1. 11 11月, 2008 2 次提交
  2. 09 11月, 2008 4 次提交
    • K
      powerpc: Updated Freescale PPC related defconfigs · ea37194d
      Kumar Gala 提交于
      unset CONFIG_PCI_LEGACY in the defconfigs as none of them enable
      ISDN drivers which seem to be the only place we are using pci_find_device
      Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      ea37194d
    • L
      powerpc: Update QE/CPM2 usb_ctlr structures for USB support · 2b487065
      Li Yang 提交于
      Fixes following build error:
      
        CC      drivers/usb/gadget/fsl_qe_udc.o
      drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_eprx_stall_change':
      drivers/usb/gadget/fsl_qe_udc.c:156: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c:163: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_eptx_stall_change':
      drivers/usb/gadget/fsl_qe_udc.c:173: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c:180: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_eprx_nack':
      drivers/usb/gadget/fsl_qe_udc.c:201: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c:201: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_eprx_normal':
      drivers/usb/gadget/fsl_qe_udc.c:218: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c:218: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_ep_reset':
      drivers/usb/gadget/fsl_qe_udc.c:325: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c:342: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_ep_register_init':
      drivers/usb/gadget/fsl_qe_udc.c:515: error: 'struct usb_ctlr' has no member named 'usb_usep'
      drivers/usb/gadget/fsl_qe_udc.c: In function 'ch9getstatus':
      drivers/usb/gadget/fsl_qe_udc.c:1981: error: 'struct usb_ctlr' has no member named 'usb_usep'
      make[2]: *** [drivers/usb/gadget/fsl_qe_udc.o] Error 1
      Signed-off-by: NLi Yang <leoli@freescale.com>
      Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
      Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      2b487065
    • M
      powerpc/86xx: Correct SOC bus-frequency in GE Fanuc SBC610 DTS · 33d2d78b
      Martyn Welch 提交于
      This patch corrects the bus-frequency value provided in the SBC610's dts.
      Signed-off-by: NMartyn Welch <martyn.welch@gefanuc.com>
      Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      33d2d78b
    • K
      powerpc/fsl-booke: Fix synchronization bug w/local tlb invalidates · b41d6fee
      Kumar Gala 提交于
      The implemetation of _tlbil_pid() on Freescale Book-E cores needs
      an msync & isync after we flash invalidate the TLBs.  This was causing
      the following oops reported by Sebastian Andrzej Siewior:
      
        VFS: Mounted root (nfs filesystem) readonly.
        Freeing unused kernel memory: 148k init
        BUG: sleeping function called from invalid context at /home/bigeasy/git/linux-2.6-powerpc/mm/mmap.c:234
        in_atomic():1, irqs_disabled():0
        Call Trace:
        [df189df0] [c0007160] show_stack+0x48/0x148 (unreliable)
        [df189e30] [c0029480] __might_sleep+0xf0/0x100
        [df189e40] [c0070ac0] remove_vma+0x28/0x98
        [df189e50] [c0070c1c] exit_mmap+0xec/0x128
        [df189e80] [c002d2f4] mmput+0x54/0xec
        [df189ea0] [c0030b6c] exit_mm+0x10c/0x120
        [df189ed0] [c003288c] do_exit+0x1ac/0x6e8
        [df189f20] [c0032e48] do_group_exit+0x80/0xac
        [df189f40] [c000e9dc] ret_from_syscall+0x0/0x3c
        BUG: scheduling while atomic: udevd/956/0x10000002
        Modules linked in:
        Call Trace:
        [df189df0] [c0007160] show_stack+0x48/0x148 (unreliable)
        [df189e30] [c002ac88] __schedule_bug+0x58/0x6c
        [df189e40] [c023e6cc] schedule+0xa8/0x4a8
        [df189e90] [c002ad6c] __cond_resched+0x38/0x64
        [df189ea0] [c023ebc8] _cond_resched+0x3c/0x58
        [df189eb0] [c0030e70] put_files_struct+0x90/0xec
        [df189ed0] [c00328a8] do_exit+0x1c8/0x6e8
        [df189f20] [c0032e48] do_group_exit+0x80/0xac
        [df189f40] [c000e9dc] ret_from_syscall+0x0/0x3c
      Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      b41d6fee
  3. 05 11月, 2008 2 次提交
  4. 03 11月, 2008 1 次提交
  5. 31 10月, 2008 24 次提交
    • C
      Cell OProfile: Incorrect local array size in activate spu profiling function · 99219b4f
      Carl Love 提交于
      Updated the patch to address comments by Michael Ellerman.
      Specifically, changed upper limit in for loop to
      ARRAY_SIZE() macro and added a check to make sure the
      number of events specified by the user, which is used as
      the max for indexing various arrays, is no bigger then the
      declared size of the arrays.
      
      The size of the pm_signal_local array should be equal to the
      number of SPUs being configured in the array.  Currently, the
      array is of size 4 (NR_PHYS_CTRS) but being indexed by a for
      loop from 0 to 7 (NUM_SPUS_PER_NODE).
      Signed-off-by: NCarl Love <carll@us.ibm.com>
      99219b4f
    • R
      22cffe49
    • P
      Revert "powerpc: Sync RPA note in zImage with kernel's RPA note" · 5663a123
      Paul Mackerras 提交于
      This reverts commit 91a00302, plus
      commit 0dcd4401 ("powerpc: Revert CHRP
      boot wrapper to real-base = 12MB on 32-bit") which depended on it.
      
      Commit 91a00302 was causing NVRAM corruption on some pSeries machines,
      for as-yet unknown reasons, so this reverts it until the cause is
      identified.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      5663a123
    • P
      powerpc: Fix compile errors with CONFIG_BUG=n · ebdba9af
      Paul Mackerras 提交于
      This makes sure we don't try to call find_bug or is_warning_bug when
      CONFIG_BUG=n and CONFIG_XMON=y.  Otherwise we get these errors:
      
      arch/powerpc/xmon/xmon.c: In function ‘print_bug_trap’:
      arch/powerpc/xmon/xmon.c:1364: error: implicit declaration of function ‘find_bug’
      arch/powerpc/xmon/xmon.c:1364: warning: assignment makes pointer from integer without a cast
      arch/powerpc/xmon/xmon.c:1367: error: implicit declaration of function ‘is_warning_bug’
      arch/powerpc/xmon/xmon.c:1374: error: dereferencing pointer to incomplete type
      make[2]: *** [arch/powerpc/xmon/xmon.o] Error 1
      make[1]: *** [arch/powerpc/xmon] Error 2
      make: *** [sub-make] Error 2
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      ebdba9af
    • S
      ftrace: nmi safe code clean ups · a26a2a27
      Steven Rostedt 提交于
      Impact: cleanup
      
      This patch cleans up the NMI safe code for dynamic ftrace as suggested
      by Andrew Morton.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a26a2a27
    • J
      powerpc: Fix format string warning in arch/powerpc/boot/main.c · 8ba4773a
      Jon Smirl 提交于
      Fix format string warning in arch/powerpc/boot/main.c.  Also correct
      a typo ("uncomressed") on the same line.
      
       BOOTCC  arch/powerpc/boot/main.o
      arch/powerpc/boot/main.c: In function 'prep_kernel':
      arch/powerpc/boot/main.c:65: warning: format '%08x' expects type
      'unsigned int', but argument 3 has type 'long unsigned int'
      Signed-off-by: NJon Smirl <jonsmirl@gmail.com>
      Acked-by: NDavid Gibson <david@gibson.dropbear.id.au>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      8ba4773a
    • D
      powerpc: Fix bug in kernel copy of libfdt's fdt_subnode_offset_namelen() · 2dccbf4e
      David Gibson 提交于
      There's currently an off-by-one bug in fdt_subnode_offset_namelen()
      which causes it to keep searching after it's finished the subnodes of
      the given parent, and into the subnodes of siblings of the original
      node which come after it in the tree.  This bug was introduced in
      commit ed95d745 ("powerpc: Update
      in-kernel dtc and libfdt to version 1.2.0").
      
      A patch has already been submitted to dtc/libfdt mainline.  We don't
      really want to pull in a new upstream version during the 2.6.28 cycle,
      but we should still fix this bug, hence this standalone version of the
      fix for the in-kernel libfdt.
      Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      2dccbf4e
    • M
      powerpc: Remove duplicate DMA entry from mpc8313erdb device tree · 65325d5c
      Mike Dyer 提交于
      Commit 57436612 added a duplicate
      DMA controller node.
      Signed-off-by: NMike Dyer <mike.dyer@provision-comm.com>
      Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      65325d5c
    • C
      powerpc/cell/OProfile: Fix on-stack array size in activate spu profiling function · 210434d7
      Carl Love 提交于
      The size of the pm_signal_local array should be equal to the
      number of SPUs being configured in the array.  Currently, the
      array is of size 4 (NR_PHYS_CTRS) but being indexed by a for
      loop from 0 to 7 (NUM_SPUS_PER_NODE).  This could potentially
      cause an oops or random memory corruption since the pm_signal_local
      array is on the stack.  This fixes it.
      Signed-off-by: NCarl Love <carll@us.ibm.com>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      210434d7
    • K
      powerpc/mpic: Fix regression caused by change of default IRQ affinity · 3c10c9c4
      Kumar Gala 提交于
      The Freescale implementation of MPIC only allows a single CPU destination
      for non-IPI interrupts.  We add a flag to the mpic_init to distinquish
      these variants of MPIC.  We pull in the irq_choose_cpu from sparc64 to
      select a single CPU as the destination of the interrupt.
      
      This is to deal with the fact that the default smp affinity was
      changed by commit 18404756 ("genirq:
      Expose default irq affinity mask (take 3)") to be all CPUs.
      Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      3c10c9c4
    • M
      powerpc: Update remaining dma_mapping_ops to use map/unmap_page · f9226d57
      Mark Nelson 提交于
      After the merge of the 32 and 64bit DMA code, dma_direct_ops lost
      their map/unmap_single() functions but gained map/unmap_page().  This
      caused a problem for Cell because Cell's dma_iommu_fixed_ops called
      the dma_direct_ops if the fixed linear mapping was to be used or the
      iommu ops if the dynamic window was to be used.  So in order to fix
      this problem we need to update the 64bit DMA code to use
      map/unmap_page.
      
      First, we update the generic IOMMU code so that iommu_map_single()
      becomes iommu_map_page() and iommu_unmap_single() becomes
      iommu_unmap_page().  Then we propagate these changes up through all
      the callers of these two functions and in the process update all the
      dma_mapping_ops so that they have map/unmap_page rahter than
      map/unmap_single.  We can do this because on 64bit there is no HIGHMEM
      memory so map/unmap_page ends up performing exactly the same function
      as map/unmap_single, just taking different arguments.
      
      This has no affect on drivers because the dma_map_single_attrs() just
      ends up calling the map_page() function of the appropriate
      dma_mapping_ops and similarly the dma_unmap_single_attrs() calls
      unmap_page().
      
      This fixes an oops on Cell blades, which oops on boot without this
      because they call dma_direct_ops.map_single, which is NULL.
      Signed-off-by: NMark Nelson <markn@au1.ibm.com>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      f9226d57
    • B
      powerpc/pci: Fix unmapping of IO space on 64-bit · b30115ea
      Benjamin Herrenschmidt 提交于
      A typo/thinko made us pass the wrong argument to __flush_hash_table_range
      when unplugging bridges, thus not flushing all the translations for
      the IO space on unplug.  The third parameter to __flush_hash_table_range
      is `end', not `size'.
      
      This causes the hypervisor to refuse unplugging slots.
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      b30115ea
    • N
      powerpc/pci: Properly allocate bus resources for hotplug PHBs · e90a1318
      Nathan Fontenot 提交于
      Resources for PHB's that are dynamically added to a system are not
      properly allocated in the resource tree.
      
      Not having these resources allocated causes an oops when removing
      the PHB when we try to release them.
      
      The diff appears a bit messy, this is mainly due to moving everything
      one tab to the left in the pcibios_allocate_bus_resources routine.
      The functionality change in this routine is only that the
      list_for_each_entry() loop is pulled out and moved to the necessary
      calling routine.
      Signed-off-by: NNathan Fontenot <nfont@austin.ibm.com>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      e90a1318
    • J
      OF-device: Don't overwrite numa_node in device registration · 6098e2ee
      Jeremy Kerr 提交于
      Currently, the numa_node of OF-devices will be overwritten during
      device_register, which simply sets the node to -1.  On cell machines,
      this means that devices can't find their IOMMU, which is referenced
      through the device's numa node.
      
      Set the numa node for OF devices with no parent, and use the
      lower-level device_initialize and device_add functions, so that the
      node is preserved.
      
      We can remove the call to set_dev_node in of_device_alloc, as it
      will be overwritten during register.
      Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      6098e2ee
    • M
      powerpc: Fix swapcontext system for VSX + old ucontext size · 16c29d18
      Michael Neuling 提交于
      Since VSX support was added, we now have two sizes of ucontext_t;
      the older, smaller size without the extra VSX state, and the new
      larger size with the extra VSX state.  A program using the
      sys_swapcontext system call and supplying smaller ucontext_t
      structures will currently get an EINVAL error if the task has
      used VSX (e.g. because of calling library code that uses VSX) and
      the old_ctx argument is non-NULL (i.e. the program is asking for
      its current context to be saved).  Thus the program will start
      getting EINVAL errors on calls that previously worked.
      
      This commit changes this behaviour so that we don't send an EINVAL in
      this case.  It will now return the smaller context but the VSX MSR bit
      will always be cleared to indicate that the ucontext_t doesn't include
      the extra VSX state, even if the task has executed VSX instructions.
      
      Both 32 and 64 bit cases are updated.
      
      [paulus@samba.org - also fix some access_ok() and get_user() calls]
      
      Thanks to Ben Herrenschmidt for noticing this problem.
      Signed-off-by: NMichael Neuling <mikey@neuling.org>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      16c29d18
    • M
      powerpc: Fix compiler warning for the relocatable kernel · b160544c
      Michael Neuling 提交于
      Fixes this warning:
       arch/powerpc/kernel/setup_64.c:447:5: warning: "kernstart_addr" is not defined
      
      which arises because PHYSICAL_START is no longer a constant when
      CONFIG_RELOCATABLE=y.
      Signed-off-by: NMichael Neuling <mikey@neuling.org>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      b160544c
    • P
      powerpc: Work around ld bug in older binutils · 2a4b9c5a
      Paul Mackerras 提交于
      Commit 549e8152 ("powerpc: Make the
      64-bit kernel as a position-independent executable") added lines to
      vmlinux.lds.S to add the extra sections needed to implement a
      relocatable kernel.  However, those lines seem to trigger a bug in
      older versions of GNU ld (such as 2.16.1) when building a
      non-relocatable kernel.  Since ld 2.16.1 is still a popular choice for
      cross-toolchains, this adds an #ifdef to vmlinux.lds.S so the added
      lines are only included when building a relocatable kernel.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      2a4b9c5a
    • M
      powerpc/ppc64/kdump: Better flag for running relocatable · 8b8b0cc1
      Milton Miller 提交于
      The __kdump_flag ABI is overly constraining for future development.
      
      As of 2.6.27, the kernel entry point has 4 constraints:  Offset 0 is
      the starting point for the master (boot) cpu (entered with r3 pointing
      to the device tree structure), offset 0x60 is code for the slave cpus
      (entered with r3 set to their device tree physical id), offset 0x20 is
      used by the iseries hypervisor, and secondary cpus must be well behaved
      when the first 256 bytes are copied to address 0.
      
      Placing the __kdump_flag at 0x18 is bad because:
      
      - It was taking the last 8 bytes before the iseries hypervisor data.
      - It was 8 bytes for a boolean flag
      - It had no way of identifying that the flag was present
      - It does leave any room for the master to add any additional code
        before branching, which hurts debug.
      - It will be unnecessarily hard for 32 bit code to be common (8 bytes)
      
      Now that we have eliminated the use of __kdump_flag in favor of
      the standard is_kdump_kernel(), this flag only controls run without
      relocating the kernel to PHYSICAL_START (0), so rename it __run_at_load.
      
      Move the flag to 0x5c, 1 word before the secondary cpu entry point at
      0x60.  Initialize it with "run0" to say it will run at 0 unless it is
      set to 1.  It only exists if we are relocatable.
      Signed-off-by: NMilton Miller <miltonm@bga.com>
      Signed-off-by: NMichael Neuling <mikey@neuling.org>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      8b8b0cc1
    • M
      powerpc: Use is_kdump_kernel() · 62a8bd6c
      Milton Miller 提交于
      linux/crash_dump.h defines is_kdump_kernel() to be used by code that
      needs to know if the previous kernel crashed instead of a (clean) boot
      or reboot.
      
      This updates the just added powerpc code to use it.  This is needed
      for the next commit, which will remove __kdump_flag.
      Signed-off-by: NMilton Miller <miltonm@bga.com>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      62a8bd6c
    • M
      powerpc: Kexec exit should not use magic numbers · 1767c8f3
      Milton Miller 提交于
      Commit 54622f10 ("powerpc: Support for
      relocatable kdump kernel") added a magic flag value in a register to
      tell purgatory that it should be a panic kernel.  This part is wrong
      and is reverted by this commit.
      
      The kernel gets a list of memory blocks and a entry point from user space.
      Its job is to copy the blocks into place and then branch to the designated
      entry point (after turning "off" the mmu).
      
      The user space tool inserts a trampoline, called purgatory, that runs
      before the user supplied code.   Its job is to establish the entry
      environment for the new kernel or other application based on the contents
      of memory.  The purgatory code is compiled and embedded in the tool,
      where it is later patched using the elf symbol table using elf symbols.
      
      Since the tool knows it is creating a purgatory that will run after a
      kernel crash, it should just patch purgatory (or the kernel directly)
      if something needs to happen.
      Signed-off-by: NMilton Miller <miltonm@bga.com>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      1767c8f3
    • T
      gianfar: Fix race in TBI/SerDes configuration · c132419e
      Trent Piepho 提交于
      The init_phy() function attaches to the PHY, then configures the
      SerDes<->TBI link (in SGMII mode).  The TBI is on the MDIO bus with the PHY
      (sort of) and is accessed via the gianfar's MDIO registers, using the
      functions gfar_local_mdio_read/write(), which don't do any locking.
      
      The previously attached PHY will start a work-queue on a timer, and
      probably an irq handler as well, which will talk to the PHY and thus use
      the MDIO bus.  This uses phy_read/write(), which have locking, but not
      against the gfar_local_mdio versions.
      
      The result is that PHY code will try to use the MDIO bus at the same time
      as the SerDes setup code, corrupting the transfers.
      
      Setting up the SerDes before attaching to the PHY will insure that there is
      no race between the SerDes code and *our* PHY, but doesn't fix everything.
      Typically the PHYs for all gianfar devices are on the same MDIO bus, which
      is associated with the first gianfar device.  This means that the first
      gianfar's SerDes code could corrupt the MDIO transfers for a different
      gianfar's PHY.
      
      The lock used by phy_read/write() is contained in the mii_bus structure,
      which is pointed to by the PHY.  This is difficult to access from the
      gianfar drivers, as there is no link between a gianfar device and the
      mii_bus which shares the same MDIO registers.  As far as the device layer
      and drivers are concerned they are two unrelated devices (which happen to
      share registers).
      
      Generally all gianfar devices' PHYs will be on the bus associated with the
      first gianfar.  But this might not be the case, so simply locking the
      gianfar's PHY's mii bus might not lock the mii bus that the SerDes setup
      code is going to use.
      
      We solve this by having the code that creates the gianfar platform device
      look in the device tree for an mdio device that shares the gianfar's
      registers.  If one is found the ID of its platform device is saved in the
      gianfar's platform data.
      
      A new function in the gianfar mii code, gfar_get_miibus(), can use the bus
      ID to search through the platform devices for a gianfar_mdio device with
      the right ID.  The platform device's driver data is the mii_bus structure,
      which the SerDes setup code can use to lock the current bus.
      Signed-off-by: NTrent Piepho <tpiepho@freescale.com>
      CC: Andy Fleming <afleming@freescale.com>
      Signed-off-by: NJeff Garzik <jgarzik@redhat.com>
      c132419e
    • J
      powerpc/44x: Update 44x defconfigs · 8531b7a8
      Josh Boyer 提交于
      Update the PowerPC 44x defconfigs for 2.6.28
      Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>
      8531b7a8
    • J
      powerpc/40x: Update 40x defconfigs · c4cd9ec4
      Josh Boyer 提交于
      Update the PowerPC 40x defconfigs for 2.6.28
      Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>
      c4cd9ec4
    • S
      ftrace: nmi safe code modification · 17666f02
      Steven Rostedt 提交于
      Impact: fix crashes that can occur in NMI handlers, if their code is modified
      
      Modifying code is something that needs special care. On SMP boxes,
      if code that is being modified is also being executed on another CPU,
      that CPU will have undefined results.
      
      The dynamic ftrace uses kstop_machine to make the system act like a
      uniprocessor system. But this does not address NMIs, that can still
      run on other CPUs.
      
      One approach to handle this is to make all code that are used by NMIs
      not be traced. But NMIs can call notifiers that spread throughout the
      kernel and this will be very hard to maintain, and the chance of missing
      a function is very high.
      
      The approach that this patch takes is to have the NMIs modify the code
      if the modification is taking place. The way this works is that just
      writing to code executing on another CPU is not harmful if what is
      written is the same as what exists.
      
      Two buffers are used: an IP buffer and a "code" buffer.
      
      The steps that the patcher takes are:
      
       1) Put in the instruction pointer into the IP buffer
          and the new code into the "code" buffer.
       2) Set a flag that says we are modifying code
       3) Wait for any running NMIs to finish.
       4) Write the code
       5) clear the flag.
       6) Wait for any running NMIs to finish.
      
      If an NMI is executed, it will also write the pending code.
      Multiple writes are OK, because what is being written is the same.
      Then the patcher must wait for all running NMIs to finish before
      going to the next line that must be patched.
      
      This is basically the RCU approach to code modification.
      
      Thanks to Ingo Molnar for suggesting the idea, and to Arjan van de Ven
      for his guidence on what is safe and what is not.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      17666f02
  6. 28 10月, 2008 5 次提交
  7. 23 10月, 2008 2 次提交