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path: root/arch/powerpc/platforms/pseries/xics.c
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2009-07-08powerpc/pseries: Use pr_devel() in xics.cMichael Ellerman
pr_debug() can now result in code being generated even when DEBUG is not defined. That's not really desirable in some places. With CONFIG_DYNAMIC_DEBUG=y: size before: text data bss dec hex filename 7720 5488 296 13504 34c0 platforms/pseries/xics.o size after: text data bss dec hex filename 7535 5456 296 13287 33e7 platforms/pseries/xics.o Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-04-28irq: change ->set_affinity() to return statusYinghai Lu
according to Ingo, change set_affinity() in irq_chip should return int, because that way we can handle failure cases in a much cleaner way, in the genirq layer. v2: fix two typos [ Impact: extend API ] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: linux-arch@vger.kernel.org LKML-Reference: <49F654E9.4070809@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12irq: update all arches for new irq_descMike Travis
Impact: cleanup, update to new cpumask API Irq_desc.affinity and irq_desc.pending_mask are now cpumask_var_t's so access to them should be using the new cpumask API. Signed-off-by: Mike Travis <travis@sgi.com>
2009-01-02Merge branch 'cpus4096-for-linus-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits) x86: export vector_used_by_percpu_irq x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and() sched: nominate preferred wakeup cpu, fix x86: fix lguest used_vectors breakage, -v2 x86: fix warning in arch/x86/kernel/io_apic.c sched: fix warning in kernel/sched.c sched: move test_sd_parent() to an SMP section of sched.h sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0 sched: activate active load balancing in new idle cpus sched: bias task wakeups to preferred semi-idle packages sched: nominate preferred wakeup cpu sched: favour lower logical cpu number for sched_mc balance sched: framework for sched_mc/smt_power_savings=N sched: convert BALANCE_FOR_xx_POWER to inline functions x86: use possible_cpus=NUM to extend the possible cpus allowed x86: fix cpu_mask_to_apicid_and to include cpu_online_mask x86: update io_apic.c to the new cpumask code x86: Introduce topology_core_cpumask()/topology_thread_cpumask() x86: xen: use smp_call_function_many() x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c ... Fixed up trivial conflict in kernel/time/tick-sched.c manually
2008-12-16powerpc/pseries: Check for GIQ indicator before calling set-indicatorNathan Lynch
Since "Factor out cpu joining/unjoining the GIQ" (b4963255ad5a426f04a0bb15c4315fa4bb40cde9) the WARN_ON in xics_set_cpu_giq() is being triggered during boot on JS20 because the GIQ indicator is not available on that platform. While the warning is harmless and the system runs normally, it's nicer to check for the existence of the indicator before trying to manipulate it. Implement rtas_indicator_present(), which searches the /rtas/rtas-indicators property for the given indicator token, and use this function in xics_set_cpu_giq(). Also use a WARN statement in xics_set_cpu_giq to get better information on failure. Signed-off-by: Nathan Lynch <ntl@pobox.com> Acked-by: Milton Miller <miltonm@bga.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-12-13cpumask: make irq_set_affinity() take a const struct cpumaskRusty Russell
Impact: change existing irq_chip API Not much point with gentle transition here: the struct irq_chip's setaffinity method signature needs to change. Fortunately, not widely used code, but hits a few architectures. Note: In irq_select_affinity() I save a temporary in by mangling irq_desc[irq].affinity directly. Ingo, does this break anything? (Folded in fix from KOSAKI Motohiro) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Grant Grundler <grundler@parisc-linux.org> Acked-by: Ingo Molnar <mingo@redhat.com> Cc: ralf@linux-mips.org Cc: grundler@parisc-linux.org Cc: jeremy@xensource.com Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
2008-12-13cpumask: change cpumask_scnprintf, cpumask_parse_user, cpulist_parse, and ↵Rusty Russell
cpulist_scnprintf to take pointers. Impact: change calling convention of existing cpumask APIs Most cpumask functions started with cpus_: these have been replaced by cpumask_ ones which take struct cpumask pointers as expected. These four functions don't have good replacement names; fortunately they're rarely used, so we just change them over. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: paulus@samba.org Cc: mingo@redhat.com Cc: tony.luck@intel.com Cc: ralf@linux-mips.org Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: cl@linux-foundation.org Cc: srostedt@redhat.com
2008-11-05powerpc/pseries: Fix getting the server number sizeSebastien Dugue
The 'ibm,interrupt-server#-size' properties are not in the cpu nodes, which is where we currently look for them, but rather live under the interrupt source controller nodes (which have "ibm,ppc-xics" in their compatible property). This moves the code that looks for the ibm,interrupt-server#-size properties from xics_update_irq_servers() into xics_init_IRQ(). Also this adds a check for mismatched sizes across the interrupt source controller nodes. Not sure this is necessary as in this case the firmware might be seriously busted. This property only appears on POWER6 boxes and is only used in the set-indicator(gqirm) call, and apparently firmware currently ignores the value we pass. Nevertheless we need to fix it in case future firmware versions use it. Signed-off-by: Sebastien Dugue <sebastien.dugue@bull.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Milton Miller <miltonm@bga.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-10-13powerpc/xics: Reduce and comment xics IPI use of memory barriersMilton Miller
A single full sync (mb()) is requrired to order the mmio to the qirr reg with the set or clear of the message word. However, test_and_clear_bit has the effect of smp_mb() and we are not doing any other io from here, so we don't need a mb per bit processed. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: Make printk format strings fit on one lineMilton Miller
Several printks were broken at word boundaries for line length. Some even referred to old function names. Using __func__ and changing the text slightly for the format allows these printk formats to fit on one line. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: Mark xics IPI interrupt as per-cpuMilton Miller
It is physically per-cpu, and we want the irq layer to treat it that way. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: EOI xics ipi by hand in kexecMilton Miller
EOI normally has the side effect of returning the cpu to the base priority to recieve the next interrupt. This is actually controlled by the top byte of the xirr register. When we are exiting the kernel in kexec we must eoi the ipi for the next kernel because we never return from the handler, but we want to leave interrupt delivery blocked until the next kernel takes action. Since the hardware ipi vector is fixed, its easiest to just do the eoi explicitly. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: Factor out cpu joining/unjoining the GIQMilton Miller
This factors out processors joining and unjoining the Global Interrupt Queue into a separate function. There is a bit of math to calculate the arguments to rtas to join or leave the global interrupt queue, and a warning on failure afterwards. Make a helper for the 3 callers. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: Initialization code cleanupsMilton Miller
We only need to check the ibm,interrupt-server#-size property once, not once per global server and thread. We can use !CONFIG_SMP cpu masks and hard_smp_processor_id() to avoid an ifdef. Put the node when breaking out of the loop on lpar systems. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: Trim #include listMilton Miller
Trim unneeded includes from xics.c. We don't use signals or gfp flags, we use only OF functions and don't need prom, and the 8259 is now handled by our caller. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: Change *_xirr_info_set() prototype to avoid castsMilton Miller
The xirr is 32 bits in hardware, but the hypervisor requries the upper bits of the register to be clear on the hcall. By changing the type from signed to unsigned int we can drop masking it back to 32 bits. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: Rearrange file to group code by functionMilton Miller
Now that xics_update_irq_servers is called only from init and hotplug code, it becomes possible to clean up the ordering of functions in the file, grouping them but the interfaces they implement. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: Consolidate ipi message encode and decodeMilton Miller
xics supports only one ipi per cpu, and expects software to use some queue to know why the interrupt was sent. In Linux, we use a an array of bitmaps indexed by cpu to identify the message. Currently the bits are set in smp.c and decoded in xics.c, with the data structure in a header file. Consolidate the code in xics.c similar to mpic and other interrupt controllers. Also, while making the the array static, the message word doesn't need to be volatile as set_bit and test_clear_bit take care of it for us, and put it under ifdef smp. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: Update default_server during migrate_irqs_awayMilton Miller
Currently, every time we determine which irq server to use, we check if default_server, which is the id of the bootcpu, is still online. But default_server is a hardware cpu, not the logical cpu id needed to index cpu_online_map. Since the default server can only go offline during a cpu hotplug event, explicitly check the default server and choose the new one when we move irqs away from the cpu being offlined. This has the added benefit of only needing the boot_cpuid to be updated and not relying on the cpu being marked offline during migrate_irqs_away. Also, since xics_update_irq_servers only reads device tree information, we can call it before xics_init_host in xics_init_IRQ and then default_server will always be valid when we can reach get_irq_server via the host ops. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-13powerpc/xics: EOI unmapped irqs after disabling themMilton Miller
When reciving an irq vector that does not have a linux mapping, the kernel prints a message and calls RTAS to disable the irq source. Previously the kernel did not EOI the interrupt, causing the source to think it is still being processed by software. While this does add an additional layer of protection against interrupt storms had RTAS failed to disable the source, it also prevents the interrupt from working when a driver later enables it. (We could alternatively send an EOI on startup, but that strategy would likely fail on an emulated xics.) All interrupts should be disabled when the kernel starts, but this can be observed if a driver does not shutdown an interrupt in its reboot hook before starting a new kernel with kexec. Michael reports this can be reproduced trivially by banging the keyboard while kexec'ing on a P5 LPAR: even though the hvc_console driver request's the console irq later in boot, the console is non-functional because we're receiving no console interrupts. Reported-By: Michael Ellerman Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-09-15powerpc: Separate the irq radix tree insertion and lookupSebastien Dugue
irq_radix_revmap() currently serves 2 purposes, irq mapping lookup and insertion which happen in interrupt and process context respectively. Separate the function into its 2 components, one for lookup only and one for insertion only. Fix the only user of the revmap tree (XICS) to use the new functions. Also, move the insertion into the radix tree of those irqs that were requested before it was initialized at said tree initialization. Mutual exclusion between the tree initialization and readers/writers is handled via a state variable (revmap_trees_allocated) set to 1 when the tree has been initialized and set to 2 after the already requested irqs have been inserted in the tree by the init path. This state is checked before any reader or writer access just like we used to check for tree.gfp_mask != 0 before. Finally, now that we're not any longer inserting nodes into the radix-tree in interrupt context, turn the GFP_ATOMIC allocations into GFP_KERNEL ones. Signed-off-by: Sebastien Dugue <sebastien.dugue@bull.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-26powerpc: convert to generic helpers for IPI function callsJens Axboe
This converts ppc to use the new helpers for smp_call_function() and friends, and adds support for smp_call_function_single(). ppc loses the timeout functionality of smp_call_function_mask() with this change, as the generic code does not provide that. Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-04-24[POWERPC] Add CONFIG_PPC_PSERIES_DEBUG to enable debugging for platforms/pseriesMichael Ellerman
Add a DEBUG config setting which turns on all (most) of the debugging under platforms/pseries. To have this take effect we need to remove all the #undef DEBUG's, in various files. We leave the #undef DEBUG in platforms/pseries/lpar.c, as this enables debugging printks from the low-level hash table routines, and tends to make your system unusable. If you want those enabled you still have to turn them on by hand. Also some of the RAS code has a DEBUG block which causes a functional change, so I've keyed this off a different (non-existant) debug #define. This is only enabled if you have PPC_EARLY_DEBUG enabled also. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-18[POWERPC] Simplify xics direct/lpar irq_host setupMichael Ellerman
The xics code currently has a direct and lpar variant of xics_host_map, the only difference being which irq_chip they use. If we remember which irq_chip we're using we can combine these two routines. That also allows us to have a single irq_host_ops instead of two. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-18[POWERPC] Move xics_setup_8259_cascade() into platforms/pseries/setup.cMichael Ellerman
The code in xics.c to setup the i8259 cascaded irq handler is not really xics specific, so move it into setup.c - we will clean this up further in a subsequent patch. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-03-30powerpc/pseries/xcis: ansifyAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07[POWERPC] Update default irq servers when boot cpu is removedNathan Fontenot
The xics code does update the default server information when the boot cpu is removed. This patch recognizes when the boot cpu is being removed and updates the appropriate information based on the new 'boot cpu'. Failure to update this information can causes us to leave irqs pinned to cpus that are being removed, especially when removing the boot cpu. The cpu is removed from the kernel, but cpu dlpar remove operations fail since we cannot return the cpu to the hypervisor. Signed-off-by: Nathan Fonteno <nfont@austin.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-07[POWERPC] Remove redundant of_get_cpu_node routineNathan Fontenot
It appears that xics.c has its own of_get_cpu_node(). Remove this and use the common one from prom.c. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-07[POWERPC] Split xics_teardown_cpu()Nathan Fontenot
This splits off the kexec path bits of the xics_teardown_cpu() routine into its own xics_kexec_teardown_cpu() routine. With the previous combined routine the CPPR for a cpu that is being removed may have its CPPR reset in the plpar_eoi() call (which explicitly sets the CPPR to a non-zero value). Splitting of the kexec bits of the code prevents this from happening in the cpu remove path. Once again, this does not cause the cpu remove from the kernel to fail, but it does cause cpu dlpar operations to not be able to return the cpu to the hypervisor. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-07[POWERPC] Update irq descriptor affinityNathan Fontenot
The affinity mask in the virq descriptor needs to be set before we reset the affinity for the virq. Without doing this the call to get the new irq server fails and we end up leaving the virq pinned to the cpu we are removing. This does not fail the cpu remove from the kernel, but it does prevent cpu dlpar remove operations from returning the cpu to the hypervisor. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-12-20[POWERPC] Push down or eliminate smp_processor_id calls in xics codeMilton Miller
The per-processor interrupt request register and current processor priority register are only accessed on the current cpu. In fact the hypervisor doesn't even let us choose which cpu's registers to access. The only function to use cpu twice is xics_migrate_irqs_away, not a fast path. But we can cache the result of get_hard_processor_id() instead of calling get_hard_smp_processor_id(cpu) in a loop across the call to rtas. Years ago the irq code passed smp_processor_id into get_irq, I thought we might initialize the CPPR third party at boot as an extra measure of saftey, and it made the code symmetric with the qirr (queued interrupt for software generated interrupts), but now it is just extra and sometimes unneeded work to pass it down. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-10-03Merge branch 'linux-2.6' into for-2.6.24Paul Mackerras
2007-10-02[POWERPC] Fix xics set_affinity codeAnton Blanchard
On a POWER6 machine running 2.6.23-rc8 I sometimes see the following error: xics_set_affinity: No online cpus in the mask 00000000,00000000,00000000,00000001 for irq 20 In a desperate attempt to get a changelog entry in 2.6.23, I took a look into it. It turns out we are passing a real and not a virtual irq into get_irq_server. This works for the case where hwirq < NR_IRQS and we set virq = hwirq. In my case however hwirq = 590082 and we try and access irq_desc[590082], slightly past the end at 512 entries. Lucky we ship lots of memory with our machines. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-09-14[POWERPC] Add an optional device_node pointer to the irq_hostMichael Ellerman
The majority of irq_host implementations (3 out of 4) are associated with a device_node, and need to stash it somewhere. Rather than having it somewhere different for each host, add an optional device_node pointer to the irq_host structure. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-25[POWERPC] Fix interrupt distribution in ppc970Mohan Kumar M
In some of the PPC970 based systems, interrupt would be distributed to offline cpus also even when booted with "maxcpus=1". So check whether cpu online map and cpu present map are equal or not. If they are equal default_distrib_server is used as interrupt server otherwise boot cpu (default_server) used as interrupt server. In addition to this, if an interrupt is assigned to a specific cpu (ie smp affinity) and if that cpu is not online, the earlier code used to return the default_distrib_server as interrupt server. This introduces an additional parameter to the get_irq function, called strict_check. Based on this parameter, if the cpu is not online either default_distrib_server or -1 is returned. Signed-off-by: Mohan Kumar M <mohan@in.ibm.com> Cc: Michael Ellerman <michael@ellerman.id.au> Acked-by: Milton Miller <miltonm@bga.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-02[POWERPC] Fix compile warning in pseries xics codeMichael Neuling
In 616883df78bd4b3fcdb6ddc39bd3d4cb902bfa32 request_irq was marked as __must_check so we must... er... check it. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-05-07[POWERPC] Rename device_is_compatible to of_device_is_compatibleStephen Rothwell
for consistency with other Open Firmware interfaces (and Sparc). This is just a straight replacement. This leaves the compatibility define in place. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-04-13[POWERPC] Rename get_property to of_get_property: arch/powerpcStephen Rothwell
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-04-13[POWERPC] Rename prom_n_addr_cells to of_n_addr_cellsStephen Rothwell
This is more consistent and gets us closer to the Sparc code. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-01-09[POWERPC] Avoid calling get_irq_server() with a real, not virtual irq.Michal Ostrowski
We can use default_server when masking an interrupt vector. get_irq_server() assumes a virtual irq, so badness may happen if we give it a real one. Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-12-04[POWERPC] pSeries/kexec: Fix for interrupt distributionMohan Kumar M
This allows any secondary CPU thread also to become boot cpu for POWER5. The patch is required to solve kdump boot issue when the kdump kernel is booted with parameter "maxcpus=1". XICS init code tries to match the current boot cpu id with "reg" property in each CPU node in the device tree. But CPU node is created only for primary thread CPU ids and "reg" property only reflects primary CPU ids. So when a kernel is booted on a secondary cpu thread above condition will never meet and the default distribution server is left as zero. This leads to route the interrupts to CPU 0, but which is not online at this time. We use ibm,ppc-interrupt-server#s to check for both primary and secondary CPU ids. Accordingly default distribution server value is initialized from "ibm,ppc-interrupt-gserver#s" property. We loop through ibm,ppc-interrupt-gserver#s property to find the global distribution server from the last entry that matches with boot cpuid. Signed-off-by: Mohan Kumar M <mohan@in.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-10-07[POWERPC] Fix up after irq changesOlaf Hering
Remove struct pt_regs * from all handlers. Also remove the regs argument from get_irq() functions. Compile tested with arch/powerpc/config/* and arch/ppc/configs/prep_defconfig Signed-off-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-08-08Merge branch 'merge'Paul Mackerras
2006-08-08[POWERPC] Fix might-sleep warning on removing cpusHaren Myneni
Noticing the following might_sleep warning (dump_stack()) during kdump testing when CONFIG_DEBUG_SPINLOCK_SLEEP is enabled. All secondary CPUs will be calling rtas_set_indicator with interrupts disabled to remove them from global interrupt queue. BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:463 in_atomic():1, irqs_disabled():1 Call Trace: [C00000000FFFB970] [C000000000010234] .show_stack+0x68/0x1b0 (unreliable) [C00000000FFFBA10] [C000000000059354] .__might_sleep+0xd8/0xf4 [C00000000FFFBA90] [C00000000001D1BC] .rtas_busy_delay+0x20/0x5c [C00000000FFFBB20] [C00000000001D8A8] .rtas_set_indicator+0x6c/0xcc [C00000000FFFBBC0] [C000000000048BF4] .xics_teardown_cpu+0x118/0x134 [C00000000FFFBC40] [C00000000004539C] .pseries_kexec_cpu_down_xics+0x74/0x8c [C00000000FFFBCC0] [C00000000002DF08] .crash_ipi_callback+0x15c/0x188 [C00000000FFFBD50] [C0000000000296EC] .smp_message_recv+0x84/0xdc [C00000000FFFBDC0] [C000000000048E08] .xics_ipi_dispatch+0xf0/0x130 [C00000000FFFBE50] [C00000000009EF10] .handle_IRQ_event+0x7c/0xf8 [C00000000FFFBF00] [C0000000000A0A14] .handle_percpu_irq+0x90/0x10c [C00000000FFFBF90] [C00000000002659C] .call_handle_irq+0x1c/0x2c [C00000000058B9C0] [C00000000000CA10] .do_IRQ+0xf4/0x1a4 [C00000000058BA50] [C0000000000044EC] hardware_interrupt_entry+0xc/0x10 --- Exception: 501 at .plpar_hcall_norets+0x14/0x1c LR = .pseries_dedicated_idle_sleep+0x190/0x1d4 [C00000000058BD40] [C00000000058BDE0] 0xc00000000058bde0 (unreliable) [C00000000058BDF0] [C00000000001270C] .cpu_idle+0x10c/0x1e0 [C00000000058BE70] [C000000000009274] .rest_init+0x44/0x5c To fix this issue, rtas_set_indicator_fast() is added so that will not wait for RTAS 'busy' delay and this new function is used for kdump (in xics_teardown_cpu()) and for CPU hotplug ( xics_migrate_irqs_away() and xics_setup_cpu()). Note that the platform architecture spec says that set-indicator on the indicator we're using here is not permitted to return the busy or extended busy status codes. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-08-01[POWERPC] clean up pseries hcall interfacesAnton Blanchard
Our pseries hcall interfaces are out of control: plpar_hcall_norets plpar_hcall plpar_hcall_8arg_2ret plpar_hcall_4out plpar_hcall_7arg_7ret plpar_hcall_9arg_9ret Create 3 interfaces to cover all cases: plpar_hcall_norets: 7 arguments no returns plpar_hcall: 6 arguments 4 returns plpar_hcall9: 9 arguments 9 returns There are only 2 cases in the kernel that need plpar_hcall9, hopefully we can keep it that way. Pass in a buffer to stash return parameters so we avoid the &dummy1, &dummy2 madness. Signed-off-by: Anton Blanchard <anton@samba.org> -- Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-08-01Merge branch 'merge'Paul Mackerras
2006-07-31[POWERPC] pseries: Constify & voidify get_property()Jeremy Kerr
Now that get_property() returns a void *, there's no need to cast its return value. Also, treat the return value as const, so we can constify get_property later. pseries platform changes. Built for pseries_defconfig Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-07-10[PATCH] powerpc: fix trigger handling in the new irq codeBenjamin Herrenschmidt
This patch slightly reworks the new irq code to fix a small design error. I removed the passing of the trigger to the map() calls entirely, it was not a good idea to have one call do two different things. It also fixes a couple of corner cases. Mapping a linux virtual irq to a physical irq now does only that. Setting the trigger is a different action which has a different call. The main changes are: - I no longer call host->ops->map() for an already mapped irq, I just return the virtual number that was already mapped. It was called before to give an opportunity to change the trigger, but that was causing issues as that could happen while the interrupt was in use by a device, and because of the trigger change, map would potentially muck around with things in a racy way. That was causing much burden on a given's controller implementation of map() to get it right. This is much simpler now. map() is only called on the initial mapping of an irq, meaning that you know that this irq is _not_ being used. You can initialize the hardware if you want (though you don't have to). - Controllers that can handle different type of triggers (level/edge/etc...) now implement the standard irq_chip->set_type() call as defined by the generic code. That means that you can use the standard set_irq_type() to configure an irq line manually if you wish or (though I don't like that interface), pass explicit trigger flags to request_irq() as defined by the generic kernel interfaces. Also, using those interfaces guarantees that your controller set_type callback is called with the descriptor lock held, thus providing locking against activity on the same interrupt (including mask/unmask/etc...) automatically. A result is that, for example, MPIC's own map() implementation calls irq_set_type(NONE) to configure the hardware to the default triggers. - To allow the above, the irq_map array entry for the new mapped interrupt is now set before map() callback is called for the controller. - The irq_create_of_mapping() (also used by irq_of_parse_and_map()) function for mapping interrupts from the device-tree now also call the separate set_irq_type(), and only does so if there is a change in the trigger type. - While I was at it, I changed pci_read_irq_line() (which is the helper I would expect most archs to use in their pcibios_fixup() to get the PCI interrupt routing from the device tree) to also handle a fallback when the DT mapping fails consisting of reading the PCI_INTERRUPT_PIN to know wether the device has an interrupt at all, and the the PCI_INTERRUPT_LINE to get an interrupt number from the device. That number is then mapped using the default controller, and the trigger is set to level low. That default behaviour works for several platforms that don't have a proper interrupt tree like Pegasos. If it doesn't work for your platform, then either provide a proper interrupt tree from the firmware so that fallback isn't needed, or don't call pci_read_irq_line() - Add back a bit that got dropped by my main rework patch for properly clearing pending IPIs on pSeries when using a kexec Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[POWERPC] Add new interrupt mapping core and change platforms to use itBenjamin Herrenschmidt
This adds the new irq remapper core and removes the old one. Because there are some fundamental conflicts with the old code, like the value of NO_IRQ which I'm now setting to 0 (as per discussions with Linus), etc..., this commit also changes the relevant platform and driver code over to use the new remapper (so as not to cause difficulties later in bisecting). This patch removes the old pre-parsing of the open firmware interrupt tree along with all the bogus assumptions it made to try to renumber interrupts according to the platform. This is all to be handled by the new code now. For the pSeries XICS interrupt controller, a single remapper host is created for the whole machine regardless of how many interrupt presentation and source controllers are found, and it's set to match any device node that isn't a 8259. That works fine on pSeries and avoids having to deal with some of the complexities of split source controllers vs. presentation controllers in the pSeries device trees. The powerpc i8259 PIC driver now always requests the legacy interrupt range. It also has the feature of being able to match any device node (including NULL) if passed no device node as an input. That will help porting over platforms with broken device-trees like Pegasos who don't have a proper interrupt tree. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>