ARC: mm: HIGHMEM: populate high memory from DT
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/boot/dts/nsim_hs.dts b/arch/arc/boot/dts/nsim_hs.dts
index 911f069..b0eb0e7 100644
--- a/arch/arc/boot/dts/nsim_hs.dts
+++ b/arch/arc/boot/dts/nsim_hs.dts
@@ -11,8 +11,16 @@
/ {
compatible = "snps,nsim_hs";
+ #address-cells = <2>;
+ #size-cells = <2>;
interrupt-parent = <&core_intc>;
+ memory {
+ device_type = "memory";
+ reg = <0x0 0x80000000 0x0 0x40000000 /* 1 GB low mem */
+ 0x1 0x00000000 0x0 0x40000000>; /* 1 GB highmem */
+ };
+
chosen {
bootargs = "earlycon=arc_uart,mmio32,0xc0fc1000,115200n8 console=ttyARC0,115200n8";
};
@@ -26,8 +34,8 @@
#address-cells = <1>;
#size-cells = <1>;
- /* child and parent address space 1:1 mapped */
- ranges;
+ /* only perip space at end of low mem accessible */
+ ranges = <0x80000000 0x0 0x80000000 0x80000000>;
core_intc: core-interrupt-controller {
compatible = "snps,archs-intc";
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index a726a22..a9305b5 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -15,6 +15,7 @@
#endif
#include <linux/swap.h>
#include <linux/module.h>
+#include <linux/highmem.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
@@ -27,6 +28,12 @@
static const unsigned long low_mem_start = CONFIG_LINUX_LINK_BASE;
static unsigned long low_mem_sz;
+#ifdef CONFIG_HIGHMEM
+static unsigned long min_high_pfn;
+static u64 high_mem_start;
+static u64 high_mem_sz;
+#endif
+
/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
static int __init setup_mem_sz(char *str)
{
@@ -41,10 +48,22 @@
void __init early_init_dt_add_memory_arch(u64 base, u64 size)
{
- low_mem_sz = size;
- BUG_ON(base != low_mem_start);
+ int in_use = 0;
- pr_info("Memory @ %llx of %ldM\n", base, TO_MB(size));
+ if (!low_mem_sz) {
+ BUG_ON(base != low_mem_start);
+ low_mem_sz = size;
+ in_use = 1;
+ } else {
+#ifdef CONFIG_HIGHMEM
+ high_mem_start = base;
+ high_mem_sz = size;
+ in_use = 1;
+#endif
+ }
+
+ pr_info("Memory @ %llx [%lldM] %s\n",
+ base, TO_MB(size), !in_use ? "Not used":"");
}
#ifdef CONFIG_BLK_DEV_INITRD
@@ -74,6 +93,7 @@
void __init setup_arch_memory(void)
{
unsigned long zones_size[MAX_NR_ZONES];
+ unsigned long zones_holes[MAX_NR_ZONES];
init_mm.start_code = (unsigned long)_text;
init_mm.end_code = (unsigned long)_etext;
@@ -86,9 +106,26 @@
/* Last usable page of low mem */
max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
- max_mapnr = max_low_pfn - min_low_pfn;
+#ifdef CONFIG_HIGHMEM
+ min_high_pfn = PFN_DOWN(high_mem_start);
+ max_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
+#endif
+
+ max_mapnr = max_pfn - min_low_pfn;
/*------------- bootmem allocator setup -----------------------*/
+
+ /*
+ * seed the bootmem allocator after any DT memory node parsing or
+ * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
+ *
+ * Only low mem is added, otherwise we have crashes when allocating
+ * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
+ * avail memory, ending in highmem with a > 32-bit address. However
+ * it then tries to memset it with a truncaed 32-bit handle, causing
+ * the crash
+ */
+
memblock_add(low_mem_start, low_mem_sz);
memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
@@ -101,7 +138,17 @@
/*----------------- node/zones setup --------------------------*/
memset(zones_size, 0, sizeof(zones_size));
+ memset(zones_holes, 0, sizeof(zones_holes));
+
zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
+ zones_holes[ZONE_NORMAL] = 0;
+
+#ifdef CONFIG_HIGHMEM
+ zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
+
+ /* This handles the peripheral address space hole */
+ zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn;
+#endif
/*
* We can't use the helper free_area_init(zones[]) because it uses
@@ -112,9 +159,12 @@
free_area_init_node(0, /* node-id */
zones_size, /* num pages per zone */
min_low_pfn, /* first pfn of node */
- NULL); /* NO holes */
+ zones_holes); /* holes */
- high_memory = (void *)end_mem;
+#ifdef CONFIG_HIGHMEM
+ high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
+ kmap_init();
+#endif
}
/*
@@ -125,6 +175,14 @@
*/
void __init mem_init(void)
{
+#ifdef CONFIG_HIGHMEM
+ unsigned long tmp;
+
+ reset_all_zones_managed_pages();
+ for (tmp = min_high_pfn; tmp < max_pfn; tmp++)
+ free_highmem_page(pfn_to_page(tmp));
+#endif
+
free_all_bootmem();
mem_init_print_info(NULL);
}