From 9078210ef4016539c909fb67164d3f1c27323d8b Mon Sep 17 00:00:00 2001
From: James Hogan <james.hogan@imgtec.com>
Date: Tue, 25 Oct 2016 16:08:19 +0100
Subject: KVM: MIPS: Fix lazy user ASID regenerate for SMP
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

kvm_mips_check_asids() runs before entering the guest and performs lazy
regeneration of host ASID for guest usermode, using last_user_gasid to
track the last guest ASID in the VCPU that was used by guest usermode on
any host CPU.

last_user_gasid is reset after performing the lazy ASID regeneration on
the current CPU, and by kvm_arch_vcpu_load() if the host ASID for guest
usermode is regenerated due to staleness (to cancel outstanding lazy
ASID regenerations). Unfortunately neither case handles SMP hosts
correctly:

 - When the lazy ASID regeneration is performed it should apply to all
   CPUs (as last_user_gasid does), so reset the ASID on other CPUs to
   zero to trigger regeneration when the VCPU is next loaded on those
   CPUs.

 - When the ASID is found to be stale on the current CPU, we should not
   cancel lazy ASID regenerations globally, so drop the reset of
   last_user_gasid altogether here.

Both cases would require a guest ASID change and two host CPU migrations
(and in the latter case one of the CPUs to start a new ASID cycle)
before guest usermode could potentially access stale user pages from a
previously running ASID in the same VCPU.

Fixes: 25b08c7fb0e4 ("KVM: MIPS: Invalidate TLB by regenerating ASIDs")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/mips/kvm/mips.c | 5 ++++-
 arch/mips/kvm/mmu.c  | 4 ----
 2 files changed, 4 insertions(+), 5 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 622037d851a3..06a60b19acfb 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -426,7 +426,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 static void kvm_mips_check_asids(struct kvm_vcpu *vcpu)
 {
 	struct mips_coproc *cop0 = vcpu->arch.cop0;
-	int cpu = smp_processor_id();
+	int i, cpu = smp_processor_id();
 	unsigned int gasid;
 
 	/*
@@ -442,6 +442,9 @@ static void kvm_mips_check_asids(struct kvm_vcpu *vcpu)
 						vcpu);
 			vcpu->arch.guest_user_asid[cpu] =
 				vcpu->arch.guest_user_mm.context.asid[cpu];
+			for_each_possible_cpu(i)
+				if (i != cpu)
+					vcpu->arch.guest_user_asid[cpu] = 0;
 			vcpu->arch.last_user_gasid = gasid;
 		}
 	}
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index 03883ba806e2..3b677c851be0 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -260,13 +260,9 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 
 	if ((vcpu->arch.guest_user_asid[cpu] ^ asid_cache(cpu)) &
 						asid_version_mask(cpu)) {
-		u32 gasid = kvm_read_c0_guest_entryhi(vcpu->arch.cop0) &
-				KVM_ENTRYHI_ASID;
-
 		kvm_get_new_mmu_context(&vcpu->arch.guest_user_mm, cpu, vcpu);
 		vcpu->arch.guest_user_asid[cpu] =
 		    vcpu->arch.guest_user_mm.context.asid[cpu];
-		vcpu->arch.last_user_gasid = gasid;
 		newasid++;
 
 		kvm_debug("[%d]: cpu_context: %#lx\n", cpu,
-- 
cgit 


From ede5f3e7b54a4347be4d8525269eae50902bd7cd Mon Sep 17 00:00:00 2001
From: James Hogan <james.hogan@imgtec.com>
Date: Tue, 25 Oct 2016 16:11:11 +0100
Subject: KVM: MIPS: Make ERET handle ERL before EXL
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The ERET instruction to return from exception is used for returning from
exception level (Status.EXL) and error level (Status.ERL). If both bits
are set however we should be returning from ERL first, as ERL can
interrupt EXL, for example when an NMI is taken. KVM however checks EXL
first.

Fix the order of the checks to match the pseudocode in the instruction
set manual.

Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: <stable@vger.kernel.org> # 3.10.x-
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/mips/kvm/emulate.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index 8770f32c9e0b..c45ef0f13dfa 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -790,15 +790,15 @@ enum emulation_result kvm_mips_emul_eret(struct kvm_vcpu *vcpu)
 	struct mips_coproc *cop0 = vcpu->arch.cop0;
 	enum emulation_result er = EMULATE_DONE;
 
-	if (kvm_read_c0_guest_status(cop0) & ST0_EXL) {
+	if (kvm_read_c0_guest_status(cop0) & ST0_ERL) {
+		kvm_clear_c0_guest_status(cop0, ST0_ERL);
+		vcpu->arch.pc = kvm_read_c0_guest_errorepc(cop0);
+	} else if (kvm_read_c0_guest_status(cop0) & ST0_EXL) {
 		kvm_debug("[%#lx] ERET to %#lx\n", vcpu->arch.pc,
 			  kvm_read_c0_guest_epc(cop0));
 		kvm_clear_c0_guest_status(cop0, ST0_EXL);
 		vcpu->arch.pc = kvm_read_c0_guest_epc(cop0);
 
-	} else if (kvm_read_c0_guest_status(cop0) & ST0_ERL) {
-		kvm_clear_c0_guest_status(cop0, ST0_ERL);
-		vcpu->arch.pc = kvm_read_c0_guest_errorepc(cop0);
 	} else {
 		kvm_err("[%#lx] ERET when MIPS_SR_EXL|MIPS_SR_ERL == 0\n",
 			vcpu->arch.pc);
-- 
cgit 


From e1e575f6b026734be3b1f075e780e91ab08ca541 Mon Sep 17 00:00:00 2001
From: James Hogan <james.hogan@imgtec.com>
Date: Tue, 25 Oct 2016 16:11:12 +0100
Subject: KVM: MIPS: Precalculate MMIO load resume PC
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The advancing of the PC when completing an MMIO load is done before
re-entering the guest, i.e. before restoring the guest ASID. However if
the load is in a branch delay slot it may need to access guest code to
read the prior branch instruction. This isn't safe in TLB mapped code at
the moment, nor in the future when we'll access unmapped guest segments
using direct user accessors too, as it could read the branch from host
user memory instead.

Therefore calculate the resume PC in advance while we're still in the
right context and save it in the new vcpu->arch.io_pc (replacing the no
longer needed vcpu->arch.pending_load_cause), and restore it on MMIO
completion.

Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: <stable@vger.kernel.org> # 3.10.x-
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/mips/include/asm/kvm_host.h |  7 ++++---
 arch/mips/kvm/emulate.c          | 24 +++++++++++++++---------
 2 files changed, 19 insertions(+), 12 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 07f58cfc1ab9..bebec370324f 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -293,7 +293,10 @@ struct kvm_vcpu_arch {
 	/* Host KSEG0 address of the EI/DI offset */
 	void *kseg0_commpage;
 
-	u32 io_gpr;		/* GPR used as IO source/target */
+	/* Resume PC after MMIO completion */
+	unsigned long io_pc;
+	/* GPR used as IO source/target */
+	u32 io_gpr;
 
 	struct hrtimer comparecount_timer;
 	/* Count timer control KVM register */
@@ -315,8 +318,6 @@ struct kvm_vcpu_arch {
 	/* Bitmask of pending exceptions to be cleared */
 	unsigned long pending_exceptions_clr;
 
-	u32 pending_load_cause;
-
 	/* Save/Restore the entryhi register when are are preempted/scheduled back in */
 	unsigned long preempt_entryhi;
 
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index c45ef0f13dfa..aa0937423e28 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -1528,13 +1528,25 @@ enum emulation_result kvm_mips_emulate_load(union mips_instruction inst,
 					    struct kvm_vcpu *vcpu)
 {
 	enum emulation_result er = EMULATE_DO_MMIO;
+	unsigned long curr_pc;
 	u32 op, rt;
 	u32 bytes;
 
 	rt = inst.i_format.rt;
 	op = inst.i_format.opcode;
 
-	vcpu->arch.pending_load_cause = cause;
+	/*
+	 * Find the resume PC now while we have safe and easy access to the
+	 * prior branch instruction, and save it for
+	 * kvm_mips_complete_mmio_load() to restore later.
+	 */
+	curr_pc = vcpu->arch.pc;
+	er = update_pc(vcpu, cause);
+	if (er == EMULATE_FAIL)
+		return er;
+	vcpu->arch.io_pc = vcpu->arch.pc;
+	vcpu->arch.pc = curr_pc;
+
 	vcpu->arch.io_gpr = rt;
 
 	switch (op) {
@@ -2494,9 +2506,8 @@ enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu,
 		goto done;
 	}
 
-	er = update_pc(vcpu, vcpu->arch.pending_load_cause);
-	if (er == EMULATE_FAIL)
-		return er;
+	/* Restore saved resume PC */
+	vcpu->arch.pc = vcpu->arch.io_pc;
 
 	switch (run->mmio.len) {
 	case 4:
@@ -2518,11 +2529,6 @@ enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu,
 		break;
 	}
 
-	if (vcpu->arch.pending_load_cause & CAUSEF_BD)
-		kvm_debug("[%#lx] Completing %d byte BD Load to gpr %d (0x%08lx) type %d\n",
-			  vcpu->arch.pc, run->mmio.len, vcpu->arch.io_gpr, *gpr,
-			  vcpu->mmio_needed);
-
 done:
 	return er;
 }
-- 
cgit 


From 682c1e52215da4a3e89c14aad60bfc0d400b025f Mon Sep 17 00:00:00 2001
From: Paul Burton <paul.burton@imgtec.com>
Date: Sat, 15 Oct 2016 23:03:43 +0100
Subject: MIPS: CPC: Provide default mips_cpc_default_phys_base to ignore CPC

Provide a default implementation of mips_cpc_default_phys_base() which
simply returns 0, and adjust mips_cpc_phys_base() to allow for
mips_cpc_default_phys_base() returning 0. This allows kernels which
include CPC support to be built without platform code & simply ignore
the CPC if it wasn't already enabled by the bootloader.

This fixes link failures such as the following from generic defconfigs:

   arch/mips/built-in.o: In function `mips_cpc_phys_base':
   arch/mips/kernel/mips-cpc.c:47: undefined reference to `mips_cpc_default_phys_base'

[ralf@linux-mips.org: changed prototype for coding style compliance.]

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14401/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/mips-cpc.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c
index 2a45867d3b4f..a4964c334cab 100644
--- a/arch/mips/kernel/mips-cpc.c
+++ b/arch/mips/kernel/mips-cpc.c
@@ -21,6 +21,11 @@ static DEFINE_PER_CPU_ALIGNED(spinlock_t, cpc_core_lock);
 
 static DEFINE_PER_CPU_ALIGNED(unsigned long, cpc_core_lock_flags);
 
+phys_addr_t __weak mips_cpc_default_phys_base(void)
+{
+	return 0;
+}
+
 /**
  * mips_cpc_phys_base - retrieve the physical base address of the CPC
  *
@@ -43,8 +48,12 @@ static phys_addr_t mips_cpc_phys_base(void)
 	if (cpc_base & CM_GCR_CPC_BASE_CPCEN_MSK)
 		return cpc_base & CM_GCR_CPC_BASE_CPCBASE_MSK;
 
-	/* Otherwise, give it the default address & enable it */
+	/* Otherwise, use the default address */
 	cpc_base = mips_cpc_default_phys_base();
+	if (!cpc_base)
+		return cpc_base;
+
+	/* Enable the CPC, mapped at the default address */
 	write_gcr_cpc_base(cpc_base | CM_GCR_CPC_BASE_CPCEN_MSK);
 	return cpc_base;
 }
-- 
cgit 


From 93032e31a5f12df847639db3ad0b7f300bf44b7b Mon Sep 17 00:00:00 2001
From: Paul Burton <paul.burton@imgtec.com>
Date: Fri, 14 Oct 2016 10:17:32 +0100
Subject: MIPS: Malta: Fixup reboot

Commit 10b6ea0959de ("MIPS: Malta: Use syscon-reboot driver to reboot")
converted the Malta board to use the generic syscon-reboot driver to
handle reboots, but incorrectly used the value 0x4d rather than 0x42 as
the magic to write to the reboot register.

I also incorrectly believed that syscon/regmap would default to native
endianness, but this isn't the case. Force this by specifying with a
native-endian property in the devicetree.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: 10b6ea0959de ("MIPS: Malta: Use syscon-reboot driver to reboot")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: linux-mips@linux-mips.org
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Maciej W. Rozycki <macro@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/14396/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/boot/dts/mti/malta.dts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'arch/mips')

diff --git a/arch/mips/boot/dts/mti/malta.dts b/arch/mips/boot/dts/mti/malta.dts
index f604a272d91d..ffe3a1508e72 100644
--- a/arch/mips/boot/dts/mti/malta.dts
+++ b/arch/mips/boot/dts/mti/malta.dts
@@ -84,12 +84,13 @@
 	fpga_regs: system-controller@1f000000 {
 		compatible = "mti,malta-fpga", "syscon", "simple-mfd";
 		reg = <0x1f000000 0x1000>;
+		native-endian;
 
 		reboot {
 			compatible = "syscon-reboot";
 			regmap = <&fpga_regs>;
 			offset = <0x500>;
-			mask = <0x4d>;
+			mask = <0x42>;
 		};
 	};
 
-- 
cgit 


From 4736697963385e6257ee8e260e97347e858cd962 Mon Sep 17 00:00:00 2001
From: Matt Redfearn <matt.redfearn@imgtec.com>
Date: Mon, 17 Oct 2016 17:21:46 +0100
Subject: MIPS: KASLR: Fix handling of NULL FDT

If platform code returns a NULL pointer to the FDT, initial_boot_params
will not get set to a valid pointer and attempting to find the /chosen
node in it will cause a NULL pointer dereference and the kernel to crash
immediately on startup - with no output to the console.

Fix this by checking that initial_boot_params is valid before using it.

Fixes: 405bc8fd12f5 ("MIPS: Kernel: Implement KASLR using CONFIG_RELOCATABLE")
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14414/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/relocate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/relocate.c b/arch/mips/kernel/relocate.c
index ca1cc30c0891..1958910b75c0 100644
--- a/arch/mips/kernel/relocate.c
+++ b/arch/mips/kernel/relocate.c
@@ -200,7 +200,7 @@ static inline __init unsigned long get_random_boot(void)
 
 #if defined(CONFIG_USE_OF)
 	/* Get any additional entropy passed in device tree */
-	{
+	if (initial_boot_params) {
 		int node, len;
 		u64 *prop;
 
-- 
cgit 


From 9a59061cfd7ac00f21111d2e8aa7f4ab11d27f6c Mon Sep 17 00:00:00 2001
From: Matt Redfearn <matt.redfearn@imgtec.com>
Date: Mon, 17 Oct 2016 17:25:24 +0100
Subject: MIPS: generic: Fix KASLR for generic kernel.

The KASLR code requires that the plat_get_fdt() function return the
address of the device tree, and it must be available early in the boot,
before prom_init() is called. Move the code determining the address of
the device tree into plat_get_fdt, and call that from prom_init().

The fdt pointer will be set up by plat_get_fdt() called from
relocate_kernel initially and once the relocated kernel has started,
prom_init() will use it again to determine the address in the relocated
image.

Fixes: eed0eabd12ef ("MIPS: generic: Introduce generic DT-based board support")
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14415/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/generic/init.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/generic/init.c b/arch/mips/generic/init.c
index 0ea73e845440..d493ccbf274a 100644
--- a/arch/mips/generic/init.c
+++ b/arch/mips/generic/init.c
@@ -29,10 +29,20 @@ static __initdata const struct mips_machine *mach;
 static __initdata const void *mach_match_data;
 
 void __init prom_init(void)
+{
+	plat_get_fdt();
+	BUG_ON(!fdt);
+}
+
+void __init *plat_get_fdt(void)
 {
 	const struct mips_machine *check_mach;
 	const struct of_device_id *match;
 
+	if (fdt)
+		/* Already set up */
+		return (void *)fdt;
+
 	if ((fw_arg0 == -2) && !fdt_check_header((void *)fw_arg1)) {
 		/*
 		 * We booted using the UHI boot protocol, so we have been
@@ -75,12 +85,6 @@ void __init prom_init(void)
 		/* Retrieve the machine's FDT */
 		fdt = mach->fdt;
 	}
-
-	BUG_ON(!fdt);
-}
-
-void __init *plat_get_fdt(void)
-{
 	return (void *)fdt;
 }
 
-- 
cgit 


From 818f38c5b7c4482abd71c64ac4d49911fbefaf9e Mon Sep 17 00:00:00 2001
From: Matt Redfearn <matt.redfearn@imgtec.com>
Date: Mon, 17 Oct 2016 10:09:39 +0100
Subject: MIPS: Fix build of compressed image

Changes introduced to arch/mips/Makefile for the generic kernel resulted
in build errors when making a compressed image if platform-y has multiple
values, like this:

make[2]: *** No rule to make target `alchemy/'.
make[1]: *** [vmlinuz] Error 2
make[1]: Target `_all' not remade because of errors.
make: *** [sub-make] Error 2
make: Target `_all' not remade because of errors.

Fix this by quoting $(platform-y) as it is passed to the Makefile in
arch/mips/boot/compressed/Makefile

Reported-by: kernelci.org bot <bot@kernelci.org>
Link: https://storage.kernelci.org/next/next-20161017/mips-gpr_defconfig/build.log
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14405/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'arch/mips')

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index fbf40d3c8123..1a6bac7b076f 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -263,7 +263,7 @@ KBUILD_CPPFLAGS += -DDATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0)
 
 bootvars-y	= VMLINUX_LOAD_ADDRESS=$(load-y) \
 		  VMLINUX_ENTRY_ADDRESS=$(entry-y) \
-		  PLATFORM=$(platform-y)
+		  PLATFORM="$(platform-y)"
 ifdef CONFIG_32BIT
 bootvars-y	+= ADDR_BITS=32
 endif
-- 
cgit 


From bcf084de5d429c0a321de6e2c508440148da1884 Mon Sep 17 00:00:00 2001
From: Matt Redfearn <matt.redfearn@imgtec.com>
Date: Wed, 19 Oct 2016 14:33:20 +0100
Subject: MIPS: traps: Fix output of show_backtrace

Since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing
continuation lines") the output from show_backtrace on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected output.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14429/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/traps.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 1f5fdee1dfc3..6ae5ea752d4c 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -156,7 +156,7 @@ static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
 		print_ip_sym(pc);
 		pc = unwind_stack(task, &sp, pc, &ra);
 	} while (pc);
-	printk("\n");
+	pr_cont("\n");
 }
 
 /*
-- 
cgit 


From fe4e09e701213213cf2024e2979ea227c2e36c60 Mon Sep 17 00:00:00 2001
From: Matt Redfearn <matt.redfearn@imgtec.com>
Date: Wed, 19 Oct 2016 14:33:21 +0100
Subject: MIPS: traps: Fix output of show_stacktrace

Since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing
continuation lines") the output from show_stacktrace on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected output. Also
start a new line with printk such that the presence of timing
information does not interfere with output.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14430/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/traps.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 6ae5ea752d4c..25ce866b2895 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -174,22 +174,24 @@ static void show_stacktrace(struct task_struct *task,
 	printk("Stack :");
 	i = 0;
 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
-		if (i && ((i % (64 / field)) == 0))
-			printk("\n	 ");
+		if (i && ((i % (64 / field)) == 0)) {
+			pr_cont("\n");
+			printk("       ");
+		}
 		if (i > 39) {
-			printk(" ...");
+			pr_cont(" ...");
 			break;
 		}
 
 		if (__get_user(stackdata, sp++)) {
-			printk(" (Bad stack address)");
+			pr_cont(" (Bad stack address)");
 			break;
 		}
 
-		printk(" %0*lx", field, stackdata);
+		pr_cont(" %0*lx", field, stackdata);
 		i++;
 	}
-	printk("\n");
+	pr_cont("\n");
 	show_backtrace(task, regs);
 }
 
-- 
cgit 


From 41000c5819ee5aea8c5c3b388e4e21e679c1b95c Mon Sep 17 00:00:00 2001
From: Matt Redfearn <matt.redfearn@imgtec.com>
Date: Wed, 19 Oct 2016 14:33:22 +0100
Subject: MIPS: traps: Fix output of show_code

Since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing
continuation lines") the output from show_code on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected output.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14431/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/traps.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 25ce866b2895..273b4a419f76 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -231,18 +231,19 @@ static void show_code(unsigned int __user *pc)
 	long i;
 	unsigned short __user *pc16 = NULL;
 
-	printk("\nCode:");
+	printk("Code:");
 
 	if ((unsigned long)pc & 1)
 		pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
 	for(i = -3 ; i < 6 ; i++) {
 		unsigned int insn;
 		if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
-			printk(" (Bad address in epc)\n");
+			pr_cont(" (Bad address in epc)\n");
 			break;
 		}
-		printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
+		pr_cont("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
 	}
+	pr_cont("\n");
 }
 
 static void __show_regs(const struct pt_regs *regs)
-- 
cgit 


From 752f5499823edb0c13c594f739363527178f714d Mon Sep 17 00:00:00 2001
From: Paul Burton <paul.burton@imgtec.com>
Date: Wed, 19 Oct 2016 14:33:23 +0100
Subject: MIPS: Fix __show_regs() output

Since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing
continuation lines") the output from __show_regs() on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected register output.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14432/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/traps.c | 42 +++++++++++++++++++++---------------------
 1 file changed, 21 insertions(+), 21 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 273b4a419f76..b9a910b208f9 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -262,15 +262,15 @@ static void __show_regs(const struct pt_regs *regs)
 		if ((i % 4) == 0)
 			printk("$%2d   :", i);
 		if (i == 0)
-			printk(" %0*lx", field, 0UL);
+			pr_cont(" %0*lx", field, 0UL);
 		else if (i == 26 || i == 27)
-			printk(" %*s", field, "");
+			pr_cont(" %*s", field, "");
 		else
-			printk(" %0*lx", field, regs->regs[i]);
+			pr_cont(" %0*lx", field, regs->regs[i]);
 
 		i++;
 		if ((i % 4) == 0)
-			printk("\n");
+			pr_cont("\n");
 	}
 
 #ifdef CONFIG_CPU_HAS_SMARTMIPS
@@ -291,46 +291,46 @@ static void __show_regs(const struct pt_regs *regs)
 
 	if (cpu_has_3kex) {
 		if (regs->cp0_status & ST0_KUO)
-			printk("KUo ");
+			pr_cont("KUo ");
 		if (regs->cp0_status & ST0_IEO)
-			printk("IEo ");
+			pr_cont("IEo ");
 		if (regs->cp0_status & ST0_KUP)
-			printk("KUp ");
+			pr_cont("KUp ");
 		if (regs->cp0_status & ST0_IEP)
-			printk("IEp ");
+			pr_cont("IEp ");
 		if (regs->cp0_status & ST0_KUC)
-			printk("KUc ");
+			pr_cont("KUc ");
 		if (regs->cp0_status & ST0_IEC)
-			printk("IEc ");
+			pr_cont("IEc ");
 	} else if (cpu_has_4kex) {
 		if (regs->cp0_status & ST0_KX)
-			printk("KX ");
+			pr_cont("KX ");
 		if (regs->cp0_status & ST0_SX)
-			printk("SX ");
+			pr_cont("SX ");
 		if (regs->cp0_status & ST0_UX)
-			printk("UX ");
+			pr_cont("UX ");
 		switch (regs->cp0_status & ST0_KSU) {
 		case KSU_USER:
-			printk("USER ");
+			pr_cont("USER ");
 			break;
 		case KSU_SUPERVISOR:
-			printk("SUPERVISOR ");
+			pr_cont("SUPERVISOR ");
 			break;
 		case KSU_KERNEL:
-			printk("KERNEL ");
+			pr_cont("KERNEL ");
 			break;
 		default:
-			printk("BAD_MODE ");
+			pr_cont("BAD_MODE ");
 			break;
 		}
 		if (regs->cp0_status & ST0_ERL)
-			printk("ERL ");
+			pr_cont("ERL ");
 		if (regs->cp0_status & ST0_EXL)
-			printk("EXL ");
+			pr_cont("EXL ");
 		if (regs->cp0_status & ST0_IE)
-			printk("IE ");
+			pr_cont("IE ");
 	}
-	printk("\n");
+	pr_cont("\n");
 
 	exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
 	printk("Cause : %08x (ExcCode %02x)\n", cause, exccode);
-- 
cgit 


From 8a98495c7008d5bdede3d53e05e69ecdc0bc614b Mon Sep 17 00:00:00 2001
From: James Hogan <james.hogan@imgtec.com>
Date: Fri, 21 Oct 2016 20:06:40 +0100
Subject: MIPS: dump_tlb: Fix printk continuations

Since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing
continuation lines") the output from TLB dumps on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected output.

Continuation is also used for the second line of each TLB entry printed
in dump_tlb.c even though it has a newline, since it is a continuation
of the interpretation of the same TLB entry. For example:

[   46.371884] Index:  0 pgmask=16kb va=77654000 asid=73 gid=00
        [ri=0 xi=0 pa=ffc18000 c=5 d=0 v=1 g=0] [ri=0 xi=0 pa=ffc1c000 c=5 d=0 v=1 g=0]
[   46.385380] Index: 12 pgmask=16kb va=004b4000 asid=73 gid=00
        [ri=0 xi=0 pa=00000000 c=0 d=0 v=0 g=0] [ri=0 xi=0 pa=ffb00000 c=5 d=1 v=1 g=0]

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14444/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/lib/dump_tlb.c     | 44 ++++++++++++++++++++++----------------------
 arch/mips/lib/r3k_dump_tlb.c | 18 +++++++++---------
 2 files changed, 31 insertions(+), 31 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/lib/dump_tlb.c b/arch/mips/lib/dump_tlb.c
index 0f80b936e75e..6eb50a7137db 100644
--- a/arch/mips/lib/dump_tlb.c
+++ b/arch/mips/lib/dump_tlb.c
@@ -135,42 +135,42 @@ static void dump_tlb(int first, int last)
 		c0 = (entrylo0 & ENTRYLO_C) >> ENTRYLO_C_SHIFT;
 		c1 = (entrylo1 & ENTRYLO_C) >> ENTRYLO_C_SHIFT;
 
-		printk("va=%0*lx asid=%0*lx",
-		       vwidth, (entryhi & ~0x1fffUL),
-		       asidwidth, entryhi & asidmask);
+		pr_cont("va=%0*lx asid=%0*lx",
+			vwidth, (entryhi & ~0x1fffUL),
+			asidwidth, entryhi & asidmask);
 		if (cpu_has_guestid)
-			printk(" gid=%02lx",
-			       (guestctl1 & MIPS_GCTL1_RID)
+			pr_cont(" gid=%02lx",
+				(guestctl1 & MIPS_GCTL1_RID)
 					>> MIPS_GCTL1_RID_SHIFT);
 		/* RI/XI are in awkward places, so mask them off separately */
 		pa = entrylo0 & ~(MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI);
 		if (xpa)
 			pa |= (unsigned long long)readx_c0_entrylo0() << 30;
 		pa = (pa << 6) & PAGE_MASK;
-		printk("\n\t[");
+		pr_cont("\n\t[");
 		if (cpu_has_rixi)
-			printk("ri=%d xi=%d ",
-			       (entrylo0 & MIPS_ENTRYLO_RI) ? 1 : 0,
-			       (entrylo0 & MIPS_ENTRYLO_XI) ? 1 : 0);
-		printk("pa=%0*llx c=%d d=%d v=%d g=%d] [",
-		       pwidth, pa, c0,
-		       (entrylo0 & ENTRYLO_D) ? 1 : 0,
-		       (entrylo0 & ENTRYLO_V) ? 1 : 0,
-		       (entrylo0 & ENTRYLO_G) ? 1 : 0);
+			pr_cont("ri=%d xi=%d ",
+				(entrylo0 & MIPS_ENTRYLO_RI) ? 1 : 0,
+				(entrylo0 & MIPS_ENTRYLO_XI) ? 1 : 0);
+		pr_cont("pa=%0*llx c=%d d=%d v=%d g=%d] [",
+			pwidth, pa, c0,
+			(entrylo0 & ENTRYLO_D) ? 1 : 0,
+			(entrylo0 & ENTRYLO_V) ? 1 : 0,
+			(entrylo0 & ENTRYLO_G) ? 1 : 0);
 		/* RI/XI are in awkward places, so mask them off separately */
 		pa = entrylo1 & ~(MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI);
 		if (xpa)
 			pa |= (unsigned long long)readx_c0_entrylo1() << 30;
 		pa = (pa << 6) & PAGE_MASK;
 		if (cpu_has_rixi)
-			printk("ri=%d xi=%d ",
-			       (entrylo1 & MIPS_ENTRYLO_RI) ? 1 : 0,
-			       (entrylo1 & MIPS_ENTRYLO_XI) ? 1 : 0);
-		printk("pa=%0*llx c=%d d=%d v=%d g=%d]\n",
-		       pwidth, pa, c1,
-		       (entrylo1 & ENTRYLO_D) ? 1 : 0,
-		       (entrylo1 & ENTRYLO_V) ? 1 : 0,
-		       (entrylo1 & ENTRYLO_G) ? 1 : 0);
+			pr_cont("ri=%d xi=%d ",
+				(entrylo1 & MIPS_ENTRYLO_RI) ? 1 : 0,
+				(entrylo1 & MIPS_ENTRYLO_XI) ? 1 : 0);
+		pr_cont("pa=%0*llx c=%d d=%d v=%d g=%d]\n",
+			pwidth, pa, c1,
+			(entrylo1 & ENTRYLO_D) ? 1 : 0,
+			(entrylo1 & ENTRYLO_V) ? 1 : 0,
+			(entrylo1 & ENTRYLO_G) ? 1 : 0);
 	}
 	printk("\n");
 
diff --git a/arch/mips/lib/r3k_dump_tlb.c b/arch/mips/lib/r3k_dump_tlb.c
index 744f4a7bc49d..85b4086e553e 100644
--- a/arch/mips/lib/r3k_dump_tlb.c
+++ b/arch/mips/lib/r3k_dump_tlb.c
@@ -53,15 +53,15 @@ static void dump_tlb(int first, int last)
 			 */
 			printk("Index: %2d ", i);
 
-			printk("va=%08lx asid=%08lx"
-			       "  [pa=%06lx n=%d d=%d v=%d g=%d]",
-			       entryhi & PAGE_MASK,
-			       entryhi & asid_mask,
-			       entrylo0 & PAGE_MASK,
-			       (entrylo0 & R3K_ENTRYLO_N) ? 1 : 0,
-			       (entrylo0 & R3K_ENTRYLO_D) ? 1 : 0,
-			       (entrylo0 & R3K_ENTRYLO_V) ? 1 : 0,
-			       (entrylo0 & R3K_ENTRYLO_G) ? 1 : 0);
+			pr_cont("va=%08lx asid=%08lx"
+				"  [pa=%06lx n=%d d=%d v=%d g=%d]",
+				entryhi & PAGE_MASK,
+				entryhi & asid_mask,
+				entrylo0 & PAGE_MASK,
+				(entrylo0 & R3K_ENTRYLO_N) ? 1 : 0,
+				(entrylo0 & R3K_ENTRYLO_D) ? 1 : 0,
+				(entrylo0 & R3K_ENTRYLO_V) ? 1 : 0,
+				(entrylo0 & R3K_ENTRYLO_G) ? 1 : 0);
 		}
 	}
 	printk("\n");
-- 
cgit 


From c9e5603974573367c4d80964a845237a2297228c Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@imgtec.com>
Date: Fri, 28 Oct 2016 08:20:09 +0100
Subject: MIPS: ptrace: Also initialize the FP context on individual FCSR
 writes

Complement commit ac9ad83bc318 ("MIPS: prevent FP context set via ptrace
being discarded") and also initialize the FP context whenever FCSR alone
is written with a PTRACE_POKEUSR request addressing FPC_CSR, rather than
along with the full FPU register set in the case of the PTRACE_SETFPREGS
request.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14459/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/ptrace.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 6103b24d1bfc..fd3a9580661a 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -817,6 +817,7 @@ long arch_ptrace(struct task_struct *child, long request,
 			break;
 #endif
 		case FPC_CSR:
+			init_fp_ctx(child);
 			ptrace_setfcr31(child, data);
 			break;
 		case DSP_BASE ... DSP_BASE + 5: {
-- 
cgit 


From 5a1aca4469fdccd5b74ba0b4e490173b2b447895 Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@imgtec.com>
Date: Fri, 28 Oct 2016 08:21:03 +0100
Subject: MIPS: Fix FCSR Cause bit handling for correct SIGFPE issue

Sanitize FCSR Cause bit handling, following a trail of past attempts:

* commit 4249548454f7 ("MIPS: ptrace: Fix FP context restoration FCSR
regression"),

* commit 443c44032a54 ("MIPS: Always clear FCSR cause bits after
emulation"),

* commit 64bedffe4968 ("MIPS: Clear [MSA]FPE CSR.Cause after
notify_die()"),

* commit b1442d39fac2 ("MIPS: Prevent user from setting FCSR cause
bits"),

* commit b54d2901517d ("Properly handle branch delay slots in connection
with signals.").

Specifically do not mask these bits out in ptrace(2) processing and send
a SIGFPE signal instead whenever a matching pair of an FCSR Cause and
Enable bit is seen as execution of an affected context is about to
resume.  Only then clear Cause bits, and even then do not clear any bits
that are set but masked with the respective Enable bits.  Adjust Cause
bit clearing throughout code likewise, except within the FPU emulator
proper where they are set according to IEEE 754 exceptions raised as the
operation emulated executed.  Do so so that any IEEE 754 exceptions
subject to their default handling are recorded like with operations
executed by FPU hardware.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14460/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/include/asm/fpu_emulator.h  | 13 +++++++
 arch/mips/include/asm/switch_to.h     | 18 +++++++++
 arch/mips/kernel/mips-r2-to-r6-emul.c | 10 ++---
 arch/mips/kernel/ptrace.c             |  7 ++--
 arch/mips/kernel/traps.c              | 72 +++++++++++++++++++----------------
 5 files changed, 78 insertions(+), 42 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/include/asm/fpu_emulator.h b/arch/mips/include/asm/fpu_emulator.h
index 355dc25172e7..c05369e0b8d6 100644
--- a/arch/mips/include/asm/fpu_emulator.h
+++ b/arch/mips/include/asm/fpu_emulator.h
@@ -63,6 +63,8 @@ do {									\
 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
 				    struct mips_fpu_struct *ctx, int has_fpu,
 				    void *__user *fault_addr);
+void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr,
+		     struct task_struct *tsk);
 int process_fpemu_return(int sig, void __user *fault_addr,
 			 unsigned long fcr31);
 int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
@@ -81,4 +83,15 @@ static inline void fpu_emulator_init_fpu(void)
 		set_fpr64(&t->thread.fpu.fpr[i], 0, SIGNALLING_NAN);
 }
 
+/*
+ * Mask the FCSR Cause bits according to the Enable bits, observing
+ * that Unimplemented is always enabled.
+ */
+static inline unsigned long mask_fcr31_x(unsigned long fcr31)
+{
+	return fcr31 & (FPU_CSR_UNI_X |
+			((fcr31 & FPU_CSR_ALL_E) <<
+			 (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E))));
+}
+
 #endif /* _ASM_FPU_EMULATOR_H */
diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/switch_to.h
index ebb5c0f2f90d..c0ae27971e31 100644
--- a/arch/mips/include/asm/switch_to.h
+++ b/arch/mips/include/asm/switch_to.h
@@ -75,6 +75,22 @@ do {	if (cpu_has_rw_llb) {						\
 	}								\
 } while (0)
 
+/*
+ * Check FCSR for any unmasked exceptions pending set with `ptrace',
+ * clear them and send a signal.
+ */
+#define __sanitize_fcr31(next)						\
+do {									\
+	unsigned long fcr31 = mask_fcr31_x(next->thread.fpu.fcr31);	\
+	void __user *pc;						\
+									\
+	if (unlikely(fcr31)) {						\
+		pc = (void __user *)task_pt_regs(next)->cp0_epc;	\
+		next->thread.fpu.fcr31 &= ~fcr31;			\
+		force_fcr31_sig(fcr31, pc, next);			\
+	}								\
+} while (0)
+
 /*
  * For newly created kernel threads switch_to() will return to
  * ret_from_kernel_thread, newly created user threads to ret_from_fork.
@@ -85,6 +101,8 @@ do {	if (cpu_has_rw_llb) {						\
 do {									\
 	__mips_mt_fpaff_switch_to(prev);				\
 	lose_fpu_inatomic(1, prev);					\
+	if (tsk_used_math(next))					\
+		__sanitize_fcr31(next);					\
 	if (cpu_has_dsp) {						\
 		__save_dsp(prev);					\
 		__restore_dsp(next);					\
diff --git a/arch/mips/kernel/mips-r2-to-r6-emul.c b/arch/mips/kernel/mips-r2-to-r6-emul.c
index 22dedd62818a..bd09853aecdf 100644
--- a/arch/mips/kernel/mips-r2-to-r6-emul.c
+++ b/arch/mips/kernel/mips-r2-to-r6-emul.c
@@ -899,7 +899,7 @@ static inline int mipsr2_find_op_func(struct pt_regs *regs, u32 inst,
  * mipsr2_decoder: Decode and emulate a MIPS R2 instruction
  * @regs: Process register set
  * @inst: Instruction to decode and emulate
- * @fcr31: Floating Point Control and Status Register returned
+ * @fcr31: Floating Point Control and Status Register Cause bits returned
  */
 int mipsr2_decoder(struct pt_regs *regs, u32 inst, unsigned long *fcr31)
 {
@@ -1172,13 +1172,13 @@ fpu_emul:
 
 		err = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
 					       &fault_addr);
-		*fcr31 = current->thread.fpu.fcr31;
 
 		/*
-		 * We can't allow the emulated instruction to leave any of
-		 * the cause bits set in $fcr31.
+		 * We can't allow the emulated instruction to leave any
+		 * enabled Cause bits set in $fcr31.
 		 */
-		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
+		*fcr31 = res = mask_fcr31_x(current->thread.fpu.fcr31);
+		current->thread.fpu.fcr31 &= ~res;
 
 		/*
 		 * this is a tricky issue - lose_fpu() uses LL/SC atomics
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index fd3a9580661a..a92994d60e91 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -79,16 +79,15 @@ void ptrace_disable(struct task_struct *child)
 }
 
 /*
- * Poke at FCSR according to its mask.  Don't set the cause bits as
- * this is currently not handled correctly in FP context restoration
- * and will cause an oops if a corresponding enable bit is set.
+ * Poke at FCSR according to its mask.  Set the Cause bits even
+ * if a corresponding Enable bit is set.  This will be noticed at
+ * the time the thread is switched to and SIGFPE thrown accordingly.
  */
 static void ptrace_setfcr31(struct task_struct *child, u32 value)
 {
 	u32 fcr31;
 	u32 mask;
 
-	value &= ~FPU_CSR_ALL_X;
 	fcr31 = child->thread.fpu.fcr31;
 	mask = boot_cpu_data.fpu_msk31;
 	child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index b9a910b208f9..3905003dfe2b 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -708,6 +708,32 @@ asmlinkage void do_ov(struct pt_regs *regs)
 	exception_exit(prev_state);
 }
 
+/*
+ * Send SIGFPE according to FCSR Cause bits, which must have already
+ * been masked against Enable bits.  This is impotant as Inexact can
+ * happen together with Overflow or Underflow, and `ptrace' can set
+ * any bits.
+ */
+void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr,
+		     struct task_struct *tsk)
+{
+	struct siginfo si = { .si_addr = fault_addr, .si_signo = SIGFPE };
+
+	if (fcr31 & FPU_CSR_INV_X)
+		si.si_code = FPE_FLTINV;
+	else if (fcr31 & FPU_CSR_DIV_X)
+		si.si_code = FPE_FLTDIV;
+	else if (fcr31 & FPU_CSR_OVF_X)
+		si.si_code = FPE_FLTOVF;
+	else if (fcr31 & FPU_CSR_UDF_X)
+		si.si_code = FPE_FLTUND;
+	else if (fcr31 & FPU_CSR_INE_X)
+		si.si_code = FPE_FLTRES;
+	else
+		si.si_code = __SI_FAULT;
+	force_sig_info(SIGFPE, &si, tsk);
+}
+
 int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
 {
 	struct siginfo si = { 0 };
@@ -718,27 +744,7 @@ int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
 		return 0;
 
 	case SIGFPE:
-		si.si_addr = fault_addr;
-		si.si_signo = sig;
-		/*
-		 * Inexact can happen together with Overflow or Underflow.
-		 * Respect the mask to deliver the correct exception.
-		 */
-		fcr31 &= (fcr31 & FPU_CSR_ALL_E) <<
-			 (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E));
-		if (fcr31 & FPU_CSR_INV_X)
-			si.si_code = FPE_FLTINV;
-		else if (fcr31 & FPU_CSR_DIV_X)
-			si.si_code = FPE_FLTDIV;
-		else if (fcr31 & FPU_CSR_OVF_X)
-			si.si_code = FPE_FLTOVF;
-		else if (fcr31 & FPU_CSR_UDF_X)
-			si.si_code = FPE_FLTUND;
-		else if (fcr31 & FPU_CSR_INE_X)
-			si.si_code = FPE_FLTRES;
-		else
-			si.si_code = __SI_FAULT;
-		force_sig_info(sig, &si, current);
+		force_fcr31_sig(fcr31, fault_addr, current);
 		return 1;
 
 	case SIGBUS:
@@ -802,13 +808,13 @@ static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
 	/* Run the emulator */
 	sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
 				       &fault_addr);
-	fcr31 = current->thread.fpu.fcr31;
 
 	/*
-	 * We can't allow the emulated instruction to leave any of
-	 * the cause bits set in $fcr31.
+	 * We can't allow the emulated instruction to leave any
+	 * enabled Cause bits set in $fcr31.
 	 */
-	current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
+	fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
+	current->thread.fpu.fcr31 &= ~fcr31;
 
 	/* Restore the hardware register state */
 	own_fpu(1);
@@ -834,7 +840,7 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
 		goto out;
 
 	/* Clear FCSR.Cause before enabling interrupts */
-	write_32bit_cp1_register(CP1_STATUS, fcr31 & ~FPU_CSR_ALL_X);
+	write_32bit_cp1_register(CP1_STATUS, fcr31 & ~mask_fcr31_x(fcr31));
 	local_irq_enable();
 
 	die_if_kernel("FP exception in kernel code", regs);
@@ -856,13 +862,13 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
 		/* Run the emulator */
 		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
 					       &fault_addr);
-		fcr31 = current->thread.fpu.fcr31;
 
 		/*
-		 * We can't allow the emulated instruction to leave any of
-		 * the cause bits set in $fcr31.
+		 * We can't allow the emulated instruction to leave any
+		 * enabled Cause bits set in $fcr31.
 		 */
-		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
+		fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
+		current->thread.fpu.fcr31 &= ~fcr31;
 
 		/* Restore the hardware register state */
 		own_fpu(1);	/* Using the FPU again.	 */
@@ -1427,13 +1433,13 @@ asmlinkage void do_cpu(struct pt_regs *regs)
 
 		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
 					       &fault_addr);
-		fcr31 = current->thread.fpu.fcr31;
 
 		/*
 		 * We can't allow the emulated instruction to leave
-		 * any of the cause bits set in $fcr31.
+		 * any enabled Cause bits set in $fcr31.
 		 */
-		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
+		fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
+		current->thread.fpu.fcr31 &= ~fcr31;
 
 		/* Send a signal if required.  */
 		if (!process_fpemu_return(sig, fault_addr, fcr31) && !err)
-- 
cgit 


From 35938a00ba86ae7a7404b66b526968ca2b8d3127 Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@imgtec.com>
Date: Mon, 31 Oct 2016 16:25:44 +0000
Subject: MIPS: Fix ISA I FP sigcontext access violation handling

Complement commit 0ae8dceaebe3 ("Merge with 2.3.10.") and use the local
`fault' handler to recover from FP sigcontext access violation faults,
like corresponding code does in r4k_fpu.S.  The `bad_stack' handler is
in syscall.c and is not suitable here as we want to propagate the error
condition up through the caller rather than killing the thread outright.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14474/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/r2300_fpu.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/r2300_fpu.S b/arch/mips/kernel/r2300_fpu.S
index b4ac6374a38f..c4c8c1b65be9 100644
--- a/arch/mips/kernel/r2300_fpu.S
+++ b/arch/mips/kernel/r2300_fpu.S
@@ -21,7 +21,7 @@
 #define EX(a,b)							\
 9:	a,##b;							\
 	.section __ex_table,"a";				\
-	PTR	9b,bad_stack;					\
+	PTR	9b,fault;					\
 	.previous
 
 	.set	noreorder
-- 
cgit 


From 6daaa3266db9cc488612690e42c23b0763e2b49a Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@imgtec.com>
Date: Mon, 31 Oct 2016 16:26:24 +0000
Subject: MIPS: Remove FIR from ISA I FP signal context

Complement commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.")
and remove the Floating Point Implementation Register (FIR) from the FP
register set recorded in a signal context with MIPS I processors too, in
line with the change applied to r4k_fpu.S.

The `sc_fpc_eir' slot is unused according to our current ABI and the FIR
register is read-only and always directly accessible from user software.

[ralf@linux-mips.org: This is also required because the next commit depends
on it.]

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14475/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/r2300_fpu.S | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/r2300_fpu.S b/arch/mips/kernel/r2300_fpu.S
index c4c8c1b65be9..ce249eae91ce 100644
--- a/arch/mips/kernel/r2300_fpu.S
+++ b/arch/mips/kernel/r2300_fpu.S
@@ -64,13 +64,9 @@ LEAF(_save_fp_context)
 	EX(swc1 $f29,(SC_FPREGS+232)(a0))
 	EX(swc1 $f30,(SC_FPREGS+240)(a0))
 	EX(swc1 $f31,(SC_FPREGS+248)(a0))
-	EX(sw	t1,(SC_FPC_CSR)(a0))
-	cfc1	t0,$0				# implementation/version
 	jr	ra
+	 EX(sw	t1,(SC_FPC_CSR)(a0))
 	.set	pop
-	.set	nomacro
-	 EX(sw	t0,(SC_FPC_EIR)(a0))
-	.set	macro
 	END(_save_fp_context)
 
 /*
-- 
cgit 


From 758ef0a939d4c003381d2a97d9fb51b2d6d7e162 Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@imgtec.com>
Date: Mon, 31 Oct 2016 16:27:01 +0000
Subject: MIPS: Fix ISA I/II FP signal context offsets

Fix a regression introduced with commit 2db9ca0a3551 ("MIPS: Use struct
mips_abi offsets to save FP context") for MIPS I/I FP signal contexts,
by converting save/restore code to the updated internal API.  Start FGR
offsets from 0 rather than SC_FPREGS from $a0 and use $a1 rather than
the offset of SC_FPC_CSR from $a0 for the Floating Point Control/Status
Register (FCSR).

Document the new internal API and adjust assembly code formatting for
consistency.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14476/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/r2300_fpu.S | 159 ++++++++++++++++++++++---------------------
 arch/mips/kernel/r6000_fpu.S |  89 +++++++++++++-----------
 2 files changed, 131 insertions(+), 117 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/r2300_fpu.S b/arch/mips/kernel/r2300_fpu.S
index ce249eae91ce..70ca63752cfa 100644
--- a/arch/mips/kernel/r2300_fpu.S
+++ b/arch/mips/kernel/r2300_fpu.S
@@ -26,97 +26,104 @@
 
 	.set	noreorder
 	.set	mips1
-	/* Save floating point context */
+
+/**
+ * _save_fp_context() - save FP context from the FPU
+ * @a0 - pointer to fpregs field of sigcontext
+ * @a1 - pointer to fpc_csr field of sigcontext
+ *
+ * Save FP context, including the 32 FP data registers and the FP
+ * control & status register, from the FPU to signal context.
+ */
 LEAF(_save_fp_context)
 	.set	push
 	SET_HARDFLOAT
 	li	v0, 0					# assume success
-	cfc1	t1,fcr31
-	EX(swc1 $f0,(SC_FPREGS+0)(a0))
-	EX(swc1 $f1,(SC_FPREGS+8)(a0))
-	EX(swc1 $f2,(SC_FPREGS+16)(a0))
-	EX(swc1 $f3,(SC_FPREGS+24)(a0))
-	EX(swc1 $f4,(SC_FPREGS+32)(a0))
-	EX(swc1 $f5,(SC_FPREGS+40)(a0))
-	EX(swc1 $f6,(SC_FPREGS+48)(a0))
-	EX(swc1 $f7,(SC_FPREGS+56)(a0))
-	EX(swc1 $f8,(SC_FPREGS+64)(a0))
-	EX(swc1 $f9,(SC_FPREGS+72)(a0))
-	EX(swc1 $f10,(SC_FPREGS+80)(a0))
-	EX(swc1 $f11,(SC_FPREGS+88)(a0))
-	EX(swc1 $f12,(SC_FPREGS+96)(a0))
-	EX(swc1 $f13,(SC_FPREGS+104)(a0))
-	EX(swc1 $f14,(SC_FPREGS+112)(a0))
-	EX(swc1 $f15,(SC_FPREGS+120)(a0))
-	EX(swc1 $f16,(SC_FPREGS+128)(a0))
-	EX(swc1 $f17,(SC_FPREGS+136)(a0))
-	EX(swc1 $f18,(SC_FPREGS+144)(a0))
-	EX(swc1 $f19,(SC_FPREGS+152)(a0))
-	EX(swc1 $f20,(SC_FPREGS+160)(a0))
-	EX(swc1 $f21,(SC_FPREGS+168)(a0))
-	EX(swc1 $f22,(SC_FPREGS+176)(a0))
-	EX(swc1 $f23,(SC_FPREGS+184)(a0))
-	EX(swc1 $f24,(SC_FPREGS+192)(a0))
-	EX(swc1 $f25,(SC_FPREGS+200)(a0))
-	EX(swc1 $f26,(SC_FPREGS+208)(a0))
-	EX(swc1 $f27,(SC_FPREGS+216)(a0))
-	EX(swc1 $f28,(SC_FPREGS+224)(a0))
-	EX(swc1 $f29,(SC_FPREGS+232)(a0))
-	EX(swc1 $f30,(SC_FPREGS+240)(a0))
-	EX(swc1 $f31,(SC_FPREGS+248)(a0))
+	cfc1	t1, fcr31
+	EX(swc1 $f0, 0(a0))
+	EX(swc1 $f1, 8(a0))
+	EX(swc1 $f2, 16(a0))
+	EX(swc1 $f3, 24(a0))
+	EX(swc1 $f4, 32(a0))
+	EX(swc1 $f5, 40(a0))
+	EX(swc1 $f6, 48(a0))
+	EX(swc1 $f7, 56(a0))
+	EX(swc1 $f8, 64(a0))
+	EX(swc1 $f9, 72(a0))
+	EX(swc1 $f10, 80(a0))
+	EX(swc1 $f11, 88(a0))
+	EX(swc1 $f12, 96(a0))
+	EX(swc1 $f13, 104(a0))
+	EX(swc1 $f14, 112(a0))
+	EX(swc1 $f15, 120(a0))
+	EX(swc1 $f16, 128(a0))
+	EX(swc1 $f17, 136(a0))
+	EX(swc1 $f18, 144(a0))
+	EX(swc1 $f19, 152(a0))
+	EX(swc1 $f20, 160(a0))
+	EX(swc1 $f21, 168(a0))
+	EX(swc1 $f22, 176(a0))
+	EX(swc1 $f23, 184(a0))
+	EX(swc1 $f24, 192(a0))
+	EX(swc1 $f25, 200(a0))
+	EX(swc1 $f26, 208(a0))
+	EX(swc1 $f27, 216(a0))
+	EX(swc1 $f28, 224(a0))
+	EX(swc1 $f29, 232(a0))
+	EX(swc1 $f30, 240(a0))
+	EX(swc1 $f31, 248(a0))
 	jr	ra
-	 EX(sw	t1,(SC_FPC_CSR)(a0))
+	 EX(sw	t1, (a1))
 	.set	pop
 	END(_save_fp_context)
 
-/*
- * Restore FPU state:
- *  - fp gp registers
- *  - cp1 status/control register
+/**
+ * _restore_fp_context() - restore FP context to the FPU
+ * @a0 - pointer to fpregs field of sigcontext
+ * @a1 - pointer to fpc_csr field of sigcontext
  *
- * We base the decision which registers to restore from the signal stack
- * frame on the current content of c0_status, not on the content of the
- * stack frame which might have been changed by the user.
+ * Restore FP context, including the 32 FP data registers and the FP
+ * control & status register, from signal context to the FPU.
  */
 LEAF(_restore_fp_context)
 	.set	push
 	SET_HARDFLOAT
 	li	v0, 0					# assume success
-	EX(lw t0,(SC_FPC_CSR)(a0))
-	EX(lwc1 $f0,(SC_FPREGS+0)(a0))
-	EX(lwc1 $f1,(SC_FPREGS+8)(a0))
-	EX(lwc1 $f2,(SC_FPREGS+16)(a0))
-	EX(lwc1 $f3,(SC_FPREGS+24)(a0))
-	EX(lwc1 $f4,(SC_FPREGS+32)(a0))
-	EX(lwc1 $f5,(SC_FPREGS+40)(a0))
-	EX(lwc1 $f6,(SC_FPREGS+48)(a0))
-	EX(lwc1 $f7,(SC_FPREGS+56)(a0))
-	EX(lwc1 $f8,(SC_FPREGS+64)(a0))
-	EX(lwc1 $f9,(SC_FPREGS+72)(a0))
-	EX(lwc1 $f10,(SC_FPREGS+80)(a0))
-	EX(lwc1 $f11,(SC_FPREGS+88)(a0))
-	EX(lwc1 $f12,(SC_FPREGS+96)(a0))
-	EX(lwc1 $f13,(SC_FPREGS+104)(a0))
-	EX(lwc1 $f14,(SC_FPREGS+112)(a0))
-	EX(lwc1 $f15,(SC_FPREGS+120)(a0))
-	EX(lwc1 $f16,(SC_FPREGS+128)(a0))
-	EX(lwc1 $f17,(SC_FPREGS+136)(a0))
-	EX(lwc1 $f18,(SC_FPREGS+144)(a0))
-	EX(lwc1 $f19,(SC_FPREGS+152)(a0))
-	EX(lwc1 $f20,(SC_FPREGS+160)(a0))
-	EX(lwc1 $f21,(SC_FPREGS+168)(a0))
-	EX(lwc1 $f22,(SC_FPREGS+176)(a0))
-	EX(lwc1 $f23,(SC_FPREGS+184)(a0))
-	EX(lwc1 $f24,(SC_FPREGS+192)(a0))
-	EX(lwc1 $f25,(SC_FPREGS+200)(a0))
-	EX(lwc1 $f26,(SC_FPREGS+208)(a0))
-	EX(lwc1 $f27,(SC_FPREGS+216)(a0))
-	EX(lwc1 $f28,(SC_FPREGS+224)(a0))
-	EX(lwc1 $f29,(SC_FPREGS+232)(a0))
-	EX(lwc1 $f30,(SC_FPREGS+240)(a0))
-	EX(lwc1 $f31,(SC_FPREGS+248)(a0))
+	EX(lw t0, (a1))
+	EX(lwc1 $f0, 0(a0))
+	EX(lwc1 $f1, 8(a0))
+	EX(lwc1 $f2, 16(a0))
+	EX(lwc1 $f3, 24(a0))
+	EX(lwc1 $f4, 32(a0))
+	EX(lwc1 $f5, 40(a0))
+	EX(lwc1 $f6, 48(a0))
+	EX(lwc1 $f7, 56(a0))
+	EX(lwc1 $f8, 64(a0))
+	EX(lwc1 $f9, 72(a0))
+	EX(lwc1 $f10, 80(a0))
+	EX(lwc1 $f11, 88(a0))
+	EX(lwc1 $f12, 96(a0))
+	EX(lwc1 $f13, 104(a0))
+	EX(lwc1 $f14, 112(a0))
+	EX(lwc1 $f15, 120(a0))
+	EX(lwc1 $f16, 128(a0))
+	EX(lwc1 $f17, 136(a0))
+	EX(lwc1 $f18, 144(a0))
+	EX(lwc1 $f19, 152(a0))
+	EX(lwc1 $f20, 160(a0))
+	EX(lwc1 $f21, 168(a0))
+	EX(lwc1 $f22, 176(a0))
+	EX(lwc1 $f23, 184(a0))
+	EX(lwc1 $f24, 192(a0))
+	EX(lwc1 $f25, 200(a0))
+	EX(lwc1 $f26, 208(a0))
+	EX(lwc1 $f27, 216(a0))
+	EX(lwc1 $f28, 224(a0))
+	EX(lwc1 $f29, 232(a0))
+	EX(lwc1 $f30, 240(a0))
+	EX(lwc1 $f31, 248(a0))
 	jr	ra
-	 ctc1	t0,fcr31
+	 ctc1	t0, fcr31
 	.set	pop
 	END(_restore_fp_context)
 	.set	reorder
diff --git a/arch/mips/kernel/r6000_fpu.S b/arch/mips/kernel/r6000_fpu.S
index 47077380c15c..9cc7bfab3419 100644
--- a/arch/mips/kernel/r6000_fpu.S
+++ b/arch/mips/kernel/r6000_fpu.S
@@ -21,7 +21,14 @@
 	.set	push
 	SET_HARDFLOAT
 
-	/* Save floating point context */
+/**
+ * _save_fp_context() - save FP context from the FPU
+ * @a0 - pointer to fpregs field of sigcontext
+ * @a1 - pointer to fpc_csr field of sigcontext
+ *
+ * Save FP context, including the 32 FP data registers and the FP
+ * control & status register, from the FPU to signal context.
+ */
 	LEAF(_save_fp_context)
 	mfc0	t0,CP0_STATUS
 	sll	t0,t0,2
@@ -30,59 +37,59 @@
 
 	cfc1	t1,fcr31
 	/* Store the 16 double precision registers */
-	sdc1	$f0,(SC_FPREGS+0)(a0)
-	sdc1	$f2,(SC_FPREGS+16)(a0)
-	sdc1	$f4,(SC_FPREGS+32)(a0)
-	sdc1	$f6,(SC_FPREGS+48)(a0)
-	sdc1	$f8,(SC_FPREGS+64)(a0)
-	sdc1	$f10,(SC_FPREGS+80)(a0)
-	sdc1	$f12,(SC_FPREGS+96)(a0)
-	sdc1	$f14,(SC_FPREGS+112)(a0)
-	sdc1	$f16,(SC_FPREGS+128)(a0)
-	sdc1	$f18,(SC_FPREGS+144)(a0)
-	sdc1	$f20,(SC_FPREGS+160)(a0)
-	sdc1	$f22,(SC_FPREGS+176)(a0)
-	sdc1	$f24,(SC_FPREGS+192)(a0)
-	sdc1	$f26,(SC_FPREGS+208)(a0)
-	sdc1	$f28,(SC_FPREGS+224)(a0)
-	sdc1	$f30,(SC_FPREGS+240)(a0)
+	sdc1	$f0,0(a0)
+	sdc1	$f2,16(a0)
+	sdc1	$f4,32(a0)
+	sdc1	$f6,48(a0)
+	sdc1	$f8,64(a0)
+	sdc1	$f10,80(a0)
+	sdc1	$f12,96(a0)
+	sdc1	$f14,112(a0)
+	sdc1	$f16,128(a0)
+	sdc1	$f18,144(a0)
+	sdc1	$f20,160(a0)
+	sdc1	$f22,176(a0)
+	sdc1	$f24,192(a0)
+	sdc1	$f26,208(a0)
+	sdc1	$f28,224(a0)
+	sdc1	$f30,240(a0)
 	jr	ra
-	 sw	t0,SC_FPC_CSR(a0)
+	 sw	t0,(a1)
 1:	jr	ra
 	 nop
 	END(_save_fp_context)
 
-/* Restore FPU state:
- *  - fp gp registers
- *  - cp1 status/control register
+/**
+ * _restore_fp_context() - restore FP context to the FPU
+ * @a0 - pointer to fpregs field of sigcontext
+ * @a1 - pointer to fpc_csr field of sigcontext
  *
- * We base the decision which registers to restore from the signal stack
- * frame on the current content of c0_status, not on the content of the
- * stack frame which might have been changed by the user.
+ * Restore FP context, including the 32 FP data registers and the FP
+ * control & status register, from signal context to the FPU.
  */
 	LEAF(_restore_fp_context)
 	mfc0	t0,CP0_STATUS
 	sll	t0,t0,2
 
 	bgez	t0,1f
-	 lw	t0,SC_FPC_CSR(a0)
+	 lw	t0,(a1)
 	/* Restore the 16 double precision registers */
-	ldc1	$f0,(SC_FPREGS+0)(a0)
-	ldc1	$f2,(SC_FPREGS+16)(a0)
-	ldc1	$f4,(SC_FPREGS+32)(a0)
-	ldc1	$f6,(SC_FPREGS+48)(a0)
-	ldc1	$f8,(SC_FPREGS+64)(a0)
-	ldc1	$f10,(SC_FPREGS+80)(a0)
-	ldc1	$f12,(SC_FPREGS+96)(a0)
-	ldc1	$f14,(SC_FPREGS+112)(a0)
-	ldc1	$f16,(SC_FPREGS+128)(a0)
-	ldc1	$f18,(SC_FPREGS+144)(a0)
-	ldc1	$f20,(SC_FPREGS+160)(a0)
-	ldc1	$f22,(SC_FPREGS+176)(a0)
-	ldc1	$f24,(SC_FPREGS+192)(a0)
-	ldc1	$f26,(SC_FPREGS+208)(a0)
-	ldc1	$f28,(SC_FPREGS+224)(a0)
-	ldc1	$f30,(SC_FPREGS+240)(a0)
+	ldc1	$f0,0(a0)
+	ldc1	$f2,16(a0)
+	ldc1	$f4,32(a0)
+	ldc1	$f6,48(a0)
+	ldc1	$f8,64(a0)
+	ldc1	$f10,80(a0)
+	ldc1	$f12,96(a0)
+	ldc1	$f14,112(a0)
+	ldc1	$f16,128(a0)
+	ldc1	$f18,144(a0)
+	ldc1	$f20,160(a0)
+	ldc1	$f22,176(a0)
+	ldc1	$f24,192(a0)
+	ldc1	$f26,208(a0)
+	ldc1	$f28,224(a0)
+	ldc1	$f30,240(a0)
 	jr	ra
 	 ctc1	t0,fcr31
 1:	jr	ra
-- 
cgit 


From f92722dc4545ebfa0f99a2f986fd88c112a22a42 Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@imgtec.com>
Date: Mon, 31 Oct 2016 16:27:40 +0000
Subject: MIPS: Correct MIPS I FP sigcontext layout

Complement commit 80cbfad79096 ("MIPS: Correct MIPS I FP context
layout") and correct the way Floating Point General registers are stored
in a signal context with MIPS I hardware.

Use the S.D and L.D assembly macros to have pairs of SWC1 instructions
and pairs of LWC1 instructions produced, respectively, in an arrangement
which makes the memory representation of floating-point data passed
compatible with that used by hardware SDC1 and LDC1 instructions, where
available, regardless of the hardware endianness used.  This matches the
layout used by r4k_fpu.S, ensuring run-time compatibility for MIPS I
software across all o32 hardware platforms.

Define an EX2 macro to handle exceptions from both hardware instructions
implicitly produced from S.D and L.D assembly macros.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14477/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/r2300_fpu.S | 103 ++++++++++++++++---------------------------
 1 file changed, 39 insertions(+), 64 deletions(-)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/r2300_fpu.S b/arch/mips/kernel/r2300_fpu.S
index 70ca63752cfa..918f2f6d3861 100644
--- a/arch/mips/kernel/r2300_fpu.S
+++ b/arch/mips/kernel/r2300_fpu.S
@@ -24,6 +24,13 @@
 	PTR	9b,fault;					\
 	.previous
 
+#define EX2(a,b)						\
+9:	a,##b;							\
+	.section __ex_table,"a";				\
+	PTR	9b,bad_stack;					\
+	PTR	9b+4,bad_stack;					\
+	.previous
+
 	.set	noreorder
 	.set	mips1
 
@@ -40,38 +47,22 @@ LEAF(_save_fp_context)
 	SET_HARDFLOAT
 	li	v0, 0					# assume success
 	cfc1	t1, fcr31
-	EX(swc1 $f0, 0(a0))
-	EX(swc1 $f1, 8(a0))
-	EX(swc1 $f2, 16(a0))
-	EX(swc1 $f3, 24(a0))
-	EX(swc1 $f4, 32(a0))
-	EX(swc1 $f5, 40(a0))
-	EX(swc1 $f6, 48(a0))
-	EX(swc1 $f7, 56(a0))
-	EX(swc1 $f8, 64(a0))
-	EX(swc1 $f9, 72(a0))
-	EX(swc1 $f10, 80(a0))
-	EX(swc1 $f11, 88(a0))
-	EX(swc1 $f12, 96(a0))
-	EX(swc1 $f13, 104(a0))
-	EX(swc1 $f14, 112(a0))
-	EX(swc1 $f15, 120(a0))
-	EX(swc1 $f16, 128(a0))
-	EX(swc1 $f17, 136(a0))
-	EX(swc1 $f18, 144(a0))
-	EX(swc1 $f19, 152(a0))
-	EX(swc1 $f20, 160(a0))
-	EX(swc1 $f21, 168(a0))
-	EX(swc1 $f22, 176(a0))
-	EX(swc1 $f23, 184(a0))
-	EX(swc1 $f24, 192(a0))
-	EX(swc1 $f25, 200(a0))
-	EX(swc1 $f26, 208(a0))
-	EX(swc1 $f27, 216(a0))
-	EX(swc1 $f28, 224(a0))
-	EX(swc1 $f29, 232(a0))
-	EX(swc1 $f30, 240(a0))
-	EX(swc1 $f31, 248(a0))
+	EX2(s.d $f0, 0(a0))
+	EX2(s.d $f2, 16(a0))
+	EX2(s.d $f4, 32(a0))
+	EX2(s.d $f6, 48(a0))
+	EX2(s.d $f8, 64(a0))
+	EX2(s.d $f10, 80(a0))
+	EX2(s.d $f12, 96(a0))
+	EX2(s.d $f14, 112(a0))
+	EX2(s.d $f16, 128(a0))
+	EX2(s.d $f18, 144(a0))
+	EX2(s.d $f20, 160(a0))
+	EX2(s.d $f22, 176(a0))
+	EX2(s.d $f24, 192(a0))
+	EX2(s.d $f26, 208(a0))
+	EX2(s.d $f28, 224(a0))
+	EX2(s.d $f30, 240(a0))
 	jr	ra
 	 EX(sw	t1, (a1))
 	.set	pop
@@ -90,38 +81,22 @@ LEAF(_restore_fp_context)
 	SET_HARDFLOAT
 	li	v0, 0					# assume success
 	EX(lw t0, (a1))
-	EX(lwc1 $f0, 0(a0))
-	EX(lwc1 $f1, 8(a0))
-	EX(lwc1 $f2, 16(a0))
-	EX(lwc1 $f3, 24(a0))
-	EX(lwc1 $f4, 32(a0))
-	EX(lwc1 $f5, 40(a0))
-	EX(lwc1 $f6, 48(a0))
-	EX(lwc1 $f7, 56(a0))
-	EX(lwc1 $f8, 64(a0))
-	EX(lwc1 $f9, 72(a0))
-	EX(lwc1 $f10, 80(a0))
-	EX(lwc1 $f11, 88(a0))
-	EX(lwc1 $f12, 96(a0))
-	EX(lwc1 $f13, 104(a0))
-	EX(lwc1 $f14, 112(a0))
-	EX(lwc1 $f15, 120(a0))
-	EX(lwc1 $f16, 128(a0))
-	EX(lwc1 $f17, 136(a0))
-	EX(lwc1 $f18, 144(a0))
-	EX(lwc1 $f19, 152(a0))
-	EX(lwc1 $f20, 160(a0))
-	EX(lwc1 $f21, 168(a0))
-	EX(lwc1 $f22, 176(a0))
-	EX(lwc1 $f23, 184(a0))
-	EX(lwc1 $f24, 192(a0))
-	EX(lwc1 $f25, 200(a0))
-	EX(lwc1 $f26, 208(a0))
-	EX(lwc1 $f27, 216(a0))
-	EX(lwc1 $f28, 224(a0))
-	EX(lwc1 $f29, 232(a0))
-	EX(lwc1 $f30, 240(a0))
-	EX(lwc1 $f31, 248(a0))
+	EX2(l.d $f0, 0(a0))
+	EX2(l.d $f2, 16(a0))
+	EX2(l.d $f4, 32(a0))
+	EX2(l.d $f6, 48(a0))
+	EX2(l.d $f8, 64(a0))
+	EX2(l.d $f10, 80(a0))
+	EX2(l.d $f12, 96(a0))
+	EX2(l.d $f14, 112(a0))
+	EX2(l.d $f16, 128(a0))
+	EX2(l.d $f18, 144(a0))
+	EX2(l.d $f20, 160(a0))
+	EX2(l.d $f22, 176(a0))
+	EX2(l.d $f24, 192(a0))
+	EX2(l.d $f26, 208(a0))
+	EX2(l.d $f28, 224(a0))
+	EX2(l.d $f30, 240(a0))
 	jr	ra
 	 ctc1	t0, fcr31
 	.set	pop
-- 
cgit 


From 16a767ec63167ef70c056795782d6c9c76ba5a5c Mon Sep 17 00:00:00 2001
From: James Hogan <james.hogan@imgtec.com>
Date: Tue, 1 Nov 2016 13:59:09 +0000
Subject: MIPS: Fix max_low_pfn with disabled highmem

When low memory doesn't reach HIGHMEM_START (e.g. up to 256MB at PA=0 is
common) and highmem is present above HIGHMEM_START (e.g. on Malta the
RAM overlayed by the IO region is aliased at PA=0x90000000), max_low_pfn
will be initially calculated very large and then clipped down to
HIGHMEM_START.

This causes crashes when reading /sys/kernel/mm/page_idle/bitmap
(i.e. CONFIG_IDLE_PAGE_TRACKING=y) when highmem is disabled. pfn_valid()
will compare against max_mapnr which is derived from max_low_pfn when
there is no highend_pfn set up, and will return true for PFNs right up
to HIGHMEM_START, even though they are beyond the end of low memory and
no page structs will actually exist for these PFNs.

This is fixed by skipping high memory regions when initially calculating
max_low_pfn if highmem is disabled, so it doesn't get clipped too high.
We also clip regions which overlap the highmem boundary when highmem is
disabled, so that max_pfn doesn't extend into highmem either.

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/14490/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/kernel/setup.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

(limited to 'arch/mips')

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 0d57909d9026..f66e5ce505b2 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -368,6 +368,19 @@ static void __init bootmem_init(void)
 		end = PFN_DOWN(boot_mem_map.map[i].addr
 				+ boot_mem_map.map[i].size);
 
+#ifndef CONFIG_HIGHMEM
+		/*
+		 * Skip highmem here so we get an accurate max_low_pfn if low
+		 * memory stops short of high memory.
+		 * If the region overlaps HIGHMEM_START, end is clipped so
+		 * max_pfn excludes the highmem portion.
+		 */
+		if (start >= PFN_DOWN(HIGHMEM_START))
+			continue;
+		if (end > PFN_DOWN(HIGHMEM_START))
+			end = PFN_DOWN(HIGHMEM_START);
+#endif
+
 		if (end > max_low_pfn)
 			max_low_pfn = end;
 		if (start < min_low_pfn)
-- 
cgit