Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 263 insertions, 0 deletions

diff --git a/kernel/arch/cris/arch-v10/mm/init.c b/kernel/arch/cris/arch-v10/mm/init.c
new file mode 100644
index 000000000..e7f806610
--- /dev/null
+++ b/kernel/arch/cris/arch-v10/mm/init.c
@@ -0,0 +1,263 @@
+/*
+ *  linux/arch/cris/arch-v10/mm/init.c
+ *
+ */
+#include <linux/mmzone.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/mm.h>
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/types.h>
+#include <asm/mmu.h>
+#include <asm/io.h>
+#include <asm/mmu_context.h>
+#include <arch/svinto.h>
+
+extern void tlb_init(void);
+
+/*
+ * The kernel is already mapped with a kernel segment at kseg_c so 
+ * we don't need to map it with a page table. However head.S also
+ * temporarily mapped it at kseg_4 so we should set up the ksegs again,
+ * clear the TLB and do some other paging setup stuff.
+ */
+
+void __init 
+paging_init(void)
+{
+	int i;
+	unsigned long zones_size[MAX_NR_ZONES];
+
+	printk("Setting up paging and the MMU.\n");
+	
+	/* clear out the init_mm.pgd that will contain the kernel's mappings */
+
+	for(i = 0; i < PTRS_PER_PGD; i++)
+		swapper_pg_dir[i] = __pgd(0);
+	
+	/* make sure the current pgd table points to something sane
+	 * (even if it is most probably not used until the next 
+	 *  switch_mm)
+	 */
+
+	per_cpu(current_pgd, smp_processor_id()) = init_mm.pgd;
+
+	/* initialise the TLB (tlb.c) */
+
+	tlb_init();
+
+	/* see README.mm for details on the KSEG setup */
+
+#ifdef CONFIG_CRIS_LOW_MAP
+	/* Etrax-100 LX version 1 has a bug so that we cannot map anything
+	 * across the 0x80000000 boundary, so we need to shrink the user-virtual
+	 * area to 0x50000000 instead of 0xb0000000 and map things slightly
+	 * different. The unused areas are marked as paged so that we can catch
+	 * freak kernel accesses there.
+	 *
+	 * The ARTPEC chip is mapped at 0xa so we pass that segment straight
+	 * through. We cannot vremap it because the vmalloc area is below 0x8
+	 * and Juliette needs an uncached area above 0x8.
+	 *
+	 * Same thing with 0xc and 0x9, which is memory-mapped I/O on some boards.
+	 * We map them straight over in LOW_MAP, but use vremap in LX version 2.
+	 */
+
+#define CACHED_BOOTROM (KSEG_F | 0x08000000UL)
+
+	*R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, seg  ) |  /* bootrom */
+			IO_STATE(R_MMU_KSEG, seg_e, page ) |
+			IO_STATE(R_MMU_KSEG, seg_d, page ) | 
+			IO_STATE(R_MMU_KSEG, seg_c, page ) |   
+			IO_STATE(R_MMU_KSEG, seg_b, seg  ) |  /* kernel reg area */
+#ifdef CONFIG_JULIETTE
+			IO_STATE(R_MMU_KSEG, seg_a, seg  ) |  /* ARTPEC etc. */
+#else
+			IO_STATE(R_MMU_KSEG, seg_a, page ) |
+#endif
+			IO_STATE(R_MMU_KSEG, seg_9, seg  ) |  /* LED's on some boards */
+			IO_STATE(R_MMU_KSEG, seg_8, seg  ) |  /* CSE0/1, flash and I/O */
+			IO_STATE(R_MMU_KSEG, seg_7, page ) |  /* kernel vmalloc area */
+			IO_STATE(R_MMU_KSEG, seg_6, seg  ) |  /* kernel DRAM area */
+			IO_STATE(R_MMU_KSEG, seg_5, seg  ) |  /* cached flash */
+			IO_STATE(R_MMU_KSEG, seg_4, page ) |  /* user area */
+			IO_STATE(R_MMU_KSEG, seg_3, page ) |  /* user area */
+			IO_STATE(R_MMU_KSEG, seg_2, page ) |  /* user area */
+			IO_STATE(R_MMU_KSEG, seg_1, page ) |  /* user area */
+			IO_STATE(R_MMU_KSEG, seg_0, page ) ); /* user area */
+
+	*R_MMU_KBASE_HI = ( IO_FIELD(R_MMU_KBASE_HI, base_f, 0x3 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_e, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_d, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_c, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_b, 0xb ) |
+#ifdef CONFIG_JULIETTE
+			    IO_FIELD(R_MMU_KBASE_HI, base_a, 0xa ) |
+#else
+			    IO_FIELD(R_MMU_KBASE_HI, base_a, 0x0 ) |
+#endif
+			    IO_FIELD(R_MMU_KBASE_HI, base_9, 0x9 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_8, 0x8 ) );
+	
+	*R_MMU_KBASE_LO = ( IO_FIELD(R_MMU_KBASE_LO, base_7, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_6, 0x4 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_5, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_4, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_3, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_2, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_1, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_0, 0x0 ) );
+#else
+	/* This code is for the corrected Etrax-100 LX version 2... */
+
+#define CACHED_BOOTROM (KSEG_A | 0x08000000UL)
+
+	*R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, seg  ) | /* cached flash */
+			IO_STATE(R_MMU_KSEG, seg_e, seg  ) | /* uncached flash */
+			IO_STATE(R_MMU_KSEG, seg_d, page ) | /* vmalloc area */
+			IO_STATE(R_MMU_KSEG, seg_c, seg  ) | /* kernel area */
+			IO_STATE(R_MMU_KSEG, seg_b, seg  ) | /* kernel reg area */
+			IO_STATE(R_MMU_KSEG, seg_a, seg  ) | /* bootrom */
+			IO_STATE(R_MMU_KSEG, seg_9, page ) | /* user area */
+			IO_STATE(R_MMU_KSEG, seg_8, page ) |
+			IO_STATE(R_MMU_KSEG, seg_7, page ) |
+			IO_STATE(R_MMU_KSEG, seg_6, page ) |
+			IO_STATE(R_MMU_KSEG, seg_5, page ) |
+			IO_STATE(R_MMU_KSEG, seg_4, page ) |
+			IO_STATE(R_MMU_KSEG, seg_3, page ) |
+			IO_STATE(R_MMU_KSEG, seg_2, page ) |
+			IO_STATE(R_MMU_KSEG, seg_1, page ) |
+			IO_STATE(R_MMU_KSEG, seg_0, page ) );
+
+	*R_MMU_KBASE_HI = ( IO_FIELD(R_MMU_KBASE_HI, base_f, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_e, 0x8 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_d, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_c, 0x4 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_b, 0xb ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_a, 0x3 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_9, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_8, 0x0 ) );
+	
+	*R_MMU_KBASE_LO = ( IO_FIELD(R_MMU_KBASE_LO, base_7, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_6, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_5, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_4, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_3, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_2, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_1, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_LO, base_0, 0x0 ) );
+#endif
+
+	*R_MMU_CONTEXT = ( IO_FIELD(R_MMU_CONTEXT, page_id, 0 ) );
+	
+	/* The MMU has been enabled ever since head.S but just to make
+	 * it totally obvious we do it here as well.
+	 */
+
+	*R_MMU_CTRL = ( IO_STATE(R_MMU_CTRL, inv_excp, enable ) |
+			IO_STATE(R_MMU_CTRL, acc_excp, enable ) |
+			IO_STATE(R_MMU_CTRL, we_excp,  enable ) );
+	
+	*R_MMU_ENABLE = IO_STATE(R_MMU_ENABLE, mmu_enable, enable);
+
+	/*
+	 * initialize the bad page table and bad page to point
+	 * to a couple of allocated pages
+	 */
+
+	empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
+	memset((void *)empty_zero_page, 0, PAGE_SIZE);
+
+	/* All pages are DMA'able in Etrax, so put all in the DMA'able zone */
+
+	zones_size[0] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT;
+
+	for (i = 1; i < MAX_NR_ZONES; i++)
+		zones_size[i] = 0;
+
+	/* Use free_area_init_node instead of free_area_init, because the former
+	 * is designed for systems where the DRAM starts at an address substantially
+	 * higher than 0, like us (we start at PAGE_OFFSET). This saves space in the
+	 * mem_map page array.
+	 */
+
+	free_area_init_node(0, zones_size, PAGE_OFFSET >> PAGE_SHIFT, 0);
+}
+
+/* Initialize remaps of some I/O-ports. It is important that this
+ * is called before any driver is initialized.
+ */
+
+static int
+__init init_ioremap(void)
+{
+  
+	/* Give the external I/O-port addresses their values */
+
+#ifdef CONFIG_CRIS_LOW_MAP
+	/* Simply a linear map (see the KSEG map above in paging_init) */
+	port_cse1_addr = (volatile unsigned long *)(MEM_CSE1_START | 
+	                                            MEM_NON_CACHEABLE);
+	port_csp0_addr = (volatile unsigned long *)(MEM_CSP0_START |
+	                                            MEM_NON_CACHEABLE);
+	port_csp4_addr = (volatile unsigned long *)(MEM_CSP4_START |
+	                                            MEM_NON_CACHEABLE);
+#else
+	/* Note that nothing blows up just because we do this remapping 
+	 * it's ok even if the ports are not used or connected 
+	 * to anything (or connected to a non-I/O thing) */        
+	port_cse1_addr = (volatile unsigned long *)
+	  ioremap((unsigned long)(MEM_CSE1_START | MEM_NON_CACHEABLE), 16);
+	port_csp0_addr = (volatile unsigned long *)
+	  ioremap((unsigned long)(MEM_CSP0_START | MEM_NON_CACHEABLE), 16);
+	port_csp4_addr = (volatile unsigned long *)
+	  ioremap((unsigned long)(MEM_CSP4_START | MEM_NON_CACHEABLE), 16);
+#endif	
+	return 0;
+}
+
+__initcall(init_ioremap);
+
+/* Helper function for the two below */
+
+static inline void
+flush_etrax_cacherange(void *startadr, int length)
+{
+	/* CACHED_BOOTROM is mapped to the boot-rom area (cached) which
+	 * we can use to get fast dummy-reads of cachelines
+	 */
+
+	volatile short *flushadr = (volatile short *)(((unsigned long)startadr & ~PAGE_MASK) |
+						      CACHED_BOOTROM);
+
+	length = length > 8192 ? 8192 : length;  /* No need to flush more than cache size */
+
+	while(length > 0) {
+		*flushadr; /* dummy read to flush */
+		flushadr += (32/sizeof(short));  /* a cacheline is 32 bytes */
+		length -= 32;
+	}
+}
+
+/* Due to a bug in Etrax100(LX) all versions, receiving DMA buffers
+ * will occasionally corrupt certain CPU writes if the DMA buffers
+ * happen to be hot in the cache.
+ * 
+ * As a workaround, we have to flush the relevant parts of the cache
+ * before (re) inserting any receiving descriptor into the DMA HW.
+ */
+
+void
+prepare_rx_descriptor(struct etrax_dma_descr *desc)
+{
+	flush_etrax_cacherange((void *)desc->buf, desc->sw_len ? desc->sw_len : 65536);
+}
+
+/* Do the same thing but flush the entire cache */
+
+void
+flush_etrax_cache(void)
+{
+	flush_etrax_cacherange(0, 8192);
+}