linux/drivers/clocksource/mips-gic-timer.c, branch v4.5

MIPS: VDSO: Add implementations of gettimeofday() and clock_gettime()

2015-11-11T07:36:41Z

Add user-mode implementations of gettimeofday() and clock_gettime() to the VDSO. This is currently usable with 2 clocksources: the CP0 count register, which is accessible to user-mode via RDHWR on R2 and later cores, or the MIPS Global Interrupt Controller (GIC) timer, which provides a "user-mode visible" section containing a mirror of its counter registers. This section must be mapped into user memory, which is done below the VDSO data page. When a supported clocksource is not in use, the VDSO functions will return -ENOSYS, which causes libc to fall back on the standard syscall path. When support for neither of these clocksources is compiled into the kernel at all, the VDSO still provides clock_gettime(), as the coarse realtime/monotonic clocks can still be implemented. However, gettimeofday() is not provided in this case as nothing can be done without a suitable clocksource. This causes the symbol lookup to fail in libc and it will then always use the standard syscall path. This patch includes a workaround for a bug in QEMU which results in RDHWR on the CP0 count register always returning a constant (incorrect) value. A fix for this has been submitted, and the workaround can be removed after the fix has been in stable releases for a reasonable amount of time. A simple performance test which calls gettimeofday() 1000 times in a loop and calculates the average execution time gives the following results on a Malta + I6400 (running at 20MHz): - Syscall: ~31000 ns - VDSO (GIC): ~15000 ns - VDSO (CP0): ~9500 ns [markos.chandras@imgtec.com: - Minor code re-arrangements in order for mappings to be made in the order they appear to the process' address space. - Move do_{monotonic, realtime} outside of the MIPS_CLOCK_VSYSCALL ifdef - Use gic_get_usm_range so we can do the GIC mapping in the arch/mips/kernel/vdso instead of the GIC irqchip driver] Signed-off-by: Alex Smith Signed-off-by: Markos Chandras Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11338/ Signed-off-by: Ralf Baechle

Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus

2015-09-03T23:55:55Z

Pull MIPS updates from Ralf Baechle: "This is the main pull request for 4.3 for MIPS. Here's the summary: Three fixes that didn't make 4.2-stable: - a -Os build might compile the kernel using the MIPS16 instruction set but the R2 optimized inline functions in are implemented using 32-bit wide instructions which is invalid. - a build error in pgtable-bits.h for a particular kernel configuration. - accessing registers of the CM GCR might have been compiled to use 64 bit accesses but these registers are onl 32 bit wide. And also a few new bits: - move the ATH79 GPIO driver to drivers/gpio - the definition of IRQCHIP_DECLARE has moved to linux/irqchip.h, change ATH79 accordingly. - fix definition of pgprot_writecombine - add an implementation of dma_map_ops.mmap - fix alignment of quiet build output for vmlinuz link - BCM47xx: Use kmemdup rather than duplicating its implementation - Netlogic: Fix 0x0x prefixes of constants. - merge Bjorn Helgaas' series to remove most of the weak keywords from function declarations. - CP0 and CP1 registers are best considered treated as unsigned values to avoid large values from becoming negative values. - improve support for the MIPS GIC timer. - enable common clock framework for Malta and SEAD3. - a number of improvments and fixes to dump_tlb(). - document the MIPS TLB dump functionality in Magic SysRq. - Cavium Octeon CN68XX improvments. - NetLogic improvments. - irq: Use access helper irq_data_get_affinity_mask. - handle MSA unaligned accesses. - a number of R6-related math-emu fixes. - support for I6400. - improvments to MSA support. - add uprobes support. - move from deprecated __initcall to arch_initcall. - remove finish_arch_switch(). - IRQ cleanups by Thomas Gleixner. - migrate to new 'set-state' interface. - random small cleanups" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (148 commits) MIPS: UAPI: Fix unrecognized opcode WSBH/DSBH/DSHD when using MIPS16. MIPS: Fix alignment of quiet build output for vmlinuz link MIPS: math-emu: Remove unused handle_dsemul function declaration MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction MIPS: math-emu: Add support for the MIPS R6 CLASS FPU instruction MIPS: math-emu: Add support for the MIPS R6 RINT FPU instruction MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction MIPS: math-emu: Add support for the MIPS R6 SELNEZ FPU instruction MIPS: math-emu: Add support for the MIPS R6 SELEQZ FPU instruction MIPS: math-emu: Add support for the CMP.condn.fmt R6 instruction MIPS: inst.h: Add new MIPS R6 FPU opcodes MIPS: Octeon: Fix management port MII address on Kontron S1901 MIPS: BCM47xx: Use kmemdup rather than duplicating its implementation STAGING: Octeon: Use common helpers for determining interface and port MIPS: Octeon: Support interfaces 4 and 5 MIPS: Octeon: Set up 1:1 mapping between CN68XX PKO queues and ports MIPS: Octeon: Initialize CN68XX PKO STAGING: Octeon: Support CN68XX style WQE ...

CLOCKSOURCE: mips-gic: Update clockevent frequency on clock rate changes

2015-09-03T10:08:07Z

This commit introduces the clockevent frequency update, using a clock notifier. It will be used to support CPUFreq on platforms using MIPS GIC based clockevents. Signed-off-by: Ezequiel Garcia Acked-by: Daniel Lezcano Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: devicetree@vger.kernel.org Cc: Thomas Gleixner Cc: Andrew Bresticker Cc: James Hartley Cc: Govindraj Raja Cc: Damien Horsley Cc: James Hogan Cc: Ezequiel Garcia Patchwork: https://patchwork.linux-mips.org/patch/10782/ Signed-off-by: Ralf Baechle

CLOCKSOURCE: mips-gic: Split clocksource and clockevent initialization

2015-09-03T10:08:06Z

This is preparation work for the introduction of clockevent frequency update with a clock notifier. This is only possible when the device is passed a clk struct, so let's split the legacy and devicetree initialization. Reviewed-by: Andrew Bresticker Signed-off-by: Ezequiel Garcia Acked-by: Daniel Lezcano Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: devicetree@vger.kernel.org Cc: Thomas Gleixner Cc: James Hartley Cc: Govindraj Raja Cc: Damien Horsley Cc: James Hogan Cc: Ezequiel Garcia Patchwork: https://patchwork.linux-mips.org/patch/10781/ Signed-off-by: Ralf Baechle

CLOCKSOURCE: mips-gic: Add missing error returns checks

2015-09-03T10:08:06Z

This commit adds the required checks on the functions that return an error. Some of them are not critical, so only a warning is printed. Signed-off-by: Ezequiel Garcia Reviewed-by: Andrew Bresticker Acked-by: Daniel Lezcano Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: devicetree@vger.kernel.org Cc: Thomas Gleixner Cc: James Hartley Cc: Govindraj Raja Cc: Damien Horsley Cc: James Hogan Cc: Ezequiel Garcia Patchwork: https://patchwork.linux-mips.org/patch/10780/ Signed-off-by: Ralf Baechle

CLOCKSOURCE: mips-gic: Enable the clock before using it

2015-09-03T10:08:05Z

For the clock to be used (e.g. get its rate through clk_get_rate) it should be prepared and enabled first. Also, while the clock is enabled the driver must hold a reference to it, so let's remove the call to clk_put. Reviewed-by: Andrew Bresticker Signed-off-by: Ezequiel Garcia Acked-by: Daniel Lezcano Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: devicetree@vger.kernel.org Cc: Thomas Gleixner Cc: James Hartley Cc: Govindraj Raja Cc: Damien Horsley Cc: James Hogan Cc: Ezequiel Garcia Patchwork: https://patchwork.linux-mips.org/patch/10779/ Signed-off-by: Ralf Baechle

clockevents/drivers/mips-gic: Migrate to new 'set-state' interface

2015-08-10T09:40:32Z

Migrate mips-gic driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now. This also enables us to implement callbacks for new states of clockevent devices, for example: ONESHOT_STOPPED. We weren't doing anything in the ->set_mode() callback. So, this patch doesn't provide any set-state callbacks. Cc: Andrew Bresticker Cc: Steven J. Hill Signed-off-by: Viresh Kumar Signed-off-by: Daniel Lezcano

CLOCKSOURCE: mips-gic: Allow GIC clock to be specified in device-tree

2015-04-01T15:22:11Z

As an alternative to the "clock-frequency" property, allow the GIC timer operating clock to be specified in the device-tree instead. This is useful on systems which use common clock or where the GIC is not fixed to a particular frequency and is instead, for example, derived from the CPU clock. Signed-off-by: Andrew Bresticker Cc: James Hogan Cc: Rob Herring Cc: Pawel Moll Cc: Mark Rutland Cc: Ian Campbell Cc: Kumar Gala Cc: Daniel Lezcano Cc: Thomas Gleixner Cc: devicetree@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9309/

CLOCKSOURCE: mips-gic-timer: Ensure GIC counter is running

2015-03-31T10:04:13Z

Start the GIC counter after configuring the clocksource since there are no guarantees the counter will be running after a CPU reset. Signed-off-by: Markos Chandras Cc: Daniel Lezcano Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9595/ Signed-off-by: Ralf Baechle

clocksource: mips-gic: Add device-tree support

2014-11-24T06:45:30Z

Parse the GIC timer frequency and interrupt from the device-tree. Signed-off-by: Andrew Bresticker Acked-by: Arnd Bergmann Cc: Rob Herring Cc: Pawel Moll Cc: Mark Rutland Cc: Ian Campbell Cc: Kumar Gala Cc: Thomas Gleixner Cc: Jason Cooper Cc: Daniel Lezcano Cc: John Crispin Cc: David Daney Cc: Qais Yousef Cc: James Hogan Cc: linux-mips@linux-mips.org Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8421/ Signed-off-by: Ralf Baechle