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authorJohn A. Williams <john.williams@petalogix.com>2011-05-24 18:57:11 +1000
committerMichal Simek <monstr@monstr.eu>2011-07-25 09:13:42 +0200
commit8904976e8ca45be3ec75acc71f5d855ef671a079 (patch)
tree9c76c35266329312ace36ab009d686d5e2cd77f8 /arch/microblaze/kernel
parent5db34eb92f5699361de355dcd7958fdd2a9fb98a (diff)
downloadlinux-linaro-stable-8904976e8ca45be3ec75acc71f5d855ef671a079.tar.gz
microblaze: Unprivileged stream instruction awareness
Add cpuinfo support for the new MicroBlaze option permitting userspace (unprivileged) access to the streaming instructions (FSL / AXI-stream). Emit a noisy warning at bootup if this is enabled, because bad user code can potentially lockup the CPU. Signed-off-by: John A. Williams <john.williams@petalogix.com> Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/kernel')
-rw-r--r--arch/microblaze/kernel/cpu/cpuinfo-pvr-full.c1
-rw-r--r--arch/microblaze/kernel/cpu/cpuinfo-static.c1
-rw-r--r--arch/microblaze/kernel/cpu/cpuinfo.c4
-rw-r--r--arch/microblaze/kernel/cpu/mb.c4
4 files changed, 10 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/cpu/cpuinfo-pvr-full.c b/arch/microblaze/kernel/cpu/cpuinfo-pvr-full.c
index f70a6047f08e..916aaedf1945 100644
--- a/arch/microblaze/kernel/cpu/cpuinfo-pvr-full.c
+++ b/arch/microblaze/kernel/cpu/cpuinfo-pvr-full.c
@@ -72,6 +72,7 @@ void set_cpuinfo_pvr_full(struct cpuinfo *ci, struct device_node *cpu)
CI(pvr_user2, USER2);
CI(mmu, USE_MMU);
+ CI(mmu_privins, MMU_PRIVINS);
CI(endian, ENDIAN);
CI(use_icache, USE_ICACHE);
diff --git a/arch/microblaze/kernel/cpu/cpuinfo-static.c b/arch/microblaze/kernel/cpu/cpuinfo-static.c
index b16b994ca3d2..592bb2e838c4 100644
--- a/arch/microblaze/kernel/cpu/cpuinfo-static.c
+++ b/arch/microblaze/kernel/cpu/cpuinfo-static.c
@@ -119,6 +119,7 @@ void __init set_cpuinfo_static(struct cpuinfo *ci, struct device_node *cpu)
ci->pvr_user2 = fcpu(cpu, "xlnx,pvr-user2");
ci->mmu = fcpu(cpu, "xlnx,use-mmu");
+ ci->mmu_privins = fcpu(cpu, "xlnx,mmu-privileged-instr");
ci->endian = fcpu(cpu, "xlnx,endianness");
ci->ver_code = 0;
diff --git a/arch/microblaze/kernel/cpu/cpuinfo.c b/arch/microblaze/kernel/cpu/cpuinfo.c
index c1640c52711f..44394d80a683 100644
--- a/arch/microblaze/kernel/cpu/cpuinfo.c
+++ b/arch/microblaze/kernel/cpu/cpuinfo.c
@@ -88,4 +88,8 @@ void __init setup_cpuinfo(void)
printk(KERN_WARNING "%s: Unsupported PVR setting\n", __func__);
set_cpuinfo_static(&cpuinfo, cpu);
}
+
+ if (cpuinfo.mmu_privins)
+ printk(KERN_WARNING "%s: Stream instructions enabled"
+ " - USERSPACE CAN LOCK THIS KERNEL!\n", __func__);
}
diff --git a/arch/microblaze/kernel/cpu/mb.c b/arch/microblaze/kernel/cpu/mb.c
index b4048af02615..0afebaebb5b5 100644
--- a/arch/microblaze/kernel/cpu/mb.c
+++ b/arch/microblaze/kernel/cpu/mb.c
@@ -97,6 +97,10 @@ static int show_cpuinfo(struct seq_file *m, void *v)
(cpuinfo.use_exc & PVR2_FPU_EXC_MASK) ? "fpu " : "",
(cpuinfo.use_exc & PVR2_USE_FSL_EXC) ? "fsl " : "");
+ count += seq_printf(m,
+ "Stream-insns:\t%sprivileged\n",
+ cpuinfo.mmu_privins ? "un" : "");
+
if (cpuinfo.use_icache)
count += seq_printf(m,
"Icache:\t\t%ukB\tline length:\t%dB\n",