x86, numa: Remove configurable node size support for numa emulation

Now that numa=fake=<size>[MG] is implemented, it is possible to remove
configurable node size support.  The command-line parsing was already
broken (numa=fake=*128, for example, would not work) and since fake nodes
are now interleaved over physical nodes, this support is no longer
required.

Signed-off-by: David Rientjes <rientjes@google.com>
LKML-Reference: <alpine.DEB.2.00.1002151343080.26927@chino.kir.corp.google.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

2 files changed, 16 insertions, 160 deletions

diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt
index 01150c64aa73..7fbbaf85f5b7 100644
--- a/Documentation/x86/x86_64/boot-options.txt
+++ b/Documentation/x86/x86_64/boot-options.txt
@@ -170,19 +170,9 @@ NUMA
                 If given as a memory unit, fills all system RAM with nodes of
                 size interleaved over physical nodes.
 
-  numa=fake=CMDLINE
-                If a number, fakes CMDLINE nodes and ignores NUMA setup of the
-                actual machine.  Otherwise, system memory is configured
-                depending on the sizes and coefficients listed.  For example:
-                        numa=fake=2*512,1024,4*256,*128
-                gives two 512M nodes, a 1024M node, four 256M nodes, and the
-                rest split into 128M chunks.  If the last character of CMDLINE
-                is a *, the remaining memory is divided up equally among its
-                coefficient:
-                        numa=fake=2*512,2*
-                gives two 512M nodes and the rest split into two nodes.
-                Otherwise, the remaining system RAM is allocated to an
-                additional node.
+  numa=fake=<N>
+                If given as an integer, fills all system RAM with N fake nodes
+                interleaved over physical nodes.
 
 ACPI
 
diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index c47c78ba3aca..3307ea8bd43a 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -598,172 +598,38 @@ static int __init split_nodes_size_interleave(u64 addr, u64 max_addr, u64 size)
 }
 
 /*
- * Splits num_nodes nodes up equally starting at node_start.  The return value
- * is the number of nodes split up and addr is adjusted to be at the end of the
- * last node allocated.
- */
-static int __init split_nodes_equally(u64 *addr, u64 max_addr, int node_start,
-                                      int num_nodes)
-{
-        unsigned int big;
-        u64 size;
-        int i;
-
-        if (num_nodes <= 0)
-                return -1;
-        if (num_nodes > MAX_NUMNODES)
-                num_nodes = MAX_NUMNODES;
-        size = (max_addr - *addr - e820_hole_size(*addr, max_addr)) /
-               num_nodes;
-        /*
-         * Calculate the number of big nodes that can be allocated as a result
-         * of consolidating the leftovers.
-         */
-        big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * num_nodes) /
-              FAKE_NODE_MIN_SIZE;
-
-        /* Round down to nearest FAKE_NODE_MIN_SIZE. */
-        size &= FAKE_NODE_MIN_HASH_MASK;
-        if (!size) {
-                printk(KERN_ERR "Not enough memory for each node.  "
-                       "NUMA emulation disabled.\n");
-                return -1;
-        }
-
-        for (i = node_start; i < num_nodes + node_start; i++) {
-                u64 end = *addr + size;
-
-                if (i < big)
-                        end += FAKE_NODE_MIN_SIZE;
-                /*
-                 * The final node can have the remaining system RAM.  Other
-                 * nodes receive roughly the same amount of available pages.
-                 */
-                if (i == num_nodes + node_start - 1)
-                        end = max_addr;
-                else
-                        end = find_end_of_node(*addr, max_addr, size);
-                if (setup_node_range(i, addr, end - *addr, max_addr) < 0)
-                        break;
-        }
-        return i - node_start + 1;
-}
-
-/*
- * Splits the remaining system RAM into chunks of size.  The remaining memory is
- * always assigned to a final node and can be asymmetric.  Returns the number of
- * nodes split.
- */
-static int __init split_nodes_by_size(u64 *addr, u64 max_addr, int node_start,
-                                      u64 size)
-{
-        int i = node_start;
-        size = (size << 20) & FAKE_NODE_MIN_HASH_MASK;
-        while (!setup_node_range(i++, addr, size, max_addr))
-                ;
-        return i - node_start;
-}
-
-/*
  * Sets up the system RAM area from start_pfn to last_pfn according to the
  * numa=fake command-line option.
  */
 static int __init numa_emulation(unsigned long start_pfn,
                         unsigned long last_pfn, int acpi, int k8)
 {
-        u64 size, addr = start_pfn << PAGE_SHIFT;
+        u64 addr = start_pfn << PAGE_SHIFT;
         u64 max_addr = last_pfn << PAGE_SHIFT;
-        int num_nodes = 0, num = 0, coeff_flag, coeff = -1, i;
         int num_phys_nodes;
+        int num_nodes;
+        int i;
 
         num_phys_nodes = setup_physnodes(addr, max_addr, acpi, k8);
         /*
          * If the numa=fake command-line contains a 'M' or 'G', it represents
-         * the fixed node size.
+         * the fixed node size.  Otherwise, if it is just a single number N,
+         * split the system RAM into N fake nodes.
          */
         if (strchr(cmdline, 'M') || strchr(cmdline, 'G')) {
+                u64 size;
+
                 size = memparse(cmdline, &cmdline);
                 num_nodes = split_nodes_size_interleave(addr, max_addr, size);
-                if (num_nodes < 0)
-                        return num_nodes;
-                goto out;
-        }
+        } else {
+                unsigned long n;
 
-        /*
-         * If the numa=fake command-line is just a single number N, split the
-         * system RAM into N fake nodes.
-         */
-        if (!strchr(cmdline, '*') && !strchr(cmdline, ',')) {
-                long n = simple_strtol(cmdline, NULL, 0);
-
-                num_nodes = split_nodes_interleave(addr, max_addr,
-                                                        num_phys_nodes, n);
-                if (num_nodes < 0)
-                        return num_nodes;
-                goto out;
+                n = simple_strtoul(cmdline, NULL, 0);
+                num_nodes = split_nodes_interleave(addr, max_addr, num_phys_nodes, n);
         }
 
-        /* Parse the command line. */
-        for (coeff_flag = 0; ; cmdline++) {
-                if (*cmdline && isdigit(*cmdline)) {
-                        num = num * 10 + *cmdline - '0';
-                        continue;
-                }
-                if (*cmdline == '*') {
-                        if (num > 0)
-                                coeff = num;
-                        coeff_flag = 1;
-                }
-                if (!*cmdline || *cmdline == ',') {
-                        if (!coeff_flag)
-                                coeff = 1;
-                        /*
-                         * Round down to the nearest FAKE_NODE_MIN_SIZE.
-                         * Command-line coefficients are in megabytes.
-                         */
-                        size = ((u64)num << 20) & FAKE_NODE_MIN_HASH_MASK;
-                        if (size)
-                                for (i = 0; i < coeff; i++, num_nodes++)
-                                        if (setup_node_range(num_nodes, &addr,
-                                                size, max_addr) < 0)
-                                                goto done;
-                        if (!*cmdline)
-                                break;
-                        coeff_flag = 0;
-                        coeff = -1;
-                }
-                num = 0;
-        }
-done:
-        if (!num_nodes)
-                return -1;
-        /* Fill remainder of system RAM, if appropriate. */
-        if (addr < max_addr) {
-                if (coeff_flag && coeff < 0) {
-                        /* Split remaining nodes into num-sized chunks */
-                        num_nodes += split_nodes_by_size(&addr, max_addr,
-                                                         num_nodes, num);
-                        goto out;
-                }
-                switch (*(cmdline - 1)) {
-                case '*':
-                        /* Split remaining nodes into coeff chunks */
-                        if (coeff <= 0)
-                                break;
-                        num_nodes += split_nodes_equally(&addr, max_addr,
-                                                         num_nodes, coeff);
-                        break;
-                case ',':
-                        /* Do not allocate remaining system RAM */
-                        break;
-                default:
-                        /* Give one final node */
-                        setup_node_range(num_nodes, &addr, max_addr - addr,
-                                         max_addr);
-                        num_nodes++;
-                }
-        }
-out:
+        if (num_nodes < 0)
+                return num_nodes;
         memnode_shift = compute_hash_shift(nodes, num_nodes, NULL);
         if (memnode_shift < 0) {
                 memnode_shift = 0;