linux.git/arch/parisc, branch v3.10

parisc: Use unshadowed index register for flush instructions in flush_dcache_page_asm and flush_icache_page_asm

2013-06-18T18:29:10+00:00

The comment at the start of pacache.S states that the base and index
registers used for fdc,fic, and pdc instructions should not use shadowed
registers. Although this is probably unnecessary for tmpalias flushes,
there is also no reason not to comply.

Signed-off-by: John David Anglin 
Signed-off-by: Helge Deller

parisc: provide pci_mmap_page_range() for parisc

2013-06-18T18:29:08+00:00

pci_mmap_page_range() is needed for X11-server support on C8000 with ATI
FireGL card.

Signed-off-by Thomas Bogendoerfer 
Signed-off-by: Helge Deller

parisc: fix serial ports on C8000 workstation

2013-06-18T18:29:07+00:00

The C8000 workstation (64 bit kernel only) has a somewhat different
serial port configuration than other models.
Thomas Bogendoerfer sent a patch to fix this in September 2010, which
was now minimally modified by me.

Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Helge Deller

parisc: fix kernel BUG at arch/parisc/include/asm/mmzone.h:50 (part 2)

2013-06-18T18:20:21+00:00

Make sure that we really return -1 (instead of 0x00ff) as node id for
page frame numbers which are not physically available.

This finally fixes the kernel panic when running
cat /proc/kpageflags /proc/kpagecount.

Theoretically this patch now limits the number of physical memory ranges
to 127 instead of 254, but currently we have MAX_PHYSMEM_RANGES
hardcoded to 8 which is sufficient for all existing parisc machines.

Signed-off-by: Helge Deller

parisc: kernel: using strlcpy() instead of strcpy()

2013-06-01T12:29:01+00:00

'boot_args' is an input args, and 'boot_command_line' has a fix length.
So use strlcpy() instead of strcpy() to avoid memory overflow.

Signed-off-by: Chen Gang 
Acked-by: Kyle McMartin 
Signed-off-by: Helge Deller

parisc: rename "CONFIG_PA7100" to "CONFIG_PA7000"

2013-06-01T12:28:47+00:00

There's a Makefile line setting cflags for CONFIG_PA7100. But that
Kconfig macro doesn't exist. There is a Kconfig symbol PA7000, which
covers both PA7000 and PA7100 processors. So let's use the corresponding
Kconfig macro.

Signed-off-by: Paul Bolle 
Signed-off-by: Helge Deller

parisc: fix kernel BUG at arch/parisc/include/asm/mmzone.h:50

2013-06-01T12:28:35+00:00

With CONFIG_DISCONTIGMEM=y and multiple physical memory areas,
cat /proc/kpageflags triggers this kernel bug:

kernel BUG at arch/parisc/include/asm/mmzone.h:50!
CPU: 2 PID: 7848 Comm: cat Tainted: G      D W 3.10.0-rc3-64bit #44
 IAOQ[0]: kpageflags_read0x128/0x238
 IAOQ[1]: kpageflags_read0x12c/0x238
 RP(r2): proc_reg_read0xbc/0x130
Backtrace:
 [<00000000402ca2d4>] proc_reg_read0xbc/0x130
 [<0000000040235bcc>] vfs_read0xc4/0x1d0
 [<0000000040235f0c>] SyS_read0x94/0xf0
 [<0000000040105fc0>] syscall_exit0x0/0x14

kpageflags_read() walks through the whole memory, even if some memory
areas are physically not available. So, we should better not BUG on an
unavailable pfn in pfn_to_nid() but just return the expected value -1 or
0.

Signed-off-by: Helge Deller

parisc: memory overflow, 'name' length is too short for using

2013-06-01T12:27:56+00:00

'path.bc[i]' can be asigned by PCI_SLOT() which can '> 10', so sizeof(6
* "%u:" + "%u" + '\0') may be 21.

Since 'name' length is 20, it may be memory overflow.

And 'path.bc[i]' is 'unsigned char' for printing, we can be sure the
max length of 'name' must be less than 28.

So simplify thinking, we can use 28 instead of 20 directly, and do not
think of whether 'patchc.bc[i]' can '> 100'.

Signed-off-by: Chen Gang 
Signed-off-by: Helge Deller

parisc: fix irq stack on UP and SMP

2013-05-24T21:29:01+00:00

The logic to detect if the irq stack was already in use with
raw_spin_trylock() is wrong, because it will generate a "trylock failure
on UP" error message with CONFIG_SMP=n and CONFIG_DEBUG_SPINLOCK=y.

arch_spin_trylock() can't be used either since in the CONFIG_SMP=n case
no atomic protection is given and we are reentrant here. A mutex didn't
worked either and brings more overhead by turning off interrupts.

So, let's use the fastest path for parisc which is the ldcw instruction.

Counting how often the irq stack was used is pretty useless, so just
drop this piece of code.

Signed-off-by: Helge Deller

parisc: make interrupt and interruption stack allocation reentrant

2013-05-24T20:35:36+00:00

The get_stack_use_cr30 and get_stack_use_r30 macros allocate a stack
frame for external interrupts and interruptions requiring a stack frame.
They are currently not reentrant in that they save register context
before the stack is set or adjusted.

I have observed a number of system crashes where there was clear
evidence of stack corruption during interrupt processing, and as a
result register corruption. Some interruptions can still occur during
interruption processing, however external interrupts are disabled and
data TLB misses don't occur for absolute accesses. So, it's not entirely
clear what triggers this issue. Also, if an interruption occurs when
Q=0, it is generally not possible to recover as the shadowed registers
are not copied.

The attached patch reworks the get_stack_use_cr30 and get_stack_use_r30
macros to allocate stack before doing register saves. The new code is a
couple of instructions shorter than the old implementation. Thus, it's
an improvement even if it doesn't fully resolve the stack corruption
issue. Based on limited testing, it improves SMP system stability.

Signed-off-by: John David Anglin 
Signed-off-by: Helge Deller