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  1. 31 5月, 2014 3 次提交
    • P
      MIPS: Malta: add suspend state entry code · b6911bba
      由 Paul Burton 提交于 
      This patch introduces code which will enter a suspend state via the
PIIX4. This can only be done when PCI support is enabled since it
requires access to PCI I/O space and the generation of a special cycle
on the PCI bus. In cases where PCI is disabled the mips_pm_suspend
function will simply always return an error.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6905/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      b6911bba
    • P
      MIPS: Define some more PIIX4 registers & values · 643c5705
      由 Paul Burton 提交于 
      This patch simply adds definitions for some I/O registers in the PIIX4
PM device, and the magic data for a special cycle which must occur on
the PCI bus in order for the PIIX4 to enter a suspend state.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6903/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      643c5705
    • M
      MIPS: Implement random_get_entropy with CP0 Random · 06947aaa
      由 Maciej W. Rozycki 提交于 
      Update to commit 9c9b415c [MIPS:
Reimplement get_cycles().]

On systems were for whatever reasons we can't use the cycle counter, fall
back to the c0_random register as an entropy source.  It has however a
very small range that makes it suitable for random_get_entropy only and
not get_cycles.

This optimised version compiles to 8 instructions in the fast path even in
the worst case of all the conditions to check being variable (including a
MFC0 move delay slot that is only required for very old processors):

     828:	8cf90000 	lw	t9,0(a3)
			828: R_MIPS_LO16	jiffies
     82c:	40057800 	mfc0	a1,c0_prid
     830:	3c0200ff 	lui	v0,0xff
     834:	00a21024 	and	v0,a1,v0
     838:	1040007d 	beqz	v0,a30 <add_interrupt_randomness+0x22c>
     83c:	3c030000 	lui	v1,0x0
			83c: R_MIPS_HI16	cpu_data
     840:	40024800 	mfc0	v0,c0_count
     844:	00000000 	nop
     848:	00409021 	move	s2,v0
     84c:	8ce20000 	lw	v0,0(a3)
			84c: R_MIPS_LO16	jiffies

On most targets the sequence will be shorter and on some it will reduce to
a single `MFC0 <reg>,c0_count', as all MIPS architecture (i.e. non-legacy
MIPS) processors require the CP0 Count register to be present.

The only known exception that reports MIPS architecture compliance, but
contrary to that lacks CP0 Count is the Ingenic JZ4740 thingy.  For broken
platforms like that this code requires cpu_has_counter to be hardcoded to
0 (i.e. no variable setting is permitted) so as not to penalise all the
other good platforms out there.

The asm barrier is required so that the compiler does not pull any
potentially costly (cold cache!) `cpu_data' variable access into the fast
path.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: John Crispin <blogic@openwrt.org>
Cc: Andrew McGregor <andrewmcgr@gmail.com>
Cc: Dave Taht <dave.taht@bufferbloat.net>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: Simon Kelley <simon@thekelleys.org.uk>
Cc: Jim Gettys <jg@freedesktop.org>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6702/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      06947aaa
  3. 30 5月, 2014 20 次提交
  5. 28 5月, 2014 11 次提交
    • P
      MIPS: cpuidle wait instruction state · da9f970f
      由 Paul Burton 提交于 
      Defines a macro intended to allow trivial use of the regular MIPS wait
instruction from cpuidle drivers, which may simply invoke the macro
within their array of states.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      da9f970f
    • P
      MIPS: pm-cps: add PM state entry code for CPS systems · 3179d37e
      由 Paul Burton 提交于 
      This patch adds code to generate entry & exit code for various low power
states available on systems based around the MIPS Coherent Processing
System architecture (ie. those with a Coherence Manager, Global
Interrupt Controller & for >=CM2 a Cluster Power Controller). States
supported are:

  - Non-coherent wait. This state first leaves the coherent domain and
    then executes a regular MIPS wait instruction. Power savings are
    found from the elimination of coherency interventions between the
    core and any other coherent requestors in the system.

  - Clock gated. This state leaves the coherent domain and then gates
    the clock input to the core. This removes all dynamic power from the
    core but leaves the core at the mercy of another to restart its
    clock. Register state is preserved, but the core can not service
    interrupts whilst its clock is gated.

  - Power gated. This deepest state removes all power input to the core.
    All register state is lost and the core will restart execution from
    its BEV when another core powers it back up. Because register state
    is lost this state requires cooperation with the CONFIG_MIPS_CPS SMP
    implementation in order for the core to exit the state successfully.

The code will detect which states are available on the current system
during boot & generate the entry/exit code for those states. This will
be used by cpuidle & hotplug implementations.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      3179d37e
    • P
      MIPS: smp-cps: function to determine whether CPS SMP is in use · 68c1232f
      由 Paul Burton 提交于 
      The core power down state for cpuidle will require that the CPS SMP
implementation is in use. This patch provides a mips_cps_smp_in_use
function which determines whether or not the CPS SMP implementation is
currently in use.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      68c1232f
    • P
      MIPS: smp-cps: rework core/VPE initialisation · 245a7868
      由 Paul Burton 提交于 
      When hotplug and/or a powered down idle state are supported cases will
arise where a non-zero VPE must be brought online without VPE 0, and it
where multiple VPEs must be onlined simultaneously. This patch prepares
for that by:

  - Splitting struct boot_config into core & VPE boot config structures,
    allocated one per core or VPE respectively. This allows for multiple
    VPEs to be onlined simultaneously without clobbering each others
    configuration.

  - Indicating which VPEs should be online within a core at any given
    time using a bitmap. This allows multiple VPEs to be brought online
    simultaneously and also indicates to VPE 0 whether it should halt
    after starting any non-zero VPEs that should be online within the
    core. For example if all VPEs within a core are offlined via hotplug
    and the user onlines the second VPE within that core:

      1) The core will be powered up.

      2) VPE 0 will run from the BEV (ie. mips_cps_core_entry) to
         initialise the core.

      3) VPE 0 will start VPE 1 because its bit is set in the cores
         bitmap.

      4) VPE 0 will halt itself because its bit is clear in the cores
         bitmap.

  - Moving the core & VPE initialisation to assembly code which does not
    make any use of the stack. This is because if a non-zero VPE is to
    be brought online in a powered down core then when VPE 0 of that
    core runs it may not have a valid stack, and even if it did then
    it's messy to run through parts of generic kernel code on VPE 0
    before starting the correct VPE.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      245a7868
    • P
      MIPS: uasm: add MT ASE yield instruction · d674dd14
      由 Paul Burton 提交于 
      This patch allows use of the MT ASE yield instruction from uasm. It will
be used by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      d674dd14
    • P
      MIPS: uasm: add wait instruction · 53ed1389
      由 Paul Burton 提交于 
      This patch allows use of the wait instruction from uasm. It will be used
by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      53ed1389
    • P
      MIPS: uasm: add sync instruction · 729ff561
      由 Paul Burton 提交于 
      This patch allows use of the sync instruction from uasm. It will be used
by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      729ff561
    • P
      MIPS: uasm: add jalr instruction · 49e9529b
      由 Paul Burton 提交于 
      This patch allows use of the jalr instruction from uasm. It will be used
by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      49e9529b
    • P
      MIPS: uasm: add a label variant of beq · 8dee5901
      由 Paul Burton 提交于 
      This patch allows for use of the beq instruction with labels from uasm,
much as bne & others already do. It will be used by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      8dee5901
    • P
      MIPS: MT: define write_c0_tchalt macro · 27476f3b
      由 Paul Burton 提交于 
      Define a macro to write to the current TCs TCHalt register. This will be
used by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      27476f3b
    • P
      MIPS: add kmap_noncoherent to wire a cached non-coherent TLB entry · e2a9e5ad
      由 Paul Burton 提交于 
      This is identical to kmap_coherent apart from the cache coherency
attribute used for the TLB entry, so kmap_coherent is abstracted to
kmap_prot which is then called for both kmap_coherent &
kmap_noncoherent. This will be used by a subsequent patch.
Suggested-by: NLeonid Yegoshin <leonid.yegoshin@imgtec.com>
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
      e2a9e5ad
  7. 27 5月, 2014 1 次提交
  9. 24 5月, 2014 1 次提交
    • R
      MIPS: MT: Remove SMTC support · b633648c
      由 Ralf Baechle 提交于 
      Nobody is maintaining SMTC anymore and there also seems to be no userbase.
Which is a pity - the SMTC technology primarily developed by Kevin D.
Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT
ASE's power and elegance.

Based on Markos Chandras <Markos.Chandras@imgtec.com> patch
https://patchwork.linux-mips.org/patch/6719/ which while very similar did
no longer apply cleanly when I tried to merge it plus some additional
post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to
merge once upon a time.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      b633648c
  11. 23 5月, 2014 4 次提交