The fixmap code from x86 allows us to have compile time virtual addresses
that we change the physical addresses of at run time.
This is useful for applications like kmap_atomic, PCI config that is done
via direct memory map, kexec/kdump.
We got ride of CONFIG_HIGHMEM_START as we can now determine a more optimal
location for PKMAP_BASE based on where the fixmap addresses start and
working back from there.
Additionally, the kmap code in asm-powerpc/highmem.h always had debug
enabled. Moved to using CONFIG_DEBUG_HIGHMEM to determine if we should
have the extra debug checking.
Signed-off-by: Kumar Gala <[EMAIL PROTECTED]>
---
arch/powerpc/Kconfig | 14 -----
arch/powerpc/mm/init_32.c | 8 ---
arch/powerpc/mm/mem.c | 32 ++++++++++--
arch/powerpc/mm/pgtable_32.c | 23 ++++++++
include/asm-powerpc/fixmap.h | 112 +++++++++++++++++++++++++++++++++++++++++
include/asm-powerpc/highmem.h | 41 ++++++++-------
6 files changed, 183 insertions(+), 47 deletions(-)
create mode 100644 include/asm-powerpc/fixmap.h
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 10e9df7..96cc0ad 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -613,20 +613,6 @@ config ADVANCED_OPTIONS
comment "Default settings for advanced configuration options are used"
depends on !ADVANCED_OPTIONS
-config HIGHMEM_START_BOOL
- bool "Set high memory pool address"
- depends on ADVANCED_OPTIONS && HIGHMEM
- help
- This option allows you to set the base address of the kernel virtual
- area used to map high memory pages. This can be useful in
- optimizing the layout of kernel virtual memory.
-
- Say N here unless you know what you are doing.
-
-config HIGHMEM_START
- hex "Virtual start address of high memory pool" if HIGHMEM_START_BOOL
- default "0xfe000000"
-
config LOWMEM_SIZE_BOOL
bool "Set maximum low memory"
depends on ADVANCED_OPTIONS
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index 578750e..1952b4d 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -71,14 +71,6 @@ unsigned long agp_special_page;
EXPORT_SYMBOL(agp_special_page);
#endif
-#ifdef CONFIG_HIGHMEM
-pte_t *kmap_pte;
-pgprot_t kmap_prot;
-
-EXPORT_SYMBOL(kmap_prot);
-EXPORT_SYMBOL(kmap_pte);
-#endif
-
void MMU_init(void);
/* XXX should be in current.h -- paulus */
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 0062e6b..5ccb579 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -45,6 +45,7 @@
#include <asm/tlb.h>
#include <asm/sections.h>
#include <asm/vdso.h>
+#include <asm/fixmap.h>
#include "mmu_decl.h"
@@ -57,6 +58,20 @@ int init_bootmem_done;
int mem_init_done;
unsigned long memory_limit;
+#ifdef CONFIG_HIGHMEM
+pte_t *kmap_pte;
+pgprot_t kmap_prot;
+
+EXPORT_SYMBOL(kmap_prot);
+EXPORT_SYMBOL(kmap_pte);
+
+static inline pte_t *virt_to_kpte(unsigned long vaddr)
+{
+ return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
+ vaddr), vaddr), vaddr);
+}
+#endif
+
int page_is_ram(unsigned long pfn)
{
unsigned long paddr = (pfn << PAGE_SHIFT);
@@ -311,14 +326,19 @@ void __init paging_init(void)
unsigned long top_of_ram = lmb_end_of_DRAM();
unsigned long max_zone_pfns[MAX_NR_ZONES];
+#ifdef CONFIG_PPC32
+ unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
+ unsigned long end = __fix_to_virt(FIX_HOLE);
+
+ for (; v < end; v += PAGE_SIZE)
+ map_page(v, 0, 0); /* XXX gross */
+#endif
+
#ifdef CONFIG_HIGHMEM
map_page(PKMAP_BASE, 0, 0); /* XXX gross */
- pkmap_page_table = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
- (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
- map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
- kmap_pte = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
- (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN),
- KMAP_FIX_BEGIN);
+ pkmap_page_table = virt_to_kpte(PKMAP_BASE);
+
+ kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
kmap_prot = PAGE_KERNEL;
#endif /* CONFIG_HIGHMEM */
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 64c44bc..5d0a601 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -29,6 +29,7 @@
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
+#include <asm/fixmap.h>
#include <asm/io.h>
#include "mmu_decl.h"
@@ -387,3 +388,25 @@ void kernel_map_pages(struct page *page, int numpages, int
enable)
change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
}
#endif /* CONFIG_DEBUG_PAGEALLOC */
+
+static int fixmaps;
+unsigned long __FIXADDR_TOP = 0xfffff000;
+EXPORT_SYMBOL(__FIXADDR_TOP);
+
+void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
+{
+ unsigned long address = __fix_to_virt(idx);
+
+ if (idx >= __end_of_fixed_addresses) {
+ BUG();
+ return;
+ }
+
+ map_page(address, phys, flags);
+ fixmaps++;
+}
+
+void __this_fixmap_does_not_exist(void)
+{
+ WARN_ON(1);
+}
diff --git a/include/asm-powerpc/fixmap.h b/include/asm-powerpc/fixmap.h
new file mode 100644
index 0000000..f303921
--- /dev/null
+++ b/include/asm-powerpc/fixmap.h
@@ -0,0 +1,112 @@
+/*
+ * fixmap.h: compile-time virtual memory allocation
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1998 Ingo Molnar
+ *
+ * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
+ *
+ * Copyright 2008 Freescale Semiconductor Inc.
+ * Port to powerpc added by Kumar Gala
+ */
+
+#ifndef _ASM_FIXMAP_H
+#define _ASM_FIXMAP_H
+
+extern unsigned long __FIXADDR_TOP;
+
+#ifndef __ASSEMBLY__
+#include <linux/kernel.h>
+#include <asm/page.h>
+#ifdef CONFIG_HIGHMEM
+#include <linux/threads.h>
+#include <asm/kmap_types.h>
+#endif
+
+/*
+ * Here we define all the compile-time 'special' virtual
+ * addresses. The point is to have a constant address at
+ * compile time, but to set the physical address only
+ * in the boot process. We allocate these special addresses
+ * from the end of virtual memory (0xfffff000) backwards.
+ * Also this lets us do fail-safe vmalloc(), we
+ * can guarantee that these special addresses and
+ * vmalloc()-ed addresses never overlap.
+ *
+ * these 'compile-time allocated' memory buffers are
+ * fixed-size 4k pages. (or larger if used with an increment
+ * highger than 1) use fixmap_set(idx,phys) to associate
+ * physical memory with fixmap indices.
+ *
+ * TLB entries of such buffers will not be flushed across
+ * task switches.
+ */
+enum fixed_addresses {
+ FIX_HOLE,
+#ifdef CONFIG_HIGHMEM
+ FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
+ FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
+#endif
+ /* FIX_PCIE_MCFG, */
+ __end_of_fixed_addresses
+};
+
+extern void __set_fixmap (enum fixed_addresses idx,
+ phys_addr_t phys, pgprot_t flags);
+
+#define set_fixmap(idx, phys) \
+ __set_fixmap(idx, phys, PAGE_KERNEL)
+/*
+ * Some hardware wants to get fixmapped without caching.
+ */
+#define set_fixmap_nocache(idx, phys) \
+ __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
+
+#define clear_fixmap(idx) \
+ __set_fixmap(idx, 0, __pgprot(0))
+
+#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
+
+#define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
+#define __FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
+#define FIXADDR_BOOT_START (FIXADDR_TOP - __FIXADDR_BOOT_SIZE)
+
+#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
+#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
+
+extern void __this_fixmap_does_not_exist(void);
+
+/*
+ * 'index to address' translation. If anyone tries to use the idx
+ * directly without tranlation, we catch the bug with a NULL-deference
+ * kernel oops. Illegal ranges of incoming indices are caught too.
+ */
+static __always_inline unsigned long fix_to_virt(const unsigned int idx)
+{
+ /*
+ * this branch gets completely eliminated after inlining,
+ * except when someone tries to use fixaddr indices in an
+ * illegal way. (such as mixing up address types or using
+ * out-of-range indices).
+ *
+ * If it doesn't get removed, the linker will complain
+ * loudly with a reasonably clear error message..
+ */
+ if (idx >= __end_of_fixed_addresses)
+ __this_fixmap_does_not_exist();
+
+ return __fix_to_virt(idx);
+}
+
+static inline unsigned long virt_to_fix(const unsigned long vaddr)
+{
+ BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
+ return __virt_to_fix(vaddr);
+}
+
+#endif /* !__ASSEMBLY__ */
+#endif
diff --git a/include/asm-powerpc/highmem.h b/include/asm-powerpc/highmem.h
index f7b21ee..d81a088 100644
--- a/include/asm-powerpc/highmem.h
+++ b/include/asm-powerpc/highmem.h
@@ -27,9 +27,7 @@
#include <asm/kmap_types.h>
#include <asm/tlbflush.h>
#include <asm/page.h>
-
-/* undef for production */
-#define HIGHMEM_DEBUG 1
+#include <asm/fixmap.h>
extern pte_t *kmap_pte;
extern pgprot_t kmap_prot;
@@ -40,14 +38,12 @@ extern pte_t *pkmap_page_table;
* easily, subsequent pte tables have to be allocated in one physical
* chunk of RAM.
*/
-#define PKMAP_BASE CONFIG_HIGHMEM_START
#define LAST_PKMAP (1 << PTE_SHIFT)
#define LAST_PKMAP_MASK (LAST_PKMAP-1)
+#define PKMAP_BASE ((FIXADDR_BOOT_START - PAGE_SIZE*(LAST_PKMAP + 1)) &
PMD_MASK)
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
-#define KMAP_FIX_BEGIN (PKMAP_BASE + 0x00400000UL)
-
extern void *kmap_high(struct page *page);
extern void kunmap_high(struct page *page);
@@ -73,7 +69,7 @@ static inline void kunmap(struct page *page)
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
-static inline void *kmap_atomic(struct page *page, enum km_type type)
+static inline void *kmap_atomic_prot(struct page *page, enum km_type type,
pgprot_t prot)
{
unsigned int idx;
unsigned long vaddr;
@@ -84,34 +80,39 @@ static inline void *kmap_atomic(struct page *page, enum
km_type type)
return page_address(page);
idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = KMAP_FIX_BEGIN + idx * PAGE_SIZE;
-#ifdef HIGHMEM_DEBUG
- BUG_ON(!pte_none(*(kmap_pte+idx)));
+ vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+#ifdef CONFIG_DEBUG_HIGHMEM
+ BUG_ON(!pte_none(*(kmap_pte-idx)));
#endif
- set_pte_at(&init_mm, vaddr, kmap_pte+idx, mk_pte(page, kmap_prot));
+ set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
flush_tlb_page(NULL, vaddr);
return (void*) vaddr;
}
+static inline void *kmap_atomic(struct page *page, enum km_type type)
+{
+ return kmap_atomic_prot(page, type, kmap_prot);
+}
+
static inline void kunmap_atomic(void *kvaddr, enum km_type type)
{
-#ifdef HIGHMEM_DEBUG
+#ifdef CONFIG_DEBUG_HIGHMEM
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- unsigned int idx = type + KM_TYPE_NR*smp_processor_id();
+ enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
- if (vaddr < KMAP_FIX_BEGIN) { // FIXME
+ if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
pagefault_enable();
return;
}
- BUG_ON(vaddr != KMAP_FIX_BEGIN + idx * PAGE_SIZE);
+ BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
/*
* force other mappings to Oops if they'll try to access
* this pte without first remap it
*/
- pte_clear(&init_mm, vaddr, kmap_pte+idx);
+ pte_clear(&init_mm, vaddr, kmap_pte-idx);
flush_tlb_page(NULL, vaddr);
#endif
pagefault_enable();
@@ -120,12 +121,14 @@ static inline void kunmap_atomic(void *kvaddr, enum
km_type type)
static inline struct page *kmap_atomic_to_page(void *ptr)
{
unsigned long idx, vaddr = (unsigned long) ptr;
+ pte_t *pte;
- if (vaddr < KMAP_FIX_BEGIN)
+ if (vaddr < FIXADDR_START)
return virt_to_page(ptr);
- idx = (vaddr - KMAP_FIX_BEGIN) >> PAGE_SHIFT;
- return pte_page(kmap_pte[idx]);
+ idx = virt_to_fix(vaddr);
+ pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
+ return pte_page(*pte);
}
#define flush_cache_kmaps() flush_cache_all()
--
1.5.4.1
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