leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

parisc: Check if secondary CPUs want own PDC calls

Browse Source 
The architecture specification says (for 64-bit systems): PDC is a per
processor resource, and operating system software must be prepared to
manage separate pointers to PDCE_PROC for each processor.  The address
of PDCE_PROC for the monarch processor is stored in the Page Zero
location MEM_PDC. The address of PDCE_PROC for each non-monarch
processor is passed in gr26 when PDCE_RESET invokes OS_RENDEZ.

Currently we still use one PDC for all CPUs, but in case we face a
machine which is following the specification let's warn about it.

Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Helge Deller 2018-01-12 22:51:22 +01:00
parent fd8d0ca256
commit 0ed1fe4ad3
2 changed files with 18 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
arch/parisc/kernel/head.S
View File

@ -138,6 +138,16 @@ $pgt_fill_loop:
std %dp,0x18(%r10)
#endif
#ifdef CONFIG_64BIT
/* Get PDCE_PROC for monarch CPU. */
#define MEM_PDC_LO 0x388
#define MEM_PDC_HI 0x35C
ldw MEM_PDC_LO(%r0),%r3
ldw MEM_PDC_HI(%r0),%r10
depd %r10, 31, 32, %r3 /* move to upper word */
#endif
#ifdef CONFIG_SMP
/* Set the smp rendezvous address into page zero.
** It would be safer to do this in init_smp_config() but
@ -196,12 +206,6 @@ common_stext:
** Someday, palo might not do this for the Monarch either.
*/
2:
#define MEM_PDC_LO 0x388
#define MEM_PDC_HI 0x35C
ldw MEM_PDC_LO(%r0),%r3
ldw MEM_PDC_HI(%r0),%r6
depd %r6, 31, 32, %r3 /* move to upper word */
mfctl %cr30,%r6 /* PCX-W2 firmware bug */
ldo PDC_PSW(%r0),%arg0 /* 21 */
@ -268,6 +272,8 @@ $install_iva:
aligned_rfi:
pcxt_ssm_bug
copy %r3, %arg0 /* PDCE_PROC for smp_callin() */
rsm PSW_SM_QUIET,%r0 /* off troublesome PSW bits */
/* Don't need NOPs, have 8 compliant insn before rfi */

7
arch/parisc/kernel/smp.c
View File

@ -292,10 +292,15 @@ smp_cpu_init(int cpunum)
* Slaves start using C here. Indirectly called from smp_slave_stext.
* Do what start_kernel() and main() do for boot strap processor (aka monarch)
*/
void __init smp_callin(void)
void __init smp_callin(unsigned long pdce_proc)
{
int slave_id = cpu_now_booting;
#ifdef CONFIG_64BIT
WARN_ON(((unsigned long)(PAGE0->mem_pdc_hi) << 32
| PAGE0->mem_pdc) != pdce_proc);
#endif
smp_cpu_init(slave_id);
preempt_disable();