ARM: mm: cleanup checks for membank overlap with vmalloc area

On Keystone platforms, physical memory is entirely outside the 32-bit
addressible range.  Therefore, the (bank->start > ULONG_MAX) check below marks
the entire system memory as highmem, and this causes unpleasentness all over.

This patch eliminates the extra bank start check (against ULONG_MAX) by
checking bank->start against the physical address corresponding to vmalloc_min
instead.

In the process, this patch also cleans up parts of the highmem sanity check
code by removing what has now become a redundant check for banks that entirely
overlap with the vmalloc range.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Subash Patel <subash.rp@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 1 insertions, 18 deletions

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index fc6ff1a9db50..ae249d1ab1d3 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -994,15 +994,12 @@ void __init sanity_check_meminfo(void)
                 struct membank *bank = &meminfo.bank[j];
                 *bank = meminfo.bank[i];
 
-                if (bank->start > ULONG_MAX)
-                        highmem = 1;
-
-#ifdef CONFIG_HIGHMEM
                 if (bank->start >= vmalloc_limit)
                         highmem = 1;
 
                 bank->highmem = highmem;
 
+#ifdef CONFIG_HIGHMEM
                 /*
                  * Split those memory banks which are partially overlapping
                  * the vmalloc area greatly simplifying things later.
@@ -1025,8 +1022,6 @@ void __init sanity_check_meminfo(void)
                         bank->size = vmalloc_limit - bank->start;
                 }
 #else
-                bank->highmem = highmem;
-
                 /*
                  * Highmem banks not allowed with !CONFIG_HIGHMEM.
                  */
@@ -1039,18 +1034,6 @@ void __init sanity_check_meminfo(void)
                 }
 
                 /*
-                 * Check whether this memory bank would entirely overlap
-                 * the vmalloc area.
-                 */
-                if (bank->start >= vmalloc_limit) {
-                        printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "
-                               "(vmalloc region overlap).\n",
-                               (unsigned long long)bank->start,
-                               (unsigned long long)bank->start + bank->size - 1);
-                        continue;
-                }
-
-                /*
                  * Check whether this memory bank would partially overlap
                  * the vmalloc area.
                  */