[PATCH 07/30] microblaze_mmu_v1: MMU initialization

monstr
2009-04-27T09:54:56Z

From: Michal Simek <monstr@monstr.eu>

Signed-off-by: Michal Simek <monstr@monstr.eu>
---
arch/microblaze/mm/init.c | 168 ++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 167 insertions(+), 1 deletions(-)

diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index b0c8213..32a54cb 100644
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -23,9 +23,17 @@
#include <asm/sections.h>
#include <asm/tlb.h>

+#ifndef CONFIG_MMU
unsigned int __page_offset;
/* EXPORT_SYMBOL(__page_offset); */

+#else
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+int mem_init_done;
+static int init_bootmem_done;
+#endif /* CONFIG_MMU */
+
char *klimit = _end;

/*
@@ -61,6 +69,7 @@ void __init setup_memory(void)
{
int i;
unsigned long map_size;
+#ifndef CONFIG_MMU
u32 kernel_align_start, kernel_align_size;

/* Find main memory where is the kernel */
@@ -93,6 +102,7 @@ void __init setup_memory(void)
__func__, kernel_align_start, kernel_align_start
+ kernel_align_size, kernel_align_size);

+#endif
/*
* Kernel:
* start: base phys address of kernel - page align
@@ -121,9 +131,13 @@ void __init setup_memory(void)
* for 4GB of memory, using 4kB pages), plus 1 page
* (in case the address isn't page-aligned).
*/
+#ifndef CONFIG_MMU
map_size = init_bootmem_node(NODE_DATA(0), PFN_UP(TOPHYS((u32)_end)),
min_low_pfn, max_low_pfn);
-
+#else
+ map_size = init_bootmem_node(&contig_page_data,
+ PFN_UP(TOPHYS((u32)_end)), min_low_pfn, max_low_pfn);
+#endif
lmb_reserve(PFN_UP(TOPHYS((u32)_end)) << PAGE_SHIFT, map_size);

/* free bootmem is whole main memory */
@@ -137,6 +151,9 @@ void __init setup_memory(void)
reserve_bootmem(lmb.reserved.region[i].base,
lmb_size_bytes(&lmb.reserved, i) - 1, BOOTMEM_DEFAULT);
}
+#ifdef CONFIG_MMU
+ init_bootmem_done = 1;
+#endif
paging_init();
}

@@ -191,11 +208,160 @@ void __init mem_init(void)
printk(KERN_INFO "Memory: %luk/%luk available\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
num_physpages << (PAGE_SHIFT-10));
+#ifdef CONFIG_MMU
+ mem_init_done = 1;
+#endif
}

+#ifndef CONFIG_MMU
/* Check against bounds of physical memory */
int ___range_ok(unsigned long addr, unsigned long size)
{
return ((addr < memory_start) ||
((addr + size) > memory_end));
}
+
+#else
+int page_is_ram(unsigned long pfn)
+{
+ return pfn < max_low_pfn;
+}
+
+/*
+ * Check for command-line options that affect what MMU_init will do.
+ */
+static void MMU_setup(void)
+{
+#if 0
+ /* Check for nobats option (used in mapin_ram). */
+ if (strstr(cmd_line, "nobats"))
+ __map_without_bats = 1;
+
+ /* Look for mem= option on command line */
+ if (strstr(cmd_line, "mem=")) {
+ char *p, *q;
+ unsigned long maxmem = 0;
+
+ for (q = cmd_line; (p = strstr(q, "mem=")) != 0; ) {
+ q = p + 4;
+ if (p > cmd_line && p[-1] != ' ')
+ continue;
+ maxmem = strict_strtoul(q, &q, NULL);
+ if (*q == 'k' || *q == 'K') {
+ maxmem <<= 10;
+ ++q;
+ } else if (*q == 'm' || *q == 'M') {
+ maxmem <<= 20;
+ ++q;
+ }
+ }
+ __max_memory = maxmem;
+ }
+
+/* if (__max_memory && memory_size > __max_memory)
+ memory_size = __max_memory; */
+
+#endif
+}
+
+/*
+ * MMU_init_hw does the chip-specific initialization of the MMU hardware.
+ */
+static void __init MMU_init_hw(void)
+{
+ /*
+ * The Zone Protection Register (ZPR) defines how protection will
+ * be applied to every page which is a member of a given zone. At
+ * present, we utilize only two of the zones.
+ * The zone index bits (of ZSEL) in the PTE are used for software
+ * indicators, except the LSB. For user access, zone 1 is used,
+ * for kernel access, zone 0 is used. We set all but zone 1
+ * to zero, allowing only kernel access as indicated in the PTE.
+ * For zone 1, we set a 01 binary (a value of 10 will not work)
+ * to allow user access as indicated in the PTE. This also allows
+ * kernel access as indicated in the PTE.
+ */
+ __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
+ "mts rzpr, r11;"
+ : : : "r11");
+}
+
+/*
+ * MMU_init sets up the basic memory mappings for the kernel,
+ * including both RAM and possibly some I/O regions,
+ * and sets up the page tables and the MMU hardware ready to go.
+ */
+
+/* called from head.S */
+asmlinkage void __init MMU_init(void)
+{
+ unsigned int kstart, ksize;
+
+ if (!lmb.reserved.cnt) {
+ printk(KERN_EMERG "Error memory count\n");
+ machine_restart(NULL);
+ }
+
+ if ((u32) lmb.memory.region[0].size < 0x1000000) {
+ printk(KERN_EMERG "Memory must be greater than 16MB\n");
+ machine_restart(NULL);
+ }
+ /* Find main memory where the kernel is */
+ memory_start = (u32) lmb.memory.region[0].base;
+ memory_end = (u32) lmb.memory.region[0].base +
+ (u32) lmb.memory.region[0].size;
+ memory_size = memory_end - memory_start;
+
+ MMU_setup(); /* FIXME parse args from command line - not used */
+
+ /*
+ * Map out the kernel text/data/bss from the available physical
+ * memory.
+ */
+ kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
+ /* kernel size */
+ ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
+ lmb_reserve(kstart, ksize);
+
+#if defined(CONFIG_BLK_DEV_INITRD)
+ /* Remove the init RAM disk from the available memory. */
+/* if (initrd_start) {
+ mem_pieces_remove(&phys_avail, __pa(initrd_start),
+ initrd_end - initrd_start, 1);
+ }*/
+#endif /* CONFIG_BLK_DEV_INITRD */
+
+ /* Initialize the MMU hardware */
+ MMU_init_hw();
+
+ /* Map in all of RAM starting at CONFIG_KERNEL_START */
+ mapin_ram();
+
+#ifdef HIGHMEM_START_BOOL
+ ioremap_base = HIGHMEM_START;
+#else
+ ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */
+#endif /* CONFIG_HIGHMEM */
+ ioremap_bot = ioremap_base;
+
+ /* Initialize the context management stuff */
+ mmu_context_init();
+}
+
+/* This is only called until mem_init is done. */
+void __init *early_get_page(void)
+{
+ void *p;
+ if (init_bootmem_done) {
+ p = alloc_bootmem_pages(PAGE_SIZE);
+ } else {
+ /*
+ * Mem start + 32MB -> here is limit
+ * because of mem mapping from head.S
+ */
+ p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
+ memory_start + 0x2000000));
+ }
+ return p;
+}
+#endif /* CONFIG_MMU */
--
1.5.5.1