BMC/Intel-BMC/linux.git/arch/powerpc/platforms/cell/interrupt.c, branch dev

powerpc/cell: Fix crash in iic_setup_cpu() after per_cpu changes

2015-04-10T10:02:49+00:00

The conversion from __get_cpu_var() to this_cpu_ptr() in iic_setup_cpu() is wrong. It causes an oops at boot. We need the per-cpu address of struct cpu_iic, not cpu_iic.regs->prio. Sparse noticed this, because we pass a non-iomem pointer to out_be64(), but we obviously don't check the sparse results often enough. Fixes: 69111bac42f5 ("powerpc: Replace __get_cpu_var uses") Signed-off-by: Michael Ellerman

powerpc: Replace __get_cpu_var uses

2014-11-03T01:12:32+00:00

This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt CC: Paul Mackerras Signed-off-by: Christoph Lameter [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman

powerpc: Implement tick broadcast IPI as a fixed IPI message

2014-03-05T04:55:04+00:00

For scalability and performance reasons, we want the tick broadcast IPIs to be handled as efficiently as possible. Fixed IPI messages are one of the most efficient mechanisms available - they are faster than the smp_call_function mechanism because the IPI handlers are fixed and hence they don't involve costly operations such as adding IPI handlers to the target CPU's function queue, acquiring locks for synchronization etc. Luckily we have an unused IPI message slot, so use that to implement tick broadcast IPIs efficiently. Signed-off-by: Srivatsa S. Bhat [Functions renamed to tick_broadcast* and Changelog modified by Preeti U. Murthy] Signed-off-by: Preeti U. Murthy Acked-by: Geoff Levand [For the PS3 part] Signed-off-by: Benjamin Herrenschmidt

powerpc: Free up the slot of PPC_MSG_CALL_FUNC_SINGLE IPI message

2014-03-05T04:53:24+00:00

The IPI handlers for both PPC_MSG_CALL_FUNC and PPC_MSG_CALL_FUNC_SINGLE map to a common implementation - generic_smp_call_function_single_interrupt(). So, we can consolidate them and save one of the IPI message slots, (which are precious on powerpc, since only 4 of those slots are available). So, implement the functionality of PPC_MSG_CALL_FUNC_SINGLE using PPC_MSG_CALL_FUNC itself and release its IPI message slot, so that it can be used for something else in the future, if desired. Signed-off-by: Srivatsa S. Bhat Signed-off-by: Preeti U. Murthy Acked-by: Geoff Levand [For the PS3 part] Signed-off-by: Benjamin Herrenschmidt

irq_domain/powerpc: constify irq_domain_ops

2012-02-16T13:11:24+00:00

Make all the irq_domain_ops structures in powerpc 'static const' Signed-off-by: Grant Likely Cc: Benjamin Herrenschmidt Cc: Thomas Gleixner Cc: Milton Miller Tested-by: Olof Johansson

irq_domain: Replace irq_alloc_host() with revmap-specific initializers

2012-02-16T13:11:22+00:00

Each revmap type has different arguments for setting up the revmap. This patch splits up the generator functions so that each revmap type can do its own setup and the user doesn't need to keep track of how each revmap type handles the arguments. This patch also adds a host_data argument to the generators. There are cases where the host_data pointer will be needed before the function returns. ie. the legacy map calls the .map callback for each irq before returning. v2: - Add void *host_data argument to irq_domain_add_*() functions - fixed failure to compile - Moved IRQ_DOMAIN_MAP_* defines into irqdomain.c Signed-off-by: Grant Likely Cc: Rob Herring Cc: Benjamin Herrenschmidt Cc: Thomas Gleixner Cc: Milton Miller Tested-by: Olof Johansson

irq_domain/powerpc: Use common irq_domain structure instead of irq_host

2012-02-14T21:06:50+00:00

This patch drops the powerpc-specific irq_host structures and uses the common irq_domain strucutres defined in linux/irqdomain.h. It also fixes all the users to use the new structure names. Renaming irq_host to irq_domain has been discussed for a long time, and this patch is a step in the process of generalizing the powerpc virq code to be usable by all architecture. An astute reader will notice that this patch actually removes the irq_host structure instead of renaming it. This is because the irq_domain structure already exists in include/linux/irqdomain.h and has the needed data members. Signed-off-by: Grant Likely Cc: Benjamin Herrenschmidt Cc: Thomas Gleixner Cc: Milton Miller Tested-by: Olof Johansson

powerpc: various straight conversions from module.h --> export.h

2011-10-31T23:30:44+00:00

All these files were including module.h just for the basic EXPORT_SYMBOL infrastructure. We can shift them off to the export.h header which is a way smaller footprint and thus realize some compile time gains. Signed-off-by: Paul Gortmaker

powerpc/cell: Rename ipi functions to match current abstractions

2011-05-26T03:38:58+00:00

Rename functions and arguments to reflect current usage. iic_cause_ipi becomes iic_message_pass and iic_ipi_to_irq becomes iic_msg_to_irq, and iic_request_ipi now takes a message (msg) instead of an ipi number. Also mesg is renamed to msg. Commit f1072939b6 (powerpc: Remove checks for MSG_ALL and MSG_ALL_BUT_SELF) connected the smp_message_pass hook for cell to the underlying iic_cause_IPI, a platform unique name. Later 23d72bfd8f (powerpc: Consolidate ipi message mux and demux) added a cause_ipi hook to the smp_ops, also used in message passing, but for controllers that can not send 4 unique messages and require multiplexing. It is even more confusing that the both take two arguments, but one is the small message ordinal and the other is an opaque long data associated with the cpu. Since cell iic maps messages one to one to ipi irqs, rename the function and argument to translate from ipi to message. Also make it clear that iic_request_ipi takes a message number as the argument for which ipi to create and request. No functionional change, just renames to avoid future confusion. Signed-off-by: Milton Miller Signed-off-by: Benjamin Herrenschmidt

powerpc/cell: Use common smp ipi actions

2011-05-26T03:38:58+00:00

The cell iic interrupt controller has enough software caused interrupts to use a unique interrupt for each of the 4 messages powerpc uses. This means each interrupt gets its own irq action/data combination. Use the seperate, optimized, arch common ipi action functions registered via the helper smp_request_message_ipi instead passing the message as action data to a single action that then demultipexes to the required acton via a switch statement. smp_request_message_ipi will register the action as IRQF_PER_CPU and IRQF_DISABLED, and WARN if the allocation fails for some reason, so no need to print on that failure. It will return positive if the message will not be used by the kernel, in which case we can free the virq. In addition to elimiating inefficient code, this also corrects the error that a kernel built with kexec but without a debugger would not register the ipi for kdump to notify the other cpus of a crash. This also restores the debugger action to be static to kernel/smp.c. Signed-off-by: Milton Miller Signed-off-by: Benjamin Herrenschmidt