Hi Andre,
On 04/11/16 17:31, Andre Przywara wrote:
> Allocating an FDT phandle (a unique identifier) using a static
> variable in a static inline function defined in a header file works
> only if all users are in the same source file. So trying to allocate
> a handle from two different compilation units fails.
> Introduce global phandle allocation and reference code to properly
> allocate unique phandles.
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> ---
> Makefile | 1 +
> arm/fdt.c | 2 +-
> arm/gic.c | 2 +-
> include/kvm/fdt.h | 10 +++++-----
> kvm-fdt.c | 26 ++++++++++++++++++++++++++
> 5 files changed, 34 insertions(+), 7 deletions(-)
> create mode 100644 kvm-fdt.c
>
> diff --git a/Makefile b/Makefile
> index 1f0196f..e4a4002 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -98,6 +98,7 @@ OBJS += kvm-ipc.o
> OBJS += builtin-sandbox.o
> OBJS += virtio/mmio.o
> OBJS += hw/i8042.o
> +OBJS += kvm-fdt.o
>
> # Translate uname -m into ARCH string
> ARCH ?= $(shell uname -m | sed -e s/i.86/i386/ -e s/ppc.*/powerpc/ \
> diff --git a/arm/fdt.c b/arm/fdt.c
> index 381d48f..8bcfffb 100644
> --- a/arm/fdt.c
> +++ b/arm/fdt.c
> @@ -114,7 +114,7 @@ static int setup_fdt(struct kvm *kvm)
> {
> struct device_header *dev_hdr;
> u8 staging_fdt[FDT_MAX_SIZE];
> - u32 gic_phandle = fdt__alloc_phandle();
> + u32 gic_phandle = fdt__get_phandle(PHANDLE_GIC);
> u64 mem_reg_prop[] = {
> cpu_to_fdt64(kvm->arch.memory_guest_start),
> cpu_to_fdt64(kvm->ram_size),
> diff --git a/arm/gic.c b/arm/gic.c
> index d6d6dd0..b60437e 100644
> --- a/arm/gic.c
> +++ b/arm/gic.c
> @@ -222,7 +222,7 @@ void gic__generate_fdt_nodes(void *fdt, u32 phandle, enum irqchip_type type)
> _FDT(fdt_property_cell(fdt, "#interrupt-cells", GIC_FDT_IRQ_NUM_CELLS));
> _FDT(fdt_property(fdt, "interrupt-controller", NULL, 0));
> _FDT(fdt_property(fdt, "reg", reg_prop, sizeof(reg_prop)));
> - _FDT(fdt_property_cell(fdt, "phandle", phandle));
> + _FDT(fdt_property_cell(fdt, "phandle", fdt__get_phandle(PHANDLE_GIC)));
> _FDT(fdt_end_node(fdt));
> }
>
> diff --git a/include/kvm/fdt.h b/include/kvm/fdt.h
> index 53d85a4..cd2bb72 100644
> --- a/include/kvm/fdt.h
> +++ b/include/kvm/fdt.h
> @@ -8,6 +8,10 @@
> #include <linux/types.h>
>
> #define FDT_MAX_SIZE 0x10000
> +#define FDT_INVALID_PHANDLE 0
> +#define FDT_IS_VALID_PHANDLE(phandle) ((phandle) != FDT_INVALID_PHANDLE)
> +
> +enum phandles {PHANDLE_GIC, PHANDLES_MAX};
>
> /* Those definitions are generic FDT values for specifying IRQ
> * types and are used in the Linux kernel internally as well as in
> @@ -33,10 +37,6 @@ enum irq_type {
> } \
> } while (0)
>
> -static inline u32 fdt__alloc_phandle(void)
> -{
> - static u32 phandle = 0;
> - return ++phandle;
> -}
> +u32 fdt__get_phandle(enum phandles phandle);
>
> #endif /* KVM__FDT_H */
> diff --git a/kvm-fdt.c b/kvm-fdt.c
> new file mode 100644
> index 0000000..d05f3fe
> --- /dev/null
> +++ b/kvm-fdt.c
> @@ -0,0 +1,26 @@
> +/*
> + * Commonly used FDT functions.
> + */
> +
> +#include <stdio.h>
> +#include "kvm/fdt.h"
> +#include "kvm/util.h"
> +
> +u32 phandles[PHANDLES_MAX] = {};
It is a bit weird that you're initializing this to zero...
> +u32 next_phandle = 1;
> +
> +u32 fdt__get_phandle(enum phandles phandle)
> +{
> + u32 ret;
> +
> + if (phandle >= PHANDLES_MAX)
> + return FDT_INVALID_PHANDLE;
> +
> + ret = phandles[phandle];
> + if (ret == FDT_INVALID_PHANDLE) {
and yet test against a #define that isn't the initializer.
Also, given that fdt__get_phandle() can now fail by returning
FDT_INVALID_HANDLE, maybe we should abort instead of returning something
that is definitely wrong and use it blindly (which is going to be fun to
debug...).
> + ret = next_phandle++;
> + phandles[phandle] = ret;
> + }
> +
> + return ret;
> +}
>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
