[PATCH] ppc64: implement page_is_ram

This patch contains - Removes __initdata from lmb definition (struct lmb
lmb;) and modified the existing page_is_ram function.

Also changed the current argument from physical address to pfn to make it
compatible across architectures.  Please review them and send me your
comments/suggestions.  If you are OK with any one patch, please include it
in the mainline kernel.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/ppc64/kernel/lmb.c b/arch/ppc64/kernel/lmb.c
index c2e320635eaa459e235cf3862af809eea58e3bed..7c93d85aede87e374fa73c56ca89f228ba59677b 100644 (file)
--- a/arch/ppc64/kernel/lmb.c
+++ b/arch/ppc64/kernel/lmb.c
@@ -20,7 +20,7 @@
 #include <asm/abs_addr.h>
 #include <asm/bitops.h>
 
-struct lmb lmb __initdata;
+struct lmb lmb;
 
 static unsigned long __init
 lmb_addrs_overlap(unsigned long base1, unsigned long size1,

diff --git a/arch/ppc64/mm/init.c b/arch/ppc64/mm/init.c
index f89f9941f7cf48b963c7b1514e7385cc04435636..5f8a72dd758decaeb3067f341cc2c6b0ca34f873 100644 (file)
--- a/arch/ppc64/mm/init.c
+++ b/arch/ppc64/mm/init.c
@@ -85,7 +85,6 @@ unsigned long __max_memory;
 /* info on what we think the IO hole is */
 unsigned long  io_hole_start;
 unsigned long  io_hole_size;
-unsigned long  top_of_ram;
 
 void show_mem(void)
 {
@@ -498,16 +497,12 @@ void __init mm_init_ppc64(void)
         * So we need some rough way to tell where your big IO hole
         * is. On pmac, it's between 2G and 4G, on POWER3, it's around
         * that area as well, on POWER4 we don't have one, etc...
-        * We need that to implement something approx. decent for
-        * page_is_ram() so that /dev/mem doesn't map cacheable IO space
-        * when XFree resquest some IO regions witout using O_SYNC, we
-        * also need that as a "hint" when sizing the TCE table on POWER3
+        * We need that as a "hint" when sizing the TCE table on POWER3
         * So far, the simplest way that seem work well enough for us it
         * to just assume that the first discontinuity in our physical
         * RAM layout is the IO hole. That may not be correct in the future
         * (and isn't on iSeries but then we don't care ;)
         */
-       top_of_ram = lmb_end_of_DRAM();
 
 #ifndef CONFIG_PPC_ISERIES
        for (i = 1; i < lmb.memory.cnt; i++) {
@@ -530,22 +525,32 @@ void __init mm_init_ppc64(void)
        ppc64_boot_msg(0x100, "MM Init Done");
 }
 
-
 /*
  * This is called by /dev/mem to know if a given address has to
  * be mapped non-cacheable or not
  */
-int page_is_ram(unsigned long physaddr)
+int page_is_ram(unsigned long pfn)
 {
-#ifdef CONFIG_PPC_ISERIES
-       return 1;
+       int i;
+       unsigned long paddr = (pfn << PAGE_SHIFT);
+
+       for (i=0; i < lmb.memory.cnt; i++) {
+               unsigned long base;
+
+#ifdef CONFIG_MSCHUNKS
+               base = lmb.memory.region[i].physbase;
+#else
+               base = lmb.memory.region[i].base;
 #endif
-       if (physaddr >= top_of_ram)
-               return 0;
-       return io_hole_start == 0 ||  physaddr < io_hole_start ||
-               physaddr >= (io_hole_start + io_hole_size);
-}
+               if ((paddr >= base) &&
+                       (paddr < (base + lmb.memory.region[i].size))) {
+                       return 1;
+               }
+       }
 
+       return 0;
+}
+EXPORT_SYMBOL(page_is_ram);
 
 /*
  * Initialize the bootmem system and give it all the memory we
@@ -599,6 +604,7 @@ void __init paging_init(void)
        unsigned long zones_size[MAX_NR_ZONES];
        unsigned long zholes_size[MAX_NR_ZONES];
        unsigned long total_ram = lmb_phys_mem_size();
+       unsigned long top_of_ram = lmb_end_of_DRAM();
 
        printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
               top_of_ram, total_ram);

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 863bed6e72d64b622f5573283b9288fa3b4c641c..a893bafd3d7db760bb9ee0f3d2c7571ef8c5b215 100644 (file)
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -86,7 +86,7 @@ static inline int uncached_access(struct file *file, unsigned long addr)
         * above the IO hole... Ah, and of course, XFree86 doesn't pass
         * O_SYNC when mapping us to tap IO space. Surprised ?
         */
-       return !page_is_ram(addr);
+       return !page_is_ram(addr >> PAGE_SHIFT);
 #else
        /*
         * Accessing memory above the top the kernel knows about or through a file pointer

diff --git a/include/asm-ppc64/lmb.h b/include/asm-ppc64/lmb.h
index 43a2f70cf4d305e29196b4bf63a8b1c36c740aec..8dc2a07eac56b35e3ca0915546e0317536dd745d 100644 (file)
--- a/include/asm-ppc64/lmb.h
+++ b/include/asm-ppc64/lmb.h
@@ -47,7 +47,7 @@ struct lmb {
        struct lmb_region reserved;
 };
 
-extern struct lmb lmb __initdata;
+extern struct lmb lmb;
 
 extern void __init lmb_init(void);
 extern void __init lmb_analyze(void);

diff --git a/include/asm-ppc64/page.h b/include/asm-ppc64/page.h
index 0bd698f6b10d2bd4c1378ff0f851af5249b97ed5..af8219b8e77533a58d1152b8e04bd89faf2a07c4 100644 (file)
--- a/include/asm-ppc64/page.h
+++ b/include/asm-ppc64/page.h
@@ -181,8 +181,7 @@ static inline int get_order(unsigned long size)
 
 #define __pa(x) ((unsigned long)(x)-PAGE_OFFSET)
 
-/* Not 100% correct, for use by /dev/mem only */
-extern int page_is_ram(unsigned long physaddr);
+extern int page_is_ram(unsigned long pfn);
 
 #endif /* __ASSEMBLY__ */