 arch/arm/mm/vmregion.h |   31 --------
 6 files changed, 123 insertions(+), 296 deletions(-)
 delete mode 100644 arch/arm/mm/vmregion.c
 delete mode 100644 arch/arm/mm/vmregion.h

-- 
1.7.9.5

[PATCH v6 1/3] ARM: vmregion: remove vmregion code entirely

[Joonsoo Kim]

Now, there is no user for vmregion.
So remove it.

Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 8a9c4cb..4e333fa 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -6,7 +6,7 @@ obj-y				:= dma-mapping.o extable.o fault.o init.o \
 				   iomap.o
 
 obj-$(CONFIG_MMU)		+= fault-armv.o flush.o idmap.o ioremap.o \
-				   mmap.o pgd.o mmu.o vmregion.o
+				   mmap.o pgd.o mmu.o
 
 ifneq ($(CONFIG_MMU),y)
 obj-y				+= nommu.o
diff --git a/arch/arm/mm/vmregion.c b/arch/arm/mm/vmregion.c
deleted file mode 100644
index a631016..0000000
diff --git a/arch/arm/mm/vmregion.h b/arch/arm/mm/vmregion.h
deleted file mode 100644
index 0f5a5f2..0000000
-- 
1.7.9.5

[PATCH v6 1/3] ARM: vmregion: remove vmregion code entirely

[Joonsoo Kim]

Now, there is no user for vmregion.
So remove it.

Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 8a9c4cb..4e333fa 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -6,7 +6,7 @@ obj-y				:= dma-mapping.o extable.o fault.o init.o \
 				   iomap.o
 
 obj-$(CONFIG_MMU)		+= fault-armv.o flush.o idmap.o ioremap.o \
-				   mmap.o pgd.o mmu.o vmregion.o
+				   mmap.o pgd.o mmu.o
 
 ifneq ($(CONFIG_MMU),y)
 obj-y				+= nommu.o
diff --git a/arch/arm/mm/vmregion.c b/arch/arm/mm/vmregion.c
deleted file mode 100644
index a631016..0000000
diff --git a/arch/arm/mm/vmregion.h b/arch/arm/mm/vmregion.h
deleted file mode 100644
index 0f5a5f2..0000000
-- 
1.7.9.5

[PATCH v6 2/3] ARM: ioremap: introduce an infrastructure for static mapped area

[Joonsoo Kim]

In current implementation, we used ARM-specific flag, that is,
VM_ARM_STATIC_MAPPING, for distinguishing ARM specific static mapped area.
The purpose of static mapped area is to re-use static mapped area when
entire physical address range of the ioremap request can be covered
by this area.

This implementation causes needless overhead for some cases.
For example, assume that there is only one static mapped area and
vmlist has 300 areas. Every time we call ioremap, we check 300 areas for
deciding whether it is matched or not. Moreover, even if there is
no static mapped area and vmlist has 300 areas, every time we call
ioremap, we check 300 areas in now.

If we construct a extra list for static mapped area, we can eliminate
above mentioned overhead.
With a extra list, if there is one static mapped area,
we just check only one area and proceed next operation quickly.

In fact, it is not a critical problem, because ioremap is not frequently
used. But reducing overhead is better idea.

Another reason for doing this work is for removing architecture dependency
on vmalloc layer. I think that vmlist and vmlist_lock is internal data
structure for vmalloc layer. Some codes for debugging and stat inevitably
use vmlist and vmlist_lock. But it is preferable that they are used
as least as possible in outside of vmalloc.c

Now, I introduce an ARM-specific infrastructure for static mapped area. In
the following patch, we will use this and resolve above mentioned problem.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 88fd86c..904c15e 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -39,6 +39,70 @@
 #include <asm/mach/pci.h>
 #include "mm.h"
 
+
+LIST_HEAD(static_vmlist);
+
+static struct static_vm *find_static_vm_paddr(phys_addr_t paddr,
+			size_t size, unsigned int mtype)
+{
+	struct static_vm *svm;
+	struct vm_struct *vm;
+
+	list_for_each_entry(svm, &static_vmlist, list) {
+		vm = &svm->vm;
+		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
+			continue;
+		if ((vm->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
+			continue;
+
+		if (vm->phys_addr > paddr ||
+			paddr + size - 1 > vm->phys_addr + vm->size - 1)
+			continue;
+
+		return svm;
+	}
+
+	return NULL;
+}
+
+struct static_vm *find_static_vm_vaddr(void *vaddr)
+{
+	struct static_vm *svm;
+	struct vm_struct *vm;
+
+	list_for_each_entry(svm, &static_vmlist, list) {
+		vm = &svm->vm;
+
+		/* static_vmlist is ascending order */
+		if (vm->addr > vaddr)
+			break;
+
+		if (vm->addr <= vaddr && vm->addr + vm->size > vaddr)
+			return svm;
+	}
+
+	return NULL;
+}
+
+void __init add_static_vm_early(struct static_vm *svm)
+{
+	struct static_vm *curr_svm;
+	struct vm_struct *vm;
+	void *vaddr;
+
+	vm = &svm->vm;
+	vm_area_add_early(vm);
+	vaddr = vm->addr;
+
+	list_for_each_entry(curr_svm, &static_vmlist, list) {
+		vm = &curr_svm->vm;
+
+		if (vm->addr > vaddr)
+			break;
+	}
+	list_add_tail(&svm->list, &curr_svm->list);
+}
+
 int ioremap_page(unsigned long virt, unsigned long phys,
 		 const struct mem_type *mtype)
 {
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index a8ee92d..d5a4e9a 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -1,4 +1,6 @@
 #ifdef CONFIG_MMU
+#include <linux/list.h>
+#include <linux/vmalloc.h>
 
 /* the upper-most page table pointer */
 extern pmd_t *top_pmd;
@@ -65,6 +67,16 @@ extern void __flush_dcache_page(struct address_space *mapping, struct page *page
 /* consistent regions used by dma_alloc_attrs() */
 #define VM_ARM_DMA_CONSISTENT	0x20000000
 
+
+struct static_vm {
+	struct vm_struct vm;
+	struct list_head list;
+};
+
+extern struct list_head static_vmlist;
+extern struct static_vm *find_static_vm_vaddr(void *vaddr);
+extern __init void add_static_vm_early(struct static_vm *svm);
+
 #endif
 
 #ifdef CONFIG_ZONE_DMA
-- 
1.7.9.5

[PATCH v6 2/3] ARM: ioremap: introduce an infrastructure for static mapped area

[Joonsoo Kim]

In current implementation, we used ARM-specific flag, that is,
VM_ARM_STATIC_MAPPING, for distinguishing ARM specific static mapped area.
The purpose of static mapped area is to re-use static mapped area when
entire physical address range of the ioremap request can be covered
by this area.

This implementation causes needless overhead for some cases.
For example, assume that there is only one static mapped area and
vmlist has 300 areas. Every time we call ioremap, we check 300 areas for
deciding whether it is matched or not. Moreover, even if there is
no static mapped area and vmlist has 300 areas, every time we call
ioremap, we check 300 areas in now.

If we construct a extra list for static mapped area, we can eliminate
above mentioned overhead.
With a extra list, if there is one static mapped area,
we just check only one area and proceed next operation quickly.

In fact, it is not a critical problem, because ioremap is not frequently
used. But reducing overhead is better idea.

Another reason for doing this work is for removing architecture dependency
on vmalloc layer. I think that vmlist and vmlist_lock is internal data
structure for vmalloc layer. Some codes for debugging and stat inevitably
use vmlist and vmlist_lock. But it is preferable that they are used
as least as possible in outside of vmalloc.c

Now, I introduce an ARM-specific infrastructure for static mapped area. In
the following patch, we will use this and resolve above mentioned problem.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 88fd86c..904c15e 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -39,6 +39,70 @@
 #include <asm/mach/pci.h>
 #include "mm.h"
 
+
+LIST_HEAD(static_vmlist);
+
+static struct static_vm *find_static_vm_paddr(phys_addr_t paddr,
+			size_t size, unsigned int mtype)
+{
+	struct static_vm *svm;
+	struct vm_struct *vm;
+
+	list_for_each_entry(svm, &static_vmlist, list) {
+		vm = &svm->vm;
+		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
+			continue;
+		if ((vm->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
+			continue;
+
+		if (vm->phys_addr > paddr ||
+			paddr + size - 1 > vm->phys_addr + vm->size - 1)
+			continue;
+
+		return svm;
+	}
+
+	return NULL;
+}
+
+struct static_vm *find_static_vm_vaddr(void *vaddr)
+{
+	struct static_vm *svm;
+	struct vm_struct *vm;
+
+	list_for_each_entry(svm, &static_vmlist, list) {
+		vm = &svm->vm;
+
+		/* static_vmlist is ascending order */
+		if (vm->addr > vaddr)
+			break;
+
+		if (vm->addr <= vaddr && vm->addr + vm->size > vaddr)
+			return svm;
+	}
+
+	return NULL;
+}
+
+void __init add_static_vm_early(struct static_vm *svm)
+{
+	struct static_vm *curr_svm;
+	struct vm_struct *vm;
+	void *vaddr;
+
+	vm = &svm->vm;
+	vm_area_add_early(vm);
+	vaddr = vm->addr;
+
+	list_for_each_entry(curr_svm, &static_vmlist, list) {
+		vm = &curr_svm->vm;
+
+		if (vm->addr > vaddr)
+			break;
+	}
+	list_add_tail(&svm->list, &curr_svm->list);
+}
+
 int ioremap_page(unsigned long virt, unsigned long phys,
 		 const struct mem_type *mtype)
 {
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index a8ee92d..d5a4e9a 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -1,4 +1,6 @@
 #ifdef CONFIG_MMU
+#include <linux/list.h>
+#include <linux/vmalloc.h>
 
 /* the upper-most page table pointer */
 extern pmd_t *top_pmd;
@@ -65,6 +67,16 @@ extern void __flush_dcache_page(struct address_space *mapping, struct page *page
 /* consistent regions used by dma_alloc_attrs() */
 #define VM_ARM_DMA_CONSISTENT	0x20000000
 
+
+struct static_vm {
+	struct vm_struct vm;
+	struct list_head list;
+};
+
+extern struct list_head static_vmlist;
+extern struct static_vm *find_static_vm_vaddr(void *vaddr);
+extern __init void add_static_vm_early(struct static_vm *svm);
+
 #endif
 
 #ifdef CONFIG_ZONE_DMA
-- 
1.7.9.5

[PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Joonsoo Kim]

A static mapped area is ARM-specific, so it is better not to use
generic vmalloc data structure, that is, vmlist and vmlist_lock
for managing static mapped area. And it causes some needless overhead and
reducing this overhead is better idea.

Now, we have newly introduced static_vm infrastructure.
With it, we don't need to iterate all mapped areas. Instead, we just
iterate static mapped areas. It helps to reduce an overhead of finding
matched area. And architecture dependency on vmalloc layer is removed,
so it will help to maintainability for vmalloc layer.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 904c15e..04d9006 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -261,13 +261,14 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
 	const struct mem_type *type;
 	int err;
 	unsigned long addr;
- 	struct vm_struct * area;
+	struct vm_struct *area;
+	phys_addr_t paddr = __pfn_to_phys(pfn);
 
 #ifndef CONFIG_ARM_LPAE
 	/*
 	 * High mappings must be supersection aligned
 	 */
-	if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK))
+	if (pfn >= 0x100000 && (paddr & ~SUPERSECTION_MASK))
 		return NULL;
 #endif
 
@@ -283,24 +284,16 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
 	/*
 	 * Try to reuse one of the static mapping whenever possible.
 	 */
-	read_lock(&vmlist_lock);
-	for (area = vmlist; area; area = area->next) {
-		if (!size || (sizeof(phys_addr_t) == 4 && pfn >= 0x100000))
-			break;
-		if (!(area->flags & VM_ARM_STATIC_MAPPING))
-			continue;
-		if ((area->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
-			continue;
-		if (__phys_to_pfn(area->phys_addr) > pfn ||
-		    __pfn_to_phys(pfn) + size-1 > area->phys_addr + area->size-1)
-			continue;
-		/* we can drop the lock here as we know *area is static */
-		read_unlock(&vmlist_lock);
-		addr = (unsigned long)area->addr;
-		addr += __pfn_to_phys(pfn) - area->phys_addr;
-		return (void __iomem *) (offset + addr);
+	if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) {
+		struct static_vm *svm;
+
+		svm = find_static_vm_paddr(paddr, size, mtype);
+		if (svm) {
+			addr = (unsigned long)svm->vm.addr;
+			addr += paddr - svm->vm.phys_addr;
+			return (void __iomem *) (offset + addr);
+		}
 	}
-	read_unlock(&vmlist_lock);
 
 	/*
 	 * Don't allow RAM to be mapped - this causes problems with ARMv6+
@@ -312,21 +305,21 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
  	if (!area)
  		return NULL;
  	addr = (unsigned long)area->addr;
-	area->phys_addr = __pfn_to_phys(pfn);
+	area->phys_addr = paddr;
 
 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
 	if (DOMAIN_IO == 0 &&
 	    (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
 	       cpu_is_xsc3()) && pfn >= 0x100000 &&
-	       !((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) {
+	       !((paddr | size | addr) & ~SUPERSECTION_MASK)) {
 		area->flags |= VM_ARM_SECTION_MAPPING;
 		err = remap_area_supersections(addr, pfn, size, type);
-	} else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
+	} else if (!((paddr | size | addr) & ~PMD_MASK)) {
 		area->flags |= VM_ARM_SECTION_MAPPING;
 		err = remap_area_sections(addr, pfn, size, type);
 	} else
 #endif
-		err = ioremap_page_range(addr, addr + size, __pfn_to_phys(pfn),
+		err = ioremap_page_range(addr, addr + size, paddr,
 					 __pgprot(type->prot_pte));
 
 	if (err) {
@@ -410,34 +403,28 @@ __arm_ioremap_exec(unsigned long phys_addr, size_t size, bool cached)
 void __iounmap(volatile void __iomem *io_addr)
 {
 	void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
-	struct vm_struct *vm;
+	struct static_vm *svm;
+
+	/* If this is a static mapping, we must leave it alone */
+	svm = find_static_vm_vaddr(addr);
+	if (svm)
+		return;
 
-	read_lock(&vmlist_lock);
-	for (vm = vmlist; vm; vm = vm->next) {
-		if (vm->addr > addr)
-			break;
-		if (!(vm->flags & VM_IOREMAP))
-			continue;
-		/* If this is a static mapping we must leave it alone */
-		if ((vm->flags & VM_ARM_STATIC_MAPPING) &&
-		    (vm->addr <= addr) && (vm->addr + vm->size > addr)) {
-			read_unlock(&vmlist_lock);
-			return;
-		}
 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
+	{
+		struct vm_struct *vm;
+
+		vm = find_vm_area(addr);
+
 		/*
 		 * If this is a section based mapping we need to handle it
 		 * specially as the VM subsystem does not know how to handle
 		 * such a beast.
 		 */
-		if ((vm->addr == addr) &&
-		    (vm->flags & VM_ARM_SECTION_MAPPING)) {
+		if (vm && (vm->flags & VM_ARM_SECTION_MAPPING))
 			unmap_area_sections((unsigned long)vm->addr, vm->size);
-			break;
-		}
-#endif
 	}
-	read_unlock(&vmlist_lock);
+#endif
 
 	vunmap(addr);
 }
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index ce328c7..b2c0356 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -757,21 +757,24 @@ void __init iotable_init(struct map_desc *io_desc, int nr)
 {
 	struct map_desc *md;
 	struct vm_struct *vm;
+	struct static_vm *svm;
 
 	if (!nr)
 		return;
 
-	vm = early_alloc_aligned(sizeof(*vm) * nr, __alignof__(*vm));
+	svm = early_alloc_aligned(sizeof(*svm) * nr, __alignof__(*svm));
 
 	for (md = io_desc; nr; md++, nr--) {
 		create_mapping(md);
+
+		vm = &svm->vm;
 		vm->addr = (void *)(md->virtual & PAGE_MASK);
 		vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
 		vm->phys_addr = __pfn_to_phys(md->pfn);
 		vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
 		vm->flags |= VM_ARM_MTYPE(md->type);
 		vm->caller = iotable_init;
-		vm_area_add_early(vm++);
+		add_static_vm_early(svm++);
 	}
 }
 
@@ -779,13 +782,16 @@ void __init vm_reserve_area_early(unsigned long addr, unsigned long size,
 				  void *caller)
 {
 	struct vm_struct *vm;
+	struct static_vm *svm;
+
+	svm = early_alloc_aligned(sizeof(*svm), __alignof__(*svm));
 
-	vm = early_alloc_aligned(sizeof(*vm), __alignof__(*vm));
+	vm = &svm->vm;
 	vm->addr = (void *)addr;
 	vm->size = size;
 	vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING;
 	vm->caller = caller;
-	vm_area_add_early(vm);
+	add_static_vm_early(svm);
 }
 
 #ifndef CONFIG_ARM_LPAE
@@ -810,14 +816,13 @@ static void __init pmd_empty_section_gap(unsigned long addr)
 
 static void __init fill_pmd_gaps(void)
 {
+	struct static_vm *svm;
 	struct vm_struct *vm;
 	unsigned long addr, next = 0;
 	pmd_t *pmd;
 
-	/* we're still single threaded hence no lock needed here */
-	for (vm = vmlist; vm; vm = vm->next) {
-		if (!(vm->flags & (VM_ARM_STATIC_MAPPING | VM_ARM_EMPTY_MAPPING)))
-			continue;
+	list_for_each_entry(svm, &static_vmlist, list) {
+		vm = &svm->vm;
 		addr = (unsigned long)vm->addr;
 		if (addr < next)
 			continue;
@@ -859,17 +864,12 @@ static void __init pci_reserve_io(void)
 {
 	struct vm_struct *vm;
 	unsigned long addr;
+	struct static_vm *svm;
 
-	/* we're still single threaded hence no lock needed here */
-	for (vm = vmlist; vm; vm = vm->next) {
-		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
-			continue;
-		addr = (unsigned long)vm->addr;
-		addr &= ~(SZ_2M - 1);
-		if (addr == PCI_IO_VIRT_BASE)
-			return;
+	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
+	if (svm)
+		return;
 
-	}
 	vm_reserve_area_early(PCI_IO_VIRT_BASE, SZ_2M, pci_reserve_io);
 }
 #else
-- 
1.7.9.5

[PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Joonsoo Kim]

A static mapped area is ARM-specific, so it is better not to use
generic vmalloc data structure, that is, vmlist and vmlist_lock
for managing static mapped area. And it causes some needless overhead and
reducing this overhead is better idea.

Now, we have newly introduced static_vm infrastructure.
With it, we don't need to iterate all mapped areas. Instead, we just
iterate static mapped areas. It helps to reduce an overhead of finding
matched area. And architecture dependency on vmalloc layer is removed,
so it will help to maintainability for vmalloc layer.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 904c15e..04d9006 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -261,13 +261,14 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
 	const struct mem_type *type;
 	int err;
 	unsigned long addr;
- 	struct vm_struct * area;
+	struct vm_struct *area;
+	phys_addr_t paddr = __pfn_to_phys(pfn);
 
 #ifndef CONFIG_ARM_LPAE
 	/*
 	 * High mappings must be supersection aligned
 	 */
-	if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK))
+	if (pfn >= 0x100000 && (paddr & ~SUPERSECTION_MASK))
 		return NULL;
 #endif
 
@@ -283,24 +284,16 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
 	/*
 	 * Try to reuse one of the static mapping whenever possible.
 	 */
-	read_lock(&vmlist_lock);
-	for (area = vmlist; area; area = area->next) {
-		if (!size || (sizeof(phys_addr_t) == 4 && pfn >= 0x100000))
-			break;
-		if (!(area->flags & VM_ARM_STATIC_MAPPING))
-			continue;
-		if ((area->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
-			continue;
-		if (__phys_to_pfn(area->phys_addr) > pfn ||
-		    __pfn_to_phys(pfn) + size-1 > area->phys_addr + area->size-1)
-			continue;
-		/* we can drop the lock here as we know *area is static */
-		read_unlock(&vmlist_lock);
-		addr = (unsigned long)area->addr;
-		addr += __pfn_to_phys(pfn) - area->phys_addr;
-		return (void __iomem *) (offset + addr);
+	if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) {
+		struct static_vm *svm;
+
+		svm = find_static_vm_paddr(paddr, size, mtype);
+		if (svm) {
+			addr = (unsigned long)svm->vm.addr;
+			addr += paddr - svm->vm.phys_addr;
+			return (void __iomem *) (offset + addr);
+		}
 	}
-	read_unlock(&vmlist_lock);
 
 	/*
 	 * Don't allow RAM to be mapped - this causes problems with ARMv6+
@@ -312,21 +305,21 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
  	if (!area)
  		return NULL;
  	addr = (unsigned long)area->addr;
-	area->phys_addr = __pfn_to_phys(pfn);
+	area->phys_addr = paddr;
 
 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
 	if (DOMAIN_IO == 0 &&
 	    (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
 	       cpu_is_xsc3()) && pfn >= 0x100000 &&
-	       !((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) {
+	       !((paddr | size | addr) & ~SUPERSECTION_MASK)) {
 		area->flags |= VM_ARM_SECTION_MAPPING;
 		err = remap_area_supersections(addr, pfn, size, type);
-	} else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
+	} else if (!((paddr | size | addr) & ~PMD_MASK)) {
 		area->flags |= VM_ARM_SECTION_MAPPING;
 		err = remap_area_sections(addr, pfn, size, type);
 	} else
 #endif
-		err = ioremap_page_range(addr, addr + size, __pfn_to_phys(pfn),
+		err = ioremap_page_range(addr, addr + size, paddr,
 					 __pgprot(type->prot_pte));
 
 	if (err) {
@@ -410,34 +403,28 @@ __arm_ioremap_exec(unsigned long phys_addr, size_t size, bool cached)
 void __iounmap(volatile void __iomem *io_addr)
 {
 	void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
-	struct vm_struct *vm;
+	struct static_vm *svm;
+
+	/* If this is a static mapping, we must leave it alone */
+	svm = find_static_vm_vaddr(addr);
+	if (svm)
+		return;
 
-	read_lock(&vmlist_lock);
-	for (vm = vmlist; vm; vm = vm->next) {
-		if (vm->addr > addr)
-			break;
-		if (!(vm->flags & VM_IOREMAP))
-			continue;
-		/* If this is a static mapping we must leave it alone */
-		if ((vm->flags & VM_ARM_STATIC_MAPPING) &&
-		    (vm->addr <= addr) && (vm->addr + vm->size > addr)) {
-			read_unlock(&vmlist_lock);
-			return;
-		}
 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
+	{
+		struct vm_struct *vm;
+
+		vm = find_vm_area(addr);
+
 		/*
 		 * If this is a section based mapping we need to handle it
 		 * specially as the VM subsystem does not know how to handle
 		 * such a beast.
 		 */
-		if ((vm->addr == addr) &&
-		    (vm->flags & VM_ARM_SECTION_MAPPING)) {
+		if (vm && (vm->flags & VM_ARM_SECTION_MAPPING))
 			unmap_area_sections((unsigned long)vm->addr, vm->size);
-			break;
-		}
-#endif
 	}
-	read_unlock(&vmlist_lock);
+#endif
 
 	vunmap(addr);
 }
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index ce328c7..b2c0356 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -757,21 +757,24 @@ void __init iotable_init(struct map_desc *io_desc, int nr)
 {
 	struct map_desc *md;
 	struct vm_struct *vm;
+	struct static_vm *svm;
 
 	if (!nr)
 		return;
 
-	vm = early_alloc_aligned(sizeof(*vm) * nr, __alignof__(*vm));
+	svm = early_alloc_aligned(sizeof(*svm) * nr, __alignof__(*svm));
 
 	for (md = io_desc; nr; md++, nr--) {
 		create_mapping(md);
+
+		vm = &svm->vm;
 		vm->addr = (void *)(md->virtual & PAGE_MASK);
 		vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
 		vm->phys_addr = __pfn_to_phys(md->pfn);
 		vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
 		vm->flags |= VM_ARM_MTYPE(md->type);
 		vm->caller = iotable_init;
-		vm_area_add_early(vm++);
+		add_static_vm_early(svm++);
 	}
 }
 
@@ -779,13 +782,16 @@ void __init vm_reserve_area_early(unsigned long addr, unsigned long size,
 				  void *caller)
 {
 	struct vm_struct *vm;
+	struct static_vm *svm;
+
+	svm = early_alloc_aligned(sizeof(*svm), __alignof__(*svm));
 
-	vm = early_alloc_aligned(sizeof(*vm), __alignof__(*vm));
+	vm = &svm->vm;
 	vm->addr = (void *)addr;
 	vm->size = size;
 	vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING;
 	vm->caller = caller;
-	vm_area_add_early(vm);
+	add_static_vm_early(svm);
 }
 
 #ifndef CONFIG_ARM_LPAE
@@ -810,14 +816,13 @@ static void __init pmd_empty_section_gap(unsigned long addr)
 
 static void __init fill_pmd_gaps(void)
 {
+	struct static_vm *svm;
 	struct vm_struct *vm;
 	unsigned long addr, next = 0;
 	pmd_t *pmd;
 
-	/* we're still single threaded hence no lock needed here */
-	for (vm = vmlist; vm; vm = vm->next) {
-		if (!(vm->flags & (VM_ARM_STATIC_MAPPING | VM_ARM_EMPTY_MAPPING)))
-			continue;
+	list_for_each_entry(svm, &static_vmlist, list) {
+		vm = &svm->vm;
 		addr = (unsigned long)vm->addr;
 		if (addr < next)
 			continue;
@@ -859,17 +864,12 @@ static void __init pci_reserve_io(void)
 {
 	struct vm_struct *vm;
 	unsigned long addr;
+	struct static_vm *svm;
 
-	/* we're still single threaded hence no lock needed here */
-	for (vm = vmlist; vm; vm = vm->next) {
-		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
-			continue;
-		addr = (unsigned long)vm->addr;
-		addr &= ~(SZ_2M - 1);
-		if (addr == PCI_IO_VIRT_BASE)
-			return;
+	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
+	if (svm)
+		return;
 
-	}
 	vm_reserve_area_early(PCI_IO_VIRT_BASE, SZ_2M, pci_reserve_io);
 }
 #else
-- 
1.7.9.5

Re: [PATCH v6 0/3] introduce static_vm for ARM-specific static mapped area

[Nicolas Pitre]

On Wed, 6 Feb 2013, Joonsoo Kim wrote:

> Changelog
> v5->v6:
>   Add Ack-by, Reviewed-by, Tested-by tags
>   [3/3]: Change from Nicolas' suggestion
>   	 - remove redundant parenthesis

This looks all fine now.  Please submit your patches here for RMK to 
merge: http://www.arm.linux.org.uk/developer/patches/


Nicolas

[PATCH v6 0/3] introduce static_vm for ARM-specific static mapped area

[Nicolas Pitre]

On Wed, 6 Feb 2013, Joonsoo Kim wrote:

> Changelog
> v5->v6:
>   Add Ack-by, Reviewed-by, Tested-by tags
>   [3/3]: Change from Nicolas' suggestion
>   	 - remove redundant parenthesis

This looks all fine now.  Please submit your patches here for RMK to 
merge: http://www.arm.linux.org.uk/developer/patches/


Nicolas

Re: [PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Arnd Bergmann]

On Wednesday 06 February 2013, Joonsoo Kim wrote:
> @@ -859,17 +864,12 @@ static void __init pci_reserve_io(void)
>  {
>  	struct vm_struct *vm;
>  	unsigned long addr;
> +	struct static_vm *svm;
>  
> -	/* we're still single threaded hence no lock needed here */
> -	for (vm = vmlist; vm; vm = vm->next) {
> -		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
> -			continue;
> -		addr = (unsigned long)vm->addr;
> -		addr &= ~(SZ_2M - 1);
> -		if (addr == PCI_IO_VIRT_BASE)
> -			return;
> +	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
> +	if (svm)
> +		return;
>  
> -	}

This is causing build warnings in a bunch of configurations now,
see patch below.

	Arnd

8<-----
ARM: mm: remove unused variables in pci_reserve_io

Patch "ARM: 7646/1: mm: use static_vm for managing static mapped areas"
removed code from pci_reserve_io but left variable declarations
in place that are now unused, as gcc correctly warns.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index c6fe15a..c6d45c8 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -901,8 +901,6 @@ static void __init fill_pmd_gaps(void)
 #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
 static void __init pci_reserve_io(void)
 {
-	struct vm_struct *vm;
-	unsigned long addr;
 	struct static_vm *svm;
 
 	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);

[PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Arnd Bergmann]

On Wednesday 06 February 2013, Joonsoo Kim wrote:
> @@ -859,17 +864,12 @@ static void __init pci_reserve_io(void)
>  {
>  	struct vm_struct *vm;
>  	unsigned long addr;
> +	struct static_vm *svm;
>  
> -	/* we're still single threaded hence no lock needed here */
> -	for (vm = vmlist; vm; vm = vm->next) {
> -		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
> -			continue;
> -		addr = (unsigned long)vm->addr;
> -		addr &= ~(SZ_2M - 1);
> -		if (addr == PCI_IO_VIRT_BASE)
> -			return;
> +	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
> +	if (svm)
> +		return;
>  
> -	}

This is causing build warnings in a bunch of configurations now,
see patch below.

	Arnd

8<-----
ARM: mm: remove unused variables in pci_reserve_io

Patch "ARM: 7646/1: mm: use static_vm for managing static mapped areas"
removed code from pci_reserve_io but left variable declarations
in place that are now unused, as gcc correctly warns.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index c6fe15a..c6d45c8 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -901,8 +901,6 @@ static void __init fill_pmd_gaps(void)
 #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
 static void __init pci_reserve_io(void)
 {
-	struct vm_struct *vm;
-	unsigned long addr;
 	struct static_vm *svm;
 
 	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);

Re: [PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Russell King - ARM Linux]

On Sat, Feb 16, 2013 at 12:49:08PM +0000, Arnd Bergmann wrote:
> 8<-----
> ARM: mm: remove unused variables in pci_reserve_io
> 
> Patch "ARM: 7646/1: mm: use static_vm for managing static mapped areas"
> removed code from pci_reserve_io but left variable declarations
> in place that are now unused, as gcc correctly warns.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> 
> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> index c6fe15a..c6d45c8 100644
> --- a/arch/arm/mm/mmu.c
> +++ b/arch/arm/mm/mmu.c
> @@ -901,8 +901,6 @@ static void __init fill_pmd_gaps(void)
>  #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
>  static void __init pci_reserve_io(void)
>  {
> -	struct vm_struct *vm;
> -	unsigned long addr;
>  	struct static_vm *svm;
>  
>  	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);

I already have such a patch in my tree - may not have pushed it out
as I've been ill (and am still recovering.)

[PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Russell King - ARM Linux]

On Sat, Feb 16, 2013 at 12:49:08PM +0000, Arnd Bergmann wrote:
> 8<-----
> ARM: mm: remove unused variables in pci_reserve_io
> 
> Patch "ARM: 7646/1: mm: use static_vm for managing static mapped areas"
> removed code from pci_reserve_io but left variable declarations
> in place that are now unused, as gcc correctly warns.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> 
> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> index c6fe15a..c6d45c8 100644
> --- a/arch/arm/mm/mmu.c
> +++ b/arch/arm/mm/mmu.c
> @@ -901,8 +901,6 @@ static void __init fill_pmd_gaps(void)
>  #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
>  static void __init pci_reserve_io(void)
>  {
> -	struct vm_struct *vm;
> -	unsigned long addr;
>  	struct static_vm *svm;
>  
>  	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);

I already have such a patch in my tree - may not have pushed it out
as I've been ill (and am still recovering.)

Re: [PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Arnd Bergmann]

On Saturday 16 February 2013, Russell King - ARM Linux wrote:
> I already have such a patch in my tree - may not have pushed it out
> as I've been ill (and am still recovering.)

Ok, thanks for the quick confirmation!

Get well soon,

	Arnd

[PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Arnd Bergmann]

On Saturday 16 February 2013, Russell King - ARM Linux wrote:
> I already have such a patch in my tree - may not have pushed it out
> as I've been ill (and am still recovering.)

Ok, thanks for the quick confirmation!

Get well soon,

	Arnd

Re: [PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Nicolas Pitre]

On Sat, 16 Feb 2013, Arnd Bergmann wrote:

> On Wednesday 06 February 2013, Joonsoo Kim wrote:
> > @@ -859,17 +864,12 @@ static void __init pci_reserve_io(void)
> >  {
> >  	struct vm_struct *vm;
> >  	unsigned long addr;
> > +	struct static_vm *svm;
> >  
> > -	/* we're still single threaded hence no lock needed here */
> > -	for (vm = vmlist; vm; vm = vm->next) {
> > -		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
> > -			continue;
> > -		addr = (unsigned long)vm->addr;
> > -		addr &= ~(SZ_2M - 1);
> > -		if (addr == PCI_IO_VIRT_BASE)
> > -			return;
> > +	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
> > +	if (svm)
> > +		return;
> >  
> > -	}
> 
> This is causing build warnings in a bunch of configurations now,
> see patch below.
> 
> 	Arnd
> 
> 8<-----
> ARM: mm: remove unused variables in pci_reserve_io
> 
> Patch "ARM: 7646/1: mm: use static_vm for managing static mapped areas"
> removed code from pci_reserve_io but left variable declarations
> in place that are now unused, as gcc correctly warns.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Acked-by: Nicolas Pitre <nico@linaro.org>


> 
> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> index c6fe15a..c6d45c8 100644
> --- a/arch/arm/mm/mmu.c
> +++ b/arch/arm/mm/mmu.c
> @@ -901,8 +901,6 @@ static void __init fill_pmd_gaps(void)
>  #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
>  static void __init pci_reserve_io(void)
>  {
> -	struct vm_struct *vm;
> -	unsigned long addr;
>  	struct static_vm *svm;
>  
>  	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
> 

[PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Nicolas Pitre]

On Sat, 16 Feb 2013, Arnd Bergmann wrote:

> On Wednesday 06 February 2013, Joonsoo Kim wrote:
> > @@ -859,17 +864,12 @@ static void __init pci_reserve_io(void)
> >  {
> >  	struct vm_struct *vm;
> >  	unsigned long addr;
> > +	struct static_vm *svm;
> >  
> > -	/* we're still single threaded hence no lock needed here */
> > -	for (vm = vmlist; vm; vm = vm->next) {
> > -		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
> > -			continue;
> > -		addr = (unsigned long)vm->addr;
> > -		addr &= ~(SZ_2M - 1);
> > -		if (addr == PCI_IO_VIRT_BASE)
> > -			return;
> > +	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
> > +	if (svm)
> > +		return;
> >  
> > -	}
> 
> This is causing build warnings in a bunch of configurations now,
> see patch below.
> 
> 	Arnd
> 
> 8<-----
> ARM: mm: remove unused variables in pci_reserve_io
> 
> Patch "ARM: 7646/1: mm: use static_vm for managing static mapped areas"
> removed code from pci_reserve_io but left variable declarations
> in place that are now unused, as gcc correctly warns.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Acked-by: Nicolas Pitre <nico@linaro.org>


> 
> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> index c6fe15a..c6d45c8 100644
> --- a/arch/arm/mm/mmu.c
> +++ b/arch/arm/mm/mmu.c
> @@ -901,8 +901,6 @@ static void __init fill_pmd_gaps(void)
>  #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
>  static void __init pci_reserve_io(void)
>  {
> -	struct vm_struct *vm;
> -	unsigned long addr;
>  	struct static_vm *svm;
>  
>  	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
> 

Re: [PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Nicolas Pitre]

On Sat, 16 Feb 2013, Russell King - ARM Linux wrote:

> On Sat, Feb 16, 2013 at 12:49:08PM +0000, Arnd Bergmann wrote:
> > 8<-----
> > ARM: mm: remove unused variables in pci_reserve_io
> > 
> > Patch "ARM: 7646/1: mm: use static_vm for managing static mapped areas"
> > removed code from pci_reserve_io but left variable declarations
> > in place that are now unused, as gcc correctly warns.
> > 
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > 
> > diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> > index c6fe15a..c6d45c8 100644
> > --- a/arch/arm/mm/mmu.c
> > +++ b/arch/arm/mm/mmu.c
> > @@ -901,8 +901,6 @@ static void __init fill_pmd_gaps(void)
> >  #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
> >  static void __init pci_reserve_io(void)
> >  {
> > -	struct vm_struct *vm;
> > -	unsigned long addr;
> >  	struct static_vm *svm;
> >  
> >  	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
> 
> I already have such a patch in my tree - may not have pushed it out
> as I've been ill (and am still recovering.)

OK, disregard my previous ACK then.


Nicolas

[PATCH v6 3/3] ARM: mm: use static_vm for managing static mapped areas

[Nicolas Pitre]

On Sat, 16 Feb 2013, Russell King - ARM Linux wrote:

> On Sat, Feb 16, 2013 at 12:49:08PM +0000, Arnd Bergmann wrote:
> > 8<-----
> > ARM: mm: remove unused variables in pci_reserve_io
> > 
> > Patch "ARM: 7646/1: mm: use static_vm for managing static mapped areas"
> > removed code from pci_reserve_io but left variable declarations
> > in place that are now unused, as gcc correctly warns.
> > 
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > 
> > diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> > index c6fe15a..c6d45c8 100644
> > --- a/arch/arm/mm/mmu.c
> > +++ b/arch/arm/mm/mmu.c
> > @@ -901,8 +901,6 @@ static void __init fill_pmd_gaps(void)
> >  #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
> >  static void __init pci_reserve_io(void)
> >  {
> > -	struct vm_struct *vm;
> > -	unsigned long addr;
> >  	struct static_vm *svm;
> >  
> >  	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
> 
> I already have such a patch in my tree - may not have pushed it out
> as I've been ill (and am still recovering.)

OK, disregard my previous ACK then.


Nicolas