Commit Graph

37 Commits

Author SHA1 Message Date
David S. Miller 301feb6524 [SPARC64]: Fix lockdep, particularly on SMP.
As noted by Al Viro, when we try to call prom_set_trap_table()
in the SMP trampoline code we try to take the PROM call spinlock
which doesn't work because the current thread pointer isn't
valid yet and lockdep depends upon that being correct.

Furthermore, we cannot set the current thread pointer register
because it can't be properly dereferenced until we return from
prom_set_trap_table().  Kernel TLB misses only work after that
call.

So do the PROM call to set the trap table directly instead of
going through the OBP library C code, and thus avoid the lock
altogether.

These calls are guarenteed to be serialized fully.

Since there are now no calls to the prom_set_trap_table{_sun4v}()
library functions, they can be deleted.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-16 11:51:15 -07:00
David S. Miller 53140b71c5 [SPARC64]: Do not touch %tick_cmpr on sun4v cpus.
This register is not a part of the sun4v architecture.

Niagara 1 and 2 happened to leave it around.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-16 01:52:44 -07:00
David S. Miller cf5adce117 [SPARC64]: Niagara-2 optimized copies.
The bzero/memset implementation stays the same as Niagara-1.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-16 01:47:25 -07:00
David S. Miller 6c70b6fc7b [SPARC64]: Do not assume sun4v chips have load-twin/store-init support.
Check the cpu type in the OBP device tree before committing to
using the optimized Niagara memcpy and memset implementation.

If we don't recognize the cpu type, use a completely generic
version.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-08 17:33:45 -07:00
David S. Miller 1966287dfa [SPARC64]: Mark most of initial bootup asm as .text.init.ref_ok
We can't mark the whole thing init because there are dependencies
in bootloaders that assume that _start, or whatever the image
entry value, is 2 instructions before the "HdrS" signature.

In fact, TILO assumes this entry is always at 0x4000, yikes!

Also, right after the bootloader info area there are OBP strings and
values that get used later in the boot process, and those are not all
provably .init yet.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-24 15:17:33 -07:00
David S. Miller 78d0012539 [SPARC64]: Fix two year old bug in early bootup asm.
We try to fetch the CIF entry pointer from %o4, but that
can get clobbered by the early OBP calls.  It is saved
in %l7 already, so actually this "mov %o4, %l7" can just
be completely removed with no other changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-19 21:50:09 -07:00
David S. Miller 2d9e2763c2 [SPARC64]: Fix two bugs wrt. kernel 4MB TSB.
1) The TSB lookup was not using the correct hash mask.

2) It was not aligned on a boundary equal to it's size,
   which is required by the sun4v Hypervisor.

wasn't having it's return value checked, and that bug will be fixed up
as well in a subsequent changeset.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-29 02:51:38 -07:00
David S. Miller 22adb358e8 [SPARC64]: Eliminate NR_CPUS limitations.
Cheetah systems can have cpuids as large as 1023, although physical
systems don't have that many cpus.

Only three limitations existed in the kernel preventing arbitrary
NR_CPUS values:

1) dcache dirty cpu state stored in page->flags on
   D-cache aliasing platforms.  With some build time
   calculations and some build-time BUG checks on
   page->flags layout, this one was easily solved.

2) The cheetah XCALL delivery code could only handle
   a cpumask with up to 32 cpus set.  Some simple looping
   logic clears that up too.

3) thread_info->cpu was a u8, easily changed to a u16.

There are a few spots in the kernel that still put NR_CPUS
sized arrays on the kernel stack, but that's not a sparc64
specific problem.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-29 02:49:49 -07:00
David S. Miller 15f1483404 [SPARC64]: Kill no-remapping-needed code in head.S
It branches around some necessary prom calls, which we would
need to do even if we are mapped at the correct location already.
So it doesn't work.

The idea was that this sort of thing could be used for the eventual
kexec implementation, but it is clear that this will need to be
done differently.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-17 14:06:55 -08:00
David S. Miller 10e267234c [SPARC64]: Add irqtrace/stacktrace/lockdep support.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-10 02:39:09 -08:00
David S. Miller d8573e20d5 [SPARC64]: Make sure IRQs are disabled properly during early boot.
Else we trigger the new irqs_disable() assertion in start_kernel().

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-14 17:00:21 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
David S. Miller 951bc82c53 [SPARC64]: Make smp_processor_id() functional before start_kernel()
Uses of smp_processor_id() get pushed earlier and earlier in
the start_kernel() sequence.  So just get it working before
we call start_kernel() to avoid all possible problems.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-05-31 01:24:02 -07:00
David S. Miller 074d82cf68 [SPARC64]: Put syscall tables after trap table.
Otherwise with too much stuff enabled in the kernel config
we can end up with an unaligned trap table.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:13:59 -08:00
David S. Miller 8ca2557c48 [SPARC64]: Niagara optimized memset/bzero/clear_user.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:13:50 -08:00
David S. Miller 6cebb52094 [SPARC64]: Fix sun4v early bootup.
prom_sun4v_name should be "sun4v" not "SUNW,sun4v"

Also, this is too early to make use of the
.sun4v_Xinsn_patch code patching, so just check
things manually.

This gets us at least to prom_init() on Niagara.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:12:21 -08:00
David S. Miller 12eaa328f9 [SPARC64]: Use ASI_SCRATCHPAD address 0x0 properly.
This is where the virtual address of the fault status
area belongs.

To set it up we don't make a hypervisor call, instead
we call OBP's SUNW,set-trap-table with the real address
of the fault status area as the second argument.  And
right before that call we write the virtual address into
ASI_SCRATCHPAD vaddr 0x0.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:12:15 -08:00
David S. Miller d82ace7dc4 [SPARC64]: Detect sun4v early in boot process.
We look for "SUNW,sun4v" in the 'compatible' property
of the root OBP device tree node.

Protect every %ver register access, to make sure it is
not touched on sun4v, as %ver is hyperprivileged there.

Lock kernel TLB entries using hypervisor calls instead of
calls into OBP.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:12:03 -08:00
David S. Miller 5b0c0572fc [SPARC64]: Sun4v interrupt handling.
Sun4v has 4 interrupt queues: cpu, device, resumable errors,
and non-resumable errors.  A set of head/tail offset pointers
help maintain a work queue in physical memory.  The entries
are 64-bytes in size.

Each queue is allocated then registered with the hypervisor
as we bring cpus up.

The two error queues each get a kernel side buffer that we
use to quickly empty the main interrupt queue before we
call up to C code to log the event and possibly take evasive
action.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:12:01 -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 8591e30272 [SPARC64]: Niagara copy/clear page.
Happily we have no D-cache aliasing issues on these
chips, so the implementation is very straightforward.

Add a stub in bootup which will be where the patching
calls will be made for niagara/sun4v/hypervisor.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:54 -08:00
David S. Miller d257d5da39 [SPARC64]: Initial sun4v TLB miss handling infrastructure.
Things are a little tricky because, unlike sun4u, we have
to:

1) do a hypervisor trap to do the TLB load.
2) do the TSB lookup calculations by hand

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:52 -08:00
David S. Miller 2f7ee7c63f [SPARC64]: Increase swapper_tsb size to 32K.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:26 -08:00
David S. Miller a8b900d801 [SPARC64]: Kill sole argument passed to setup_tba().
No longer used, and move extern declaration to a header file.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:25 -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 c9c1083074 [SPARC64]: Fix boot failures on SunBlade-150
The sequence to move over to the Linux trap tables from
the firmware ones needs to be more air tight.  It turns
out that to be %100 safe we do need to be able to translate
OBP mappings in our TLB miss handlers early.

In order not to eat up a lot of kernel image memory with
static page tables, just use the translations array in
the OBP TLB miss handlers.  That solves the bulk of the
problem.

Furthermore, to make sure the OBP TLB miss path will work
even before the fixed MMU globals are loaded, explicitly
load %g1 to TLB_SFSR at the beginning of the i-TLB and
d-TLB miss handlers.

To ease the OBP TLB miss walking of the prom_trans[] array,
we sort it then delete all of the non-OBP entries in there
(for example, there are entries for the kernel image itself
which we're not interested in at all).

We also save about 32K of kernel image size with this change.
Not a bad side effect :-)

There are still some reasons why trampoline.S can't use the
setup_trap_table() yet.  The most noteworthy are:

1) OBP boots secondary processors with non-bias'd stack for
   some reason.  This is easily fixed by using a small bootup
   stack in the kernel image explicitly for this purpose.

2) Doing a firmware call via the normal C call prom_set_trap_table()
   goes through the whole OBP enter/exit sequence that saves and
   restores OBP and Linux kernel state in the MMUs.  This path
   unfortunately does a "flush %g6" while loading up the OBP locked
   TLB entries for the firmware call.

   If we setup the %g6 in the trampoline.S code properly, that
   is in the PAGE_OFFSET linear mapping, but we're not on the
   kernel trap table yet so those addresses won't translate properly.

   One idea is to do a by-hand firmware call like we do in the
   early bootup code and elsewhere here in trampoline.S  But this
   fails as well, as aparently the secondary processors are not
   booted with OBP's special locked TLB entries loaded.  These
   are necessary for the firwmare to processes TLB misses correctly
   up until the point where we take over the trap table.

This does need to be resolved at some point.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-12 12:22:46 -07:00
David S. Miller b1b510aa28 [SPARC64]: Fix net booting on Ultra5
We were not doing alignment properly when remapping the kernel image.

What we want is a 4MB aligned physical address to map at KERNBASE.
Mistakedly we were 4MB aligning the virtual address where the kernel
initially sits, that's wrong.

Instead, we should PAGE align the virtual address, then 4MB align the
physical address result the prom gives to us.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-11 15:45:16 -07:00
David S. Miller 5d8e1b181c [SPARC64]: Fix Ultra5, Ultra60, et al. boot failures.
On the boot processor, we need to do the move onto the Linux trap
table a little bit differently else we'll take unhandlable faults in
the firmware address space.

Previously we would do the following:

1) Disable PSTATE_IE in %pstate.
2) Set %tba by hand to sparc64_ttable_tl0
3) Initialize alternate, mmu, and interrupt global
   trap registers.
4) Call prom_set_traptable()

That doesn't work very well actually with the way we boot the kernel
VM these days.  It worked by luck on many systems because the firmware
accesses for the prom_set_traptable() call happened to be loaded into
the TLB already, something we cannot assume.

So the new scheme is this:

1) Clear PSTATE_IE in %pstate and set %pil to 15
2) Call prom_set_traptable()
3) Initialize alternate, mmu, and interrupt global
   trap registers.

and this works quite well.  This sequence has been moved into a
callable function in assembler named setup-trap_table().  The idea is
that eventually trampoline.S can use this code as well.  That isn't
possible currently due to some complications, but eventually we should
be able to do it.

Thanks to Meelis Roos for the Ultra5 boot failure report.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-10 16:12:13 -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 5fd29752f0 [SPARC64]: Fix fault handling in unaligned trap handler.
We were not calling kernel_mna_trap_fault() correctly.
Instead of being fancy, just return 0 vs. -EFAULT from
the assembler stubs, and handle that return value as
appropriate.

Create an "__retl_efault" stub for assembler exception
table entries and use it where possible.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-28 20:41:45 -07:00
David S. Miller 5642530651 [SPARC64]: Add CONFIG_DEBUG_PAGEALLOC support.
The trick is that we do the kernel linear mapping TLB miss starting
with an instruction sequence like this:

	ba,pt		%xcc, kvmap_load
	 xor		%g2, %g4, %g5

succeeded by an instruction sequence which performs a full page table
walk starting at swapper_pg_dir.

We first take over the trap table from the firmware.  Then, using this
constant PTE generation for the linear mapping area above, we build
the kernel page tables for the linear mapping.

After this is setup, we patch that branch above into a "nop", which
will cause TLB misses to fall through to the full page table walk.

With this, the page unmapping for CONFIG_DEBUG_PAGEALLOC is trivial.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-25 16:46:57 -07:00
David S. Miller a8201c6106 [SPARC64]: Fix comment typo in head.S
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-22 20:31:29 -07:00
David S. Miller bff06d5522 [SPARC64]: Rewrite bootup sequence.
Instead of all of this cpu-specific code to remap the kernel
to the correct location, use portable firmware calls to do
this instead.

What we do now is the following in position independant
assembler:

	chosen_node = prom_finddevice("/chosen");
	prom_mmu_ihandle_cache = prom_getint(chosen_node, "mmu");
	vaddr = 4MB_ALIGN(current_text_addr());
	prom_translate(vaddr, &paddr_high, &paddr_low, &mode);
	prom_boot_mapping_mode = mode;
	prom_boot_mapping_phys_high = paddr_high;
	prom_boot_mapping_phys_low = paddr_low;
	prom_map(-1, 8 * 1024 * 1024, KERNBASE, paddr_low);

and that replaces the massive amount of by-hand TLB probing and
programming we used to do here.

The new code should also handle properly the case where the kernel
is mapped at the correct address already (think: future kexec
support).

Consequently, the bulk of remap_kernel() dies as does the entirety
of arch/sparc64/prom/map.S

We try to share some strings in the PROM library with the ones used
at bootup, and while we're here mark input strings to oplib.h routines
with "const" when appropriate.

There are many more simplifications now possible.  For one thing, we
can consolidate the two copies we now have of a lot of cpu setup code
sitting in head.S and trampoline.S.

This is a significant step towards CONFIG_DEBUG_PAGEALLOC support.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-22 20:11:33 -07:00
David S. Miller 2a7e299034 [SPARC64]: Move kernel TLB miss handling into a seperate file.
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-21 18:50:51 -07:00
David S. Miller dbd2fdf549 [SPARC64]: Kill BRANCH_IF_ANY_CHEETAH() from copy page.
Just patch the branch at boot time instead.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-30 11:26:15 -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