lkml.org 
[lkml]   [2005]   [Mar]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    SubjectRe: swsusp_restore crap
    Date
    Hi,

    On Tuesday, 15 of March 2005 13:02, Pavel Machek wrote:
    > Hi!
    >
    > > > > > Please kill that swsusp_restore() call that itself calls
    > > > > > flush_tlb_global(), it's junk. First, the flush_tlb_global() thing is
    > > > > > arch specific, and that's all swsusp_restore() does. Then, the asm just
    > > > > > calls this before returning to C code, so it makes no sense to have a
    > > > > > hook there. The x86 asm can have it's own call to some arch stuff if it
    > > > > > wants or just do the tlb flush in asm...
    > > > >
    > > > > Better, here is a patch... (note: flush_tlb_global() is an x86'ism,
    > > > > doesn't exist on ppc, thus breaks compile, and that has nothing to do in
    > > > > the generic code imho, it should be clearly defined as the
    > > > > responsibility of the asm code).
    > > >
    > > > x86-64 needs this, too.... Otherwise it looks okay.
    > >
    > > It breaks compilation on i386 either, because nr_copy_pages_check
    > > is static in swsusp.c. May I propose the following patch instead (tested on
    > > x86-64 and i386)?
    >
    >
    > > +asmlinkage int __swsusp_flush_tlb(void)
    > > +{
    > > + swsusp_restore_check();
    >
    > Someone will certainly forget this one, and it is probably
    > nicer/easier to just move BUG_ON into swsusp_suspend(), just after
    > restore_processor_state() or something like that...

    ... in which case __swsusp_flush_tlb() would only contain a "call" to
    __flush_tlb_global(), but this is a macro on both x86-64 and i386, so we can
    drop the __swsusp_flush_tlb() altogether and do it in assembly (before the
    GPRs are restored, perhaps). Patch follows.

    Greets,
    Rafael


    Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

    diff -Nrup linux-2.6.11-bk10-a/arch/i386/power/swsusp.S linux-2.6.11-bk10-b/arch/i386/power/swsusp.S
    --- linux-2.6.11-bk10-a/arch/i386/power/swsusp.S 2005-03-15 09:20:53.000000000 +0100
    +++ linux-2.6.11-bk10-b/arch/i386/power/swsusp.S 2005-03-15 15:37:25.000000000 +0100
    @@ -51,6 +51,15 @@ copy_loop:
    .p2align 4,,7

    done:
    + /* Flush TLB, including "global" things (vmalloc) */
    + movl mmu_cr4_features, %eax
    + movl %eax, %edx
    + andl $~(1<<7), %edx; # PGE
    + movl %edx, %cr4; # turn off PGE
    + movl %cr3, %ecx; # flush TLB
    + movl %ecx, %cr3
    + movl %eax, %cr4; # turn PGE back on
    +
    movl saved_context_esp, %esp
    movl saved_context_ebp, %ebp
    movl saved_context_ebx, %ebx
    @@ -58,5 +67,5 @@ done:
    movl saved_context_edi, %edi

    pushl saved_context_eflags ; popfl
    - call swsusp_restore
    +
    ret
    diff -Nrup linux-2.6.11-bk10-a/arch/x86_64/kernel/suspend_asm.S linux-2.6.11-bk10-b/arch/x86_64/kernel/suspend_asm.S
    --- linux-2.6.11-bk10-a/arch/x86_64/kernel/suspend_asm.S 2005-03-15 09:20:53.000000000 +0100
    +++ linux-2.6.11-bk10-b/arch/x86_64/kernel/suspend_asm.S 2005-03-15 15:36:29.000000000 +0100
    @@ -69,6 +69,14 @@ loop:
    movq pbe_next(%rdx), %rdx
    jmp loop
    done:
    + /* Flush TLB, including "global" things (vmalloc) */
    + movq %rax, %rdx; # mmu_cr4_features(%rip)
    + andq $~(1<<7), %rdx; # PGE
    + movq %rdx, %cr4; # turn off PGE
    + movq %cr3, %rcx; # flush TLB
    + movq %rcx, %cr3
    + movq %rax, %cr4; # turn PGE back on
    +
    movl $24, %eax
    movl %eax, %ds

    @@ -89,5 +97,5 @@ done:
    movq saved_context_r14(%rip), %r14
    movq saved_context_r15(%rip), %r15
    pushq saved_context_eflags(%rip) ; popfq
    - call swsusp_restore
    +
    ret
    diff -Nrup linux-2.6.11-bk10-a/kernel/power/swsusp.c linux-2.6.11-bk10-b/kernel/power/swsusp.c
    --- linux-2.6.11-bk10-a/kernel/power/swsusp.c 2005-03-15 09:21:23.000000000 +0100
    +++ linux-2.6.11-bk10-b/kernel/power/swsusp.c 2005-03-15 15:35:44.000000000 +0100
    @@ -900,22 +900,13 @@ int swsusp_suspend(void)
    error = swsusp_arch_suspend();
    /* Restore control flow magically appears here */
    restore_processor_state();
    + BUG_ON (nr_copy_pages_check != nr_copy_pages);
    restore_highmem();
    device_power_up();
    local_irq_enable();
    return error;
    }

    -
    -asmlinkage int swsusp_restore(void)
    -{
    - BUG_ON (nr_copy_pages_check != nr_copy_pages);
    -
    - /* Even mappings of "global" things (vmalloc) need to be fixed */
    - __flush_tlb_global();
    - return 0;
    -}
    -
    int swsusp_resume(void)
    {
    int error;
    --
    - Would you tell me, please, which way I ought to go from here?
    - That depends a good deal on where you want to get to.
    -- Lewis Carroll "Alice's Adventures in Wonderland"
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 14:11    [W:0.026 / U:10.040 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site