[mirror_ubuntu-jammy-kernel.git] / arch / powerpc / mm / vphn.c

// SPDX-License-Identifier: GPL-2.0
#include <asm/byteorder.h>
#include "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.
 */
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;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
4b6cfb2a GK	2	#include <asm/byteorder.h>
	3	#include "vphn.h"
	4
	5	/*
3338a65b GK	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.
4b6cfb2a GK	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;
3338a65b GK	30	u16 last = 0;
3338a65b GK	31	bool is_32bit = false;
4b6cfb2a GK	32
	33	#define VPHN_FIELD_UNUSED (0xffff)
	34	#define VPHN_FIELD_MSB (0x8000)
	35	#define VPHN_FIELD_MASK (~VPHN_FIELD_MSB)
	36
3338a65b	37	/* Let's fix the values returned by plpar_hcall9() */
4b6cfb2a GK	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++) {
3338a65b GK	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
4b6cfb2a	47	*/
3338a65b GK	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) {
4b6cfb2a	55	/* Data is in the lower 15 bits of this field */
3338a65b GK	56	unpacked[++nr_assoc_doms] =
3338a65b GK	57	cpu_to_be32(new & VPHN_FIELD_MASK);
4b6cfb2a GK	58	} else {
	59	/* Data is in the lower 15 bits of this field
	60	* concatenated with the next 16 bit field
	61	*/
3338a65b GK	62	last = new;
3338a65b GK	63	is_32bit = true;
4b6cfb2a GK	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	}