1 // SPDX-License-Identifier: GPL-2.0 2 #include <asm/byteorder.h> 3 #include <asm/vphn.h> 4 5 /* 6 * The associativity domain numbers are returned from the hypervisor as a 7 * stream of mixed 16-bit and 32-bit fields. The stream is terminated by the 8 * special value of "all ones" (aka. 0xffff) and its size may not exceed 48 9 * bytes. 10 * 11 * --- 16-bit fields --> 12 * _________________________ 13 * | 0 | 1 | 2 | 3 | be_packed[0] 14 * ------+-----+-----+------ 15 * _________________________ 16 * | 4 | 5 | 6 | 7 | be_packed[1] 17 * ------------------------- 18 * ... 19 * _________________________ 20 * | 20 | 21 | 22 | 23 | be_packed[5] 21 * ------------------------- 22 * 23 * Convert to the sequence they would appear in the ibm,associativity property. 24 */ 25 static int vphn_unpack_associativity(const long *packed, __be32 *unpacked) 26 { 27 __be64 be_packed[VPHN_REGISTER_COUNT]; 28 int i, nr_assoc_doms = 0; 29 const __be16 *field = (const __be16 *) be_packed; 30 u16 last = 0; 31 bool is_32bit = false; 32 33 #define VPHN_FIELD_UNUSED (0xffff) 34 #define VPHN_FIELD_MSB (0x8000) 35 #define VPHN_FIELD_MASK (~VPHN_FIELD_MSB) 36 37 /* Let's fix the values returned by plpar_hcall9() */ 38 for (i = 0; i < VPHN_REGISTER_COUNT; i++) 39 be_packed[i] = cpu_to_be64(packed[i]); 40 41 for (i = 1; i < VPHN_ASSOC_BUFSIZE; i++) { 42 u16 new = be16_to_cpup(field++); 43 44 if (is_32bit) { 45 /* 46 * Let's concatenate the 16 bits of this field to the 47 * 15 lower bits of the previous field 48 */ 49 unpacked[++nr_assoc_doms] = 50 cpu_to_be32(last << 16 | new); 51 is_32bit = false; 52 } else if (new == VPHN_FIELD_UNUSED) 53 /* This is the list terminator */ 54 break; 55 else if (new & VPHN_FIELD_MSB) { 56 /* Data is in the lower 15 bits of this field */ 57 unpacked[++nr_assoc_doms] = 58 cpu_to_be32(new & VPHN_FIELD_MASK); 59 } else { 60 /* 61 * Data is in the lower 15 bits of this field 62 * concatenated with the next 16 bit field 63 */ 64 last = new; 65 is_32bit = true; 66 } 67 } 68 69 /* The first cell contains the length of the property */ 70 unpacked[0] = cpu_to_be32(nr_assoc_doms); 71 72 return nr_assoc_doms; 73 } 74 75 /* NOTE: This file is included by a selftest and built in userspace. */ 76 #ifdef __KERNEL__ 77 #include <asm/hvcall.h> 78 79 long hcall_vphn(unsigned long cpu, u64 flags, __be32 *associativity) 80 { 81 long rc; 82 long retbuf[PLPAR_HCALL9_BUFSIZE] = {0}; 83 84 rc = plpar_hcall9(H_HOME_NODE_ASSOCIATIVITY, retbuf, flags, cpu); 85 if (rc == H_SUCCESS) 86 vphn_unpack_associativity(retbuf, associativity); 87 88 return rc; 89 } 90 #endif 91