| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 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 | */ |
| 25 | 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 | /* 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 | } |