Merge tag 'parisc-for-6.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc fixes from Helge Deller:
- fix random faults in mmap'd memory on pre PA8800 processors
- fix boot crash with nr_cpus=1 on kernel command line
* tag 'parisc-for-6.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Restore __ldcw_align for PA-RISC 2.0 processors
parisc: Fix crash with nr_cpus=1 option
diff --git a/arch/parisc/include/asm/ldcw.h b/arch/parisc/include/asm/ldcw.h
index 6d28b55..ee9e071 100644
--- a/arch/parisc/include/asm/ldcw.h
+++ b/arch/parisc/include/asm/ldcw.h
@@ -2,39 +2,42 @@
#ifndef __PARISC_LDCW_H
#define __PARISC_LDCW_H
-#ifndef CONFIG_PA20
/* Because kmalloc only guarantees 8-byte alignment for kmalloc'd data,
and GCC only guarantees 8-byte alignment for stack locals, we can't
be assured of 16-byte alignment for atomic lock data even if we
specify "__attribute ((aligned(16)))" in the type declaration. So,
we use a struct containing an array of four ints for the atomic lock
type and dynamically select the 16-byte aligned int from the array
- for the semaphore. */
+ for the semaphore. */
+
+/* From: "Jim Hull" <jim.hull of hp.com>
+ I've attached a summary of the change, but basically, for PA 2.0, as
+ long as the ",CO" (coherent operation) completer is implemented, then the
+ 16-byte alignment requirement for ldcw and ldcd is relaxed, and instead
+ they only require "natural" alignment (4-byte for ldcw, 8-byte for
+ ldcd).
+
+ Although the cache control hint is accepted by all PA 2.0 processors,
+ it is only implemented on PA8800/PA8900 CPUs. Prior PA8X00 CPUs still
+ require 16-byte alignment. If the address is unaligned, the operation
+ of the instruction is undefined. The ldcw instruction does not generate
+ unaligned data reference traps so misaligned accesses are not detected.
+ This hid the problem for years. So, restore the 16-byte alignment dropped
+ by Kyle McMartin in "Remove __ldcw_align for PA-RISC 2.0 processors". */
#define __PA_LDCW_ALIGNMENT 16
-#define __PA_LDCW_ALIGN_ORDER 4
#define __ldcw_align(a) ({ \
unsigned long __ret = (unsigned long) &(a)->lock[0]; \
__ret = (__ret + __PA_LDCW_ALIGNMENT - 1) \
& ~(__PA_LDCW_ALIGNMENT - 1); \
(volatile unsigned int *) __ret; \
})
-#define __LDCW "ldcw"
-#else /*CONFIG_PA20*/
-/* From: "Jim Hull" <jim.hull of hp.com>
- I've attached a summary of the change, but basically, for PA 2.0, as
- long as the ",CO" (coherent operation) completer is specified, then the
- 16-byte alignment requirement for ldcw and ldcd is relaxed, and instead
- they only require "natural" alignment (4-byte for ldcw, 8-byte for
- ldcd). */
-
-#define __PA_LDCW_ALIGNMENT 4
-#define __PA_LDCW_ALIGN_ORDER 2
-#define __ldcw_align(a) (&(a)->slock)
+#ifdef CONFIG_PA20
#define __LDCW "ldcw,co"
-
-#endif /*!CONFIG_PA20*/
+#else
+#define __LDCW "ldcw"
+#endif
/* LDCW, the only atomic read-write operation PA-RISC has. *sigh*.
We don't explicitly expose that "*a" may be written as reload
diff --git a/arch/parisc/include/asm/spinlock_types.h b/arch/parisc/include/asm/spinlock_types.h
index efd06a8..7b986b0 100644
--- a/arch/parisc/include/asm/spinlock_types.h
+++ b/arch/parisc/include/asm/spinlock_types.h
@@ -9,15 +9,10 @@
#ifndef __ASSEMBLY__
typedef struct {
-#ifdef CONFIG_PA20
- volatile unsigned int slock;
-# define __ARCH_SPIN_LOCK_UNLOCKED { __ARCH_SPIN_LOCK_UNLOCKED_VAL }
-#else
volatile unsigned int lock[4];
# define __ARCH_SPIN_LOCK_UNLOCKED \
{ { __ARCH_SPIN_LOCK_UNLOCKED_VAL, __ARCH_SPIN_LOCK_UNLOCKED_VAL, \
__ARCH_SPIN_LOCK_UNLOCKED_VAL, __ARCH_SPIN_LOCK_UNLOCKED_VAL } }
-#endif
} arch_spinlock_t;
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 4098f9a..2019c1f 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -440,7 +440,9 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle)
if (cpu_online(cpu))
return 0;
- if (num_online_cpus() < setup_max_cpus && smp_boot_one_cpu(cpu, tidle))
+ if (num_online_cpus() < nr_cpu_ids &&
+ num_online_cpus() < setup_max_cpus &&
+ smp_boot_one_cpu(cpu, tidle))
return -EIO;
return cpu_online(cpu) ? 0 : -EIO;
