[Xen-changelog] [xen master] xen/arm: Propagate clock-frequency to DOMU if present in the DT timer node

[patchbot@xxxxxxx]

commit 59ccb33c40c84af729d6c4c5042a7962a40e8537
Author:     Julien Grall <julien.grall@xxxxxxxxxx>
AuthorDate: Fri Jun 19 13:41:29 2015 +0100
Commit:     Ian Campbell <ian.campbell@xxxxxxxxxx>
CommitDate: Thu Jun 25 10:59:08 2015 +0100

    xen/arm: Propagate clock-frequency to DOMU if present in the DT timer node
    
    When the property "clock-frequency" is present in the DT timer node, it
    means that the bootloader/firmware didn't correctly configure the
    CNTFRQ/CNTFRQ_EL0 on each processor.
    
    The best solution would be to fix the offending firmware/bootloader,
    although it may not always be possible to modify and re-flash it.
    
    As it's not possible to trap the register CNTFRQ/CNTFRQ_EL0, we have
    to extend xen_arch_domainconfig to provide the timer frequency to the
    toolstack when the property "clock-frequency" is present to the host DT
    timer node. Then, a property "clock-frequency" will be created in the guest
    DT timer node if the value is not 0.
    
    We could have set the property in the guest DT no matter if the property
    is present in the host DT. Although, we still want to let the guest
    using CNTFRQ in normal case. After all, the property "clock-frequency"
    is just a workaround for buggy firmware.
    
    Also add a stub for fdt_property_u32 which is not present in libfdt <
    1.4.0 used by distribution such as Debian Wheezy.
    
    Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
    Tested-by: Chris Brand <chris.brand@xxxxxxxxxxxx>
    Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
    [ ijc -- ran autogen.sh ]
---
 tools/config.h.in                 |    4 ++++
 tools/configure                   |   15 +++++++++++++++
 tools/configure.ac                |    4 ++++
 tools/libxl/libxl_arm.c           |    9 +++++++--
 tools/libxl/libxl_libfdt_compat.h |    9 +++++++++
 xen/arch/arm/domain.c             |    2 +-
 xen/arch/arm/time.c               |    5 +++++
 xen/arch/arm/vtimer.c             |    4 +++-
 xen/arch/arm/vtimer.h             |    3 ++-
 xen/include/asm-arm/time.h        |    6 ++++++
 xen/include/public/arch-arm.h     |   14 ++++++++++++++
 11 files changed, 70 insertions(+), 5 deletions(-)

diff --git a/tools/config.h.in b/tools/config.h.in
index d55173b..478a2cc 100644
--- a/tools/config.h.in
+++ b/tools/config.h.in
@@ -14,6 +14,10 @@
    you don't. */
 #undef HAVE_DECL_FDT_NEXT_SUBNODE
 
+/* Define to 1 if you have the declaration of `fdt_property_u32', and to 0 if
+   you don't. */
+#undef HAVE_DECL_FDT_PROPERTY_U32
+
 /* Define to 1 if you have the `fdt_first_subnode' function. */
 #undef HAVE_FDT_FIRST_SUBNODE
 
diff --git a/tools/configure b/tools/configure
index 896d892..9e87e90 100755
--- a/tools/configure
+++ b/tools/configure
@@ -8906,6 +8906,21 @@ cat >>confdefs.h <<_ACEOF
 #define HAVE_DECL_FDT_NEXT_SUBNODE $ac_have_decl
 _ACEOF
 
+
+# The helper fdt_property_u32 is only present in libfdt >= 1.4.0
+# It's an inline function, so only check if the declaration is present
+ac_fn_c_check_decl "$LINENO" "fdt_property_u32" 
"ac_cv_have_decl_fdt_property_u32" "#include <libfdt.h>
+"
+if test "x$ac_cv_have_decl_fdt_property_u32" = xyes; then :
+  ac_have_decl=1
+else
+  ac_have_decl=0
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_DECL_FDT_PROPERTY_U32 $ac_have_decl
+_ACEOF
+
 esac
 
 # Checks for header files.
diff --git a/tools/configure.ac b/tools/configure.ac
index 1a06ddf..2886cb5 100644
--- a/tools/configure.ac
+++ b/tools/configure.ac
@@ -379,6 +379,10 @@ AS_IF([test "x$partial_dt" = "xy" ],
 #   * The prototype exists but the functions are not exposed. Don't ask why...
 AC_CHECK_FUNCS([fdt_first_subnode fdt_next_subnode])
 AC_CHECK_DECLS([fdt_first_subnode, fdt_next_subnode],,,[#include <libfdt.h>])
+
+# The helper fdt_property_u32 is only present in libfdt >= 1.4.0
+# It's an inline function, so only check if the declaration is present
+AC_CHECK_DECLS([fdt_property_u32],,,[#include <libfdt.h>])
 esac
 
 # Checks for header files.
diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c
index 4fb5e26..f09c860 100644
--- a/tools/libxl/libxl_arm.c
+++ b/tools/libxl/libxl_arm.c
@@ -444,7 +444,9 @@ static int make_gicv3_node(libxl__gc *gc, void *fdt)
     return 0;
 }
 
-static int make_timer_node(libxl__gc *gc, void *fdt, const struct arch_info 
*ainfo)
+static int make_timer_node(libxl__gc *gc, void *fdt,
+                           const struct arch_info *ainfo,
+                           uint32_t frequency)
 {
     int res;
     gic_interrupt ints[3];
@@ -462,6 +464,9 @@ static int make_timer_node(libxl__gc *gc, void *fdt, const 
struct arch_info *ain
     res = fdt_property_interrupts(gc, fdt, ints, 3);
     if (res) return res;
 
+    if ( frequency )
+        fdt_property_u32(fdt, "clock-frequency", frequency);
+
     res = fdt_end_node(fdt);
     if (res) return res;
 
@@ -805,7 +810,7 @@ next_resize:
             goto out;
         }
 
-        FDT( make_timer_node(gc, fdt, ainfo) );
+        FDT( make_timer_node(gc, fdt, ainfo, xc_config->clock_frequency) );
         FDT( make_hypervisor_node(gc, fdt, vers) );
 
         if (pfdt)
diff --git a/tools/libxl/libxl_libfdt_compat.h 
b/tools/libxl/libxl_libfdt_compat.h
index 53a5076..23230b5 100644
--- a/tools/libxl/libxl_libfdt_compat.h
+++ b/tools/libxl/libxl_libfdt_compat.h
@@ -61,6 +61,7 @@
 #define LIBXL_LIBFDT_COMPAT_H
 
 #include "libxl_internal.h"
+#include <libfdt.h>
 
 #if !HAVE_DECL_FDT_FIRST_SUBNODE
 _hidden int fdt_first_subnode(const void *fdt, int offset);
@@ -70,6 +71,14 @@ _hidden int fdt_first_subnode(const void *fdt, int offset);
 _hidden int fdt_next_subnode(const void *fdt, int offset);
 #endif
 
+#if !HAVE_DECL_FDT_PROPERTY_U32
+static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
+{
+       uint32_t tmp = cpu_to_fdt32(val);
+       return fdt_property(fdt, name, &tmp, sizeof(tmp));
+}
+#endif
+
 #endif
 
 /*
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 24b8938..8b1bf5a 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -593,7 +593,7 @@ int arch_domain_create(struct domain *d, unsigned int 
domcr_flags,
     if ( (rc = domain_vgic_init(d, config->nr_spis)) != 0 )
         goto fail;
 
-    if ( (rc = domain_vtimer_init(d)) != 0 )
+    if ( (rc = domain_vtimer_init(d, config)) != 0 )
         goto fail;
 
     /*
diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
index ce6d3fd..5ded30c 100644
--- a/xen/arch/arm/time.c
+++ b/xen/arch/arm/time.c
@@ -42,6 +42,8 @@ uint64_t __read_mostly boot_count;
  * register-mapped time source in the SoC. */
 unsigned long __read_mostly cpu_khz;  /* CPU clock frequency in kHz. */
 
+uint32_t __read_mostly timer_dt_clock_frequency;
+
 static unsigned int timer_irq[MAX_TIMER_PPI];
 
 unsigned int timer_get_irq(enum timer_ppi ppi)
@@ -86,7 +88,10 @@ void __init preinit_xen_time(void)
 
     res = dt_property_read_u32(timer, "clock-frequency", &rate);
     if ( res )
+    {
         cpu_khz = rate / 1000;
+        timer_dt_clock_frequency = rate;
+    }
     else
         cpu_khz = READ_SYSREG32(CNTFRQ_EL0) / 1000;
 
diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c
index 685bfea..1418092 100644
--- a/xen/arch/arm/vtimer.c
+++ b/xen/arch/arm/vtimer.c
@@ -60,11 +60,13 @@ static void virt_timer_expired(void *data)
     perfc_incr(vtimer_virt_inject);
 }
 
-int domain_vtimer_init(struct domain *d)
+int domain_vtimer_init(struct domain *d, struct xen_arch_domainconfig *config)
 {
     d->arch.phys_timer_base.offset = NOW();
     d->arch.virt_timer_base.offset = READ_SYSREG64(CNTPCT_EL0);
 
+    config->clock_frequency = timer_dt_clock_frequency;
+
     /* At this stage vgic_reserve_virq can't fail */
     if ( is_hardware_domain(d) )
     {
diff --git a/xen/arch/arm/vtimer.h b/xen/arch/arm/vtimer.h
index 6d2e46e..99e8145 100644
--- a/xen/arch/arm/vtimer.h
+++ b/xen/arch/arm/vtimer.h
@@ -20,7 +20,8 @@
 #ifndef __ARCH_ARM_VTIMER_H__
 #define __ARCH_ARM_VTIMER_H__
 
-extern int domain_vtimer_init(struct domain *d);
+extern int domain_vtimer_init(struct domain *d,
+                              struct xen_arch_domainconfig *config);
 extern int vcpu_vtimer_init(struct vcpu *v);
 extern int vtimer_emulate(struct cpu_user_regs *regs, union hsr hsr);
 extern int virt_timer_save(struct vcpu *v);
diff --git a/xen/include/asm-arm/time.h b/xen/include/asm-arm/time.h
index 039039a..d755f36 100644
--- a/xen/include/asm-arm/time.h
+++ b/xen/include/asm-arm/time.h
@@ -22,6 +22,12 @@ enum timer_ppi
     MAX_TIMER_PPI = 4,
 };
 
+/*
+ * Value of "clock-frequency" in the DT timer node if present.
+ * 0 means the property doesn't exist.
+ */
+extern uint32_t timer_dt_clock_frequency;
+
 /* Get one of the timer IRQ number */
 unsigned int timer_get_irq(enum timer_ppi ppi);
 
diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
index 6f24c5f..805483e 100644
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -311,6 +311,20 @@ struct xen_arch_domainconfig {
     uint8_t gic_version;
     /* IN */
     uint32_t nr_spis;
+    /*
+     * OUT
+     * Based on the property clock-frequency in the DT timer node.
+     * The property may be present when the bootloader/firmware doesn't
+     * set correctly CNTFRQ which hold the timer frequency.
+     *
+     * As it's not possible to trap this register, we have to replicate
+     * the value in the guest DT.
+     *
+     * = 0 => property not present
+     * > 0 => Value of the property
+     *
+     */
+    uint32_t clock_frequency;
 };
 #endif /* __XEN__ || __XEN_TOOLS__ */
 
--
generated by git-patchbot for /home/xen/git/xen.git#master

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