1 files changed, 247 insertions, 32 deletions

diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index b237988ba6d7..24c1a57abb40 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -22,6 +22,11 @@
 #include <linux/bootmem.h>
 #include <linux/kernel.h>
 
+#ifdef CONFIG_OF
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+#endif
+
 #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
 # include <linux/console.h>
 #endif
@@ -42,6 +47,7 @@
 #include <asm/page.h>
 #include <asm/setup.h>
 #include <asm/param.h>
+#include <asm/traps.h>
 
 #include <platform/hardware.h>
 
@@ -64,6 +70,11 @@ int initrd_is_mapped = 0;
 extern int initrd_below_start_ok;
 #endif
 
+#ifdef CONFIG_OF
+extern u32 __dtb_start[];
+void *dtb_start = __dtb_start;
+#endif
+
 unsigned char aux_device_present;
 extern unsigned long loops_per_jiffy;
 
@@ -83,6 +94,8 @@ extern void init_mmu(void);
 static inline void init_mmu(void) { }
 #endif
 
+extern int mem_reserve(unsigned long, unsigned long, int);
+extern void bootmem_init(void);
 extern void zones_init(void);
 
 /*
@@ -104,28 +117,33 @@ typedef struct tagtable {
 
 /* parse current tag */
 
-static int __init parse_tag_mem(const bp_tag_t *tag)
+static int __init add_sysmem_bank(unsigned long type, unsigned long start,
+                unsigned long end)
 {
-        meminfo_t *mi = (meminfo_t*)(tag->data);
-
-        if (mi->type != MEMORY_TYPE_CONVENTIONAL)
-                return -1;
-
         if (sysmem.nr_banks >= SYSMEM_BANKS_MAX) {
                 printk(KERN_WARNING
-                       "Ignoring memory bank 0x%08lx size %ldKB\n",
-                       (unsigned long)mi->start,
-                       (unsigned long)mi->end - (unsigned long)mi->start);
+                                "Ignoring memory bank 0x%08lx size %ldKB\n",
+                                start, end - start);
                 return -EINVAL;
         }
-        sysmem.bank[sysmem.nr_banks].type  = mi->type;
-        sysmem.bank[sysmem.nr_banks].start = PAGE_ALIGN(mi->start);
-        sysmem.bank[sysmem.nr_banks].end   = mi->end & PAGE_MASK;
+        sysmem.bank[sysmem.nr_banks].type  = type;
+        sysmem.bank[sysmem.nr_banks].start = PAGE_ALIGN(start);
+        sysmem.bank[sysmem.nr_banks].end   = end & PAGE_MASK;
         sysmem.nr_banks++;
 
         return 0;
 }
 
+static int __init parse_tag_mem(const bp_tag_t *tag)
+{
+        meminfo_t *mi = (meminfo_t *)(tag->data);
+
+        if (mi->type != MEMORY_TYPE_CONVENTIONAL)
+                return -1;
+
+        return add_sysmem_bank(mi->type, mi->start, mi->end);
+}
+
 __tagtable(BP_TAG_MEMORY, parse_tag_mem);
 
 #ifdef CONFIG_BLK_DEV_INITRD
@@ -142,12 +160,31 @@ static int __init parse_tag_initrd(const bp_tag_t* tag)
 
 __tagtable(BP_TAG_INITRD, parse_tag_initrd);
 
+#ifdef CONFIG_OF
+
+static int __init parse_tag_fdt(const bp_tag_t *tag)
+{
+        dtb_start = (void *)(tag->data[0]);
+        return 0;
+}
+
+__tagtable(BP_TAG_FDT, parse_tag_fdt);
+
+void __init early_init_dt_setup_initrd_arch(unsigned long start,
+                unsigned long end)
+{
+        initrd_start = (void *)__va(start);
+        initrd_end = (void *)__va(end);
+        initrd_below_start_ok = 1;
+}
+
+#endif /* CONFIG_OF */
+
 #endif /* CONFIG_BLK_DEV_INITRD */
 
 static int __init parse_tag_cmdline(const bp_tag_t* tag)
 {
-        strncpy(command_line, (char*)(tag->data), COMMAND_LINE_SIZE);
-        command_line[COMMAND_LINE_SIZE - 1] = '\0';
+        strlcpy(command_line, (char *)(tag->data), COMMAND_LINE_SIZE);
         return 0;
 }
 
@@ -185,6 +222,58 @@ static int __init parse_bootparam(const bp_tag_t* tag)
         return 0;
 }
 
+#ifdef CONFIG_OF
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+        size &= PAGE_MASK;
+        add_sysmem_bank(MEMORY_TYPE_CONVENTIONAL, base, base + size);
+}
+
+void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+        return __alloc_bootmem(size, align, 0);
+}
+
+void __init early_init_devtree(void *params)
+{
+        /* Setup flat device-tree pointer */
+        initial_boot_params = params;
+
+        /* Retrieve various informations from the /chosen node of the
+         * device-tree, including the platform type, initrd location and
+         * size, TCE reserve, and more ...
+         */
+        if (!command_line[0])
+                of_scan_flat_dt(early_init_dt_scan_chosen, command_line);
+
+        /* Scan memory nodes and rebuild MEMBLOCKs */
+        of_scan_flat_dt(early_init_dt_scan_root, NULL);
+        if (sysmem.nr_banks == 0)
+                of_scan_flat_dt(early_init_dt_scan_memory, NULL);
+}
+
+static void __init copy_devtree(void)
+{
+        void *alloc = early_init_dt_alloc_memory_arch(
+                        be32_to_cpu(initial_boot_params->totalsize), 0);
+        if (alloc) {
+                memcpy(alloc, initial_boot_params,
+                                be32_to_cpu(initial_boot_params->totalsize));
+                initial_boot_params = alloc;
+        }
+}
+
+static int __init xtensa_device_probe(void)
+{
+        of_platform_populate(NULL, NULL, NULL, NULL);
+        return 0;
+}
+
+device_initcall(xtensa_device_probe);
+
+#endif /* CONFIG_OF */
+
 /*
  * Initialize architecture. (Early stage)
  */
@@ -193,14 +282,14 @@ void __init init_arch(bp_tag_t *bp_start)
 {
         sysmem.nr_banks = 0;
 
-#ifdef CONFIG_CMDLINE_BOOL
-        strcpy(command_line, default_command_line);
-#endif
-
         /* Parse boot parameters */
 
-        if (bp_start)
-          parse_bootparam(bp_start);
+        if (bp_start)
+                parse_bootparam(bp_start);
+
+#ifdef CONFIG_OF
+        early_init_devtree(dtb_start);
+#endif
 
         if (sysmem.nr_banks == 0) {
                 sysmem.nr_banks = 1;
@@ -209,6 +298,11 @@ void __init init_arch(bp_tag_t *bp_start)
                                      + PLATFORM_DEFAULT_MEM_SIZE;
         }
 
+#ifdef CONFIG_CMDLINE_BOOL
+        if (!command_line[0])
+                strlcpy(command_line, default_command_line, COMMAND_LINE_SIZE);
+#endif
+
         /* Early hook for platforms */
 
         platform_init(bp_start);
@@ -235,15 +329,130 @@ extern char _UserExceptionVector_text_end;
 extern char _DoubleExceptionVector_literal_start;
 extern char _DoubleExceptionVector_text_end;
 
-void __init setup_arch(char **cmdline_p)
+
+#ifdef CONFIG_S32C1I_SELFTEST
+#if XCHAL_HAVE_S32C1I
+
+static int __initdata rcw_word, rcw_probe_pc, rcw_exc;
+
+/*
+ * Basic atomic compare-and-swap, that records PC of S32C1I for probing.
+ *
+ * If *v == cmp, set *v = set.  Return previous *v.
+ */
+static inline int probed_compare_swap(int *v, int cmp, int set)
+{
+        int tmp;
+
+        __asm__ __volatile__(
+                        "       movi    %1, 1f\n"
+                        "       s32i    %1, %4, 0\n"
+                        "       wsr     %2, scompare1\n"
+                        "1:     s32c1i  %0, %3, 0\n"
+                        : "=a" (set), "=&a" (tmp)
+                        : "a" (cmp), "a" (v), "a" (&rcw_probe_pc), "0" (set)
+                        : "memory"
+                        );
+        return set;
+}
+
+/* Handle probed exception */
+
+void __init do_probed_exception(struct pt_regs *regs, unsigned long exccause)
+{
+        if (regs->pc == rcw_probe_pc) { /* exception on s32c1i ? */
+                regs->pc += 3;          /* skip the s32c1i instruction */
+                rcw_exc = exccause;
+        } else {
+                do_unhandled(regs, exccause);
+        }
+}
+
+/* Simple test of S32C1I (soc bringup assist) */
+
+void __init check_s32c1i(void)
+{
+        int n, cause1, cause2;
+        void *handbus, *handdata, *handaddr; /* temporarily saved handlers */
+
+        rcw_probe_pc = 0;
+        handbus  = trap_set_handler(EXCCAUSE_LOAD_STORE_ERROR,
+                        do_probed_exception);
+        handdata = trap_set_handler(EXCCAUSE_LOAD_STORE_DATA_ERROR,
+                        do_probed_exception);
+        handaddr = trap_set_handler(EXCCAUSE_LOAD_STORE_ADDR_ERROR,
+                        do_probed_exception);
+
+        /* First try an S32C1I that does not store: */
+        rcw_exc = 0;
+        rcw_word = 1;
+        n = probed_compare_swap(&rcw_word, 0, 2);
+        cause1 = rcw_exc;
+
+        /* took exception? */
+        if (cause1 != 0) {
+                /* unclean exception? */
+                if (n != 2 || rcw_word != 1)
+                        panic("S32C1I exception error");
+        } else if (rcw_word != 1 || n != 1) {
+                panic("S32C1I compare error");
+        }
+
+        /* Then an S32C1I that stores: */
+        rcw_exc = 0;
+        rcw_word = 0x1234567;
+        n = probed_compare_swap(&rcw_word, 0x1234567, 0xabcde);
+        cause2 = rcw_exc;
+
+        if (cause2 != 0) {
+                /* unclean exception? */
+                if (n != 0xabcde || rcw_word != 0x1234567)
+                        panic("S32C1I exception error (b)");
+        } else if (rcw_word != 0xabcde || n != 0x1234567) {
+                panic("S32C1I store error");
+        }
+
+        /* Verify consistency of exceptions: */
+        if (cause1 || cause2) {
+                pr_warn("S32C1I took exception %d, %d\n", cause1, cause2);
+                /* If emulation of S32C1I upon bus error gets implemented,
+                   we can get rid of this panic for single core (not SMP) */
+                panic("S32C1I exceptions not currently supported");
+        }
+        if (cause1 != cause2)
+                panic("inconsistent S32C1I exceptions");
+
+        trap_set_handler(EXCCAUSE_LOAD_STORE_ERROR, handbus);
+        trap_set_handler(EXCCAUSE_LOAD_STORE_DATA_ERROR, handdata);
+        trap_set_handler(EXCCAUSE_LOAD_STORE_ADDR_ERROR, handaddr);
+}
+
+#else /* XCHAL_HAVE_S32C1I */
+
+/* This condition should not occur with a commercially deployed processor.
+   Display reminder for early engr test or demo chips / FPGA bitstreams */
+void __init check_s32c1i(void)
+{
+        pr_warn("Processor configuration lacks atomic compare-and-swap support!\n");
+}
+
+#endif /* XCHAL_HAVE_S32C1I */
+#else /* CONFIG_S32C1I_SELFTEST */
+
+void __init check_s32c1i(void)
 {
-        extern int mem_reserve(unsigned long, unsigned long, int);
-        extern void bootmem_init(void);
+}
+
+#endif /* CONFIG_S32C1I_SELFTEST */
 
-        memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
-        boot_command_line[COMMAND_LINE_SIZE-1] = '\0';
+
+void __init setup_arch(char **cmdline_p)
+{
+        strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
         *cmdline_p = command_line;
 
+        check_s32c1i();
+
         /* Reserve some memory regions */
 
 #ifdef CONFIG_BLK_DEV_INITRD
@@ -251,7 +460,7 @@ void __init setup_arch(char **cmdline_p)
                 initrd_is_mapped = mem_reserve(__pa(initrd_start),
                                                __pa(initrd_end), 0);
                 initrd_below_start_ok = 1;
-        } else {
+        } else {
                 initrd_start = 0;
         }
 #endif
@@ -275,8 +484,12 @@ void __init setup_arch(char **cmdline_p)
 
         bootmem_init();
 
-        platform_setup(cmdline_p);
+#ifdef CONFIG_OF
+        copy_devtree();
+        unflatten_device_tree();
+#endif
 
+        platform_setup(cmdline_p);
 
         paging_init();
         zones_init();
@@ -326,7 +539,7 @@ c_show(struct seq_file *f, void *slot)
                      "core ID\t\t: " XCHAL_CORE_ID "\n"
                      "build ID\t: 0x%x\n"
                      "byte order\t: %s\n"
-                     "cpu MHz\t\t: %lu.%02lu\n"
+                     "cpu MHz\t\t: %lu.%02lu\n"
                      "bogomips\t: %lu.%02lu\n",
                      XCHAL_BUILD_UNIQUE_ID,
                      XCHAL_HAVE_BE ?  "big" : "little",
@@ -381,6 +594,9 @@ c_show(struct seq_file *f, void *slot)
 #if XCHAL_HAVE_FP
                      "fpu "
 #endif
+#if XCHAL_HAVE_S32C1I
+                     "s32c1i "
+#endif
                      "\n");
 
         /* Registers. */
@@ -412,7 +628,7 @@ c_show(struct seq_file *f, void *slot)
                      "icache size\t: %d\n"
                      "icache flags\t: "
 #if XCHAL_ICACHE_LINE_LOCKABLE
-                     "lock"
+                     "lock "
 #endif
                      "\n"
                      "dcache line size: %d\n"
@@ -420,10 +636,10 @@ c_show(struct seq_file *f, void *slot)
                      "dcache size\t: %d\n"
                      "dcache flags\t: "
 #if XCHAL_DCACHE_IS_WRITEBACK
-                     "writeback"
+                     "writeback "
 #endif
 #if XCHAL_DCACHE_LINE_LOCKABLE
-                     "lock"
+                     "lock "
 #endif
                      "\n",
                      XCHAL_ICACHE_LINESIZE,
@@ -465,4 +681,3 @@ const struct seq_operations cpuinfo_op =
 };
 
 #endif /* CONFIG_PROC_FS */
-