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	These messages: clipped [mem size 0x00000000 64bit] to [mem size 0xfffffffffffa0000 64bit] for e820 entry [mem 0x0009f000-0x000fffff] aren't as useful as they could be because (a) the resource is often IORESOURCE_UNSET, so we print the size instead of the start/end and (b) we print the available resource even if it is empty after removing the E820 entry. Print the available space by hand to avoid the IORESOURCE_UNSET problem and only if it's non-empty. No functional change intended. Link: https://lore.kernel.org/r/20221208190341.1560157-4-helgaas@kernel.org Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Hans de Goede <hdegoede@redhat.com>
		
			
				
	
	
		
			72 lines
		
	
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			72 lines
		
	
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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#include <linux/ioport.h>
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#include <linux/printk.h>
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#include <asm/e820/api.h>
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#include <asm/pci_x86.h>
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static void resource_clip(struct resource *res, resource_size_t start,
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			  resource_size_t end)
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{
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	resource_size_t low = 0, high = 0;
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	if (res->end < start || res->start > end)
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		return;		/* no conflict */
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	if (res->start < start)
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		low = start - res->start;
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	if (res->end > end)
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		high = res->end - end;
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	/* Keep the area above or below the conflict, whichever is larger */
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	if (low > high)
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		res->end = start - 1;
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	else
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		res->start = end + 1;
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}
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static void remove_e820_regions(struct resource *avail)
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{
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	int i;
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	struct e820_entry *entry;
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	u64 e820_start, e820_end;
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	struct resource orig = *avail;
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	if (!pci_use_e820)
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		return;
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	for (i = 0; i < e820_table->nr_entries; i++) {
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		entry = &e820_table->entries[i];
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		e820_start = entry->addr;
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		e820_end = entry->addr + entry->size - 1;
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		resource_clip(avail, e820_start, e820_end);
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		if (orig.start != avail->start || orig.end != avail->end) {
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			pr_info("resource: avoiding allocation from e820 entry [mem %#010Lx-%#010Lx]\n",
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				e820_start, e820_end);
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			if (avail->end > avail->start)
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				/*
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				 * Use %pa instead of %pR because "avail"
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				 * is typically IORESOURCE_UNSET, so %pR
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				 * shows the size instead of addresses.
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				 */
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				pr_info("resource: remaining [mem %pa-%pa] available\n",
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					&avail->start, &avail->end);
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			orig = *avail;
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		}
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	}
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}
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void arch_remove_reservations(struct resource *avail)
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{
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	/*
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	 * Trim out BIOS area (high 2MB) and E820 regions. We do not remove
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	 * the low 1MB unconditionally, as this area is needed for some ISA
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	 * cards requiring a memory range, e.g. the i82365 PCMCIA controller.
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	 */
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	if (avail->flags & IORESOURCE_MEM) {
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		resource_clip(avail, BIOS_ROM_BASE, BIOS_ROM_END);
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		remove_e820_regions(avail);
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	}
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}
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