When discovering the number of VPEs per core, smp_num_siblings will be
incorrect for kernels built without support for the MIPS MultiThreading
(MT) ASE running on systems which implement said ASE. This leads to
accesses to VPEs in secondary cores being performed incorrectly since
mips_cm_vp_id calculates the wrong ID to write to the local "other"
registers. Fix this by examining the number of VPEs in the core as
reported by the CM.
This patch presumes that the number of VPEs will be the same in each
core of the system. As this path only applies to systems with CM version
2.5 or lower, and this property is true of all such known systems, this
is likely to be fine but is described in a comment for good measure.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14338/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix mips_cm_max_vp_width for UP kernels where it previously referenced
smp_num_siblings, which is not declared for UP kernels. This led to
build errors such as the following:
drivers/built-in.o: In function `$L446':
irq-mips-gic.c:(.text+0x1994): undefined reference to `smp_num_siblings'
drivers/built-in.o:irq-mips-gic.c:(.text+0x199c): more undefined references to `smp_num_siblings' follow
On UP kernels simply return 1, leaving the reference to smp_num_siblings
in place only for SMP kernels.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12332/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The kernel currently assumes that a core will start up in legacy mode
using the exception base provided through the CM GCR registers. If a
core has been configured in hardware to start in EVA mode, these
assumptions will fail.
This patch ensures that secondary cores are initialized to meet these
assumptions.
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11907/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Introduce mips_cm_lock_other & mips_cm_unlock_other, mirroring the
existing CPC equivalents, in order to lock access from the current core
to another via the core-other GCR region. This hasn't been required in
the past but with CM3 the CPC starts using GCR_CL_OTHER rather than
CPC_CL_OTHER and this will be required for safety.
[ralf@linux-mips.org: Fix merge conflict.]
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
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/11207/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The VP ID of a given CPU may not match up with the CPU number used by
Linux. For example, if the width of the VP part of the VP ID is wider
than log2(number of VPs per core) and the system has multiple cores then
this will be the case. Alternatively, if a pre-r6 system implements the
MT ASE with multiple VPEs per core and Linux is built without support
for the MT ASE then the numbers won't match up either. Provide a
function to convert from CPU number to VP ID.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
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/11211/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Provide a function to trivially return the version of the CM present in
the system, or 0 if no CM is present. The mips_cm_revision() will be
used later on to determine the CM register width, so it must not use
the regular CM accessors to read the revision register since that will
lead to build failures due to recursive inlines.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10655/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Sparse emits a bunch of warnings in mips-cm.h due to casting away of
__iomem by the addr_gcr_*() functions:
arch/mips/include/asm/mips-cm.h:134:1: warning: cast removes address space of expression
And subsequent passing of the return values to __raw_readl() and
__raw_writel() in the read_gcr_*() and write_gcr_*() functions:
arch/mips/include/asm/mips-cm.h:134:1: warning: incorrect type in argument 2 (different address spaces)
arch/mips/include/asm/mips-cm.h:134:1: expected void volatile [noderef] <asn:2>*mem
arch/mips/include/asm/mips-cm.h:134:1: got unsigned int [usertype] *
arch/mips/include/asm/mips-cm.h:134:1: warning: incorrect type in argument 1 (different address spaces)
arch/mips/include/asm/mips-cm.h:134:1: expected void const volatile [noderef] <asn:2>*mem
arch/mips/include/asm/mips-cm.h:134:1: got unsigned int [usertype] *
Fix by adding __iomem to the addr_gcr_*() return type and cast.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8874/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The kernel currently only probes for a MIPS Coherence Manager in the
Malta interrupt code in order to detect & enable the GIC. However CM is
not Malta-specific, so this should really be more generic. This patch
introduces some non-Malta-specific code which probes for a CM and
performs some basic initialisation.
A new header, with temporarily duplicated register definitions, is
introduced in order to:
1) Allow the new definitions to be correct with regards to the
CM documentation, as many of those in gcmpregs.h aren't.
2) Allow switching away from the REG() macro used via a few layers of
nested macros in order to access registers in gcmpregs.h. This
patch instead introduced accessor functions akin to the
{read,write}_c0_* functions used for cop0 registers.
3) Allow users of the CM to be migrated one by one.
4) Switch from the name 'GCMP' to 'CM' since the Coherence Manager is
what this code is actually dealing with.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6360/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
