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authorAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
committerAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
commitb4b6116a13633898cf868f2f103c96a90c4c20f8 (patch)
tree93d1b7e2cfcdf473d8d4ff3ad141fa864f8491f6 /arch/mips/dec/prom/memory.c
parentedd4be777c953e5faafc80d091d3084b4343f5d3 (diff)
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fedora kernel: d9aad82f3319f3cfd1aebc01234254ef0c37ad84v3.3.2-1
Signed-off-by: Anton Arapov <anton@redhat.com>
Diffstat (limited to 'arch/mips/dec/prom/memory.c')
-rw-r--r--arch/mips/dec/prom/memory.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/mips/dec/prom/memory.c b/arch/mips/dec/prom/memory.c
new file mode 100644
index 00000000000..e95ff3054ff
--- /dev/null
+++ b/arch/mips/dec/prom/memory.c
@@ -0,0 +1,118 @@
+/*
+ * memory.c: memory initialisation code.
+ *
+ * Copyright (C) 1998 Harald Koerfgen, Frieder Streffer and Paul M. Antoine
+ * Copyright (C) 2000, 2002 Maciej W. Rozycki
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/bootmem.h>
+#include <linux/types.h>
+
+#include <asm/addrspace.h>
+#include <asm/bootinfo.h>
+#include <asm/dec/machtype.h>
+#include <asm/dec/prom.h>
+#include <asm/page.h>
+#include <asm/sections.h>
+
+
+volatile unsigned long mem_err; /* So we know an error occurred */
+
+/*
+ * Probe memory in 4MB chunks, waiting for an error to tell us we've fallen
+ * off the end of real memory. Only suitable for the 2100/3100's (PMAX).
+ */
+
+#define CHUNK_SIZE 0x400000
+
+static inline void pmax_setup_memory_region(void)
+{
+ volatile unsigned char *memory_page, dummy;
+ char old_handler[0x80];
+ extern char genexcept_early;
+
+ /* Install exception handler */
+ memcpy(&old_handler, (void *)(CKSEG0 + 0x80), 0x80);
+ memcpy((void *)(CKSEG0 + 0x80), &genexcept_early, 0x80);
+
+ /* read unmapped and uncached (KSEG1)
+ * DECstations have at least 4MB RAM
+ * Assume less than 480MB of RAM, as this is max for 5000/2xx
+ * FIXME this should be replaced by the first free page!
+ */
+ for (memory_page = (unsigned char *)CKSEG1 + CHUNK_SIZE;
+ mem_err == 0 && memory_page < (unsigned char *)CKSEG1 + 0x1e00000;
+ memory_page += CHUNK_SIZE) {
+ dummy = *memory_page;
+ }
+ memcpy((void *)(CKSEG0 + 0x80), &old_handler, 0x80);
+
+ add_memory_region(0, (unsigned long)memory_page - CKSEG1 - CHUNK_SIZE,
+ BOOT_MEM_RAM);
+}
+
+/*
+ * Use the REX prom calls to get hold of the memory bitmap, and thence
+ * determine memory size.
+ */
+static inline void rex_setup_memory_region(void)
+{
+ int i, bitmap_size;
+ unsigned long mem_start = 0, mem_size = 0;
+ memmap *bm;
+
+ /* some free 64k */
+ bm = (memmap *)CKSEG0ADDR(0x28000);
+
+ bitmap_size = rex_getbitmap(bm);
+
+ for (i = 0; i < bitmap_size; i++) {
+ /* FIXME: very simplistically only add full sets of pages */
+ if (bm->bitmap[i] == 0xff)
+ mem_size += (8 * bm->pagesize);
+ else if (!mem_size)
+ mem_start += (8 * bm->pagesize);
+ else {
+ add_memory_region(mem_start, mem_size, BOOT_MEM_RAM);
+ mem_start += mem_size + (8 * bm->pagesize);
+ mem_size = 0;
+ }
+ }
+ if (mem_size)
+ add_memory_region(mem_start, mem_size, BOOT_MEM_RAM);
+}
+
+void __init prom_meminit(u32 magic)
+{
+ if (!prom_is_rex(magic))
+ pmax_setup_memory_region();
+ else
+ rex_setup_memory_region();
+}
+
+void __init prom_free_prom_memory(void)
+{
+ unsigned long end;
+
+ /*
+ * Free everything below the kernel itself but leave
+ * the first page reserved for the exception handlers.
+ */
+
+#if defined(CONFIG_DECLANCE) || defined(CONFIG_DECLANCE_MODULE)
+ /*
+ * Leave 128 KB reserved for Lance memory for
+ * IOASIC DECstations.
+ *
+ * XXX: save this address for use in dec_lance.c?
+ */
+ if (IOASIC)
+ end = __pa(&_text) - 0x00020000;
+ else
+#endif
+ end = __pa(&_text);
+
+ free_init_pages("unused PROM memory", PAGE_SIZE, end);
+}