1 // SPDX-License-Identifier: GPL-2.0 2 #include <asm/byteorder.h> 3 #include "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 */ vphn_unpack_associativity(const long * packed,__be32 * unpacked)25int 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 /* Let's concatenate the 16 bits of this field to the 46 * 15 lower bits of the previous field 47 */ 48 unpacked[++nr_assoc_doms] = 49 cpu_to_be32(last << 16 | new); 50 is_32bit = false; 51 } else if (new == VPHN_FIELD_UNUSED) 52 /* This is the list terminator */ 53 break; 54 else if (new & VPHN_FIELD_MSB) { 55 /* Data is in the lower 15 bits of this field */ 56 unpacked[++nr_assoc_doms] = 57 cpu_to_be32(new & VPHN_FIELD_MASK); 58 } else { 59 /* Data is in the lower 15 bits of this field 60 * concatenated with the next 16 bit field 61 */ 62 last = new; 63 is_32bit = true; 64 } 65 } 66 67 /* The first cell contains the length of the property */ 68 unpacked[0] = cpu_to_be32(nr_assoc_doms); 69 70 return nr_assoc_doms; 71 } 72
