powerpc: make mem= work on iSeries again

By parsing the command line earlier, we can add the mem= value to the
flattened device tree and let the generic code sort out the memory limit
for us.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

1 files changed, 25 insertions, 17 deletions

diff --git a/arch/powerpc/platforms/iseries/setup.c b/arch/powerpc/platforms/iseries/setup.c
index 1544c6f10a38..06431e642533 100644
--- a/arch/powerpc/platforms/iseries/setup.c
+++ b/arch/powerpc/platforms/iseries/setup.c
@@ -27,6 +27,7 @@
 #include <linux/kdev_t.h>
 #include <linux/major.h>
 #include <linux/root_dev.h>
+#include <linux/kernel.h>
 
 #include <asm/processor.h>
 #include <asm/machdep.h>
@@ -94,6 +95,8 @@ extern unsigned long iSeries_recal_titan;
 
 static int mf_initialized;
 
+static unsigned long cmd_mem_limit;
+
 struct MemoryBlock {
         unsigned long absStart;
         unsigned long absEnd;
@@ -341,23 +344,6 @@ static void __init iSeries_init_early(void)
          */
         iommu_init_early_iSeries();
 
-        iSeries_get_cmdline();
-
-        /* Save unparsed command line copy for /proc/cmdline */
-        strlcpy(saved_command_line, cmd_line, COMMAND_LINE_SIZE);
-
-        /* Parse early parameters, in particular mem=x */
-        parse_early_param();
-
-        if (memory_limit) {
-                if (memory_limit < systemcfg->physicalMemorySize)
-                        systemcfg->physicalMemorySize = memory_limit;
-                else {
-                        printk("Ignoring mem=%lu >= ram_top.\n", memory_limit);
-                        memory_limit = 0;
-                }
-        }
-
         /* Initialize machine-dependency vectors */
 #ifdef CONFIG_SMP
         smp_init_iSeries();
@@ -971,6 +957,8 @@ void build_flat_dt(struct iseries_flat_dt *dt)
         /* /chosen */
         dt_start_node(dt, "chosen");
         dt_prop_u32(dt, "linux,platform", PLATFORM_ISERIES_LPAR);
+        if (cmd_mem_limit)
+                dt_prop_u64(dt, "linux,memory-limit", cmd_mem_limit);
         dt_end_node(dt);
 
         dt_cpus(dt);
@@ -990,7 +978,27 @@ void * __init iSeries_early_setup(void)
          */
         build_iSeries_Memory_Map();
 
+        iSeries_get_cmdline();
+
+        /* Save unparsed command line copy for /proc/cmdline */
+        strlcpy(saved_command_line, cmd_line, COMMAND_LINE_SIZE);
+
+        /* Parse early parameters, in particular mem=x */
+        parse_early_param();
+
         build_flat_dt(&iseries_dt);
 
         return (void *) __pa(&iseries_dt);
 }
+
+/*
+ * On iSeries we just parse the mem=X option from the command line.
+ * On pSeries it's a bit more complicated, see prom_init_mem()
+ */
+static int __init early_parsemem(char *p)
+{
+        if (p)
+                cmd_mem_limit = ALIGN(memparse(p, &p), PAGE_SIZE);
+        return 0;
+}
+early_param("mem", early_parsemem);