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2018-02-05MIPS: CPS: Fix MIPS_ISA_LEVEL_RAW falloutJames Hogan
Commit 17278a91e04f ("MIPS: CPS: Fix r1 .set mt assembler warning") added .set MIPS_ISA_LEVEL_RAW to silence warnings about .set mt on r1, however this can result in a MOVE being encoded as a 64-bit DADDU instruction on certain version of binutils (e.g. 2.22), and reserved instruction exceptions at runtime on 32-bit hardware. Reduce the sizes of the push/pop sections to include only instructions that are part of the MT ASE or which won't convert to 64-bit instructions after .set mips64r2/mips64r6. Reported-by: Greg Ungerer <gerg@linux-m68k.org> Fixes: 17278a91e04f ("MIPS: CPS: Fix r1 .set mt assembler warning") Signed-off-by: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 4.15 Tested-by: Greg Ungerer <gerg@linux-m68k.org> Patchwork: https://patchwork.linux-mips.org/patch/18578/
2017-12-12MIPS: CPS: Fix r1 .set mt assembler warningJames Hogan
MIPS CPS has a build warning on kernels configured for MIPS32R1 or MIPS64R1, due to the use of .set mt without a prior .set mips{32,64}r2: arch/mips/kernel/cps-vec.S Assembler messages: arch/mips/kernel/cps-vec.S:238: Warning: the `mt' extension requires MIPS32 revision 2 or greater Add .set MIPS_ISA_LEVEL_RAW before .set mt to silence the warning. Fixes: 245a7868d2f2 ("MIPS: smp-cps: rework core/VPE initialisation") Signed-off-by: James Hogan <jhogan@kernel.org> Cc: Paul Burton <paul.burton@mips.com> Cc: James Hogan <james.hogan@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: Paul Burton <paul.burton@mips.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17699/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-11-03Update MIPS email addressesPaul Burton
MIPS will soon not be a part of Imagination Technologies, and as such many @imgtec.com email addresses will no longer be valid. This patch updates the addresses for those who: - Have 10 or more patches in mainline authored using an @imgtec.com email address, or any patches dated within the past year. - Are still with Imagination but leaving as part of the MIPS business unit, as determined from an internal email address list. - Haven't already updated their email address (ie. JamesH) or expressed a desire to be excluded (ie. Maciej). - Acked v2 or earlier of this patch, which leaves Deng-Cheng, Matt & myself. New addresses are of the form firstname.lastname@mips.com, and all verified against an internal email address list. An entry is added to .mailmap for each person such that get_maintainer.pl will report the new addresses rather than @imgtec.com addresses which will soon be dead. Instances of the affected addresses throughout the tree are then mechanically replaced with the new @mips.com address. Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com> Cc: Deng-Cheng Zhu <dengcheng.zhu@mips.com> Acked-by: Dengcheng Zhu <dengcheng.zhu@mips.com> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Matt Redfearn <matt.redfearn@mips.com> Acked-by: Matt Redfearn <matt.redfearn@mips.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: trivial@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-30MIPS: CPS: Use GlobalNumber macros rather than magic numbersPaul Burton
We now have definitions for the GlobalNumber register in asm/mipsregs.h, so use them in place of magic numbers in cps-vec.S. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17008/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-06-29MIPS: CPS: Handle spurious VP starts more gracefullyPaul Burton
On pre-r6 systems with the MT ASE the CPS SMP code included checks to halt the VPE running mips_cps_boot_vpes() if its bit in the struct core_boot_config vpe_mask field is clear. This was largely done in order to allow us to start arbitrary VPEs within a core despite the fact that hardware is typically configured to run only VPE0 after powering up a core. VPE0 would start the desired other VPEs, halt itself, and the fact that VPE0 started would be largely hidden & irrelevant. In MIPSr6 multithreading we have control over which VPs start executing when a core powers up via the cores CPC registers accessed remotely through the redirect block. For this reason the MIPSr6 multithreading path in mips_cps_boot_vpes() hasn't bothered up until now to handle halting the VP running it. However it is possible to power up cores entirely in hardware by using a pwr_up pin associated with the core. Unfortunately some systems wire this pin to a logic 1, which means that it is possible for a core to power up at a point that software doesn't expect. The result is that we generally go execute the kernel on a CPU that ought not to be running & the results can be unpredictable. Handle this case by stopping VPs that we don't expect to be running in mips_cps_boot_vpes() - with this change even if a core powers up it will do nothing useful & all VPs within it will stop running before they proceed to run general kernel code & do any damage. Ideally we would produce some sort of warning here, but given the stage of core bringup this happens at that would be non-trivial. We also will only hit this if a core starts up after being offlined via hotplug, and when that happens we will already produce a warning that the CPU didn't power down in cps_cpu_die() which seems sufficient. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16198/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-03-21MIPS: smp-cps: Fix retrieval of VPE mask on big endian CPUsMatt Redfearn
The vpe_mask member of struct core_boot_config is of type atomic_t, which is a 32bit type. In cps-vec.S this member was being retrieved by a PTR_L macro, which on 64bit systems is a 64bit load. On little endian systems this is OK, since the double word that is retrieved will have the required less significant word in the correct position. However, on big endian systems the less significant word of the load is retrieved from address+4, and the more significant from address+0. The destination register therefore ends up with the required word in the more significant word e.g. when starting the second VP of a big endian 64bit system, the load PTR_L ta2, COREBOOTCFG_VPEMASK(a0) ends up setting register ta2 to 0x0000000300000000 When this value is written to the CPC it is ignored, since it is invalid to write anything larger than 4 bits. This results in any VP other than VP0 in a core failing to start in 64bit big endian systems. Change the load to a 32bit load word instruction to fix the bug. Fixes: f12401d7219f ("MIPS: smp-cps: Pull boot config retrieval out of mips_cps_boot_vpes") Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15787/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: CPS: Copy EVA configuration when starting secondary VPs.Matt Redfearn
When starting secondary VPEs which support EVA and the SegCtl registers, copy the memory segmentation configuration from the running VPE to ensure that all VPEs in the core have a consistent virtual memory map. The EVA configuration of secondary cores is dealt with when starting the core via the CM. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13291/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: smp-cps: Stop printing EJTAG exceptions to UARTPaul Burton
When CONFIG_MIPS_CPS_NS16550 is enabled, some register state is dumped to the UART when an exception is taken via the BEV on secondary cores. EJTAG exceptions are architecturally expected to be handled by the BEV even when Status.BEV is 0. This effectively means that if userland executes an sdbbp instruction on a secondary core then the kernel dumps register state to the UART even though the exception is perfectly normal & expected. Prevent this by simply not dumping information to the UART for EJTAG exceptions. Fixes: 609cf6f2291a ("MIPS: CPS: Early debug using an ns16550-compatible UART") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12341/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: smp-cps: Support MIPSr6 Virtual ProcessorsPaul Burton
Introduce support for bringing up Virtual Processors in MIPSr6 systems as CPUs, much like their VPE parallel from the now-deprecated MT ASE. The existing mips_cps_boot_vpes function fits the MIPSr6 architecture pretty well - it can now simply write the mask of running VPs to the VC_RUN register, rather than looping through each & starting or stopping as appropriate as is done for VPEs from the MT ASE. Thus the VP support is in general an extension & simplification of the existing MT ASE VPE (aka SMVP) support. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Niklas Cassel <niklas.cassel@axis.com> Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12339/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: smp-cps: Skip core setup if coherentPaul Burton
In preparation for supporting MIPSr6 multithreading (ie. VPs) which will begin execution from the core reset vector, skip core level setup if the core is already coherent. This is never the case when a core is first started, since boot_core explicitly clears the cores GCR_Cx_COH_EN register, and always the case when secondary VPs start since the first VP to start will have enabled coherence after initialising the core & its caches. One notable side effect of this patch is that eva_init gets called slightly earlier, prior to mips_cps_core_init rather than after it. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12338/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: smp-cps: Pull boot config retrieval out of mips_cps_boot_vpesPaul Burton
The mips_cps_boot_vpes function previously included code to retrieve pointers to the core & VPE boot configuration structs. These structures were used both by mips_cps_boot_vpes and by its mips_cps_core_entry callsite. In preparation for skipping the call to mips_cps_boot_vpes on some invocations of mips_cps_core_entry, pull the calculation of those pointers out into a separate function such that it can continue to be shared. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Niklas Cassel <niklas.cassel@axis.com> Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12337/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: smp-cps: Pull cache init into a functionPaul Burton
In preparation for further modifications to mips_cps_core_entry, pull the L1 cache initialisation out into a separate function. This both makes the code in mips_cps_core_entry read more clearly, particularly when modifying it, and shortens it which will become important as code is added that needs to continue to fit within the reset vector. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12336/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-12-22MIPS: CPS: drop .set mips64r2 directivesPaul Burton
Commit 977e043d5ea1 ("MIPS: kernel: cps-vec: Replace mips32r2 ISA level with mips64r2") leads to .set mips64r2 directives being present in 32 bit (ie. CONFIG_32BIT=y) kernels. This is incorrect & leads to MIPS64 instructions being emitted by the assembler when expanding pseudo-instructions. For example the "move" instruction can legitimately be expanded to a "daddu". This causes problems when the kernel is run on a MIPS32 CPU, as CONFIG_32BIT kernels of course often are... Fix this by dropping the .set <ISA> directives entirely now that Kconfig should be ensuring that kernels including this code are built with a suitable -march= compiler flag. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: <stable@vger.kernel.org> # 3.16+ Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10869/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11MIPS: CPS: Skip Config1 presence checkPaul Burton
The Config1 register is architecturally defined as required, and is thus present in all systems which may make use of cps-vec.S. Skip the check for its presence via the Config.M bit. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11204/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11MIPS: CPS: Read CM GCR base from cop0Paul Burton
Rather than patching the start of mips_cps_core_entry to provide the base address of the CM GCRs, simply read that base address from the cop0 CMGCRBase register, converting from the physical address to an uncached virtual address. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Bresticker <abrestic@chromium.org> Cc: linux-kernel@vger.kernel.org Cc: Niklas Cassel <niklas.cassel@axis.com> Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/11203/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11MIPS: CPS: Early debug using an ns16550-compatible UARTPaul Burton
Provide support for outputting early debug information, in the form of various register values should an exception occur, during the early bringup of secondary cores. This code requires an ns16550-compatible UART accessible from the secondary core, and is written in assembly due to the environment in which such early exceptions occur where way may not have a stack, be coherent or even have initialised caches. [ralf@linux-mips.org: Fix merge conflict.] Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: Andrew Bresticker <abrestic@chromium.org> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Jason Cooper <jason@lakedaemon.net> Cc: linux-kernel@vger.kernel.org Cc: James Hogan <james.hogan@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/11202/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-10-26MIPS: CPS: Set Status.KX on entry for MIPS64 kernelsPaul Burton
If the kernel may make use of 64 bit addresses outside of the compatibility address space then we need to set KX such that those accesses can succeed. Do so for MIPS64 kernels. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11201/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-10-26MIPS: CPS: Set Status.BEV bit during early bootPaul Burton
Set the Status.BEV bit throughout the early startup of a secondary core such that if an exception occurs the core branches to one of the exception vector entries from cps-vec.S, rather than branching to whatever is set in EBase. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11200/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-30MIPS: CPS: #ifdef on CONFIG_MIPS_MT_SMP rather than CONFIG_MIPS_MTPaul Burton
The CONFIG_MIPS_MT symbol can be selected by CONFIG_MIPS_VPE_LOADER in addition to CONFIG_MIPS_MT_SMP. We only want MT code in the CPS SMP boot vector if we're using MT for SMP. Thus switch the config symbol we ifdef against to CONFIG_MIPS_MT_SMP. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: <stable@vger.kernel.org> # 3.16+ Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10867/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-30MIPS: CPS: Don't include MT code in non-MT kernels.Paul Burton
The MT-specific code in mips_cps_boot_vpes can safely be omitted from kernels which don't support MT, with the default VPE==0 case being used as it would be after the has_mt (Config3.MT) check failed at runtime. Discarding the code entirely will save us a few bytes & allow cleaner handling of MT ASE instructions by later patches. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: <stable@vger.kernel.org> # 3.16+ Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10866/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-30MIPS: CPS: Stop dangling delay slot from has_mt.Paul Burton
The has_mt macro ended with a branch, leaving its callers with a delay slot that would be executed if Config3.MT is not set. However it would not be executed if Config3 (or earlier Config registers) don't exist which makes it somewhat inconsistent at best. Fill the delay slot in the macro & fix the mips_cps_boot_vpes caller appropriately. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: <stable@vger.kernel.org> # 3.16+ Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10865/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-08-28MIPS: CPS: use 32b accesses to GCRsPaul Burton
Commit b677bc03d757 ("MIPS: cps-vec: Use macros for various arithmetics and memory operations") replaced various load & store instructions through cps-vec.S with the PTR_L & PTR_S macros. However it was somewhat overzealous in doing so for CM GCR accesses, since the bit width of the CM doesn't necessarily match that of the CPU. The registers accessed (GCR_CL_COHERENCE & GCR_CL_ID) should be safe to simply always access using 32b instructions, so do so in order to avoid issues when using a 32b CM with a 64b CPU. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: <stable@vger.kernel.org> # 3.16+ Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: James Hogan <james.hogan@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/10864/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-07-09MIPS: cps-vec: Use macros for various arithmetics and memory operationsMarkos Chandras
Replace lw/sw and various arithmetic instructions with macros so the code can work on 64-bit kernels as well. Cc: <stable@vger.kernel.org> # 3.16+ Reviewed-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10591/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-07-09MIPS: kernel: cps-vec: Replace KSEG0 with CKSEG0Markos Chandras
In preparation for 64-bit CPS support, we replace KSEG0 with CKSEG0 so 64-bit kernels can be supported. Cc: <stable@vger.kernel.org> # 3.16+ Reviewed-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10590/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-07-09MIPS: kernel: cps-vec: Use ta0-ta3 pseudo-registers for 64-bitMarkos Chandras
The cps-vec code assumes O32 ABI and uses t4-t7 in quite a few places. This breaks the build on 64-bit. As a result of which, use the pseudo-registers ta0-ta3 to make the code compatible with 64-bit. Cc: <stable@vger.kernel.org> # 3.16+ Reviewed-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10589/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-07-09MIPS: kernel: cps-vec: Replace mips32r2 ISA level with mips64r2Markos Chandras
mips32r2 is a subset of mips64r2, so we replace mips32r2 with mips64r2 in preparation for 64-bit CPS support. Cc: <stable@vger.kernel.org> # 3.16+ Reviewed-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10588/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-07-09MIPS: kernel: cps-vec: Replace 'la' macro with PTR_LAMarkos Chandras
The PTR_LA macro will pick the correct "la" or "dla" macro to load an address to a register. This gets rids of the following warnings (and others) when building a 64-bit CPS kernel: arch/mips/kernel/cps-vec.S:63: Warning: la used to load 64-bit address arch/mips/kernel/cps-vec.S:159: Warning: la used to load 64-bit address arch/mips/kernel/cps-vec.S:220: Warning: la used to load 64-bit address arch/mips/kernel/cps-vec.S:240: Warning: la used to load 64-bit address [...] Cc: <stable@vger.kernel.org> # 3.16+ Reviewed-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10587/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-17MIPS: kernel: cps-vec: Replace "addi" with "addiu"Markos Chandras
The "addi" instruction will trap on overflows which is not something we need in this code, so we replace that with "addiu". Link: http://www.linux-mips.org/archives/linux-mips/2015-01/msg00430.html Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: <stable@vger.kernel.org> # v3.15+ Cc: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2014-11-24MIPS: kernel: cps-vec: Set ISA level to mips32r2 for the MIPS MT ASEMarkos Chandras
Fixes the following build warnings: arch/mips/kernel/cps-vec.S: Assembler messages: arch/mips/kernel/cps-vec.S:228: Warning: the `mt' extension requires MIPS32 revision 2 or greater [...] arch/mips/kernel/cps-vec.S: Assembler messages: arch/mips/kernel/cps-vec.S:345: Warning: the `mt' extension requires MIPS32 revision 2 or greater Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: Paul Burton <Paul.Burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7355/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-08-19MIPS: CPS: Initialize EVA before bringing up VPEs from secondary coresMarkos Chandras
The CPS code is doing several memory loads when configuring the VPEs from secondary cores, so the segmentation control registers must be initialized in time otherwise the kernel will crash with strange TLB exceptions. Reviewed-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Patchwork: http://patchwork.linux-mips.org/patch/7424/ Signed-off-by: James Hogan <james.hogan@imgtec.com>
2014-05-28MIPS: smp-cps: duplicate core0 CCA on secondary coresPaul Burton
Rather than hardcoding CCA=0x5 for secondary cores, re-use the CCA from the boot CPU. This allows overrides of the CCA using the cca= kernel parameter to take effect on all CPUs for consistency. Signed-off-by: Paul Burton <paul.burton@imgtec.com>
2014-05-28MIPS: pm-cps: add PM state entry code for CPS systemsPaul Burton
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: Paul Burton <paul.burton@imgtec.com>
2014-05-28MIPS: smp-cps: rework core/VPE initialisationPaul Burton
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: Paul Burton <paul.burton@imgtec.com>
2014-03-26MIPS: Coherent Processing System SMP implementationPaul Burton
This patch introduces a new SMP implementation for systems implementing the MIPS Coherent Processing System architecture. The kernel will make use of the Coherence Manager, Cluster Power Controller & Global Interrupt Controller in order to detect, bring up & make use of other cores in the system. SMTC is not supported, so only a single TC per VPE in the system is used. That is, this option enables an SMVP style setup but across multiple cores. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6362/ Patchwork: https://patchwork.linux-mips.org/patch/6611/ Patchwork: https://patchwork.linux-mips.org/patch/6651/ Patchwork: https://patchwork.linux-mips.org/patch/6652/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>