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  1. 16 9月, 2008 9 次提交
    • P
      powerpc: Make the 64-bit kernel as a position-independent executable · 549e8152
      由 Paul Mackerras 提交于 
      This implements CONFIG_RELOCATABLE for 64-bit by making the kernel as
a position-independent executable (PIE) when it is set.  This involves
processing the dynamic relocations in the image in the early stages of
booting, even if the kernel is being run at the address it is linked at,
since the linker does not necessarily fill in words in the image for
which there are dynamic relocations.  (In fact the linker does fill in
such words for 64-bit executables, though not for 32-bit executables,
so in principle we could avoid calling relocate() entirely when we're
running a 64-bit kernel at the linked address.)

The dynamic relocations are processed by a new function relocate(addr),
where the addr parameter is the virtual address where the image will be
run.  In fact we call it twice; once before calling prom_init, and again
when starting the main kernel.  This means that reloc_offset() returns
0 in prom_init (since it has been relocated to the address it is running
at), which necessitated a few adjustments.

This also changes __va and __pa to use an equivalent definition that is
simpler.  With the relocatable kernel, PAGE_OFFSET and MEMORY_START are
constants (for 64-bit) whereas PHYSICAL_START is a variable (and
KERNELBASE ideally should be too, but isn't yet).

With this, relocatable kernels still copy themselves down to physical
address 0 and run there.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      549e8152
    • P
      powerpc: Use LOAD_REG_IMMEDIATE only for constants on 64-bit · e31aa453
      由 Paul Mackerras 提交于 
      Using LOAD_REG_IMMEDIATE to get the address of kernel symbols
generates 5 instructions where LOAD_REG_ADDR can do it in one,
and will generate R_PPC64_ADDR16_* relocations in the output when
we get to making the kernel as a position-independent executable,
which we'd rather not have to handle.  This changes various bits
of assembly code to use LOAD_REG_ADDR when we need to get the
address of a symbol, or to use suitable position-independent code
for cases where we can't access the TOC for various reasons, or
if we're not running at the address we were linked at.

It also cleans up a few minor things; there's no reason to save and
restore SRR0/1 around RTAS calls, __mmu_off can get the return
address from LR more conveniently than the caller can supply it in
R4 (and we already assume elsewhere that EA == RA if the MMU is on
in early boot), and enable_64b_mode was using 5 instructions where
2 would do.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      e31aa453
    • P
      powerpc: Make it possible to move the interrupt handlers away from the kernel · 1f6a93e4
      由 Paul Mackerras 提交于 
      This changes the way that the exception prologs transfer control to
the handlers in 64-bit kernels with the aim of making it possible to
have the prologs separate from the main body of the kernel.  Now,
instead of computing the address of the handler by taking the top
32 bits of the paca address (to get the 0xc0000000........ part) and
ORing in something in the bottom 16 bits, we get the base address of
the kernel by doing a load from the paca and add an offset.

This also replaces an mfmsr and an ori to compute the MSR value for
the handler with a load from the paca.  That makes it unnecessary to
have a separate version of EXCEPTION_PROLOG_PSERIES that forces 64-bit
mode.

We can no longer use a direct branches in the exception prolog code,
which means that the SLB miss handlers can't branch directly to
.slb_miss_realmode any more.  Instead we have to compute the address
and do an indirect branch.  This is conditional on CONFIG_RELOCATABLE;
for non-relocatable kernels we use a direct branch as before.  (A later
change will allow CONFIG_RELOCATABLE to be set on 64-bit powerpc.)

Since the secondary CPUs on pSeries start execution in the first 0x100
bytes of real memory and then have to get to wherever the kernel is,
we can't use a direct branch to get there.  Instead this changes
__secondary_hold_spinloop from a flag to a function pointer.  When it
is set to a non-NULL value, the secondary CPUs jump to the function
pointed to by that value.

Finally this eliminates one code difference between 32-bit and 64-bit
by making __secondary_hold be the text address of the secondary CPU
spinloop rather than a function descriptor for it.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      1f6a93e4
    • P
      powerpc: Rearrange head_64.S to move interrupt handler code to the beginning · 9a955167
      由 Paul Mackerras 提交于 
      This rearranges head_64.S so that we have all the first-level exception
prologs together starting at 0x100, followed by all the second-level
handlers that are invoked from the first-level prologs, followed by
other code.  This doesn't make any functional change but will make
following changes for relocatable kernel support easier.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      9a955167
    • C
      powerpc: Add support for dynamic reconfiguration memory in kexec/kdump kernels · cf00085d
      由 Chandru 提交于 
      Kdump kernel needs to use only those memory regions that it is allowed
to use (crashkernel, rtas, tce, etc.).  Each of these regions have
their own sizes and are currently added under 'linux,usable-memory'
property under each memory@xxx node of the device tree.

The ibm,dynamic-memory property of ibm,dynamic-reconfiguration-memory
node (on POWER6) now stores in it the representation for most of the
logical memory blocks with the size of each memory block being a
constant (lmb_size).  If one or more or part of the above mentioned
regions lie under one of the lmb from ibm,dynamic-memory property,
there is a need to identify those regions within the given lmb.

This makes the kernel recognize a new 'linux,drconf-usable-memory'
property added by kexec-tools.  Each entry in this property is of the
form of a count followed by that many (base, size) pairs for the above
mentioned regions.  The number of cells in the count value is given by
the #size-cells property of the root node.
Signed-off-by: NChandru Siddalingappa <chandru@in.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      cf00085d
    • N
      powerpc: Check rc of notifier chain for memory remove · 525c411d
      由 Nathan Fontenot 提交于 
      The return code from invocation of the notifier for
pSeries_reconfig_chain during update of the device tree is not
checked.  This causes writes to /proc/ppc64/ofdt to update memory
properties (i.e. ibm,dyamic-reconfiguration-memory) to always
return success, instead of the result of the notifier chain.

This happens specifically when we remove/add memory from the
device tree on machines using memory specified in the
ibm,dynamic-reconfiguration-memory property of the device tree.
Signed-off-by: NNathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      525c411d
    • M
      powerpc: New copy_4K_page() · 57dda6ef
      由 Mark Nelson 提交于 
      This new copy_4K_page() function was originally tuned for the best
performance on the Cell processor, but after testing on more 64bit
powerpc chips it was found that with a small modification it either
matched the performance offered by the current mainline version or
bettered it by a small amount.

It was found that on a Cell-based QS22 blade the amount of system
time measured when compiling a 2.6.26 pseries_defconfig decreased
by 4%. Using the same test, a 4-way 970MP machine saw a decrease of
2% in system time. No noticeable change was seen on Power4, Power5
or Power6.

The 4096 byte page is copied in thirty-two 128 byte strides. An
initial setup loop executes dcbt instructions for the whole source
page and dcbz instructions for the whole destination page. To do
this, the cache line size is retrieved from ppc64_caches.

A new CPU feature bit, CPU_FTR_CP_USE_DCBTZ, (introduced in the
previous patch) is used to make the modification to this new copy
routine - on Power4, 970 and Cell the feature bit is set so the
setup loop is executed, but on all other 64bit chips the setup
loop is nop'ed out.
Signed-off-by: NMark Nelson <markn@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      57dda6ef
    • M
      powerpc: Add new CPU feature: CPU_FTR_CP_USE_DCBTZ · 2a929436
      由 Mark Nelson 提交于 
      Add a new CPU feature bit, CPU_FTR_CP_USE_DCBTZ, to be added to the
64bit powerpc chips that benefit from having dcbt and dcbz
instructions used in their memory copy routines.

This will be used in a subsequent patch that updates copy_4K_page().
The new bit is added to Cell, PPC970 and Power4 because they show
better performance with the new copy_4K_page() when dcbt and dcbz
instructions are used.
Signed-off-by: NMark Nelson <markn@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      2a929436
    • R
      powerpc: Fix duplicate test of MACIO_FLAG_SCCB_ON · 1b3c83e6
      由 roel kluin 提交于 
      Evidently MACIO_FLAG_SCCA_ON was meant.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      1b3c83e6
  3. 10 9月, 2008 9 次提交
  5. 09 9月, 2008 22 次提交