@@ -2,44 +2,64 @@
#include "vphn.h"
/*
- * Convert the associativity domain numbers returned from the hypervisor
- * to the sequence they would appear in the ibm,associativity property.
+ * 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 recreate the original stream. */
+ /* 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++) {
- if (be16_to_cpup(field) == VPHN_FIELD_UNUSED) {
- /* All significant fields processed, and remaining
- * fields contain the reserved value of all 1's.
- * Just store them.
+ 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[i] = *((__be32 *)field);
- field += 2;
- } else if (be16_to_cpup(field) & VPHN_FIELD_MSB) {
+ 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[i] = cpu_to_be32(
- be16_to_cpup(field) & VPHN_FIELD_MASK);
- field++;
- nr_assoc_doms++;
+ 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
*/
- unpacked[i] = *((__be32 *)field);
- field += 2;
- nr_assoc_doms++;
+ last = new;
+ is_32bit = true;
}
}
@@ -6,10 +6,10 @@
#define VPHN_REGISTER_COUNT 6
/*
- * 6 64-bit registers unpacked into 12 32-bit associativity values. To form
- * the complete property we have to add the length in the first cell.
+ * 6 64-bit registers unpacked into up to 24 be32 associativity values. To
+ * form the complete property we have to add the length in the first cell.
*/
-#define VPHN_ASSOC_BUFSIZE (VPHN_REGISTER_COUNT*sizeof(u64)/sizeof(u32) + 1)
+#define VPHN_ASSOC_BUFSIZE (VPHN_REGISTER_COUNT*sizeof(u64)/sizeof(u16) + 1)
extern int vphn_unpack_associativity(const long *packed, __be32 *unpacked);
The current VPHN parsing logic has some flaws that this patch aims to fix: 1) when the value 0xffff is read, the value 0xffffffff gets added to the the output list and its element count isn't incremented. This is wrong. According to PAPR+ the domain identifiers are packed into a sequence terminated by the "reserved value of all ones". This means that 0xffff is a stream terminator. 2) the combination of byteswaps and casts make the code hardly readable. Let's parse the stream one 16-bit field at a time instead. 3) it is assumed that the hypercall returns 12 32-bit values packed into 6 64-bit registers. According to PAPR+, the domain identifiers may be streamed as 16-bit values. Let's increase the number of expected numbers to 24. Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> --- arch/powerpc/mm/vphn.c | 54 +++++++++++++++++++++++++++++++++--------------- arch/powerpc/mm/vphn.h | 6 +++-- 2 files changed, 40 insertions(+), 20 deletions(-)