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-rw-r--r--arch/i386/kernel/e820.c894
1 files changed, 894 insertions, 0 deletions
diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
new file mode 100644
index 0000000..2f7d0a9
--- /dev/null
+++ b/arch/i386/kernel/e820.c
@@ -0,0 +1,894 @@
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/ioport.h>
+#include <linux/string.h>
+#include <linux/kexec.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/efi.h>
+#include <linux/pfn.h>
+#include <linux/uaccess.h>
+
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/e820.h>
+
+#ifdef CONFIG_EFI
+int efi_enabled = 0;
+EXPORT_SYMBOL(efi_enabled);
+#endif
+
+struct e820map e820;
+struct change_member {
+ struct e820entry *pbios; /* pointer to original bios entry */
+ unsigned long long addr; /* address for this change point */
+};
+static struct change_member change_point_list[2*E820MAX] __initdata;
+static struct change_member *change_point[2*E820MAX] __initdata;
+static struct e820entry *overlap_list[E820MAX] __initdata;
+static struct e820entry new_bios[E820MAX] __initdata;
+/* For PCI or other memory-mapped resources */
+unsigned long pci_mem_start = 0x10000000;
+#ifdef CONFIG_PCI
+EXPORT_SYMBOL(pci_mem_start);
+#endif
+extern int user_defined_memmap;
+struct resource data_resource = {
+ .name = "Kernel data",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_BUSY | IORESOURCE_MEM
+};
+
+struct resource code_resource = {
+ .name = "Kernel code",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_BUSY | IORESOURCE_MEM
+};
+
+static struct resource system_rom_resource = {
+ .name = "System ROM",
+ .start = 0xf0000,
+ .end = 0xfffff,
+ .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
+};
+
+static struct resource extension_rom_resource = {
+ .name = "Extension ROM",
+ .start = 0xe0000,
+ .end = 0xeffff,
+ .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
+};
+
+static struct resource adapter_rom_resources[] = { {
+ .name = "Adapter ROM",
+ .start = 0xc8000,
+ .end = 0,
+ .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
+}, {
+ .name = "Adapter ROM",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
+}, {
+ .name = "Adapter ROM",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
+}, {
+ .name = "Adapter ROM",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
+}, {
+ .name = "Adapter ROM",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
+}, {
+ .name = "Adapter ROM",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
+} };
+
+static struct resource video_rom_resource = {
+ .name = "Video ROM",
+ .start = 0xc0000,
+ .end = 0xc7fff,
+ .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
+};
+
+static struct resource video_ram_resource = {
+ .name = "Video RAM area",
+ .start = 0xa0000,
+ .end = 0xbffff,
+ .flags = IORESOURCE_BUSY | IORESOURCE_MEM
+};
+
+static struct resource standard_io_resources[] = { {
+ .name = "dma1",
+ .start = 0x0000,
+ .end = 0x001f,
+ .flags = IORESOURCE_BUSY | IORESOURCE_IO
+}, {
+ .name = "pic1",
+ .start = 0x0020,
+ .end = 0x0021,
+ .flags = IORESOURCE_BUSY | IORESOURCE_IO
+}, {
+ .name = "timer0",
+ .start = 0x0040,
+ .end = 0x0043,
+ .flags = IORESOURCE_BUSY | IORESOURCE_IO
+}, {
+ .name = "timer1",
+ .start = 0x0050,
+ .end = 0x0053,
+ .flags = IORESOURCE_BUSY | IORESOURCE_IO
+}, {
+ .name = "keyboard",
+ .start = 0x0060,
+ .end = 0x006f,
+ .flags = IORESOURCE_BUSY | IORESOURCE_IO
+}, {
+ .name = "dma page reg",
+ .start = 0x0080,
+ .end = 0x008f,
+ .flags = IORESOURCE_BUSY | IORESOURCE_IO
+}, {
+ .name = "pic2",
+ .start = 0x00a0,
+ .end = 0x00a1,
+ .flags = IORESOURCE_BUSY | IORESOURCE_IO
+}, {
+ .name = "dma2",
+ .start = 0x00c0,
+ .end = 0x00df,
+ .flags = IORESOURCE_BUSY | IORESOURCE_IO
+}, {
+ .name = "fpu",
+ .start = 0x00f0,
+ .end = 0x00ff,
+ .flags = IORESOURCE_BUSY | IORESOURCE_IO
+} };
+
+static int romsignature(const unsigned char *x)
+{
+ unsigned short sig;
+ int ret = 0;
+ if (probe_kernel_address((const unsigned short *)x, sig) == 0)
+ ret = (sig == 0xaa55);
+ return ret;
+}
+
+static int __init romchecksum(unsigned char *rom, unsigned long length)
+{
+ unsigned char *p, sum = 0;
+
+ for (p = rom; p < rom + length; p++)
+ sum += *p;
+ return sum == 0;
+}
+
+static void __init probe_roms(void)
+{
+ unsigned long start, length, upper;
+ unsigned char *rom;
+ int i;
+
+ /* video rom */
+ upper = adapter_rom_resources[0].start;
+ for (start = video_rom_resource.start; start < upper; start += 2048) {
+ rom = isa_bus_to_virt(start);
+ if (!romsignature(rom))
+ continue;
+
+ video_rom_resource.start = start;
+
+ /* 0 < length <= 0x7f * 512, historically */
+ length = rom[2] * 512;
+
+ /* if checksum okay, trust length byte */
+ if (length && romchecksum(rom, length))
+ video_rom_resource.end = start + length - 1;
+
+ request_resource(&iomem_resource, &video_rom_resource);
+ break;
+ }
+
+ start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
+ if (start < upper)
+ start = upper;
+
+ /* system rom */
+ request_resource(&iomem_resource, &system_rom_resource);
+ upper = system_rom_resource.start;
+
+ /* check for extension rom (ignore length byte!) */
+ rom = isa_bus_to_virt(extension_rom_resource.start);
+ if (romsignature(rom)) {
+ length = extension_rom_resource.end - extension_rom_resource.start + 1;
+ if (romchecksum(rom, length)) {
+ request_resource(&iomem_resource, &extension_rom_resource);
+ upper = extension_rom_resource.start;
+ }
+ }
+
+ /* check for adapter roms on 2k boundaries */
+ for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
+ rom = isa_bus_to_virt(start);
+ if (!romsignature(rom))
+ continue;
+
+ /* 0 < length <= 0x7f * 512, historically */
+ length = rom[2] * 512;
+
+ /* but accept any length that fits if checksum okay */
+ if (!length || start + length > upper || !romchecksum(rom, length))
+ continue;
+
+ adapter_rom_resources[i].start = start;
+ adapter_rom_resources[i].end = start + length - 1;
+ request_resource(&iomem_resource, &adapter_rom_resources[i]);
+
+ start = adapter_rom_resources[i++].end & ~2047UL;
+ }
+}
+
+/*
+ * Request address space for all standard RAM and ROM resources
+ * and also for regions reported as reserved by the e820.
+ */
+static void __init
+legacy_init_iomem_resources(struct resource *code_resource, struct resource *data_resource)
+{
+ int i;
+
+ probe_roms();
+ for (i = 0; i < e820.nr_map; i++) {
+ struct resource *res;
+#ifndef CONFIG_RESOURCES_64BIT
+ if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
+ continue;
+#endif
+ res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
+ switch (e820.map[i].type) {
+ case E820_RAM: res->name = "System RAM"; break;
+ case E820_ACPI: res->name = "ACPI Tables"; break;
+ case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
+ default: res->name = "reserved";
+ }
+ res->start = e820.map[i].addr;
+ res->end = res->start + e820.map[i].size - 1;
+ res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+ if (request_resource(&iomem_resource, res)) {
+ kfree(res);
+ continue;
+ }
+ if (e820.map[i].type == E820_RAM) {
+ /*
+ * We don't know which RAM region contains kernel data,
+ * so we try it repeatedly and let the resource manager
+ * test it.
+ */
+ request_resource(res, code_resource);
+ request_resource(res, data_resource);
+#ifdef CONFIG_KEXEC
+ request_resource(res, &crashk_res);
+#endif
+ }
+ }
+}
+
+/*
+ * Request address space for all standard resources
+ *
+ * This is called just before pcibios_init(), which is also a
+ * subsys_initcall, but is linked in later (in arch/i386/pci/common.c).
+ */
+static int __init request_standard_resources(void)
+{
+ int i;
+
+ printk("Setting up standard PCI resources\n");
+ if (efi_enabled)
+ efi_initialize_iomem_resources(&code_resource, &data_resource);
+ else
+ legacy_init_iomem_resources(&code_resource, &data_resource);
+
+ /* EFI systems may still have VGA */
+ request_resource(&iomem_resource, &video_ram_resource);
+
+ /* request I/O space for devices used on all i[345]86 PCs */
+ for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
+ request_resource(&ioport_resource, &standard_io_resources[i]);
+ return 0;
+}
+
+subsys_initcall(request_standard_resources);
+
+void __init add_memory_region(unsigned long long start,
+ unsigned long long size, int type)
+{
+ int x;
+
+ if (!efi_enabled) {
+ x = e820.nr_map;
+
+ if (x == E820MAX) {
+ printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
+ return;
+ }
+
+ e820.map[x].addr = start;
+ e820.map[x].size = size;
+ e820.map[x].type = type;
+ e820.nr_map++;
+ }
+} /* add_memory_region */
+
+/*
+ * Sanitize the BIOS e820 map.
+ *
+ * Some e820 responses include overlapping entries. The following
+ * replaces the original e820 map with a new one, removing overlaps.
+ *
+ */
+int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
+{
+ struct change_member *change_tmp;
+ unsigned long current_type, last_type;
+ unsigned long long last_addr;
+ int chgidx, still_changing;
+ int overlap_entries;
+ int new_bios_entry;
+ int old_nr, new_nr, chg_nr;
+ int i;
+
+ /*
+ Visually we're performing the following (1,2,3,4 = memory types)...
+
+ Sample memory map (w/overlaps):
+ ____22__________________
+ ______________________4_
+ ____1111________________
+ _44_____________________
+ 11111111________________
+ ____________________33__
+ ___________44___________
+ __________33333_________
+ ______________22________
+ ___________________2222_
+ _________111111111______
+ _____________________11_
+ _________________4______
+
+ Sanitized equivalent (no overlap):
+ 1_______________________
+ _44_____________________
+ ___1____________________
+ ____22__________________
+ ______11________________
+ _________1______________
+ __________3_____________
+ ___________44___________
+ _____________33_________
+ _______________2________
+ ________________1_______
+ _________________4______
+ ___________________2____
+ ____________________33__
+ ______________________4_
+ */
+ printk("sanitize start\n");
+ /* if there's only one memory region, don't bother */
+ if (*pnr_map < 2) {
+ printk("sanitize bail 0\n");
+ return -1;
+ }
+
+ old_nr = *pnr_map;
+
+ /* bail out if we find any unreasonable addresses in bios map */
+ for (i=0; i<old_nr; i++)
+ if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr) {
+ printk("sanitize bail 1\n");
+ return -1;
+ }
+
+ /* create pointers for initial change-point information (for sorting) */
+ for (i=0; i < 2*old_nr; i++)
+ change_point[i] = &change_point_list[i];
+
+ /* record all known change-points (starting and ending addresses),
+ omitting those that are for empty memory regions */
+ chgidx = 0;
+ for (i=0; i < old_nr; i++) {
+ if (biosmap[i].size != 0) {
+ change_point[chgidx]->addr = biosmap[i].addr;
+ change_point[chgidx++]->pbios = &biosmap[i];
+ change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
+ change_point[chgidx++]->pbios = &biosmap[i];
+ }
+ }
+ chg_nr = chgidx; /* true number of change-points */
+
+ /* sort change-point list by memory addresses (low -> high) */
+ still_changing = 1;
+ while (still_changing) {
+ still_changing = 0;
+ for (i=1; i < chg_nr; i++) {
+ /* if <current_addr> > <last_addr>, swap */
+ /* or, if current=<start_addr> & last=<end_addr>, swap */
+ if ((change_point[i]->addr < change_point[i-1]->addr) ||
+ ((change_point[i]->addr == change_point[i-1]->addr) &&
+ (change_point[i]->addr == change_point[i]->pbios->addr) &&
+ (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
+ )
+ {
+ change_tmp = change_point[i];
+ change_point[i] = change_point[i-1];
+ change_point[i-1] = change_tmp;
+ still_changing=1;
+ }
+ }
+ }
+
+ /* create a new bios memory map, removing overlaps */
+ overlap_entries=0; /* number of entries in the overlap table */
+ new_bios_entry=0; /* index for creating new bios map entries */
+ last_type = 0; /* start with undefined memory type */
+ last_addr = 0; /* start with 0 as last starting address */
+ /* loop through change-points, determining affect on the new bios map */
+ for (chgidx=0; chgidx < chg_nr; chgidx++)
+ {
+ /* keep track of all overlapping bios entries */
+ if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
+ {
+ /* add map entry to overlap list (> 1 entry implies an overlap) */
+ overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
+ }
+ else
+ {
+ /* remove entry from list (order independent, so swap with last) */
+ for (i=0; i<overlap_entries; i++)
+ {
+ if (overlap_list[i] == change_point[chgidx]->pbios)
+ overlap_list[i] = overlap_list[overlap_entries-1];
+ }
+ overlap_entries--;
+ }
+ /* if there are overlapping entries, decide which "type" to use */
+ /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
+ current_type = 0;
+ for (i=0; i<overlap_entries; i++)
+ if (overlap_list[i]->type > current_type)
+ current_type = overlap_list[i]->type;
+ /* continue building up new bios map based on this information */
+ if (current_type != last_type) {
+ if (last_type != 0) {
+ new_bios[new_bios_entry].size =
+ change_point[chgidx]->addr - last_addr;
+ /* move forward only if the new size was non-zero */
+ if (new_bios[new_bios_entry].size != 0)
+ if (++new_bios_entry >= E820MAX)
+ break; /* no more space left for new bios entries */
+ }
+ if (current_type != 0) {
+ new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
+ new_bios[new_bios_entry].type = current_type;
+ last_addr=change_point[chgidx]->addr;
+ }
+ last_type = current_type;
+ }
+ }
+ new_nr = new_bios_entry; /* retain count for new bios entries */
+
+ /* copy new bios mapping into original location */
+ memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
+ *pnr_map = new_nr;
+
+ printk("sanitize end\n");
+ return 0;
+}
+
+/*
+ * Copy the BIOS e820 map into a safe place.
+ *
+ * Sanity-check it while we're at it..
+ *
+ * If we're lucky and live on a modern system, the setup code
+ * will have given us a memory map that we can use to properly
+ * set up memory. If we aren't, we'll fake a memory map.
+ *
+ * We check to see that the memory map contains at least 2 elements
+ * before we'll use it, because the detection code in setup.S may
+ * not be perfect and most every PC known to man has two memory
+ * regions: one from 0 to 640k, and one from 1mb up. (The IBM
+ * thinkpad 560x, for example, does not cooperate with the memory
+ * detection code.)
+ */
+int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
+{
+ /* Only one memory region (or negative)? Ignore it */
+ if (nr_map < 2)
+ return -1;
+
+ do {
+ unsigned long long start = biosmap->addr;
+ unsigned long long size = biosmap->size;
+ unsigned long long end = start + size;
+ unsigned long type = biosmap->type;
+ printk("copy_e820_map() start: %016Lx size: %016Lx end: %016Lx type: %ld\n", start, size, end, type);
+
+ /* Overflow in 64 bits? Ignore the memory map. */
+ if (start > end)
+ return -1;
+
+ /*
+ * Some BIOSes claim RAM in the 640k - 1M region.
+ * Not right. Fix it up.
+ */
+ if (type == E820_RAM) {
+ printk("copy_e820_map() type is E820_RAM\n");
+ if (start < 0x100000ULL && end > 0xA0000ULL) {
+ printk("copy_e820_map() lies in range...\n");
+ if (start < 0xA0000ULL) {
+ printk("copy_e820_map() start < 0xA0000ULL\n");
+ add_memory_region(start, 0xA0000ULL-start, type);
+ }
+ if (end <= 0x100000ULL) {
+ printk("copy_e820_map() end <= 0x100000ULL\n");
+ continue;
+ }
+ start = 0x100000ULL;
+ size = end - start;
+ }
+ }
+ add_memory_region(start, size, type);
+ } while (biosmap++,--nr_map);
+ return 0;
+}
+
+/*
+ * Callback for efi_memory_walk.
+ */
+static int __init
+efi_find_max_pfn(unsigned long start, unsigned long end, void *arg)
+{
+ unsigned long *max_pfn = arg, pfn;
+
+ if (start < end) {
+ pfn = PFN_UP(end -1);
+ if (pfn > *max_pfn)
+ *max_pfn = pfn;
+ }
+ return 0;
+}
+
+static int __init
+efi_memory_present_wrapper(unsigned long start, unsigned long end, void *arg)
+{
+ memory_present(0, PFN_UP(start), PFN_DOWN(end));
+ return 0;
+}
+
+/*
+ * Find the highest page frame number we have available
+ */
+void __init find_max_pfn(void)
+{
+ int i;
+
+ max_pfn = 0;
+ if (efi_enabled) {
+ efi_memmap_walk(efi_find_max_pfn, &max_pfn);
+ efi_memmap_walk(efi_memory_present_wrapper, NULL);
+ return;
+ }
+
+ for (i = 0; i < e820.nr_map; i++) {
+ unsigned long start, end;
+ /* RAM? */
+ if (e820.map[i].type != E820_RAM)
+ continue;
+ start = PFN_UP(e820.map[i].addr);
+ end = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
+ if (start >= end)
+ continue;
+ if (end > max_pfn)
+ max_pfn = end;
+ memory_present(0, start, end);
+ }
+}
+
+/*
+ * Free all available memory for boot time allocation. Used
+ * as a callback function by efi_memory_walk()
+ */
+
+static int __init
+free_available_memory(unsigned long start, unsigned long end, void *arg)
+{
+ /* check max_low_pfn */
+ if (start >= (max_low_pfn << PAGE_SHIFT))
+ return 0;
+ if (end >= (max_low_pfn << PAGE_SHIFT))
+ end = max_low_pfn << PAGE_SHIFT;
+ if (start < end)
+ free_bootmem(start, end - start);
+
+ return 0;
+}
+/*
+ * Register fully available low RAM pages with the bootmem allocator.
+ */
+void __init register_bootmem_low_pages(unsigned long max_low_pfn)
+{
+ int i;
+
+ if (efi_enabled) {
+ efi_memmap_walk(free_available_memory, NULL);
+ return;
+ }
+ for (i = 0; i < e820.nr_map; i++) {
+ unsigned long curr_pfn, last_pfn, size;
+ /*
+ * Reserve usable low memory
+ */
+ if (e820.map[i].type != E820_RAM)
+ continue;
+ /*
+ * We are rounding up the start address of usable memory:
+ */
+ curr_pfn = PFN_UP(e820.map[i].addr);
+ if (curr_pfn >= max_low_pfn)
+ continue;
+ /*
+ * ... and at the end of the usable range downwards:
+ */
+ last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
+
+ if (last_pfn > max_low_pfn)
+ last_pfn = max_low_pfn;
+
+ /*
+ * .. finally, did all the rounding and playing
+ * around just make the area go away?
+ */
+ if (last_pfn <= curr_pfn)
+ continue;
+
+ size = last_pfn - curr_pfn;
+ free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
+ }
+}
+
+void __init register_memory(void)
+{
+ unsigned long gapstart, gapsize, round;
+ unsigned long long last;
+ int i;
+
+ /*
+ * Search for the bigest gap in the low 32 bits of the e820
+ * memory space.
+ */
+ last = 0x100000000ull;
+ gapstart = 0x10000000;
+ gapsize = 0x400000;
+ i = e820.nr_map;
+ while (--i >= 0) {
+ unsigned long long start = e820.map[i].addr;
+ unsigned long long end = start + e820.map[i].size;
+
+ /*
+ * Since "last" is at most 4GB, we know we'll
+ * fit in 32 bits if this condition is true
+ */
+ if (last > end) {
+ unsigned long gap = last - end;
+
+ if (gap > gapsize) {
+ gapsize = gap;
+ gapstart = end;
+ }
+ }
+ if (start < last)
+ last = start;
+ }
+
+ /*
+ * See how much we want to round up: start off with
+ * rounding to the next 1MB area.
+ */
+ round = 0x100000;
+ while ((gapsize >> 4) > round)
+ round += round;
+ /* Fun with two's complement */
+ pci_mem_start = (gapstart + round) & -round;
+
+ printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
+ pci_mem_start, gapstart, gapsize);
+}
+
+void __init print_memory_map(char *who)
+{
+ int i;
+
+ for (i = 0; i < e820.nr_map; i++) {
+ printk(" %s: %016Lx - %016Lx ", who,
+ e820.map[i].addr,
+ e820.map[i].addr + e820.map[i].size);
+ switch (e820.map[i].type) {
+ case E820_RAM: printk("(usable)\n");
+ break;
+ case E820_RESERVED:
+ printk("(reserved)\n");
+ break;
+ case E820_ACPI:
+ printk("(ACPI data)\n");
+ break;
+ case E820_NVS:
+ printk("(ACPI NVS)\n");
+ break;
+ default: printk("type %lu\n", e820.map[i].type);
+ break;
+ }
+ }
+}
+
+static __init __always_inline void efi_limit_regions(unsigned long long size)
+{
+ unsigned long long current_addr = 0;
+ efi_memory_desc_t *md, *next_md;
+ void *p, *p1;
+ int i, j;
+
+ j = 0;
+ p1 = memmap.map;
+ for (p = p1, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) {
+ md = p;
+ next_md = p1;
+ current_addr = md->phys_addr +
+ PFN_PHYS(md->num_pages);
+ if (is_available_memory(md)) {
+ if (md->phys_addr >= size) continue;
+ memcpy(next_md, md, memmap.desc_size);
+ if (current_addr >= size) {
+ next_md->num_pages -=
+ PFN_UP(current_addr-size);
+ }
+ p1 += memmap.desc_size;
+ next_md = p1;
+ j++;
+ } else if ((md->attribute & EFI_MEMORY_RUNTIME) ==
+ EFI_MEMORY_RUNTIME) {
+ /* In order to make runtime services
+ * available we have to include runtime
+ * memory regions in memory map */
+ memcpy(next_md, md, memmap.desc_size);
+ p1 += memmap.desc_size;
+ next_md = p1;
+ j++;
+ }
+ }
+ memmap.nr_map = j;
+ memmap.map_end = memmap.map +
+ (memmap.nr_map * memmap.desc_size);
+}
+
+void __init limit_regions(unsigned long long size)
+{
+ unsigned long long current_addr;
+ int i;
+
+ print_memory_map("limit_regions start");
+ if (efi_enabled) {
+ efi_limit_regions(size);
+ return;
+ }
+ for (i = 0; i < e820.nr_map; i++) {
+ current_addr = e820.map[i].addr + e820.map[i].size;
+ if (current_addr < size)
+ continue;
+
+ if (e820.map[i].type != E820_RAM)
+ continue;
+
+ if (e820.map[i].addr >= size) {
+ /*
+ * This region starts past the end of the
+ * requested size, skip it completely.
+ */
+ e820.nr_map = i;
+ } else {
+ e820.nr_map = i + 1;
+ e820.map[i].size -= current_addr - size;
+ }
+ print_memory_map("limit_regions endfor");
+ return;
+ }
+ print_memory_map("limit_regions endfunc");
+}
+
+ /*
+ * This function checks if the entire range <start,end> is mapped with type.
+ *
+ * Note: this function only works correct if the e820 table is sorted and
+ * not-overlapping, which is the case
+ */
+int __init
+e820_all_mapped(unsigned long s, unsigned long e, unsigned type)
+{
+ u64 start = s;
+ u64 end = e;
+ int i;
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ if (type && ei->type != type)
+ continue;
+ /* is the region (part) in overlap with the current region ?*/
+ if (ei->addr >= end || ei->addr + ei->size <= start)
+ continue;
+ /* if the region is at the beginning of <start,end> we move
+ * start to the end of the region since it's ok until there
+ */
+ if (ei->addr <= start)
+ start = ei->addr + ei->size;
+ /* if start is now at or beyond end, we're done, full
+ * coverage */
+ if (start >= end)
+ return 1; /* we're done */
+ }
+ return 0;
+}
+
+static int __init parse_memmap(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ if (strcmp(arg, "exactmap") == 0) {
+#ifdef CONFIG_CRASH_DUMP
+ /* If we are doing a crash dump, we
+ * still need to know the real mem
+ * size before original memory map is
+ * reset.
+ */
+ find_max_pfn();
+ saved_max_pfn = max_pfn;
+#endif
+ e820.nr_map = 0;
+ user_defined_memmap = 1;
+ } else {
+ /* If the user specifies memory size, we
+ * limit the BIOS-provided memory map to
+ * that size. exactmap can be used to specify
+ * the exact map. mem=number can be used to
+ * trim the existing memory map.
+ */
+ unsigned long long start_at, mem_size;
+
+ mem_size = memparse(arg, &arg);
+ if (*arg == '@') {
+ start_at = memparse(arg+1, &arg);
+ add_memory_region(start_at, mem_size, E820_RAM);
+ } else if (*arg == '#') {
+ start_at = memparse(arg+1, &arg);
+ add_memory_region(start_at, mem_size, E820_ACPI);
+ } else if (*arg == '$') {
+ start_at = memparse(arg+1, &arg);
+ add_memory_region(start_at, mem_size, E820_RESERVED);
+ } else {
+ limit_regions(mem_size);
+ user_defined_memmap = 1;
+ }
+ }
+ return 0;
+}
+early_param("memmap", parse_memmap);
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