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>
This commit is contained in:
John A. Williams 2011-05-24 18:57:11 +10:00 committed by Michal Simek
parent 5db34eb92f
commit 8904976e8c
6 changed files with 13 additions and 1 deletions

View File

@ -38,6 +38,7 @@ struct cpuinfo {
u32 use_exc;
u32 ver_code;
u32 mmu;
u32 mmu_privins;
u32 endian;
/* CPU caches */

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@ -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)

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@ -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);

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@ -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;

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@ -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__);
}

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@ -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",