From 8904976e8ca45be3ec75acc71f5d855ef671a079 Mon Sep 17 00:00:00 2001 From: "John A. Williams" Date: Tue, 24 May 2011 18:57:11 +1000 Subject: [PATCH] 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 Signed-off-by: Michal Simek --- arch/microblaze/include/asm/cpuinfo.h | 1 + arch/microblaze/include/asm/pvr.h | 3 ++- arch/microblaze/kernel/cpu/cpuinfo-pvr-full.c | 1 + arch/microblaze/kernel/cpu/cpuinfo-static.c | 1 + arch/microblaze/kernel/cpu/cpuinfo.c | 4 ++++ arch/microblaze/kernel/cpu/mb.c | 4 ++++ 6 files changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/microblaze/include/asm/cpuinfo.h b/arch/microblaze/include/asm/cpuinfo.h index d8f013347a9e..7d6831ac8a46 100644 --- a/arch/microblaze/include/asm/cpuinfo.h +++ b/arch/microblaze/include/asm/cpuinfo.h @@ -38,6 +38,7 @@ struct cpuinfo { u32 use_exc; u32 ver_code; u32 mmu; + u32 mmu_privins; u32 endian; /* CPU caches */ diff --git a/arch/microblaze/include/asm/pvr.h b/arch/microblaze/include/asm/pvr.h index 56a80e45c4e2..4bbdb4c03b57 100644 --- a/arch/microblaze/include/asm/pvr.h +++ b/arch/microblaze/include/asm/pvr.h @@ -117,10 +117,10 @@ struct pvr_s { #define PVR11_MMU_DTLB_SIZE 0x07000000 #define PVR11_MMU_TLB_ACCESS 0x00C00000 #define PVR11_MMU_ZONES 0x003C0000 +#define PVR11_MMU_PRIVINS 0x00010000 /* MSR Reset value PVR mask */ #define PVR11_MSR_RESET_VALUE_MASK 0x000007FF - /* PVR access macros */ #define PVR_IS_FULL(_pvr) (_pvr.pvr[0] & PVR0_PVR_FULL_MASK) #define PVR_USE_BARREL(_pvr) (_pvr.pvr[0] & PVR0_USE_BARREL_MASK) @@ -216,6 +216,7 @@ struct pvr_s { #define PVR_MMU_DTLB_SIZE(_pvr) (_pvr.pvr[11] & PVR11_MMU_DTLB_SIZE) #define PVR_MMU_TLB_ACCESS(_pvr) (_pvr.pvr[11] & PVR11_MMU_TLB_ACCESS) #define PVR_MMU_ZONES(_pvr) (_pvr.pvr[11] & PVR11_MMU_ZONES) +#define PVR_MMU_PRIVINS(pvr) (pvr.pvr[11] & PVR11_MMU_PRIVINS) /* endian */ #define PVR_ENDIAN(_pvr) (_pvr.pvr[0] & PVR0_ENDI) 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", -- 2.39.5