[PATCH 13/41] powerpc: Put exception configuration in a common place
Benjamin Herrenschmidt
benh at kernel.crashing.org
Tue Jul 5 15:03:49 AEST 2016
The various calls to establish exception endianness and AIL are
now done from a single point using already established CPU and FW
feature bits to decide what to do.
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
v3: Rework a bit, move error handling in the functions themselves
and fix a few more cases of compile failures on odd configs
---
arch/powerpc/include/asm/hvcall.h | 11 ----
arch/powerpc/include/asm/opal.h | 1 +
arch/powerpc/include/asm/setup.h | 12 +++++
arch/powerpc/kernel/setup_64.c | 55 ++++++++++++++------
arch/powerpc/kvm/book3s_pr.c | 6 +--
arch/powerpc/platforms/powernv/opal.c | 13 ++---
arch/powerpc/platforms/pseries/lpar.c | 20 +-------
arch/powerpc/platforms/pseries/setup.c | 92 ++++++++++++++++------------------
8 files changed, 107 insertions(+), 103 deletions(-)
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 0bc9c28..708edeb 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -431,17 +431,6 @@ static inline unsigned long cmo_get_page_size(void)
{
return CMO_PageSize;
}
-
-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)
-#define pSeries_disable_reloc_on_exc() do {} while (0)
-
#endif /* CONFIG_PPC_PSERIES */
#endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 9d86c66..6135816 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -215,6 +215,7 @@ extern int early_init_dt_scan_opal(unsigned long node, const char *uname,
int depth, void *data);
extern int early_init_dt_scan_recoverable_ranges(unsigned long node,
const char *uname, int depth, void *data);
+extern void opal_configure_cores(void);
extern int opal_get_chars(uint32_t vtermno, char *buf, int count);
extern int opal_put_chars(uint32_t vtermno, const char *buf, int total_len);
diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index fa0687e..1ba25c8 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -30,6 +30,18 @@ void initmem_init(void);
void setup_panic(void);
#define ARCH_PANIC_TIMEOUT 180
+#ifdef CONFIG_PPC_PSERIES
+extern void pseries_enable_reloc_on_exc(void);
+extern void pseries_disable_reloc_on_exc(void);
+extern void pseries_big_endian_exceptions(void);
+extern void pseries_little_endian_exceptions(void);
+#else
+static inline void pseries_enable_reloc_on_exc(void) {}
+static inline void pseries_disable_reloc_on_exc(void) {}
+static inline void pseries_big_endian_exceptions(void) {}
+static inline void pseries_little_endian_exceptions(void) {}
+#endif /* CONFIG_PPC_PSERIES */
+
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_POWERPC_SETUP_H */
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index a641753..978c48c 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -69,6 +69,7 @@
#include <asm/kvm_ppc.h>
#include <asm/hugetlb.h>
#include <asm/livepatch.h>
+#include <asm/opal.h>
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
@@ -205,21 +206,47 @@ static void fixup_boot_paca(void)
get_paca()->data_offset = 0;
}
+static void configure_exceptions(void)
+{
+ /* Setup the trampolines from the lowmem exception vectors
+ * to the kdump kernel when not using a relocatable kernel.
+ */
+ setup_kdump_trampoline();
+
+ /* Under a PAPR hypervisor, we need hypercalls */
+ if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
+ /* Enable AIL if possible */
+ pseries_enable_reloc_on_exc();
+
+ /*
+ * Tell the hypervisor that we want our exceptions to
+ * be taken in little endian mode.
+ *
+ * We don't call this for big endian as our calling convention
+ * makes us always enter in BE, and the call may fail under
+ * some circumstances with kdump.
+ */
+#ifdef __LITTLE_ENDIAN__
+ pseries_little_endian_exceptions();
+#endif
+ } else {
+ /* Set endian mode using OPAL */
+ if (firmware_has_feature(FW_FEATURE_OPAL))
+ opal_configure_cores();
+
+ /* Enable AIL if supported, and we are in hypervisor mode */
+ if (cpu_has_feature(CPU_FTR_HVMODE) &&
+ cpu_has_feature(CPU_FTR_ARCH_207S)) {
+ unsigned long lpcr = mfspr(SPRN_LPCR);
+ mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3);
+ }
+ }
+}
+
static void cpu_ready_for_interrupts(void)
{
/* Set IR and DR in PACA MSR */
get_paca()->kernel_msr = MSR_KERNEL;
-
- /*
- * Enable AIL if supported, and we are in hypervisor mode. If we are
- * not in hypervisor mode, we enable relocation-on interrupts later
- * in pSeries_setup_arch() using the H_SET_MODE hcall.
- */
- if (cpu_has_feature(CPU_FTR_HVMODE) &&
- cpu_has_feature(CPU_FTR_ARCH_207S)) {
- unsigned long lpcr = mfspr(SPRN_LPCR);
- mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3);
- }
}
/*
@@ -276,10 +303,10 @@ void __init early_setup(unsigned long dt_ptr)
/* Probe the machine type */
probe_machine();
- /* Setup the trampolines from the lowmem exception vectors
- * to the kdump kernel when not using a relocatable kernel.
+ /* Configure exception handlers. This include setting up trampolines
+ * if needed, setting exception endian mode, etc...
*/
- setup_kdump_trampoline();
+ configure_exceptions();
/* Initialize the hash table or TLB handling */
early_init_mmu();
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 8e4f64f..c4f7d6b 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -35,7 +35,7 @@
#include <asm/mmu_context.h>
#include <asm/switch_to.h>
#include <asm/firmware.h>
-#include <asm/hvcall.h>
+#include <asm/setup.h>
#include <linux/gfp.h>
#include <linux/sched.h>
#include <linux/vmalloc.h>
@@ -1690,7 +1690,7 @@ static int kvmppc_core_init_vm_pr(struct kvm *kvm)
if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
spin_lock(&kvm_global_user_count_lock);
if (++kvm_global_user_count == 1)
- pSeries_disable_reloc_on_exc();
+ pseries_disable_reloc_on_exc();
spin_unlock(&kvm_global_user_count_lock);
}
return 0;
@@ -1706,7 +1706,7 @@ static void kvmppc_core_destroy_vm_pr(struct kvm *kvm)
spin_lock(&kvm_global_user_count_lock);
BUG_ON(kvm_global_user_count == 0);
if (--kvm_global_user_count == 0)
- pSeries_enable_reloc_on_exc();
+ pseries_enable_reloc_on_exc();
spin_unlock(&kvm_global_user_count_lock);
}
}
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 0256d07..802f3b7 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -56,7 +56,7 @@ static DEFINE_SPINLOCK(opal_write_lock);
static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX];
static uint32_t opal_heartbeat;
-static void opal_reinit_cores(void)
+void opal_configure_cores(void)
{
/* Do the actual re-init, This will clobber all FPRs, VRs, etc...
*
@@ -69,6 +69,10 @@ static void opal_reinit_cores(void)
#else
opal_reinit_cpus(OPAL_REINIT_CPUS_HILE_LE);
#endif
+
+ /* Restore some bits */
+ if (cur_cpu_spec->cpu_restore)
+ cur_cpu_spec->cpu_restore();
}
int __init early_init_dt_scan_opal(unsigned long node,
@@ -105,13 +109,6 @@ int __init early_init_dt_scan_opal(unsigned long node,
panic("OPAL != V3 detected, no longer supported.\n");
}
- /* Reinit all cores with the right endian */
- opal_reinit_cores();
-
- /* Restore some bits */
- if (cur_cpu_spec->cpu_restore)
- cur_cpu_spec->cpu_restore();
-
return 1;
}
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 7f6100d..eb2374e 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -260,24 +260,8 @@ static void pSeries_lpar_hptab_clear(void)
* This is also called on boot when a fadump happens. In that case we
* must not change the exception endian mode.
*/
- if (firmware_has_feature(FW_FEATURE_SET_MODE) && !is_fadump_active()) {
- 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.
- *
- * There is a known problem when kdump'ing, if cpus are offline
- * the above call will fail. Rather than panicking again, keep
- * going and hope the kdump kernel is also little endian, which
- * it usually is.
- */
- if (rc && !kdump_in_progress())
- panic("Could not enable big endian exceptions");
- }
+ if (firmware_has_feature(FW_FEATURE_SET_MODE) && !is_fadump_active())
+ pseries_big_endian_exceptions();
#endif
}
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index f1fe7aa..1543be0 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -392,15 +392,23 @@ static void pseries_lpar_idle(void)
* to ever be a problem in practice we can move this into a kernel thread to
* finish off the process later in boot.
*/
-long pSeries_enable_reloc_on_exc(void)
+void pseries_enable_reloc_on_exc(void)
{
long rc;
unsigned int delay, total_delay = 0;
while (1) {
rc = enable_reloc_on_exceptions();
- if (!H_IS_LONG_BUSY(rc))
- return rc;
+ if (!H_IS_LONG_BUSY(rc)) {
+ if (rc == H_P2) {
+ pr_info("Relocation on exceptions not"
+ " supported\n");
+ } else if (rc != H_SUCCESS) {
+ pr_warn("Unable to enable relocation"
+ " on exceptions: %ld\n", rc);
+ }
+ break;
+ }
delay = get_longbusy_msecs(rc);
total_delay += delay;
@@ -408,66 +416,81 @@ long pSeries_enable_reloc_on_exc(void)
pr_warn("Warning: Giving up waiting to enable "
"relocation on exceptions (%u msec)!\n",
total_delay);
- return rc;
+ return;
}
mdelay(delay);
}
}
-EXPORT_SYMBOL(pSeries_enable_reloc_on_exc);
+EXPORT_SYMBOL(pseries_enable_reloc_on_exc);
-long pSeries_disable_reloc_on_exc(void)
+void pseries_disable_reloc_on_exc(void)
{
long rc;
while (1) {
rc = disable_reloc_on_exceptions();
if (!H_IS_LONG_BUSY(rc))
- return rc;
+ break;
mdelay(get_longbusy_msecs(rc));
}
+ if (rc != H_SUCCESS)
+ pr_warning("Warning: Failed to disable relocation on "
+ "exceptions: %ld\n", rc);
}
-EXPORT_SYMBOL(pSeries_disable_reloc_on_exc);
+EXPORT_SYMBOL(pseries_disable_reloc_on_exc);
#ifdef CONFIG_KEXEC
static void pSeries_machine_kexec(struct kimage *image)
{
- long rc;
-
- if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
- rc = pSeries_disable_reloc_on_exc();
- if (rc != H_SUCCESS)
- pr_warning("Warning: Failed to disable relocation on "
- "exceptions: %ld\n", rc);
- }
+ if (firmware_has_feature(FW_FEATURE_SET_MODE))
+ pseries_disable_reloc_on_exc();
default_machine_kexec(image);
}
#endif
#ifdef __LITTLE_ENDIAN__
-long pseries_big_endian_exceptions(void)
+void pseries_big_endian_exceptions(void)
{
long rc;
while (1) {
rc = enable_big_endian_exceptions();
if (!H_IS_LONG_BUSY(rc))
- return rc;
+ break;
mdelay(get_longbusy_msecs(rc));
}
+
+ /*
+ * At this point it is unlikely panic() will get anything
+ * out to the user, since this is called very late in kexec
+ * but at least this will stop us from continuing on further
+ * and creating an even more difficult to debug situation.
+ *
+ * There is a known problem when kdump'ing, if cpus are offline
+ * the above call will fail. Rather than panicking again, keep
+ * going and hope the kdump kernel is also little endian, which
+ * it usually is.
+ */
+ if (rc && !kdump_in_progress())
+ panic("Could not enable big endian exceptions");
}
-static long pseries_little_endian_exceptions(void)
+void pseries_little_endian_exceptions(void)
{
long rc;
while (1) {
rc = enable_little_endian_exceptions();
if (!H_IS_LONG_BUSY(rc))
- return rc;
+ break;
mdelay(get_longbusy_msecs(rc));
}
+ if (rc) {
+ ppc_md.progress("H_SET_MODE LE exception fail", 0);
+ panic("Could not enable little endian exceptions");
+ }
}
#endif
@@ -537,18 +560,6 @@ static void __init pSeries_setup_arch(void)
}
ppc_md.pcibios_root_bridge_prepare = pseries_root_bridge_prepare;
-
- if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
- long rc;
-
- rc = pSeries_enable_reloc_on_exc();
- if (rc == H_P2) {
- pr_info("Relocation on exceptions not supported\n");
- } else if (rc != H_SUCCESS) {
- pr_warn("Unable to enable relocation on exceptions: "
- "%ld\n", rc);
- }
- }
}
static int __init pSeries_init_panel(void)
@@ -751,23 +762,6 @@ static int __init pSeries_probe(void)
pr_debug("pSeries detected, looking for LPAR capability...\n");
-
-#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
--
2.7.4
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