--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Request memory topology information via diag0x310.
+ *
+ * Copyright IBM Corp. 2025
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <asm/diag.h>
+#include <asm/sclp.h>
+#include <uapi/asm/diag.h>
+#include "diag_ioctl.h"
+
+#define DIAG310_LEVELMIN 1
+#define DIAG310_LEVELMAX 6
+
+enum diag310_sc {
+ DIAG310_SUBC_0 = 0,
+ DIAG310_SUBC_1 = 1,
+ DIAG310_SUBC_4 = 4,
+ DIAG310_SUBC_5 = 5
+};
+
+enum diag310_retcode {
+ DIAG310_RET_SUCCESS = 0x0001,
+ DIAG310_RET_BUSY = 0x0101,
+ DIAG310_RET_OPNOTSUPP = 0x0102,
+ DIAG310_RET_SC4_INVAL = 0x0401,
+ DIAG310_RET_SC4_NODATA = 0x0402,
+ DIAG310_RET_SC5_INVAL = 0x0501,
+ DIAG310_RET_SC5_NODATA = 0x0502,
+ DIAG310_RET_SC5_ESIZE = 0x0503
+};
+
+union diag310_response {
+ u64 response;
+ struct {
+ u64 result : 32;
+ u64 : 16;
+ u64 rc : 16;
+ };
+};
+
+union diag310_req_subcode {
+ u64 subcode;
+ struct {
+ u64 : 48;
+ u64 st : 8;
+ u64 sc : 8;
+ };
+};
+
+union diag310_req_size {
+ u64 size;
+ struct {
+ u64 page_count : 32;
+ u64 : 32;
+ };
+};
+
+static inline unsigned long diag310(unsigned long subcode, unsigned long size, void *addr)
+{
+ union register_pair rp = { .even = (unsigned long)addr, .odd = size };
+
+ diag_stat_inc(DIAG_STAT_X310);
+ asm volatile("diag %[rp],%[subcode],0x310\n"
+ : [rp] "+d" (rp.pair)
+ : [subcode] "d" (subcode)
+ : "memory");
+ return rp.odd;
+}
+
+static int diag310_result_to_errno(unsigned int result)
+{
+ switch (result) {
+ case DIAG310_RET_BUSY:
+ return -EBUSY;
+ case DIAG310_RET_OPNOTSUPP:
+ return -EOPNOTSUPP;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int diag310_get_subcode_mask(unsigned long *mask)
+{
+ union diag310_response res;
+
+ res.response = diag310(DIAG310_SUBC_0, 0, NULL);
+ if (res.rc != DIAG310_RET_SUCCESS)
+ return diag310_result_to_errno(res.rc);
+ *mask = res.response;
+ return 0;
+}
+
+static int diag310_get_memtop_stride(unsigned long *stride)
+{
+ union diag310_response res;
+
+ res.response = diag310(DIAG310_SUBC_1, 0, NULL);
+ if (res.rc != DIAG310_RET_SUCCESS)
+ return diag310_result_to_errno(res.rc);
+ *stride = res.result;
+ return 0;
+}
+
+static int diag310_get_memtop_size(unsigned long *pages, unsigned long level)
+{
+ union diag310_req_subcode req = { .sc = DIAG310_SUBC_4, .st = level };
+ union diag310_response res;
+
+ res.response = diag310(req.subcode, 0, NULL);
+ switch (res.rc) {
+ case DIAG310_RET_SUCCESS:
+ *pages = res.result;
+ return 0;
+ case DIAG310_RET_SC4_NODATA:
+ return -ENODATA;
+ case DIAG310_RET_SC4_INVAL:
+ return -EINVAL;
+ default:
+ return diag310_result_to_errno(res.rc);
+ }
+}
+
+static int diag310_store_topology_map(void *buf, unsigned long pages, unsigned long level)
+{
+ union diag310_req_subcode req_sc = { .sc = DIAG310_SUBC_5, .st = level };
+ union diag310_req_size req_size = { .page_count = pages };
+ union diag310_response res;
+
+ res.response = diag310(req_sc.subcode, req_size.size, buf);
+ switch (res.rc) {
+ case DIAG310_RET_SUCCESS:
+ return 0;
+ case DIAG310_RET_SC5_NODATA:
+ return -ENODATA;
+ case DIAG310_RET_SC5_ESIZE:
+ return -EOVERFLOW;
+ case DIAG310_RET_SC5_INVAL:
+ return -EINVAL;
+ default:
+ return diag310_result_to_errno(res.rc);
+ }
+}
+
+static int diag310_check_features(void)
+{
+ static int features_available;
+ unsigned long mask;
+ int rc;
+
+ if (READ_ONCE(features_available))
+ return 0;
+ if (!sclp.has_diag310)
+ return -EOPNOTSUPP;
+ rc = diag310_get_subcode_mask(&mask);
+ if (rc)
+ return rc;
+ if (!test_bit_inv(DIAG310_SUBC_1, &mask))
+ return -EOPNOTSUPP;
+ if (!test_bit_inv(DIAG310_SUBC_4, &mask))
+ return -EOPNOTSUPP;
+ if (!test_bit_inv(DIAG310_SUBC_5, &mask))
+ return -EOPNOTSUPP;
+ WRITE_ONCE(features_available, 1);
+ return 0;
+}
+
+static int memtop_get_stride_len(unsigned long *res)
+{
+ static unsigned long memtop_stride;
+ unsigned long stride;
+ int rc;
+
+ stride = READ_ONCE(memtop_stride);
+ if (!stride) {
+ rc = diag310_get_memtop_stride(&stride);
+ if (rc)
+ return rc;
+ WRITE_ONCE(memtop_stride, stride);
+ }
+ *res = stride;
+ return 0;
+}
+
+static int memtop_get_page_count(unsigned long *res, unsigned long level)
+{
+ static unsigned long memtop_pages[DIAG310_LEVELMAX];
+ unsigned long pages;
+ int rc;
+
+ if (level > DIAG310_LEVELMAX || level < DIAG310_LEVELMIN)
+ return -EINVAL;
+ pages = READ_ONCE(memtop_pages[level - 1]);
+ if (!pages) {
+ rc = diag310_get_memtop_size(&pages, level);
+ if (rc)
+ return rc;
+ WRITE_ONCE(memtop_pages[level - 1], pages);
+ }
+ *res = pages;
+ return 0;
+}
+
+long diag310_memtop_stride(unsigned long arg)
+{
+ size_t __user *argp = (void __user *)arg;
+ unsigned long stride;
+ int rc;
+
+ rc = diag310_check_features();
+ if (rc)
+ return rc;
+ rc = memtop_get_stride_len(&stride);
+ if (rc)
+ return rc;
+ if (put_user(stride, argp))
+ return -EFAULT;
+ return 0;
+}
+
+long diag310_memtop_len(unsigned long arg)
+{
+ size_t __user *argp = (void __user *)arg;
+ unsigned long pages, level;
+ int rc;
+
+ rc = diag310_check_features();
+ if (rc)
+ return rc;
+ if (get_user(level, argp))
+ return -EFAULT;
+ rc = memtop_get_page_count(&pages, level);
+ if (rc)
+ return rc;
+ if (put_user(pages * PAGE_SIZE, argp))
+ return -EFAULT;
+ return 0;
+}
+
+long diag310_memtop_buf(unsigned long arg)
+{
+ struct diag310_memtop __user *udata = (struct diag310_memtop __user *)arg;
+ unsigned long level, pages, data_size;
+ u64 address;
+ void *buf;
+ int rc;
+
+ rc = diag310_check_features();
+ if (rc)
+ return rc;
+ if (get_user(level, &udata->nesting_lvl))
+ return -EFAULT;
+ if (get_user(address, &udata->address))
+ return -EFAULT;
+ rc = memtop_get_page_count(&pages, level);
+ if (rc)
+ return rc;
+ data_size = pages * PAGE_SIZE;
+ buf = __vmalloc_node(data_size, PAGE_SIZE, GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT,
+ NUMA_NO_NODE, __builtin_return_address(0));
+ if (!buf)
+ return -ENOMEM;
+ rc = diag310_store_topology_map(buf, pages, level);
+ if (rc)
+ goto out;
+ if (copy_to_user((void __user *)address, buf, data_size))
+ rc = -EFAULT;
+out:
+ vfree(buf);
+ return rc;
+}
projects / thirdparty / kernel / linux.git / commitdiff
