Commit Graph

17 Commits

Author SHA1 Message Date
David S. Miller
fc50492867 [SPARC64]: Drop %gl to 0 before re-enabling PSTATE_IE in rtrap
If we take a window fault, on SUN4V set %gl to zero before we
turn PSTATE_IE back on in %pstate.  Otherwise if we take an
interrupt we'll end up with corrupt register state.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:13:57 -08:00
David S. Miller
af02bec662 [SPARC64]: Fix return from trap on SUN4V.
We need to set the global register set _AND_ disable
PSTATE_IE in %pstate.  The original patch sequence was
leaving PSTATE_IE enabled when returning to kernel mode,
oops.

This fixes the random register corruption being seen
on SUN4V.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:13:19 -08:00
David S. Miller
8b11bd12af [SPARC64]: Patch up mmu context register writes for sun4v.
sun4v uses ASI_MMU instead of ASI_DMMU

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:56 -08:00
David S. Miller
df7d6aec96 [SPARC64]: Rename gl_{1,2}insn_patch --> sun4v_{1,2}insn_patch
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:53 -08:00
David S. Miller
314981ac71 [SPARC64]: Kill all %pstate changes in context switch code.
They are totally unnecessary because:

1) Interrupts are already disabled when switch_to()
   runs.

2) We don't use hard-coded alternate globals any longer.

This found a case in rtrap, which still assumed alternate
global %g6 was current_thread_info(), and that is fixed
by this changeset as well.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:49 -08:00
David S. Miller
936f482af1 [SPARC64]: Add initial code to twiddle %gl on trap entry/exit.
Instead of setting/clearing PSTATE_AG we have to change
the %gl register value on sun4v.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:48 -08:00
David S. Miller
314ef68597 [SPARC64]: Refine register window trap handling.
When saving and restoing trap state, do the window spill/fill
handling inline so that we never trap deeper than 2 trap levels.
This is important for chips like Niagara.

The window fixup code is massively simplified, and many more
improvements are now possible.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:36 -08:00
David S. Miller
ffe483d552 [SPARC64]: Add explicit register args to trap state loading macros.
This, as well as making the code cleaner, allows a simplification in
the TSB miss handling path.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:35 -08:00
David S. Miller
86b818687d [SPARC64]: Fix race in LOAD_PER_CPU_BASE()
Since we use %g5 itself as a temporary, it can get clobbered
if we take an interrupt mid-stream and thus cause end up with
the final %g5 value too early as a result of rtrap processing.

Set %g5 at the very end, atomically, to avoid this problem.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:29 -08:00
David S. Miller
4da808c352 [SPARC64]: Fix bogus flush instruction usage.
Some of the trap code was still assuming that alternate
global %g6 was hard coded with current_thread_info().
Let's just consistently flush at KERNBASE when we need
a pipeline synchronization.  That's locked into the TLB
and will always work.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:22 -08:00
David S. Miller
56fb4df6da [SPARC64]: Elminate all usage of hard-coded trap globals.
UltraSPARC has special sets of global registers which are switched to
for certain trap types.  There is one set for MMU related traps, one
set of Interrupt Vector processing, and another set (called the
Alternate globals) for all other trap types.

For what seems like forever we've hard coded the values in some of
these trap registers.  Some examples include:

1) Interrupt Vector global %g6 holds current processors interrupt
   work struct where received interrupts are managed for IRQ handler
   dispatch.

2) MMU global %g7 holds the base of the page tables of the currently
   active address space.

3) Alternate global %g6 held the current_thread_info() value.

Such hardcoding has resulted in some serious issues in many areas.
There are some code sequences where having another register available
would help clean up the implementation.  Taking traps such as
cross-calls from the OBP firmware requires some trick code sequences
wherein we have to save away and restore all of the special sets of
global registers when we enter/exit OBP.

We were also using the IMMU TSB register on SMP to hold the per-cpu
area base address, which doesn't work any longer now that we actually
use the TSB facility of the cpu.

The implementation is pretty straight forward.  One tricky bit is
getting the current processor ID as that is different on different cpu
variants.  We use a stub with a fancy calling convention which we
patch at boot time.  The calling convention is that the stub is
branched to and the (PC - 4) to return to is in register %g1.  The cpu
number is left in %g6.  This stub can be invoked by using the
__GET_CPUID macro.

We use an array of per-cpu trap state to store the current thread and
physical address of the current address space's page tables.  The
TRAP_LOAD_THREAD_REG loads %g6 with the current thread from this
table, it uses __GET_CPUID and also clobbers %g1.

TRAP_LOAD_IRQ_WORK is used by the interrupt vector processing to load
the current processor's IRQ software state into %g6.  It also uses
__GET_CPUID and clobbers %g1.

Finally, TRAP_LOAD_PGD_PHYS loads the physical address base of the
current address space's page tables into %g7, it clobbers %g1 and uses
__GET_CPUID.

Many refinements are possible, as well as some tuning, with this stuff
in place.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:16 -08:00
David S. Miller
74bf4312ff [SPARC64]: Move away from virtual page tables, part 1.
We now use the TSB hardware assist features of the UltraSPARC
MMUs.

SMP is currently knowingly broken, we need to find another place
to store the per-cpu base pointers.  We hid them away in the TSB
base register, and that obviously will not work any more :-)

Another known broken case is non-8KB base page size.

Also noticed that flush_tlb_all() is not referenced anywhere, only
the internal __flush_tlb_all() (local cpu only) is used by the
sparc64 port, so we can get rid of flush_tlb_all().

The kernel gets it's own 8KB TSB (swapper_tsb) and each address space
gets it's own private 8K TSB.  Later we can add code to dynamically
increase the size of per-process TSB as the RSS grows.  An 8KB TSB is
good enough for up to about a 4MB RSS, after which the TSB starts to
incur many capacity and conflict misses.

We even accumulate OBP translations into the kernel TSB.

Another area for refinement is large page size support.  We could use
a secondary address space TSB to handle those.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:13 -08:00
David S. Miller
2d7d5f0511 [SPARC]: Add support for *at(), ppoll, and pselect syscalls.
This also includes by necessity _TIF_RESTORE_SIGMASK support,
which actually resulted in a lot of cleanups.

The sparc signal handling code is quite a mess and I should
clean it up some day.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-19 02:42:49 -08:00
David S. Miller
ba6399334d [SPARC64]: Fix userland FPU state corruption.
We need to use stricter memory barriers around the block
load and store instructions we use to save and restore the
FPU register file.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-07 13:30:49 -07:00
David S. Miller
0835ae0f27 [SPARC64]: Replace cheetah+ code patching with variables.
Instead of code patching to handle the page size fields in
the context registers, just use variables from which we get
the proper values.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-04 15:23:20 -07:00
David S. Miller
d7ce78fd9a [SPARC64]: Eliminate irq_cpustat_t.
We can put the __softirq_pending mask in the cpudata,
no need for the silly NR_CPUS array in kernel/softirq.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 22:46:43 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00