| 1 | |
| 2 | #include <linux/ioport.h>
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| 3 | #include <linux/printk.h>
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| 4 | #include <asm/e820/api.h>
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| 5 | #include <asm/pci_x86.h>
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| 6 |
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| 7 | static void resource_clip(struct resource *res, resource_size_t start,
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| 8 | resource_size_t end)
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| 9 | {
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| 10 | resource_size_t low = 0, high = 0;
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| 11 |
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| 12 | if (res->end < start || res->start > end)
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| 13 | return;
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| 14 |
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| 15 | if (res->start < start)
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| 16 | low = start - res->start;
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| 17 |
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| 18 | if (res->end > end)
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| 19 | high = res->end - end;
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| 20 |
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| 21 |
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| 22 | if (low > high)
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| 23 | res->end = start - 1;
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| 24 | else
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| 25 | res->start = end + 1;
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| 26 | }
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| 27 |
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| 28 | static void remove_e820_regions(struct resource *avail)
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| 29 | {
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| 30 | int i;
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| 31 | struct e820_entry *entry;
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| 32 | u64 e820_start, e820_end;
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| 33 | struct resource orig = *avail;
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| 34 |
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| 35 | if (!pci_use_e820)
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| 36 | return;
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| 37 |
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| 38 | for (i = 0; i < e820_table->nr_entries; i++) {
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| 39 | entry = &e820_table->entries[i];
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| 40 | e820_start = entry->addr;
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| 41 | e820_end = entry->addr + entry->size - 1;
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| 42 |
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| 43 | resource_clip(avail, e820_start, e820_end);
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| 44 | if (orig.start != avail->start || orig.end != avail->end) {
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| 45 | pr_info("resource: avoiding allocation from e820 entry [mem %#010Lx-%#010Lx]\n",
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| 46 | e820_start, e820_end);
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| 47 | if (avail->end > avail->start)
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| 48 | |
| 49 | * Use %pa instead of %pR because "avail"
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| 50 | * is typically IORESOURCE_UNSET, so %pR
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| 51 | * shows the size instead of addresses.
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| 52 |
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| 53 | pr_info("resource: remaining [mem %pa-%pa] available\n",
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| 54 | &avail->start, &avail->end);
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| 55 | orig = *avail;
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| 56 | }
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| 57 | }
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| 58 | }
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| 59 |
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| 60 | void arch_remove_reservations(struct resource *avail)
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| 61 | {
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| 62 | |
| 63 | * Trim out BIOS area (high 2MB) and E820 regions. We do not remove
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| 64 | * the low 1MB unconditionally, as this area is needed for some ISA
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| 65 | * cards requiring a memory range.
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| 66 |
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| 67 | if (avail->flags & IORESOURCE_MEM) {
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| 68 | resource_clip(avail, BIOS_ROM_BASE, BIOS_ROM_END);
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| 69 |
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| 70 | remove_e820_regions(avail);
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| 71 | }
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| 72 | }
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