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![Rafael J. Wysocki](/assets/img/avatar_default.png)
Impact: fix trampoline sizing bug, save space While debugging a suspend-to-RAM related issue it occured to me that if the trampoline code had grown past 4 KB, we would have been allocating too little memory for it, since the 4 KB size of the trampoline is hardcoded into arch/x86/kernel/e820.c . Change that by making the kernel compute the trampoline size and allocate as much memory as necessary. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
33 lines
934 B
C
33 lines
934 B
C
#include <linux/io.h>
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#include <asm/trampoline.h>
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#include <asm/e820.h>
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/* ready for x86_64 and x86 */
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unsigned char *trampoline_base = __va(TRAMPOLINE_BASE);
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void __init reserve_trampoline_memory(void)
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{
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#ifdef CONFIG_X86_32
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/*
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* But first pinch a few for the stack/trampoline stuff
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* FIXME: Don't need the extra page at 4K, but need to fix
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* trampoline before removing it. (see the GDT stuff)
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*/
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reserve_early(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE, "EX TRAMPOLINE");
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#endif
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/* Has to be in very low memory so we can execute real-mode AP code. */
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reserve_early(TRAMPOLINE_BASE, TRAMPOLINE_BASE + TRAMPOLINE_SIZE,
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"TRAMPOLINE");
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}
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/*
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* Currently trivial. Write the real->protected mode
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* bootstrap into the page concerned. The caller
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* has made sure it's suitably aligned.
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*/
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unsigned long setup_trampoline(void)
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{
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memcpy(trampoline_base, trampoline_data, TRAMPOLINE_SIZE);
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return virt_to_phys(trampoline_base);
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}
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