MIPS: Netlogic: Update comments in smpboot.S

No change in logic, comments update and whitespace cleanup.

* A few comments in the file were in assembler style and the rest
  int C style, convert all of them to C style.
* Mark workarounds for Ax silicon with a macro XLP_AX_WORKAROUND
* Whitespace fixes - use tabs consistently
* rename __config_lsu macro to xlp_config_lsu

Signed-off-by: Jayachandran C <jayachandranc@netlogicmicro.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3749/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 58 insertions, 48 deletions

diff --git a/arch/mips/netlogic/common/smpboot.S b/arch/mips/netlogic/common/smpboot.S
index c138b1a6dec3..c4872a714cfe 100644
--- a/arch/mips/netlogic/common/smpboot.S
+++ b/arch/mips/netlogic/common/smpboot.S
@@ -54,28 +54,36 @@
                         XLP_IO_SYS_OFFSET(node) + XLP_IO_PCI_HDRSZ + \
                         SYS_CPU_NONCOHERENT_MODE * 4
 
-.macro __config_lsu
-        li      t0, LSU_DEFEATURE
-        mfcr    t1, t0
+#define XLP_AX_WORKAROUND       /* enable Ax silicon workarounds */
 
-        lui     t2, 0x4080  /* Enable Unaligned Access, L2HPE */
-        or      t1, t1, t2
-        li      t2, ~0xe    /* S1RCM */
+/* Enable XLP features and workarounds in the LSU */
+.macro xlp_config_lsu
+        li      t0, LSU_DEFEATURE
+        mfcr    t1, t0
+
+        lui     t2, 0x4080      /* Enable Unaligned Access, L2HPE */
+        or      t1, t1, t2
+#ifdef XLP_AX_WORKAROUND
+        li      t2, ~0xe        /* S1RCM */
         and     t1, t1, t2
+#endif
         mtcr    t1, t0
 
-        li      t0, SCHED_DEFEATURE
-        lui     t1, 0x0100  /* Experimental: Disable BRU accepting ALU ops */
-        mtcr    t1, t0
+#ifdef XLP_AX_WORKAROUND
+        li      t0, SCHED_DEFEATURE
+        lui     t1, 0x0100      /* Disable BRU accepting ALU ops */
+        mtcr    t1, t0
+#endif
 .endm
 
 /*
- * The cores can come start when they are woken up. This is also the NMI
- * entry, so check that first.
+ * This is the code that will be copied to the reset entry point for
+ * XLR and XLP. The XLP cores start here when they are woken up. This
+ * is also the NMI entry point.
  *
- * The data corresponding to reset is stored at RESET_DATA_PHYS location,
- * this will have the thread mask (used when core is woken up) and the
- * current NMI handler in case we reached here for an NMI.
+ * The data corresponding to reset/NMI is stored at RESET_DATA_PHYS
+ * location, this will have the thread mask (used when core is woken up)
+ * and the current NMI handler in case we reached here for an NMI.
  *
  * When a core or thread is newly woken up, it loops in a 'wait'. When
  * the CPU really needs waking up, we send an NMI to it, with the NMI
@@ -89,12 +97,12 @@
 FEXPORT(nlm_reset_entry)
         dmtc0   k0, $22, 6
         dmtc0   k1, $22, 7
-        mfc0    k0, CP0_STATUS
-        li      k1, 0x80000
-        and     k1, k0, k1
-        beqz    k1, 1f         /* go to real reset entry */
+        mfc0    k0, CP0_STATUS
+        li      k1, 0x80000
+        and     k1, k0, k1
+        beqz    k1, 1f          /* go to real reset entry */
         nop
-        li      k1, CKSEG1ADDR(RESET_DATA_PHYS)   /* NMI */
+        li      k1, CKSEG1ADDR(RESET_DATA_PHYS) /* NMI */
         ld      k0, BOOT_NMI_HANDLER(k1)
         jr      k0
         nop
@@ -114,21 +122,23 @@ FEXPORT(nlm_reset_entry)
         li      t2, SYS_CPU_COHERENT_BASE(0)
         add     t2, t2, t3              /* t2 <- SYS offset for node */
         lw      t1, 0(t2)
-        and     t1, t1, t0
-        sw      t1, 0(t2)
+        and     t1, t1, t0
+        sw      t1, 0(t2)
 
         /* read back to ensure complete */
-        lw      t1, 0(t2)
+        lw      t1, 0(t2)
         sync
 
         /* Configure LSU on Non-0 Cores. */
-        __config_lsu
+        xlp_config_lsu
+        /* FALL THROUGH */
 
 /*
  * Wake up sibling threads from the initial thread in
  * a core.
  */
 EXPORT(nlm_boot_siblings)
+        /* Enable hw threads by writing to MAP_THREADMODE of the core */
         li      t0, CKSEG1ADDR(RESET_DATA_PHYS)
         lw      t1, BOOT_THREAD_MODE(t0)        /* t1 <- thread mode */
         li      t0, ((CPU_BLOCKID_MAP << 8) | MAP_THREADMODE)
@@ -139,13 +149,14 @@ EXPORT(nlm_boot_siblings)
         /*
          * The new hardware thread starts at the next instruction
          * For all the cases other than core 0 thread 0, we will
-         * jump to the secondary wait function.
-         */
+        * jump to the secondary wait function.
+        */
         mfc0    v0, CP0_EBASE, 1
         andi    v0, 0x7f                /* v0 <- node/core */
 
-#if 1
-        /* A0 errata - Write MMU_SETUP after changing thread mode register. */
+        /* Init MMU in the first thread after changing THREAD_MODE
+         * register (Ax Errata?)
+         */
         andi    v1, v0, 0x3             /* v1 <- thread id */
         bnez    v1, 2f
         nop
@@ -154,9 +165,8 @@ EXPORT(nlm_boot_siblings)
         li      t1, 0
         mtcr    t1, t0
         ehb
-#endif
 
-2:      beqz    v0, 4f
+2:      beqz    v0, 4f          /* boot cpu (cpuid == 0)? */
         nop
 
         /* setup status reg */
@@ -183,9 +193,9 @@ EXPORT(nlm_boot_siblings)
          * For the boot CPU, we have to restore registers and
          * return
          */
-4:      dmfc0   t0, $4, 2       /* restore SP from UserLocal */
+4:      dmfc0   t0, $4, 2       /* restore SP from UserLocal */
         li      t1, 0xfadebeef
-        dmtc0   t1, $4, 2       /* restore SP from UserLocal */
+        dmtc0   t1, $4, 2       /* restore SP from UserLocal */
         PTR_SUBU sp, t0, PT_SIZE
         RESTORE_ALL
         jr   ra
@@ -193,7 +203,7 @@ EXPORT(nlm_boot_siblings)
 EXPORT(nlm_reset_entry_end)
 
 FEXPORT(xlp_boot_core0_siblings)        /* "Master" cpu starts from here */
-        __config_lsu
+        xlp_config_lsu
         dmtc0   sp, $4, 2               /* SP saved in UserLocal */
         SAVE_ALL
         sync
@@ -234,36 +244,36 @@ END(nlm_boot_secondary_cpus)
  */
         __CPUINIT
 NESTED(nlm_rmiboot_preboot, 16, sp)
-        mfc0    t0, $15, 1      # read ebase
-        andi    t0, 0x1f        # t0 has the processor_id()
-        andi    t2, t0, 0x3     # thread no
-        sll     t0, 2           # offset in cpu array
+        mfc0    t0, $15, 1      /* read ebase */
+        andi    t0, 0x1f        /* t0 has the processor_id() */
+        andi    t2, t0, 0x3     /* thread num */
+        sll     t0, 2           /* offset in cpu array */
 
-        PTR_LA  t1, nlm_cpu_ready # mark CPU ready
+        PTR_LA  t1, nlm_cpu_ready /* mark CPU ready */
         PTR_ADDU t1, t0
         li      t3, 1
         sw      t3, 0(t1)
 
-        bnez    t2, 1f          # skip thread programming
-        nop                     # for non zero hw threads
+        bnez    t2, 1f          /* skip thread programming */
+        nop                     /* for thread id != 0 */
 
         /*
-         * MMU setup only for first thread in core
+         * XLR MMU setup only for first thread in core
          */
         li      t0, 0x400
         mfcr    t1, t0
-        li      t2, 6           # XLR thread mode mask
+        li      t2, 6           /* XLR thread mode mask */
         nor     t3, t2, zero
-        and     t2, t1, t2      # t2 - current thread mode
+        and     t2, t1, t2      /* t2 - current thread mode */
         li      v0, CKSEG1ADDR(RESET_DATA_PHYS)
-        lw      v1, BOOT_THREAD_MODE(v0) # v1 - new thread mode
+        lw      v1, BOOT_THREAD_MODE(v0) /* v1 - new thread mode */
         sll     v1, 1
-        beq     v1, t2, 1f      # same as request value
-        nop                     # nothing to do */
+        beq     v1, t2, 1f      /* same as request value */
+        nop                     /* nothing to do */
 
-        and     t2, t1, t3      # mask out old thread mode
-        or      t1, t2, v1      # put in new value
-        mtcr    t1, t0          # update core control
+        and     t2, t1, t3      /* mask out old thread mode */
+        or      t1, t2, v1      /* put in new value */
+        mtcr    t1, t0          /* update core control */
 
 1:      wait
         j       1b