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 <b...@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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