linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Zhou Yanjie <zhouyanjie@zoho.com>,
	Paul Burton <paul.burton@mips.com>,
	linux-mips@vger.kernel.org, ralf@linux-mips.org,
	paul@crapouillou.net, jhogan@kernel.org, malat@debian.org,
	gregkh@linuxfoundation.org, tglx@linutronix.de,
	allison@lohutok.net, syq@debian.org, chenhc@lemote.com,
	jiaxun.yang@flygoat.com, Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 5.3 01/49] MIPS: Ingenic: Disable broken BTB lookup optimization.
Date: Sun, 29 Sep 2019 13:30:01 -0400	[thread overview]
Message-ID: <20190929173053.8400-1-sashal@kernel.org> (raw)

From: Zhou Yanjie <zhouyanjie@zoho.com>

[ Upstream commit 053951dda71ecb4b554a2cdbe26f5f6f9bee9dd2 ]

In order to further reduce power consumption, the XBurst core
by default attempts to avoid branch target buffer lookups by
detecting & special casing loops. This feature will cause
BogoMIPS and lpj calculate in error. Set cp0 config7 bit 4 to
disable this feature.

Signed-off-by: Zhou Yanjie <zhouyanjie@zoho.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: ralf@linux-mips.org
Cc: paul@crapouillou.net
Cc: jhogan@kernel.org
Cc: malat@debian.org
Cc: gregkh@linuxfoundation.org
Cc: tglx@linutronix.de
Cc: allison@lohutok.net
Cc: syq@debian.org
Cc: chenhc@lemote.com
Cc: jiaxun.yang@flygoat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/mips/include/asm/mipsregs.h | 4 ++++
 arch/mips/kernel/cpu-probe.c     | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index 1e6966e8527e9..bdbdc19a2b8f8 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -689,6 +689,9 @@
 #define MIPS_CONF7_IAR		(_ULCAST_(1) << 10)
 #define MIPS_CONF7_AR		(_ULCAST_(1) << 16)
 
+/* Ingenic Config7 bits */
+#define MIPS_CONF7_BTB_LOOP_EN	(_ULCAST_(1) << 4)
+
 /* Config7 Bits specific to MIPS Technologies. */
 
 /* Performance counters implemented Per TC */
@@ -2813,6 +2816,7 @@ __BUILD_SET_C0(status)
 __BUILD_SET_C0(cause)
 __BUILD_SET_C0(config)
 __BUILD_SET_C0(config5)
+__BUILD_SET_C0(config7)
 __BUILD_SET_C0(intcontrol)
 __BUILD_SET_C0(intctl)
 __BUILD_SET_C0(srsmap)
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 9635c1db3ae6a..e654ffc1c8a0d 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -1964,6 +1964,13 @@ static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
 		c->cputype = CPU_JZRISC;
 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
 		__cpu_name[cpu] = "Ingenic JZRISC";
+		/*
+		 * The XBurst core by default attempts to avoid branch target
+		 * buffer lookups by detecting & special casing loops. This
+		 * feature will cause BogoMIPS and lpj calculate in error.
+		 * Set cp0 config7 bit 4 to disable this feature.
+		 */
+		set_c0_config7(MIPS_CONF7_BTB_LOOP_EN);
 		break;
 	default:
 		panic("Unknown Ingenic Processor ID!");
-- 
2.20.1


             reply	other threads:[~2019-09-29 17:30 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-29 17:30 Sasha Levin [this message]
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 02/49] clk: jz4740: Add TCU clock Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 03/49] MIPS: Don't use bc_false uninitialized in __mm_isBranchInstr Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 04/49] MIPS: tlbex: Explicitly cast _PAGE_NO_EXEC to a boolean Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 05/49] i2c-cht-wc: Fix lockdep warning Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 06/49] mfd: intel-lpss: Remove D3cold delay Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 07/49] PCI: tegra: Fix OF node reference leak Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 08/49] HID: wacom: Fix several minor compiler warnings Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 09/49] rtc: bd70528: fix driver dependencies Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 10/49] mips/atomic: Fix loongson_llsc_mb() wreckage Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 11/49] PCI: pci-hyperv: Fix build errors on non-SYSFS config Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 12/49] PCI: layerscape: Add the bar_fixed_64bit property to the endpoint driver Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 13/49] livepatch: Nullify obj->mod in klp_module_coming()'s error path Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 14/49] mips/atomic: Fix smp_mb__{before,after}_atomic() Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 15/49] ARM: 8898/1: mm: Don't treat faults reported from cache maintenance as writes Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 16/49] soundwire: intel: fix channel number reported by hardware Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 17/49] PCI: mobiveil: Fix the CPU base address setup in inbound window Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 18/49] ARM: 8875/1: Kconfig: default to AEABI w/ Clang Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 19/49] MIPS: lantiq: update the clock alias' for the mainline PCIe PHY driver Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 20/49] firmware: bcm47xx_nvram: Correct size_t printf format Sasha Levin
2019-09-29 19:39   ` Florian Fainelli
2019-10-05 22:53     ` Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 21/49] rtc: snvs: fix possible race condition Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 22/49] rtc: pcf85363/pcf85263: fix regmap error in set_time Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 23/49] power: supply: register HWMON devices with valid names Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 24/49] selinux: fix residual uses of current_security() for the SELinux blob Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 25/49] PCI: Add pci_info_ratelimited() to ratelimit PCI separately Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 26/49] HID: apple: Fix stuck function keys when using FN Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 27/49] PCI: rockchip: Propagate errors for optional regulators Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 28/49] PCI: histb: " Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 29/49] PCI: imx6: " Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 30/49] PCI: exynos: Propagate errors for optional PHYs Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 31/49] security: smack: Fix possible null-pointer dereferences in smack_socket_sock_rcv_skb() Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 32/49] PCI: Use static const struct, not const static struct Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 33/49] ARM: 8905/1: Emit __gnu_mcount_nc when using Clang 10.0.0 or newer Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 34/49] ARM: 8903/1: ensure that usable memory in bank 0 starts from a PMD-aligned address Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 35/49] i2c: tegra: Move suspend handling to NOIRQ phase Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 36/49] block, bfq: push up injection only after setting service time Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 37/49] fat: work around race with userspace's read via blockdev while mounting Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 38/49] pktcdvd: remove warning on attempting to register non-passthrough dev Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 39/49] hypfs: Fix error number left in struct pointer member Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 40/49] tools/power/x86/intel-speed-select: Fix high priority core mask over count Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 41/49] crypto: hisilicon - Fix double free in sec_free_hw_sgl() Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 42/49] mm: add dummy can_do_mlock() helper Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 43/49] kbuild: clean compressed initramfs image Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 44/49] ocfs2: wait for recovering done after direct unlock request Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 45/49] kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16K Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 46/49] arm64: consider stack randomization for mmap base only when necessary Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 47/49] mips: properly account for stack randomization and stack guard gap Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 48/49] arm: " Sasha Levin
2019-09-29 17:30 ` [PATCH AUTOSEL 5.3 49/49] arm: use STACK_TOP when computing mmap base address Sasha Levin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190929173053.8400-1-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=allison@lohutok.net \
    --cc=chenhc@lemote.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jhogan@kernel.org \
    --cc=jiaxun.yang@flygoat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=malat@debian.org \
    --cc=paul.burton@mips.com \
    --cc=paul@crapouillou.net \
    --cc=ralf@linux-mips.org \
    --cc=stable@vger.kernel.org \
    --cc=syq@debian.org \
    --cc=tglx@linutronix.de \
    --cc=zhouyanjie@zoho.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).