Added simple accessor functions for rtas in memory buffers which performs accesses of appropriate type and performs endian conversions.
Signed-off-by: Cyril Bur <cyril....@au1.ibm.com> --- arch/powerpc/platforms/pseries/Makefile | 4 +- arch/powerpc/platforms/pseries/pseries.h | 41 +++++++++ arch/powerpc/platforms/pseries/rtas_buffer.c | 126 +++++++++++++++++++++++++++ 3 files changed, 170 insertions(+), 1 deletion(-) create mode 100644 arch/powerpc/platforms/pseries/rtas_buffer.c diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile index 0348079..7eb7c46 100644 --- a/arch/powerpc/platforms/pseries/Makefile +++ b/arch/powerpc/platforms/pseries/Makefile @@ -3,7 +3,9 @@ ccflags-$(CONFIG_PPC_PSERIES_DEBUG) += -DDEBUG obj-y := lpar.o hvCall.o nvram.o reconfig.o \ setup.o iommu.o event_sources.o ras.o \ - firmware.o power.o dlpar.o mobility.o rng.o + firmware.o power.o dlpar.o mobility.o \ + rng.o rtas_buffer.o + obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_SCANLOG) += scanlog.o obj-$(CONFIG_EEH) += eeh_pseries.o diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h index 361add6..f24e352 100644 --- a/arch/powerpc/platforms/pseries/pseries.h +++ b/arch/powerpc/platforms/pseries/pseries.h @@ -66,4 +66,45 @@ int pseries_root_bridge_prepare(struct pci_host_bridge *bridge); unsigned long pseries_memory_block_size(void); +/* Manipulation of the in memory data returned from an RTAS call */ + +/* Data pointed to by ptr is in big endian */ +struct rtas_buffer { + void *ptr; + int len; + int pos; +}; + +/* Buffer is already zeroed */ +int make_rtas_buf(struct rtas_buffer *b, size_t size); +void free_rtas_buf(struct rtas_buffer *b); + +/* Return pointer to the buffer being used */ +void *get_rtas_buf(struct rtas_buffer *b); + +/* Checks if the buffer exists and the read position is less than the length*/ +bool check_rtas_buf(struct rtas_buffer *b); +size_t get_rtas_buf_size(struct rtas_buffer *b); + +/* Advance the internal position of the buffer by size bytes */ +bool advance_rtas_buf(struct rtas_buffer *b, size_t size); + +/* Put a value val into the buffer at position pos. Function expect val in cpu + * endian. Returns true if the write to the buffer was successful. + */ +bool put_rtas_buf_32(struct rtas_buffer *b, u32 val, int pos); + +/* Grab the byte at the current position of the buffer without incrementing + * the internal position of the buffer */ +bool peek_rtas_buf(struct rtas_buffer *b, u8 *c); + +/* Accessor functions return true if access succeeded and value is written to + * val in cpu endian. Automatically advances its reference into the buffer by + * the requested amount. + */ +bool get_rtas_buf_32(struct rtas_buffer *b, u32 *val); +bool get_rtas_buf_64(struct rtas_buffer *b, u64 *val); +bool get_rtas_buf_mem(struct rtas_buffer *b, void **p, size_t len); +bool get_rtas_buf_str(struct rtas_buffer *b, char **s); + #endif /* _PSERIES_PSERIES_H */ diff --git a/arch/powerpc/platforms/pseries/rtas_buffer.c b/arch/powerpc/platforms/pseries/rtas_buffer.c new file mode 100644 index 0000000..f06b73c --- /dev/null +++ b/arch/powerpc/platforms/pseries/rtas_buffer.c @@ -0,0 +1,126 @@ +#include <linux/kernel.h> +#include <linux/slab.h> + +#include "pseries.h" + + +int make_rtas_buf(struct rtas_buffer *b, size_t sz) +{ + b->ptr = kzalloc(sz, GFP_KERNEL); + b->len = sz; + b->pos = 0; + return (!b->ptr) ? -ENOMEM : 0; +} + +void free_rtas_buf(struct rtas_buffer *b) +{ + kfree(b->ptr); +} + +void *get_rtas_buf(struct rtas_buffer *b) +{ + return (b) ? b->ptr : NULL; +} + +size_t get_rtas_buf_size(struct rtas_buffer *b) +{ + return (b) ? b->len : 0; +} + +bool check_rtas_buf(struct rtas_buffer *b) +{ + return (b && b->ptr && b->pos < b->len); +} + +static inline void *buf_pos(struct rtas_buffer *b) +{ + return (b && b->ptr) ? b->ptr + b->pos : NULL; +} + +bool peek_rtas_buf(struct rtas_buffer *b, u8 *c) +{ + if (!b || !c || b->pos >= b->len) + return false; + + *c = *(u8 *)buf_pos(b); + + return true; +} + +bool put_rtas_buf_32(struct rtas_buffer *b, u32 val, int pos) +{ + if (!b || b->pos >= b->len) + return false; + + *((__be32 *)buf_pos(b)) = cpu_to_be32(val); + + return true; +} + +bool get_rtas_buf_32(struct rtas_buffer *b, u32 *val) +{ + if (!b || !val || b->len - b->pos < sizeof(u32)) + return false; + + *val = be32_to_cpu(*((__be32 *)buf_pos(b))); + b->pos += sizeof(u32); + return true; +} + +bool get_rtas_buf_64(struct rtas_buffer *b, u64 *val) +{ + if (!b || !val || b->len - b->pos < sizeof(u64)) + return false; + + *val = be64_to_cpu(*((__be64 *)buf_pos(b))); + b->pos += sizeof(u64); + return true; +} + +bool get_rtas_buf_str(struct rtas_buffer *b, char **s) +{ + int i; + if (!b || !s) + return false; + + /* Get length of string */ + i = b->pos; + while (i < b->len) { + if (*(char *)(b->ptr + i) == '\0') { + *s = (char *)buf_pos(b); + if (!*s) + return false; + + b->pos = i + 1; + return true; + } + i++; + } + + return false; +} + +bool get_rtas_buf_mem(struct rtas_buffer *b, void **p, size_t len) +{ + if (!b || !p || b->len - b->pos < len) + return false; + + *p = buf_pos(b); + if (!*p) + return false; + + b->pos += len; + + return true; +} + +bool advance_rtas_buf(struct rtas_buffer *b, size_t len) +{ + if (!b || b->len - b->pos < len) + return false; + + b->pos += len; + + return true; +} + -- 1.9.1 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev