This reverts commit 45cb08f4.

For some reason this is causing IRQ problems on Freescale Book3E
machines, eg on my p5020ds:

  irq 25: nobody cared (try booting with the "irqpoll" option)
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc3-gcc-6.3.1-00037-g45cb08f4 #624
  Call Trace:
  [c0000000fffdbb10] [c00000000049962c] .dump_stack+0xa8/0xe8 (unreliable)
  [c0000000fffdbba0] [c0000000000babf4] .__report_bad_irq+0x54/0x140
  [c0000000fffdbc40] [c0000000000bb11c] .note_interrupt+0x324/0x380
  [c0000000fffdbd00] [c0000000000b7110] .handle_irq_event_percpu+0x68/0x88
  [c0000000fffdbd90] [c0000000000b718c] .handle_irq_event+0x5c/0xa8
  [c0000000fffdbe10] [c0000000000bc01c] .handle_fasteoi_irq+0xe4/0x298
  [c0000000fffdbe90] [c0000000000b59c4] .generic_handle_irq+0x50/0x74
  [c0000000fffdbf10] [c0000000000075d8] .__do_irq+0x74/0x1f0
  [c0000000fffdbf90] [c0000000000189f8] .call_do_irq+0x14/0x24
  [c0000000f7173060] [c0000000000077e4] .do_IRQ+0x90/0x120
  [c0000000f7173100] [c00000000001d93c] exc_0x500_common+0xfc/0x100
  --- interrupt: 501 at .prepare_to_wait_event+0xc/0x14c
      LR = .fsl_elbc_run_command+0xc8/0x23c
  [c0000000f71734d0] [c00000000065f418] .nand_reset+0xb8/0x168
  [c0000000f7173560] [c00000000065fec4] .nand_scan_ident+0x2b0/0x1638
  [c0000000f7173650] [c000000000666cd8] .fsl_elbc_nand_probe+0x34c/0x5f0
  ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
  [c0000000f7173750] [c0000000005a3c60] .platform_drv_probe+0x64/0xb0
  [c0000000f71737d0] [c0000000005a12e0] .really_probe+0x290/0x334
  [c0000000f7173870] [c0000000005a14a0] .__driver_attach+0x11c/0x120
  [c0000000f7173900] [c00000000059e6a0] .bus_for_each_dev+0x98/0xfc
  [c0000000f71739a0] [c0000000005a0b3c] .driver_attach+0x34/0x4c
  [c0000000f7173a20] [c0000000005a04b0] .bus_add_driver+0x1ac/0x2e0
  [c0000000f7173ac0] [c0000000005a2170] .driver_register+0x94/0x160
  [c0000000f7173b40] [c0000000005a3be0] .__platform_driver_register+0x60/0x7c
  [c0000000f7173bc0] [c000000000d6aab4] .fsl_elbc_nand_driver_init+0x24/0x38
  [c0000000f7173c30] [c000000000001934] .do_one_initcall+0x68/0x1b8
  [c0000000f7173d00] [c000000000d210f8] .kernel_init_freeable+0x260/0x338
  [c0000000f7173db0] [c0000000000021b0] .kernel_init+0x20/0xe70
  [c0000000f7173e30] [c0000000000009bc] .ret_from_kernel_thread+0x58/0x9c
  handlers:
  [<c000000000ed85c8>] .fsl_lbc_ctrl_irq
  Disabling IRQ #25

Ben also had concerns with the implementation being potentially slow on
some PICs, so revert it for now.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The i-side 0111b machine check, which is "Instruction Fetch to foreign
address space", was missed by 7b9f71f9 ("powerpc/64s: POWER9 machine
check handler").

    The POWER9 processor core considers host real addresses with a
    nonzero value in RA(8:12) as foreign address space, accessible only
    by the copy and paste instructions. The copy and paste instruction
    pair can be used to invoke the Nest accelerators via the Virtual
    Accelerator Switchboard (VAS).

It is an error for any regular load/store or ifetch to go to a foreign
addresses. When relocation is on, this causes an MMU exception. When
relocation is off, a machine check exception. It is possible to trigger
this machine check by branching to a foreign address with MSR[IR]=0.

Fixes: 7b9f71f9 ("powerpc/64s: POWER9 machine check handler")
Reported-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

We should unlock if get_cxl_adapter() fails.

Fixes: 594ff7d0 ("cxl: Support to flash a new image on the adapter from a guest")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

These two functions implement the same semantics, so unify their naming so we
can share code that calls them. The longer name is more descriptive so use it.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add __GFP_ACCOUNT to __hugepte_alloc()
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add support in pte_alloc_one() and pgd_alloc() by
passing __GFP_ACCOUNT in the flags
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Introduce a helper pgtable_gfp_flags() which
just returns the current gfp flags and adds
__GFP_ACCOUNT to account for page table allocation.
The generic helper is added to include/asm/pgalloc.h
and has two variants - WARNING ugly bits ahead

1. If the header is included from a module, no check
for mm == &init_mm is done, since init_mm is not
exported
2. For kernel includes, the check is done and required
see (3e79ec7d arch: x86: charge page tables to kmemcg)

The fundamental assumption is that no module should be
doing pgd/pud/pmd and pte alloc's on behalf of init_mm
directly.

NOTE: This adds an overhead to pmd/pud/pgd allocations
similar to x86.  The other alternative was to implement
pmd_alloc_kernel/pud_alloc_kernel and pgd_alloc_kernel
with their offset variants.

For 4k page size, pte_alloc_one no longer calls
pte_alloc_one_kernel.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Currently in hpte_need_flush() if there is no batch pending we always do a
global TLB flush, which is inefficient if the mm has never run on another
thread.

Instead do the same check that __flush_tlb_pending() does and check if a local
flush is sufficient when batch->active is false. Instead of open-coding it we
use mm_is_thread_local().
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Don't use a local, just inline mm_is_thread_local()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Signed-off-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add myself as the maintainer for drivers/fsl/soc/ and fix the scope for
device tree bindings.
Signed-off-by: Li Yang <leoyang.li@nxp.com>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This reduces overhead of mutex locking and increases context switch
rate significantly (which helps to measure and profile the context
switch path).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Collation of some spelling fixes from Colin.

 Attemping   -> Attempting
 intialized  -> initialized
 missmanaged -> mismanaged
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The xor_vmx.c file is used for the RAID5 xor operations. In these functions
altivec is enabled to run the operation and then disabled.

The code uses enable_kernel_altivec() around the core of the algorithm, however
the whole file is built with -maltivec, so the compiler is within its rights to
generate altivec code anywhere. This has been seen at least once in the wild:

  0:mon> di $xor_altivec_2
  c0000000000b97d0  3c4c01d9	addis   r2,r12,473
  c0000000000b97d4  3842db30	addi    r2,r2,-9424
  c0000000000b97d8  7c0802a6	mflr    r0
  c0000000000b97dc  f8010010	std     r0,16(r1)
  c0000000000b97e0  60000000	nop
  c0000000000b97e4  7c0802a6	mflr    r0
  c0000000000b97e8  faa1ffa8	std     r21,-88(r1)
  ...
  c0000000000b981c  f821ff41	stdu    r1,-192(r1)
  c0000000000b9820  7f8101ce	stvx    v28,r1,r0		<-- POP
  c0000000000b9824  38000030	li      r0,48
  c0000000000b9828  7fa101ce	stvx    v29,r1,r0
  ...
  c0000000000b984c  4bf6a06d	bl      c0000000000238b8 # enable_kernel_altivec

This patch splits the non-altivec code into xor_vmx_glue.c which calls the
altivec functions in xor_vmx.c. By compiling xor_vmx_glue.c without
-maltivec we can guarantee that altivec instruction will not be executed
outside of the enable/disable block.
Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com>
[mpe: Rework change log and include disassembly]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

By default, 5% of system RAM is reserved for preserving boot memory.
Alternatively, a user can specify the amount of memory to reserve.
See Documentation/powerpc/firmware-assisted-dump.txt for details. In
addition to the memory reserved for preserving boot memory, some more
memory is reserved, to save HPTE region, CPU state data and ELF core
headers.

Memory Reservation during first kernel looks like below:

  Low memory                                        Top of memory
  0      boot memory size                                       |
  |           |                       |<--Reserved dump area -->|
  V           V                       |   Permanent Reservation V
  +-----------+----------/ /----------+---+----+-----------+----+
  |           |                       |CPU|HPTE|  DUMP     |ELF |
  +-----------+----------/ /----------+---+----+-----------+----+
        |                                           ^
        |                                           |
        \                                           /
         -------------------------------------------
          Boot memory content gets transferred to
          reserved area by firmware at the time of
          crash

This implicitly means that the sum of the sizes of boot memory, CPU
state data, HPTE region, DUMP preserving area and ELF core headers
can't be greater than the total memory size. But currently, a user is
allowed to specify any value as boot memory size. So, the above rule
is violated when a boot memory size around 50% of the total available
memory is specified. As the kernel is not handling this currently, it
may lead to undefined behavior. Fix it by setting an upper limit for
boot memory size to 25% of the total available memory. Also, instead
of using memblock_end_of_DRAM(), which doesn't take the holes, if any,
in the memory layout into account, use memblock_phys_mem_size() to
calculate the percentage of total available memory.
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

With commit f6e6bedb ("powerpc/fadump: Reserve memory at an offset
closer to bottom of RAM"), memory for fadump is no longer reserved at
the top of RAM. But there are still a few places which say so. Change
them appropriately.
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

With commit 11550dc0 ("powerpc/fadump: reuse crashkernel parameter
for fadump memory reservation"), 'fadump_reserve_mem=' parameter is
deprecated in favor of 'crashkernel=' parameter. Add a warning if
'fadump_reserve_mem=' is still used.

Fixes: 11550dc0 ("powerpc/fadump: reuse crashkernel parameter for fadump memory reservation")
Suggested-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
[mpe: Unsplit long printk strings]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

 - log an error message when registration fails and no error code listed
   in the switch is returned
 - translate the hv error code to posix error code and return it from
   fw_register
 - return the posix error code from fw_register to the process writing
   to sysfs
 - return EEXIST on re-registration
 - return success on deregistration when fadump is not registered
 - return ENODEV when no memory is reserved for fadump
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Tested-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
[mpe: Use pr_err() to shrink the error print]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

With the __ilog2() function as defined in
arch/powerpc/include/asm/bitops.h, GCC will not optimise the code
in case of constant parameter.

The generic ilog2() function in include/linux/log2.h is written
to handle the case of the constant parameter.

This patch discards the three __ilog2() functions and
defines __ilog2() as ilog2()

For non constant calls, the generated code is doing the same:
int test__ilog2(unsigned long x)
{
	return __ilog2(x);
}

int test__ilog2_u32(u32 n)
{
	return __ilog2_u32(n);
}

int test__ilog2_u64(u64 n)
{
	return __ilog2_u64(n);
}

On PPC32 before the patch:
00000000 <test__ilog2>:
   0:	7c 63 00 34 	cntlzw  r3,r3
   4:	20 63 00 1f 	subfic  r3,r3,31
   8:	4e 80 00 20 	blr

0000000c <test__ilog2_u32>:
   c:	7c 63 00 34 	cntlzw  r3,r3
  10:	20 63 00 1f 	subfic  r3,r3,31
  14:	4e 80 00 20 	blr

On PPC32 after the patch:
00000000 <test__ilog2>:
   0:	7c 63 00 34 	cntlzw  r3,r3
   4:	20 63 00 1f 	subfic  r3,r3,31
   8:	4e 80 00 20 	blr

0000000c <test__ilog2_u32>:
   c:	7c 63 00 34 	cntlzw  r3,r3
  10:	20 63 00 1f 	subfic  r3,r3,31
  14:	4e 80 00 20 	blr

On PPC64 before the patch:
0000000000000000 <.test__ilog2>:
   0:	7c 63 00 74 	cntlzd  r3,r3
   4:	20 63 00 3f 	subfic  r3,r3,63
   8:	7c 63 07 b4 	extsw   r3,r3
   c:	4e 80 00 20 	blr

0000000000000010 <.test__ilog2_u32>:
  10:	7c 63 00 34 	cntlzw  r3,r3
  14:	20 63 00 1f 	subfic  r3,r3,31
  18:	7c 63 07 b4 	extsw   r3,r3
  1c:	4e 80 00 20 	blr

0000000000000020 <.test__ilog2_u64>:
  20:	7c 63 00 74 	cntlzd  r3,r3
  24:	20 63 00 3f 	subfic  r3,r3,63
  28:	7c 63 07 b4 	extsw   r3,r3
  2c:	4e 80 00 20 	blr

On PPC64 after the patch:
0000000000000000 <.test__ilog2>:
   0:	7c 63 00 74 	cntlzd  r3,r3
   4:	20 63 00 3f 	subfic  r3,r3,63
   8:	7c 63 07 b4 	extsw   r3,r3
   c:	4e 80 00 20 	blr

0000000000000010 <.test__ilog2_u32>:
  10:	7c 63 00 34 	cntlzw  r3,r3
  14:	20 63 00 1f 	subfic  r3,r3,31
  18:	7c 63 07 b4 	extsw   r3,r3
  1c:	4e 80 00 20 	blr

0000000000000020 <.test__ilog2_u64>:
  20:	7c 63 00 74 	cntlzd  r3,r3
  24:	20 63 00 3f 	subfic  r3,r3,63
  28:	7c 63 07 b4 	extsw   r3,r3
  2c:	4e 80 00 20 	blr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

With the ffz() function as defined in arch/powerpc/include/asm/bitops.h
GCC will not optimise the code in case of constant parameter.

This patch replaces ffz() by the generic function.

The generic ffz(x) expects to never be called with ~x == 0
as written in the comment in include/asm-generic/bitops/ffz.h
The only user of ffz() within arch/powerpc/ is
platforms/512x/mpc5121_ads_cpld.c, which checks if x is not 0xff

For non constant calls, the generated code is doing the same:

unsigned long testffz(unsigned long x)
{
	return ffz(x);
}

On PPC32, before the patch:
00000018 <testffz>:
  18:	7c 63 18 f9 	not.    r3,r3
  1c:	40 82 00 0c 	bne     28 <testffz+0x10>
  20:	38 60 00 20 	li      r3,32
  24:	4e 80 00 20 	blr
  28:	7d 23 00 d0 	neg     r9,r3
  2c:	7d 23 18 38 	and     r3,r9,r3
  30:	7c 63 00 34 	cntlzw  r3,r3
  34:	20 63 00 1f 	subfic  r3,r3,31
  38:	4e 80 00 20 	blr

On PPC32, after the patch:
00000018 <testffz>:
  18:	39 23 00 01 	addi    r9,r3,1
  1c:	7d 23 18 78 	andc    r3,r9,r3
  20:	7c 63 00 34 	cntlzw  r3,r3
  24:	20 63 00 1f 	subfic  r3,r3,31
  28:	4e 80 00 20 	blr

On PPC64, before the patch:
0000000000000030 <.testffz>:
  30:	7c 60 18 f9 	not.    r0,r3
  34:	38 60 00 40 	li      r3,64
  38:	4d 82 00 20 	beqlr
  3c:	7c 60 00 d0 	neg     r3,r0
  40:	7c 63 00 38 	and     r3,r3,r0
  44:	7c 63 00 74 	cntlzd  r3,r3
  48:	20 63 00 3f 	subfic  r3,r3,63
  4c:	7c 63 07 b4 	extsw   r3,r3
  50:	4e 80 00 20 	blr

On PPC64, after the patch:
0000000000000030 <.testffz>:
  30:	38 03 00 01 	addi    r0,r3,1
  34:	7c 03 18 78 	andc    r3,r0,r3
  38:	7c 63 00 74 	cntlzd  r3,r3
  3c:	20 63 00 3f 	subfic  r3,r3,63
  40:	4e 80 00 20 	blr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

With the fls() functions as defined in arch/powerpc/include/asm/bitops.h
GCC will not optimise the code in case of constant parameter.

This patch replaces __fls() by the builtin function, and modifies
fls() and fls64() to use builtins instead of inline assembly

For non constant calls, the generated code is doing the same:

int testfls(unsigned int x)
{
	return fls(x);
}

unsigned long test__fls(unsigned long x)
{
	return __fls(x);
}

int testfls64(__u64 x)
{
	return fls64(x);
}

On PPC32, before the patch:
00000064 <testfls>:
  64:	7c 63 00 34 	cntlzw  r3,r3
  68:	20 63 00 20 	subfic  r3,r3,32
  6c:	4e 80 00 20 	blr

00000070 <test__fls>:
  70:	7c 63 00 34 	cntlzw  r3,r3
  74:	20 63 00 1f 	subfic  r3,r3,31
  78:	4e 80 00 20 	blr

0000007c <testfls64>:
  7c:	2c 03 00 00 	cmpwi   r3,0
  80:	40 82 00 10 	bne     90 <testfls64+0x14>
  84:	7c 83 00 34 	cntlzw  r3,r4
  88:	20 63 00 20 	subfic  r3,r3,32
  8c:	4e 80 00 20 	blr
  90:	7c 63 00 34 	cntlzw  r3,r3
  94:	20 63 00 40 	subfic  r3,r3,64
  98:	4e 80 00 20 	blr

On PPC32, after the patch:
00000054 <testfls>:
  54:	7c 63 00 34 	cntlzw  r3,r3
  58:	20 63 00 20 	subfic  r3,r3,32
  5c:	4e 80 00 20 	blr

00000060 <test__fls>:
  60:	7c 63 00 34 	cntlzw  r3,r3
  64:	20 63 00 1f 	subfic  r3,r3,31
  68:	4e 80 00 20 	blr

0000006c <testfls64>:
  6c:	2c 03 00 00 	cmpwi   r3,0
  70:	41 82 00 10 	beq     80 <testfls64+0x14>
  74:	7c 63 00 34 	cntlzw  r3,r3
  78:	20 63 00 40 	subfic  r3,r3,64
  7c:	4e 80 00 20 	blr
  80:	7c 83 00 34 	cntlzw  r3,r4
  84:	20 63 00 40 	subfic  r3,r3,32
  88:	4e 80 00 20 	blr

On PPC64, before the patch:
00000000000000a0 <.testfls>:
  a0:	7c 63 00 34 	cntlzw  r3,r3
  a4:	20 63 00 20 	subfic  r3,r3,32
  a8:	7c 63 07 b4 	extsw   r3,r3
  ac:	4e 80 00 20 	blr

00000000000000b0 <.test__fls>:
  b0:	7c 63 00 74 	cntlzd  r3,r3
  b4:	20 63 00 3f 	subfic  r3,r3,63
  b8:	7c 63 07 b4 	extsw   r3,r3
  bc:	4e 80 00 20 	blr

00000000000000c0 <.testfls64>:
  c0:	7c 63 00 74 	cntlzd  r3,r3
  c4:	20 63 00 40 	subfic  r3,r3,64
  c8:	7c 63 07 b4 	extsw   r3,r3
  cc:	4e 80 00 20 	blr

On PPC64, after the patch:
0000000000000090 <.testfls>:
  90:	7c 63 00 34 	cntlzw  r3,r3
  94:	20 63 00 20 	subfic  r3,r3,32
  98:	7c 63 07 b4 	extsw   r3,r3
  9c:	4e 80 00 20 	blr

00000000000000a0 <.test__fls>:
  a0:	7c 63 00 74 	cntlzd  r3,r3
  a4:	20 63 00 3f 	subfic  r3,r3,63
  a8:	4e 80 00 20 	blr
  ac:	60 00 00 00 	nop

00000000000000b0 <.testfls64>:
  b0:	7c 63 00 74 	cntlzd  r3,r3
  b4:	20 63 00 40 	subfic  r3,r3,64
  b8:	7c 63 07 b4 	extsw   r3,r3
  bc:	4e 80 00 20 	blr

Those builtins have been in GCC since at least 3.4.6 (see
https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Other-Builtins.html )
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

With the ffs() function as defined in arch/powerpc/include/asm/bitops.h
GCC will not optimise the code in case of constant parameter, as shown
by the small exemple below.

int ffs_test(void)
{
	return 4 << ffs(31);
}

c0012334 <ffs_test>:
c0012334:       39 20 00 01     li      r9,1
c0012338:       38 60 00 04     li      r3,4
c001233c:       7d 29 00 34     cntlzw  r9,r9
c0012340:       21 29 00 20     subfic  r9,r9,32
c0012344:       7c 63 48 30     slw     r3,r3,r9
c0012348:       4e 80 00 20     blr

With this patch, the same function will compile as follows:

c0012334 <ffs_test>:
c0012334:       38 60 00 08     li      r3,8
c0012338:       4e 80 00 20     blr

The same happens with __ffs()

For non constant calls, the generated code is doing the same,
allthought it is slightly different on 64 bits for ffs():

unsigned long test__ffs(unsigned long x)
{
	return __ffs(x);
}

int testffs(int x)
{
	return ffs(x);
}

On PPC32, before the patch:
0000003c <test__ffs>:
  3c:	7d 23 00 d0 	neg     r9,r3
  40:	7d 23 18 38 	and     r3,r9,r3
  44:	7c 63 00 34 	cntlzw  r3,r3
  48:	20 63 00 1f 	subfic  r3,r3,31
  4c:	4e 80 00 20 	blr

00000050 <testffs>:
  50:	7d 23 00 d0 	neg     r9,r3
  54:	7d 23 18 38 	and     r3,r9,r3
  58:	7c 63 00 34 	cntlzw  r3,r3
  5c:	20 63 00 20 	subfic  r3,r3,32
  60:	4e 80 00 20 	blr

On PPC32, after the patch:
0000002c <test__ffs>:
  2c:	7d 23 00 d0 	neg     r9,r3
  30:	7d 23 18 38 	and     r3,r9,r3
  34:	7c 63 00 34 	cntlzw  r3,r3
  38:	20 63 00 1f 	subfic  r3,r3,31
  3c:	4e 80 00 20 	blr

00000040 <testffs>:
  40:	7d 23 00 d0 	neg     r9,r3
  44:	7d 23 18 38 	and     r3,r9,r3
  48:	7c 63 00 34 	cntlzw  r3,r3
  4c:	20 63 00 20 	subfic  r3,r3,32
  50:	4e 80 00 20 	blr

On PPC64, before the patch:
0000000000000060 <.test__ffs>:
  60:	7c 03 00 d0 	neg     r0,r3
  64:	7c 03 18 38 	and     r3,r0,r3
  68:	7c 63 00 74 	cntlzd  r3,r3
  6c:	20 63 00 3f 	subfic  r3,r3,63
  70:	7c 63 07 b4 	extsw   r3,r3
  74:	4e 80 00 20 	blr

0000000000000080 <.testffs>:
  80:	7c 03 00 d0 	neg     r0,r3
  84:	7c 03 18 38 	and     r3,r0,r3
  88:	7c 63 00 74 	cntlzd  r3,r3
  8c:	20 63 00 40 	subfic  r3,r3,64
  90:	7c 63 07 b4 	extsw   r3,r3
  94:	4e 80 00 20 	blr

On PPC64, after the patch:
0000000000000050 <.test__ffs>:
  50:	7c 03 00 d0 	neg     r0,r3
  54:	7c 03 18 38 	and     r3,r0,r3
  58:	7c 63 00 74 	cntlzd  r3,r3
  5c:	20 63 00 3f 	subfic  r3,r3,63
  60:	4e 80 00 20 	blr

0000000000000070 <.testffs>:
  70:	7c 03 00 d0 	neg     r0,r3
  74:	7c 03 18 38 	and     r3,r0,r3
  78:	7c 63 00 34 	cntlzw  r3,r3
  7c:	20 63 00 20 	subfic  r3,r3,32
  80:	7c 63 07 b4 	extsw   r3,r3
  84:	4e 80 00 20 	blr
(ffs() operates on an int so cntlzw is equivalent to cntlzd)

In addition, when reading the generated vmlinux, we can observe
that with the builtin functions, GCC sometimes efficiently spreads
the instructions within the generated functions while the inline
assembly force them to remain grouped together.

__builtin_ffs() is already used in arch/powerpc/include/asm/page_32.h

Those builtins have been in GCC since at least 3.4.6 (see
https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Other-Builtins.html )
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

It often happens to have simultaneous interrupts, for instance
when having double Ethernet attachment. With the current
implementation, we suffer the cost of kernel entry/exit for each
interrupt.

This patch introduces a loop in __do_irq() to handle all interrupts
at once before returning.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

IRQ 0 is a valid HW interrupt. So get_irq() shall return 0 when
there is no irq, instead of returning irq_linear_revmap(... ,0)

Fixes: f2a0bd37 ("[POWERPC] 8xx: powerpc port of core CPM PIC")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The 8xx has a dedicated exception for breakpoints, that directly
calls do_break()
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Analysis of the assembly code shows that when using user_mode(regs),
at least the 'andi.' is redone all the time, and also
the 'lwz ,132(r31)' most of the time. With the new form, the 'is_user'
is mapped to cr4, then all further use of is_user results in just
things like 'beq cr4,218 <do_page_fault+0x218>'

Without the patch:

  50:	81 1e 00 84 	lwz     r8,132(r30)
  54:	71 09 40 00 	andi.   r9,r8,16384
  58:	40 82 00 0c 	bne     64 <do_page_fault+0x64>

  84:	81 3e 00 84 	lwz     r9,132(r30)
  8c:	71 2a 40 00 	andi.   r10,r9,16384
  90:	41 a2 01 64 	beq     1f4 <do_page_fault+0x1f4>

  d4:	81 3e 00 84 	lwz     r9,132(r30)
  dc:	71 28 40 00 	andi.   r8,r9,16384
  e0:	41 82 02 08 	beq     2e8 <do_page_fault+0x2e8>

 108:	81 3e 00 84 	lwz     r9,132(r30)
 110:	71 28 40 00 	andi.   r8,r9,16384
 118:	41 82 02 28 	beq     340 <do_page_fault+0x340>

 1e4:	81 3e 00 84 	lwz     r9,132(r30)
 1e8:	71 2a 40 00 	andi.   r10,r9,16384
 1ec:	40 82 01 68 	bne     354 <do_page_fault+0x354>

 228:	81 3e 00 84 	lwz     r9,132(r30)
 22c:	71 28 40 00 	andi.   r8,r9,16384
 230:	41 82 ff c4 	beq     1f4 <do_page_fault+0x1f4>

 288:	71 2a 40 00 	andi.   r10,r9,16384
 294:	41 a2 fe 60 	beq     f4 <do_page_fault+0xf4>

 50c:	81 3e 00 84 	lwz     r9,132(r30)
 514:	71 2a 40 00 	andi.   r10,r9,16384
 518:	40 a2 fc e0 	bne     1f8 <do_page_fault+0x1f8>

 534:	81 3e 00 84 	lwz     r9,132(r30)
 53c:	71 2a 40 00 	andi.   r10,r9,16384
 540:	41 82 fc b8 	beq     1f8 <do_page_fault+0x1f8>

This patch creates a local var called 'is_user' which contains the
result of user_mode(regs)

With the patch:

  20:	81 03 00 84 	lwz     r8,132(r3)
  48:	55 09 97 fe 	rlwinm  r9,r8,18,31,31
  58:	2e 09 00 00 	cmpwi   cr4,r9,0
  5c:	40 92 00 0c 	bne     cr4,68 <do_page_fault+0x68>

  88:	41 b2 01 90 	beq     cr4,218 <do_page_fault+0x218>

  d4:	40 92 01 d0 	bne     cr4,2a4 <do_page_fault+0x2a4>

 120:	41 b2 00 f8 	beq     cr4,218 <do_page_fault+0x218>

 138:	41 b2 ff a0 	beq     cr4,d8 <do_page_fault+0xd8>

 1d4:	40 92 00 e0 	bne     cr4,2b4 <do_page_fault+0x2b4>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The result of (trap == 0x400) is already in is_exec.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Function store_updates_sp() checks whether the faulting
instruction is a store updating r1. Therefore we can limit its calls
to store exceptions.

This patch is an improvement of commit a7a9dcd8 ("powerpc: Avoid
taking a data miss on every userspace instruction miss")

With the same microbenchmark app, run with 500 as argument, on an
MPC885 we get:

Before this patch: 152000 DTLB misses
After this patch:  147000 DTLB misses
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This function has not been used since commit 9494a1e8
("powerpc: use generic fixmap.h)
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The check in hpte_find() should be < and not <= for PAGE_OFFSET
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add --orphan-handling=warn to final link flags. This ensures we can
handle all sections explicitly. This would have caught subtle breakage
such as 7de3b27b at build-time.

Also bring existing orphan sections into the fold:
- .text.hot and .text.unlikely are compiler generated sections.
- .sdata2, .dynsbss, .plt are used by PPC32
- We previously did not specify DWARF_DEBUG or STABS_DEBUG
- DWARF_DEBUG did not include all DWARF sections that can be emitted
- A number of sections are unused and can be discarded.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Use a tool to check that the location of "fixed sections" are where
we expected them to be, which catches cases the linker script can't
(stubs being added to start of .text section), and which ends up
being neater.

Sample output:

  ERROR: start_text address is c000000000008100, should be c000000000008000
  ERROR: see comments in arch/powerpc/tools/head_check.sh
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fold in fix from Nick for 4.6 era toolchains]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Very large kernels may require linker stubs for branches from HEAD
text code. The linker may place these stubs before the HEAD text
sections, which breaks the assumption that HEAD text is located at 0
(or the .text section being located at 0x7000/0x8000 on Book3S
kernels).

Provide an option to create a small section just before the .text
section with an empty 256 - 4 bytes, and adjust the start of the .text
section to match. The linker will tend to put stubs in that section
and not break our relative-to-absolute offset assumptions.

This causes a small waste of space on common kernels, but allows large
kernels to build and boot. For now, it is an EXPERT config option,
defaulting to =n, but a reference is provided for it in the build-time
check for such breakage. This is good enough for allyesconfig and
custom users / hackers.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Direct banches from code below __end_interrupts to code above
__end_interrupts when built with CONFIG_RELOCATABLE are disallowed
because they will break when the kernel is not located at 0.

Sample output:

    WARNING: Unrelocated relative branches
    c000000000000118 bl-> 0xc000000000038fb8 <pnv_restore_hyp_resource>
    c00000000000013c b-> 0xc0000000001068a4 <kvm_start_guest>
    c000000000000148 b-> 0xc00000000003919c <pnv_wakeup_loss>
    c00000000000014c b-> 0xc00000000003923c <pnv_wakeup_noloss>
    c0000000000005a4 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
    c000000000001af0 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
    c000000000001b24 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
    c000000000001b58 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

For final link, the powerpc64 linker generates fpr save/restore
functions on-demand, placing them in the .sfpr section. Starting with
binutils 2.25, these can be provided for non-final links with
--save-restore-funcs. Use that where possible for module links.

This saves about 200 bytes per module (~60kB) on powernv defconfig
build.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

There is no need to create a new section for these. Consolidate with
32-bit and just use .text.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

crtsaveres.S is empty with 64-bit builds already, so just don't
build and link it to match the vmlinux build.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Use CONFIG_PPC64_BOOT_WRAPPER not CONFIG_PPC32 to fix BE build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The 64-bit linker creates save/restore functions on demand with final
links, so vmlinux does not require crtsavres.o.

Make crtsavres.o extra-y on 64-bit (it is still required by modules).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The arch version is identical except for comments and white space.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>