linux-toradex.git/arch/sparc/include/asm/tsb.h, branch v3.10

sparc64: Fix huge PMD to PTE translation for sun4u in TLB miss handler.

2013-02-20T21:34:41+00:00

When we set the sun4u version of the PTE execute bit, it's:

	or	REG, _PAGE_EXEC_4U, REG

_PAGE_EXEC_4U is 0x1000, unfortunately the immedate field of the
'or' instruction is a signed 13-bit value.  So the above actually
assembles into:

	or	REG, -4096, REG

completely corrupting the final PTE value.

Set it with a:

	sethi	%hi(_PAGE_EXEC_4U), TMP
	or	REG, TMP, REG

sequence instead.

This fixes "git gc" crashes on sun4u machines.

Reported-by: Meelis Roos 
Signed-off-by: David S. Miller

sparc64: Support transparent huge pages.

2012-10-09T07:23:06+00:00

This is relatively easy since PMD's now cover exactly 4MB of memory.

Our PMD entries are 32-bits each, so we use a special encoding.  The
lowest bit, PMD_ISHUGE, determines the interpretation.  This is possible
because sparc64's page tables are purely software entities so we can use
whatever encoding scheme we want.  We just have to make the TLB miss
assembler page table walkers aware of the layout.

set_pmd_at() works much like set_pte_at() but it has to operate in two
page from a table of non-huge PTEs, so we have to queue up TLB flushes
based upon what mappings are valid in the PTE table.  In the second regime
we are going from huge-page to non-huge-page, and in that case we need
only queue up a single TLB flush to push out the huge page mapping.

We still have 5 bits remaining in the huge PMD encoding so we can very
likely support any new pieces of THP state tracking that might get added
in the future.

With lots of help from Johannes Weiner.

Signed-off-by: David S. Miller 
Cc: Andrea Arcangeli 
Cc: Johannes Weiner 
Cc: Gerald Schaefer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sparc64: Document PGD and PMD layout.

2012-10-09T07:23:05+00:00

We're going to be messing around with the PMD interpretation and layout
for the sake of transparent huge pages, so we better clearly document what
we're starting with.

Signed-off-by: David S. Miller 
Cc: Andrea Arcangeli 
Cc: Johannes Weiner 
Cc: Gerald Schaefer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sparc64: Halve the size of PTE tables

2012-10-09T07:23:04+00:00

The reason we want to do this is to facilitate transparent huge page
support.

Right now PMD's cover 8MB of address space, and our huge page size is 4MB.
 The current transparent hugepage support is not able to handle HPAGE_SIZE
!= PMD_SIZE.

So make PTE tables be sized to half of a page instead of a full page.

We can still map properly the whole supported virtual address range which
on sparc64 requires 44 bits.  Add a compile time CPP test which ensures
that this requirement is always met.

There is a minor inefficiency added by this change.  We only use half of
the page for PTE tables.  It's not trivial to use only half of the page
yet still get all of the pgtable_page_{ctor,dtor}() stuff working
properly.  It is doable, and that will come in a subsequent change.

Signed-off-by: David S. Miller 
Cc: Andrea Arcangeli 
Cc: Johannes Weiner 
Cc: Gerald Schaefer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sparc: Access kernel TSB using physical addressing when possible.

2011-08-05T07:53:57+00:00

On sun4v this is basically required since we point the hypervisor and
the TSB walking hardware at these tables using physical addressing
too.

Signed-off-by: David S. Miller

sparc64: Stop using memory barriers for atomics and locks.

2008-12-04T17:16:47+00:00

The kernel always executes in the TSO memory model now,
so none of this stuff is necessary any more.

With helpful feedback from Nick Piggin.

Signed-off-by: David S. Miller

sparc, sparc64: use arch/sparc/include

2008-07-27T21:00:59+00:00

The majority of this patch was created by the following script:

***
ASM=arch/sparc/include/asm
mkdir -p $ASM
git mv include/asm-sparc64/ftrace.h $ASM
git rm include/asm-sparc64/*
git mv include/asm-sparc/* $ASM
sed -ie 's/asm-sparc64/asm/g' $ASM/*
sed -ie 's/asm-sparc/asm/g' $ASM/*
***

The rest was an update of the top-level Makefile to use sparc
for header files when sparc64 is being build.
And a small fixlet to pick up the correct unistd.h from
sparc64 code.

Signed-off-by: Sam Ravnborg