lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

sparc64: Store per-cpu offset in trap_block[]

Browse Source 
Surprisingly this actually makes LOAD_PER_CPU_BASE() a little
more efficient.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
2009-04-01 01:47:10 -07:00
parent 19f0fa3fb3
commit 5a5488d3bb
5 changed files with 21 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
arch/sparc/kernel/head_64.S
View File

@@ -641,28 +641,6 @@ tlb_fixup_done:
/* Not reached... */
1:
/* If we boot on a non-zero cpu, all of the per-cpu
* variable references we make before setting up the
* per-cpu areas will use a bogus offset. Put a
* compensating factor into __per_cpu_base to handle
* this cleanly.
*
* What the per-cpu code calculates is:
*
* __per_cpu_base + (cpu << __per_cpu_shift)
*
* These two variables are zero initially, so to
* make it all cancel out to zero we need to put
* "0 - (cpu << 0)" into __per_cpu_base so that the
* above formula evaluates to zero.
*
* We cannot even perform a printk() until this stuff
* is setup as that calls cpu_clock() which uses
* per-cpu variables.
*/
sub %g0, %o0, %o1
sethi %hi(__per_cpu_base), %o2
stx %o1, [%o2 + %lo(__per_cpu_base)]
#else
mov 0, %o0
#endif

18
arch/sparc/kernel/smp_64.c
View File

@@ -1371,23 +1371,17 @@ void smp_send_stop(void)
{
}
unsigned long __per_cpu_base __read_mostly;
unsigned long __per_cpu_shift __read_mostly;
EXPORT_SYMBOL(__per_cpu_base);
EXPORT_SYMBOL(__per_cpu_shift);
void __init real_setup_per_cpu_areas(void)
{
unsigned long paddr, goal, size, i;
unsigned long base, shift, paddr, goal, size, i;
char *ptr;
/* Copy section for each CPU (we discard the original) */
goal = PERCPU_ENOUGH_ROOM;
__per_cpu_shift = PAGE_SHIFT;
shift = PAGE_SHIFT;
for (size = PAGE_SIZE; size < goal; size <<= 1UL)
__per_cpu_shift++;
shift++;
paddr = lmb_alloc(size * NR_CPUS, PAGE_SIZE);
if (!paddr) {
@@ -1396,10 +1390,12 @@ void __init real_setup_per_cpu_areas(void)
}
ptr = __va(paddr);
__per_cpu_base = ptr - __per_cpu_start;
base = ptr - __per_cpu_start;
for (i = 0; i < NR_CPUS; i++, ptr += size)
for (i = 0; i < NR_CPUS; i++, ptr += size) {
__per_cpu_offset(i) = base + (i * size);
memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
}
/* Setup %g5 for the boot cpu. */
__local_per_cpu_offset = __per_cpu_offset(smp_processor_id());

5
arch/sparc/kernel/traps_64.c
View File

@@ -2509,6 +2509,7 @@ void do_getpsr(struct pt_regs *regs)
}
struct trap_per_cpu trap_block[NR_CPUS];
EXPORT_SYMBOL(trap_block);
/* This can get invoked before sched_init() so play it super safe
* and use hard_smp_processor_id().
@@ -2592,7 +2593,9 @@ void __init trap_init(void)
(TRAP_PER_CPU_RESUM_QMASK !=
offsetof(struct trap_per_cpu, resum_qmask)) ||
(TRAP_PER_CPU_NONRESUM_QMASK !=
offsetof(struct trap_per_cpu, nonresum_qmask)))
offsetof(struct trap_per_cpu, nonresum_qmask)) ||
(TRAP_PER_CPU_PER_CPU_BASE !=
offsetof(struct trap_per_cpu, __per_cpu_base)))
trap_per_cpu_offsets_are_bolixed_dave();
if ((TSB_CONFIG_TSB !=