diff options
| author | Paul Burton <paul.burton@imgtec.com> | 2015-09-25 08:59:38 -0700 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2015-09-27 14:15:26 +0200 |
| commit | e060f6ed281669b6d2f22d8dafd664b532386918 (patch) | |
| tree | fa74247359834941661b76a318ca6ad790b01041 /arch/mips/mm | |
| parent | 651ca7f4dab77f07fdac9cfb68bcab6bd2b7f827 (diff) | |
MIPS: Initialise MAARs on secondary CPUs
MAARs should be initialised on each CPU (or rather, core) in the system
in order to achieve consistent behaviour & performance. Previously they
have only been initialised on the boot CPU which leads to performance
problems if tasks are later scheduled on a secondary CPU, particularly
if those tasks make use of unaligned vector accesses where some CPUs
don't handle any cases in hardware for non-speculative memory regions.
Fix this by recording the MAAR configuration from the boot CPU and
applying it to secondary CPUs as part of their bringup.
Reported-by: Doug Gilmore <doug.gilmore@imgtec.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Hemmo Nieminen <hemmo.nieminen@iki.fi>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11239/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/mm')
| -rw-r--r-- | arch/mips/mm/init.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index 023c164b9eb6..8770e619185e 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -44,6 +44,7 @@ #include <asm/pgalloc.h> #include <asm/tlb.h> #include <asm/fixmap.h> +#include <asm/maar.h> /* * We have up to 8 empty zeroed pages so we can map one of the right colour @@ -288,10 +289,14 @@ unsigned __weak platform_maar_init(unsigned num_pairs) return num_configured; } -static void maar_init(void) +void maar_init(void) { unsigned num_maars, used, i; phys_addr_t lower, upper, attr; + static struct { + struct maar_config cfgs[3]; + unsigned used; + } recorded = { { { 0 } }, 0 }; if (!cpu_has_maar) return; @@ -304,8 +309,14 @@ static void maar_init(void) /* MAARs should be in pairs */ WARN_ON(num_maars % 2); - /* Configure the required MAARs */ - used = platform_maar_init(num_maars / 2); + /* Set MAARs using values we recorded already */ + if (recorded.used) { + used = maar_config(recorded.cfgs, recorded.used, num_maars / 2); + BUG_ON(used != recorded.used); + } else { + /* Configure the required MAARs */ + used = platform_maar_init(num_maars / 2); + } /* Disable any further MAARs */ for (i = (used * 2); i < num_maars; i++) { @@ -315,6 +326,9 @@ static void maar_init(void) back_to_back_c0_hazard(); } + if (recorded.used) + return; + pr_info("MAAR configuration:\n"); for (i = 0; i < num_maars; i += 2) { write_c0_maari(i); @@ -341,6 +355,14 @@ static void maar_init(void) pr_cont(" speculate"); pr_cont("\n"); + + /* Record the setup for use on secondary CPUs */ + if (used <= ARRAY_SIZE(recorded.cfgs)) { + recorded.cfgs[recorded.used].lower = lower; + recorded.cfgs[recorded.used].upper = upper; + recorded.cfgs[recorded.used].attrs = attr; + recorded.used++; + } } } |