1e3500666f
This patch enables the use of wrapper routines to access the debug/breakpoint registers on cpu management. The hardcoded debug registers save and restore operations for threads breakpoints are replaced by wrappers. And now that we handle the kernel breakpoints too, we also need to handle them on cpu hotplug operations. [ Impact: adapt new hardware breakpoint api to cpu hotplug ] Original-patch-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
169 lines
4.3 KiB
C
169 lines
4.3 KiB
C
/*
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* Suspend and hibernation support for x86-64
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*
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* Distribute under GPLv2
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*
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* Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
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* Copyright (c) 2002 Pavel Machek <pavel@suse.cz>
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* Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
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*/
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#include <linux/smp.h>
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#include <linux/suspend.h>
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#include <asm/proto.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/mtrr.h>
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#include <asm/xcr.h>
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#include <asm/suspend.h>
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#include <asm/debugreg.h>
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static void fix_processor_context(void);
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struct saved_context saved_context;
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/**
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* __save_processor_state - save CPU registers before creating a
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* hibernation image and before restoring the memory state from it
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* @ctxt - structure to store the registers contents in
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*
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* NOTE: If there is a CPU register the modification of which by the
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* boot kernel (ie. the kernel used for loading the hibernation image)
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* might affect the operations of the restored target kernel (ie. the one
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* saved in the hibernation image), then its contents must be saved by this
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* function. In other words, if kernel A is hibernated and different
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* kernel B is used for loading the hibernation image into memory, the
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* kernel A's __save_processor_state() function must save all registers
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* needed by kernel A, so that it can operate correctly after the resume
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* regardless of what kernel B does in the meantime.
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*/
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static void __save_processor_state(struct saved_context *ctxt)
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{
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kernel_fpu_begin();
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/*
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* descriptor tables
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*/
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store_gdt((struct desc_ptr *)&ctxt->gdt_limit);
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store_idt((struct desc_ptr *)&ctxt->idt_limit);
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store_tr(ctxt->tr);
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/* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
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/*
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* segment registers
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*/
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asm volatile ("movw %%ds, %0" : "=m" (ctxt->ds));
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asm volatile ("movw %%es, %0" : "=m" (ctxt->es));
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asm volatile ("movw %%fs, %0" : "=m" (ctxt->fs));
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asm volatile ("movw %%gs, %0" : "=m" (ctxt->gs));
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asm volatile ("movw %%ss, %0" : "=m" (ctxt->ss));
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rdmsrl(MSR_FS_BASE, ctxt->fs_base);
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rdmsrl(MSR_GS_BASE, ctxt->gs_base);
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rdmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);
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mtrr_save_fixed_ranges(NULL);
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/*
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* control registers
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*/
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rdmsrl(MSR_EFER, ctxt->efer);
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ctxt->cr0 = read_cr0();
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ctxt->cr2 = read_cr2();
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ctxt->cr3 = read_cr3();
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ctxt->cr4 = read_cr4();
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ctxt->cr8 = read_cr8();
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hw_breakpoint_disable();
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}
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void save_processor_state(void)
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{
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__save_processor_state(&saved_context);
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}
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static void do_fpu_end(void)
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{
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/*
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* Restore FPU regs if necessary
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*/
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kernel_fpu_end();
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}
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/**
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* __restore_processor_state - restore the contents of CPU registers saved
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* by __save_processor_state()
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* @ctxt - structure to load the registers contents from
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*/
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static void __restore_processor_state(struct saved_context *ctxt)
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{
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/*
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* control registers
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*/
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wrmsrl(MSR_EFER, ctxt->efer);
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write_cr8(ctxt->cr8);
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write_cr4(ctxt->cr4);
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write_cr3(ctxt->cr3);
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write_cr2(ctxt->cr2);
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write_cr0(ctxt->cr0);
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/*
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* now restore the descriptor tables to their proper values
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* ltr is done i fix_processor_context().
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*/
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load_gdt((const struct desc_ptr *)&ctxt->gdt_limit);
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load_idt((const struct desc_ptr *)&ctxt->idt_limit);
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/*
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* segment registers
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*/
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asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds));
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asm volatile ("movw %0, %%es" :: "r" (ctxt->es));
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asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs));
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load_gs_index(ctxt->gs);
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asm volatile ("movw %0, %%ss" :: "r" (ctxt->ss));
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wrmsrl(MSR_FS_BASE, ctxt->fs_base);
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wrmsrl(MSR_GS_BASE, ctxt->gs_base);
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wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);
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/*
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* restore XCR0 for xsave capable cpu's.
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*/
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if (cpu_has_xsave)
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xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask);
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fix_processor_context();
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do_fpu_end();
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mtrr_ap_init();
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}
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void restore_processor_state(void)
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{
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__restore_processor_state(&saved_context);
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}
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static void fix_processor_context(void)
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{
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int cpu = smp_processor_id();
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struct tss_struct *t = &per_cpu(init_tss, cpu);
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/*
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* This just modifies memory; should not be necessary. But... This
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* is necessary, because 386 hardware has concept of busy TSS or some
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* similar stupidity.
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*/
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set_tss_desc(cpu, t);
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get_cpu_gdt_table(cpu)[GDT_ENTRY_TSS].type = 9;
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syscall_init(); /* This sets MSR_*STAR and related */
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load_TR_desc(); /* This does ltr */
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load_LDT(¤t->active_mm->context); /* This does lldt */
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/*
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* Now maybe reload the debug registers
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*/
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load_debug_registers();
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}
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