iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

pseries: Add H_SET_MODE to change exception endianness

Browse Source 
On little endian builds call H_SET_MODE so exceptions have the
correct endianness. We need to reset the endian during kexec
so do that in the MMU hashtable clear callback.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Anton Blanchard 2013-11-20 22:14:59 +11:00 committed by Benjamin Herrenschmidt
parent b91da2d4ce
commit e844b1eeae
4 changed files with 87 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/powerpc/include/asm/hvcall.h
View File

@ -403,6 +403,8 @@ static inline unsigned long cmo_get_page_size(void)
extern long pSeries_enable_reloc_on_exc(void);
extern long pSeries_disable_reloc_on_exc(void);
extern long pseries_big_endian_exceptions(void);
#else
#define pSeries_enable_reloc_on_exc() do {} while (0)

26
arch/powerpc/include/asm/plpar_wrappers.h
View File

@ -287,6 +287,32 @@ static inline long disable_reloc_on_exceptions(void) {
return plpar_set_mode(0, 3, 0, 0);
}
/*
* Take exceptions in big endian mode on this partition
*
* Note: this call has a partition wide scope and can take a while to complete.
* If it returns H_LONG_BUSY_* it should be retried periodically until it
* returns H_SUCCESS.
*/
static inline long enable_big_endian_exceptions(void)
{
/* mflags = 0: big endian exceptions */
return plpar_set_mode(0, 4, 0, 0);
}
/*
* Take exceptions in little endian mode on this partition
*
* Note: this call has a partition wide scope and can take a while to complete.
* If it returns H_LONG_BUSY_* it should be retried periodically until it
* returns H_SUCCESS.
*/
static inline long enable_little_endian_exceptions(void)
{
/* mflags = 1: little endian exceptions */
return plpar_set_mode(1, 4, 0, 0);
}
static inline long plapr_set_ciabr(unsigned long ciabr)
{
return plpar_set_mode(0, 1, ciabr, 0);

17
arch/powerpc/platforms/pseries/lpar.c
View File

@ -245,6 +245,23 @@ static void pSeries_lpar_hptab_clear(void)
&(ptes[j].pteh), &(ptes[j].ptel));
}
}
#ifdef __LITTLE_ENDIAN__
/* Reset exceptions to big endian */
if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
long rc;
rc = pseries_big_endian_exceptions();
/*
* At this point it is unlikely panic() will get anything
* out to the user, but at least this will stop us from
* continuing on further and creating an even more
* difficult to debug situation.
*/
if (rc)
panic("Could not enable big endian exceptions");
}
#endif
}
/*

42
arch/powerpc/platforms/pseries/setup.c
View File

@ -442,6 +442,32 @@ static void pSeries_machine_kexec(struct kimage *image)
}
#endif
#ifdef __LITTLE_ENDIAN__
long pseries_big_endian_exceptions(void)
{
long rc;
while (1) {
rc = enable_big_endian_exceptions();
if (!H_IS_LONG_BUSY(rc))
return rc;
mdelay(get_longbusy_msecs(rc));
}
}
static long pseries_little_endian_exceptions(void)
{
long rc;
while (1) {
rc = enable_little_endian_exceptions();
if (!H_IS_LONG_BUSY(rc))
return rc;
mdelay(get_longbusy_msecs(rc));
}
}
#endif
static void __init pSeries_setup_arch(void)
{
panic_timeout = 10;
@ -698,6 +724,22 @@ static int __init pSeries_probe(void)
/* Now try to figure out if we are running on LPAR */
of_scan_flat_dt(pseries_probe_fw_features, NULL);
#ifdef __LITTLE_ENDIAN__
if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
long rc;
/*
* Tell the hypervisor that we want our exceptions to
* be taken in little endian mode. If this fails we don't
* want to use BUG() because it will trigger an exception.
*/
rc = pseries_little_endian_exceptions();
if (rc) {
ppc_md.progress("H_SET_MODE LE exception fail", 0);
panic("Could not enable little endian exceptions");
}
}
#endif
if (firmware_has_feature(FW_FEATURE_LPAR))
hpte_init_lpar();
else