[PATCH v8 01/16] FDT: introduce global phandle allocation
From: Marc Zyngier <hidden>
Date: 2016-12-09 11:55:50
Also in:
kvm, kvmarm
Hi Andre, On 04/11/16 17:31, Andre Przywara wrote:
quoted hunk ↗ jump to hunk
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@arm.com> --- 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.cdiff --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...