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2009-01-14byteorder: make swab.h include asm/swab.h like a regular headerHarvey Harrison
Add swab.h to kbuild.asm and remove the individual entries from each arch, mark as unifdef as some arches have some kernel-only bits inside. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-14[CVE-2009-0029] powerpc: Enable syscall wrappers for 64-bitBenjamin Herrenschmidt
This enables the use of syscall wrappers to do proper sign extension for 64-bit programs. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14[CVE-2009-0029] Rename old_readdir to sys_old_readdirHeiko Carstens
This way it matches the generic system call name convention. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-13powerpc/83xx: Move mcu_mpc8349emitx driver out of drivers/i2c/chips/Anton Vorontsov
This patch is used to help Jean Delvare to get rid of drivers/i2c/chips/ directory. The new location suggested by Kumar Gala: as the driver is 83xx specific it's placed into arch/powerpc/platforms/83xx/. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2009-01-13powerpc/83xx: Make serial ports work on MPC8315E-RDB w/ FSL U-BootsAnton Vorontsov
FSL U-Boots use /soc8315@e0000000 node to search and fixup serial nodes' clock-frequency properties. Though in upstream kernels we use new naming convention -- for IMMR address space dts files specify /immr@e0000000 nodes. This makes FSL U-Boots fail to fixup the clock frequencies, and that leads to serial ports misbehaviour. We can workaround the issue by filling the clock frequency values manually. p.s. For the same reason FSL U-Boots fail to fixup MAC addresses for ethernet nodes, so users should either change the .dts file locally or set MAC address via `ifconfig hw ether' command. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2009-01-13powerpc/e500mc: Doorbells need to be taken w/exceptions disabledKumar Gala
We use Doorbell interrupts for IPIs and thus we need to make sure we aren't interrupted in the process of processing the IPI. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Dave Liu <daveliu@freescale.com>
2009-01-13powerpc: Enable PS3 options and QPACE in ppc64_defconfigMichael Ellerman
To increase the amount of code that's built for a defconfig build. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-13powerpc/powermac: Fix occasional SMP boot failureBenjamin Herrenschmidt
The PowerMac kernel occasionally fails to bring up the secondary CPUs on SMP, the trigger factor seem to be fairly random and related to location of code and data. This appears to be due to the initial loading of the TOC value by the secondary processor which now happens before we clear HID4:RM_CI (Real Mode Cache Invalidate). This bit should really be cleared before we do any load or store other than fetching code. This fix works based on the assumption that all SMP 64-bit PowerMacs use variants of the 970, which fortunately is true, by explicitely clearing that bit, adding an slbia for good measure as RM_CI mode is known to create bogus ERAT entries. I also removed some spurrious debug output that was left enabled by mistake while at it. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-13powerpc/cacheinfo: Rename cache_dir per-cpu variableNathan Lynch
The per_cpu__ prefix on DECLARE_PER_CPU'd variables is going away; rename cache_dir to cache_dir_pcpu. Signed-off-by: Nathan Lynch <ntl@pobox.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-13powerpc: Cleanup from l64 to ll64 change: arch codeStephen Rothwell
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-13powerpc: Change u64/s64 to a long long integer typeIngo Molnar
Convert arch/powerpc/ over to long long based u64: -#ifdef __powerpc64__ -# include <asm-generic/int-l64.h> -#else -# include <asm-generic/int-ll64.h> -#endif +#include <asm-generic/int-ll64.h> This will avoid reoccuring spurious warnings in core kernel code that comes when people test on their own hardware. (i.e. x86 in ~98% of the cases) This is what x86 uses and it generally helps keep 64-bit code 32-bit clean too. [Adjusted to not impact user mode (from paulus) - sfr] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-13powerpc/kexec: Check crash_base for relocatable kernelMilton Miller
Enforce that the crash kernel region never overlaps the current kernel, as it will be written directly on kexec load. Also, default to the previous KDUMP_KERNELBASE if the start is 0. Other architectures (x86, ia64) state that specifying the start address 0 (or omitting it) will result in the kernel allocating it. Before the relocatable patch in 2.6.28, powerpc would adjust any other start value to the hardcoded KDUMP_KERNELBASE of 32M. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-13powerpc: Make dummy section a valid note headerMilton Miller
We are declaring the dummy section (used to work around a binutils bug) as PT_NOTE, but we don't have enough bytes for it to be a valid note header, and kexec userspace complains: Warning: Elf Note name is not null terminated Warning: append= option is not passed. Using the first kernel root partition Warning: Elf Note name is not null terminated Instead of using the arbitray value 0xf177 (aka "fill"), declare a no-name no-description note of type 0. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-13Merge commit 'gcl/gcl-next' into nextBenjamin Herrenschmidt
2009-01-13Merge commit 'kumar/kumar-next' into nextBenjamin Herrenschmidt
2009-01-12[WATCHDOG] Enable watchdog timer on GE Fanuc's SBC610Martyn Welch
Support for the FPGA based watchdog timer on GE Fanuc's SBC610. This patch enables one of the watchdog timers found on the SBC610. There are two identical watchdog timers at different offsets in the above mentioned boards, however the current driver is only capable of supporting one of them. The watchdog timers are also capable of generating interrupts at a user-configurable threshold, though support for this operation is currently not supported by the driver. Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2009-01-11powerpc: Fix cpufreq drivers after cpufreq core changesBenjamin Herrenschmidt
This updates the cpufreq drivers in arch/powerpc so they build again after the core cpufreq changes that broke them in commit in835481d9bcd65720b473db6b38746a74a3964218. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-09powerpc/mpc52xx: remove dead code from GPIO driverWolfram Sang
Eliminate duplicate return statements Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-01-09powerpc/mpc52xx: Properly update irq_desc when set_type() is called.Grant Likely
The MPC5200 PIC driver doesn't correctly update the .status field of the irq_desc structure when the set_type hook is called. This patch adds the required code. Also cleans up the external IRQ typename field to be something easier to read (very minor). Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-01-09powerpc/mpc5121: fix NULL test in mpc5121_clk_get utility function.roel kluin
strcmp on NULL results in a segmentation fault, also, remove the second, redundant test on dev Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-01-09Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile: (31 commits) powerpc/oprofile: fix whitespaces in op_model_cell.c powerpc/oprofile: IBM CELL: add SPU event profiling support powerpc/oprofile: fix cell/pr_util.h powerpc/oprofile: IBM CELL: cleanup and restructuring oprofile: make new cpu buffer functions part of the api oprofile: remove #ifdef CONFIG_OPROFILE_IBS in non-ibs code ring_buffer: fix ring_buffer_event_length() oprofile: use new data sample format for ibs oprofile: add op_cpu_buffer_get_data() oprofile: add op_cpu_buffer_add_data() oprofile: rework implementation of cpu buffer events oprofile: modify op_cpu_buffer_read_entry() oprofile: add op_cpu_buffer_write_reserve() oprofile: rename variables in add_ibs_begin() oprofile: rename add_sample() in cpu_buffer.c oprofile: rename variable ibs_allowed to has_ibs in op_model_amd.c oprofile: making add_sample_entry() inline oprofile: remove backtrace code for ibs oprofile: remove unused ibs macro oprofile: remove unused components in struct oprofile_cpu_buffer ...
2009-01-08Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (53 commits) serial: Add driver for the Cell Network Processor serial port NWP device powerpc: enable dynamic ftrace powerpc/cell: Fix the prototype of create_vma_map() powerpc/mm: Make clear_fixmap() actually work powerpc/kdump: Use ppc_save_regs() in crash_setup_regs() powerpc: Export cacheable_memzero as its now used in a driver powerpc: Fix missing semicolons in mmu_decl.h powerpc/pasemi: local_irq_save uses an unsigned long powerpc/cell: Fix some u64 vs. long types powerpc/cell: Use correct types in beat files powerpc: Use correct type in prom_init.c powerpc: Remove unnecessary casts mtd/ps3vram: Use _PAGE_NO_CACHE in memory ioremap mtd/ps3vram: Use msleep in waits mtd/ps3vram: Use proper kernel types mtd/ps3vram: Cleanup ps3vram driver messages mtd/ps3vram: Remove ps3vram debug routines mtd/ps3vram: Add modalias support to the ps3vram driver mtd/ps3vram: Add ps3vram driver for accessing video RAM as MTD powerpc: Fix iseries drivers build failure without CONFIG_VIOPATH ...
2009-01-08fix similar typos to successfullColy Li
When I review ocfs2 code, find there are 2 typos to "successfull". After doing grep "successfull " in kernel tree, 22 typos found totally -- great minds always think alike :) This patch fixes all the similar typos. Thanks for Randy's ack and comments. Signed-off-by: Coly Li <coyli@suse.de> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Roland Dreier <rolandd@cisco.com> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Jeff Garzik <jeff@garzik.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Vlad Yasevich <vladislav.yasevich@hp.com> Cc: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08powerpc/oprofile: fix whitespaces in op_model_cell.cRobert Richter
Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-08powerpc/oprofile: IBM CELL: add SPU event profiling supportCarl Love
This patch adds the SPU event based profiling funcitonality for the IBM Cell processor. Previously, the CELL OProfile kernel code supported PPU event, PPU cycle profiling and SPU cycle profiling. The addition of SPU event profiling allows the users to identify where in their SPU code various SPU evnets are occuring. This should help users further identify issues with their code. Note, SPU profiling has some limitations due to HW constraints. Only one event at a time can be used for profiling and SPU event profiling must be time sliced across all of the SPUs in a node. The patch adds a new arch specific file to the OProfile file system. The file has bit 0 set to indicate that the kernel supports SPU event profiling. The user tool must check this file/bit to make sure the kernel supports SPU event profiling before trying to do SPU event profiling. The user tool check is part of the user tool patch for SPU event profiling. Signed-off-by: Carl Love <carll@us.ibm.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-08powerpc/oprofile: fix cell/pr_util.hRobert Richter
Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-08powerpc/oprofile: IBM CELL: cleanup and restructuringCarl Love
This patch restructures and cleans up the code a bit to make it easier to add new functionality later. The patch makes no functional changes to the existing code. Signed-off-by: Carl Love <carll@us.ibm.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-08powerpc: enable dynamic ftraceSteven Rostedt
This patch enables dynamic ftrace. The PowerPC port was dependent on other code not yet in mainline. Now that the code is, we can now let PowerPC compile with dynamic ftrace. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc/cell: Fix the prototype of create_vma_map()Stephen Rothwell
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc/mm: Make clear_fixmap() actually workAnton Vorontsov
The clear_fixmap() routine issues map_page() with flags set to 0. Currently this causes a BUG_ON() inside the map_page(), as it assumes that a PTE should be clear before mapping. This patch makes the map_page() to trigger the BUG_ON() only if the flags were set. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc/kdump: Use ppc_save_regs() in crash_setup_regs()Anton Vorontsov
The patch replaces internal registers dump implementation with ppc_save_regs(). From now on PPC64 and PPC32 are using the same code for crash_setup_regs(). NOTE: The old regs dump implementation was capturing SP (r1) directly as is, so you could see crash_kexec() function on top of the back-trace. But ppc_save_regs() goes up one stack frame, so you'll not see it anymore, at the top-level you'll see who actually triggered the crash dump instead. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc: Export cacheable_memzero as its now used in a driverKumar Gala
The Freescale PowerPC specific gianfar driver (gig-e) uses cacheable_memzero for performance reasons we need to export the symbol to allow the driver to be built as a module. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc: Fix missing semicolons in mmu_decl.hBenjamin Herrenschmidt
This is a brown paper bag from one of my earlier patches that breaks build on 40x and 8xx. And yes, I've now added 40x and 8xx to my list of test configs :-) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc/pasemi: local_irq_save uses an unsigned longIngo Molnar
[Split from a larger patch - sfr] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc/cell: Fix some u64 vs. long typesIngo Molnar
in/out_be64() work on u64s. The first parameter to ppc_md.ioremap is a phys_addr_t. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc/cell: Use correct types in beat filesIngo Molnar
Only pass the address of a u64 if that is what the function requires. [Split out of a larger patch - sfr] [update comment - sfr] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc: Use correct type in prom_init.cIngo Molnar
tce_entryp is a "u64 *" not an "unsigned long *". [Split from a large patch -sfr] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc: Remove unnecessary castsStephen Rothwell
of_get_flat_dt_prop() returns a "void *", so we don't need to cast when assigning its result to a pointer variable. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08mtd/ps3vram: Add modalias support to the ps3vram driverGeert Uytterhoeven
Update ps3vram driver to use the new ps3 three id modalias support. Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08mtd/ps3vram: Add ps3vram driver for accessing video RAM as MTDJim Paris
Add ps3vram driver, which exposes unused video RAM on the PS3 as a MTD device suitable for storage or swap. Fast data transfer is achieved using a local cache in system RAM and DMA transfers via the GPU. Signed-off-by: Vivien Chappelier <vivien.chappelier@free.fr> Signed-off-by: Jim Paris <jim@jtan.com> Acked-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc: Fix iseries drivers build failure without CONFIG_VIOPATHKamalesh Babulal
iSeries dependent drivers fail to build, when CONFIG_VIOPATH is disabled. Fix the problem by making those drivers select it. Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc: Enable RELOCATABLE option for CRASH_DUMPMohan Kumar M
Enable RELOCATABLE option if user selects CRASH_DUMP option. Without this patch user has to first select RELOCATABLE option and then has to enable CRASH_DUMP option. Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc: Remove the redundant _tlbil_pid at SMP caseDave Liu
Signed-off-by: Dave Liu <daveliu@freescale.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc/cell: local_irq_save takes an unsigned longStephen Rothwell
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc/cell: Bitops work on unsigned longsStephen Rothwell
So change the flags member of struct spu from u64 to unsigned long. This change will also prevent some warnings when we change u64 to unsigned long long. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc: Add ioctls for RS485 mode control of serial driversMatthias Fuchs
These ioctls take a struct serial_rs485 (see linux/serial.h) as argument. They are already available on x86. This patch adds them for the powerpc architecture. Signed-off-by: Matthias Fuchs <mfuchs@ma-fu.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc: Fix pciconfig_iobase system call on PCI-Express powermacPaul Mackerras
X has been failing to start on my quad G5 powermac since commit 1fd0f52583a85b21a394201b007bc1ee104b235d ("powerpc: Fix domain numbers in /proc on 64-bit") went in. The reason is that the change allows X to see the PCI-PCI bridge above the video card (previously it was obscured by the fact that there were two "00" directories in /proc/bus/pci), and the pciconfig_iobase system call on the bridge is failing because of a hack that we have to return information about the AGP bus when X asks about bus 0. This machine doesn't have an AGP bus (it has PCI Express) and so the pciconfig_iobase call is returning -1, which ultimately causes X to fail to start. This fixes it by checking that we have an AGP bridge before redirecting the pciconfig_iobase call to return information about the AGP bus. With this, X starts successfully both on a quad G5 with PCI Express and on an older dual G5 with AGP. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc/pasemi: Use DEFINE_SPINLOCKJulia Lawall
SPIN_LOCK_UNLOCKED is deprecated. The following makes the change suggested in Documentation/spinlocks.txt The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @@ declarer name DEFINE_SPINLOCK; identifier xxx_lock; @@ - spinlock_t xxx_lock = SPIN_LOCK_UNLOCKED; + DEFINE_SPINLOCK(xxx_lock); // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc/52xx: Use DEFINE_SPINLOCKJulia Lawall
SPIN_LOCK_UNLOCKED is deprecated. The following makes the change suggested in Documentation/spinlocks.txt The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @@ declarer name DEFINE_SPINLOCK; identifier xxx_lock; @@ - spinlock_t xxx_lock = SPIN_LOCK_UNLOCKED; + DEFINE_SPINLOCK(xxx_lock); // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-08powerpc: Rewrite sysfs processor cache info codeNathan Lynch
The current code for providing processor cache information in sysfs has the following deficiencies: - several complex functions that are hard to understand - implicit recursion (cache_desc_release -> kobject_put -> cache_desc_release) - explicit recursion (create_cache_index_info) - use of two per-cpu arrays when one would suffice - duplication of work on systems where CPUs share cache Also, when I looked at implementing support for a shared_cpu_map attribute, it was pretty much impossible to handle hotplug without checking every single online CPU's cache_desc list and fixing things up... not that this is a hot path, but it would have introduced O(n^2)-ish behavior during boot. Addressing this involved rethinking the core data structures used, which didn't lend itself to an incremental approach. This implementation maintains a "forest" (potentially more than one tree) of cache objects which reflects the system's cache topology. Cache objects are instantiated as needed as CPUs come online. A per-cpu array is used mainly for sysfs-related bookkeeping; the objects in the array just point to the appropriate points in the forest. This maintains compatibility with the existing code and includes some enhancements: - Implement the shared_cpu_map attribute, which is essential for enabling userspace to discover the system's overall cache topology. - Use cache-block-size properties if cache-line-size is not available. I chose to place this implementation in a new file since it would have roughly doubled the size of sysfs.c, which is already kind of messy. Signed-off-by: Nathan Lynch <ntl@pobox.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>