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Move MIPS_MAX_TLB_ENTRIES definition from cpuregs.h to tlb.c

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Having MIPS_MAX_TLB_ENTRIES defined to 128 is misleading, since it used
to be 64 in older releases of MIPS architecture (where it could be read
from Config1) and can be much more than 128 for the newer processors.

For now, move the definition to the only file using it (mips/mips/tlb.c)
and define MIPS_MAX_TLB_ENTRIES depending on the MIPS cpu defined. Also
add few checks so that we do not write beyond the end of the tlb_state
array.

This fixes a kernel data corruption seen in Netlogic XLP, which was casued
by tlb_save() writing beyond the end of tlb_state array when breaking into
debugger.
This commit is contained in:
Jayachandran C. 2013-04-12 17:22:12 +00:00
parent ef816ea3d7
commit 0f6d5fdb54
2 changed files with 22 additions and 6 deletions
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1
sys/mips/include/cpuregs.h
View File

@ -521,7 +521,6 @@
#define MIPS_CONFIG1_TLBSZ_MASK 0x7E000000 /* bits 30..25 # tlb entries minus one */
#define MIPS_CONFIG1_TLBSZ_SHIFT 25
#define MIPS_MAX_TLB_ENTRIES 128
#define MIPS_CONFIG1_IS_MASK 0x01C00000 /* bits 24..22 icache sets per way */
#define MIPS_CONFIG1_IS_SHIFT 22

27
sys/mips/mips/tlb.c
View File

@ -40,6 +40,14 @@
#include <machine/pte.h>
#include <machine/tlb.h>
#if defined(CPU_CNMIPS)
#define MIPS_MAX_TLB_ENTRIES 128
#elif defined(CPU_NLM)
#define MIPS_MAX_TLB_ENTRIES (2048 + 128)
#else
#define MIPS_MAX_TLB_ENTRIES 64
#endif
struct tlb_state {
unsigned wired;
struct tlb_entry {
@ -264,12 +272,15 @@ tlb_invalidate_range(pmap_t pmap, vm_offset_t start, vm_offset_t end)
void
tlb_save(void)
{
unsigned i, cpu;
unsigned ntlb, i, cpu;
cpu = PCPU_GET(cpuid);
if (num_tlbentries > MIPS_MAX_TLB_ENTRIES)
ntlb = MIPS_MAX_TLB_ENTRIES;
else
ntlb = num_tlbentries;
tlb_state[cpu].wired = mips_rd_wired();
for (i = 0; i < num_tlbentries; i++) {
for (i = 0; i < ntlb; i++) {
mips_wr_index(i);
tlb_read();
@ -329,7 +340,7 @@ tlb_invalidate_one(unsigned i)
DB_SHOW_COMMAND(tlb, ddb_dump_tlb)
{
register_t ehi, elo0, elo1;
unsigned i, cpu;
unsigned i, cpu, ntlb;
/*
* XXX
@ -344,12 +355,18 @@ DB_SHOW_COMMAND(tlb, ddb_dump_tlb)
db_printf("Invalid CPU %u\n", cpu);
return;
}
if (num_tlbentries > MIPS_MAX_TLB_ENTRIES) {
ntlb = MIPS_MAX_TLB_ENTRIES;
db_printf("Warning: Only %d of %d TLB entries saved!\n",
ntlb, num_tlbentries);
} else
ntlb = num_tlbentries;
if (cpu == PCPU_GET(cpuid))
tlb_save();
db_printf("Beginning TLB dump for CPU %u...\n", cpu);
for (i = 0; i < num_tlbentries; i++) {
for (i = 0; i < ntlb; i++) {
if (i == tlb_state[cpu].wired) {
if (i != 0)
db_printf("^^^ WIRED ENTRIES ^^^\n");