diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/vphn.c')
-rw-r--r-- | arch/powerpc/platforms/pseries/vphn.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/vphn.c b/arch/powerpc/platforms/pseries/vphn.c new file mode 100644 index 0000000000..3f85ece3c8 --- /dev/null +++ b/arch/powerpc/platforms/pseries/vphn.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <asm/byteorder.h> +#include <asm/vphn.h> + +/* + * The associativity domain numbers are returned from the hypervisor as a + * stream of mixed 16-bit and 32-bit fields. The stream is terminated by the + * special value of "all ones" (aka. 0xffff) and its size may not exceed 48 + * bytes. + * + * --- 16-bit fields --> + * _________________________ + * | 0 | 1 | 2 | 3 | be_packed[0] + * ------+-----+-----+------ + * _________________________ + * | 4 | 5 | 6 | 7 | be_packed[1] + * ------------------------- + * ... + * _________________________ + * | 20 | 21 | 22 | 23 | be_packed[5] + * ------------------------- + * + * Convert to the sequence they would appear in the ibm,associativity property. + */ +static int vphn_unpack_associativity(const long *packed, __be32 *unpacked) +{ + __be64 be_packed[VPHN_REGISTER_COUNT]; + int i, nr_assoc_doms = 0; + const __be16 *field = (const __be16 *) be_packed; + u16 last = 0; + bool is_32bit = false; + +#define VPHN_FIELD_UNUSED (0xffff) +#define VPHN_FIELD_MSB (0x8000) +#define VPHN_FIELD_MASK (~VPHN_FIELD_MSB) + + /* Let's fix the values returned by plpar_hcall9() */ + for (i = 0; i < VPHN_REGISTER_COUNT; i++) + be_packed[i] = cpu_to_be64(packed[i]); + + for (i = 1; i < VPHN_ASSOC_BUFSIZE; i++) { + u16 new = be16_to_cpup(field++); + + if (is_32bit) { + /* + * Let's concatenate the 16 bits of this field to the + * 15 lower bits of the previous field + */ + unpacked[++nr_assoc_doms] = + cpu_to_be32(last << 16 | new); + is_32bit = false; + } else if (new == VPHN_FIELD_UNUSED) + /* This is the list terminator */ + break; + else if (new & VPHN_FIELD_MSB) { + /* Data is in the lower 15 bits of this field */ + unpacked[++nr_assoc_doms] = + cpu_to_be32(new & VPHN_FIELD_MASK); + } else { + /* + * Data is in the lower 15 bits of this field + * concatenated with the next 16 bit field + */ + last = new; + is_32bit = true; + } + } + + /* The first cell contains the length of the property */ + unpacked[0] = cpu_to_be32(nr_assoc_doms); + + return nr_assoc_doms; +} + +/* NOTE: This file is included by a selftest and built in userspace. */ +#ifdef __KERNEL__ +#include <asm/hvcall.h> + +long hcall_vphn(unsigned long cpu, u64 flags, __be32 *associativity) +{ + long rc; + long retbuf[PLPAR_HCALL9_BUFSIZE] = {0}; + + rc = plpar_hcall9(H_HOME_NODE_ASSOCIATIVITY, retbuf, flags, cpu); + if (rc == H_SUCCESS) + vphn_unpack_associativity(retbuf, associativity); + + return rc; +} +#endif |