From 0ed1fe4ad394e54783bbffa84102faf435661a2e Mon Sep 17 00:00:00 2001
From: Helge Deller <deller@gmx.de>
Date: Fri, 12 Jan 2018 22:51:22 +0100
Subject: [PATCH] parisc: Check if secondary CPUs want own PDC calls
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>
---
arch/parisc/kernel/head.S | 18 ++++++++++++------
arch/parisc/kernel/smp.c | 7 ++++++-
2 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/arch/parisc/kernel/head.S b/arch/parisc/kernel/head.S
index bbbe360b458f..fbb4e43fda05 100644
--- a/arch/parisc/kernel/head.S
+++ b/arch/parisc/kernel/head.S
@@ -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 */
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 30c28ab14540..4065b5e48c9d 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -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();
--
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