MIPS: BMIPS: Add early CPU initialization code

Port the stblinux-3.3 code to perform a bunch of CPU-specific initialization,
make it compatible with run-time detection of the CPU, and unroll the
brcmstb-specific macros: BDEV_RB(), BDEV_UNSET.

The "pref 30" disabling is done as a quirk. This is a preliminary change to
allow the use of the "rotr" instruction gated by cpu_has_rixi.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: john@phrozen.org
Cc: cernekee@gmail.com
Cc: jon.fraser@broadcom.com
Cc: pgynther@google.com
Cc: paul.burton@imgtec.com
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12504/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 89 insertions, 0 deletions

diff --git a/arch/mips/bmips/setup.c b/arch/mips/bmips/setup.c
index 35535284b39e..b764995343c1 100644
--- a/arch/mips/bmips/setup.c
+++ b/arch/mips/bmips/setup.c
@@ -111,6 +111,7 @@ static const struct bmips_quirk bmips_quirk_list[] = {
 
 void __init prom_init(void)
 {
+        bmips_cpu_setup();
         register_bmips_smp_ops();
 }
 
diff --git a/arch/mips/include/asm/bmips.h b/arch/mips/include/asm/bmips.h
index 6d25ad33ec78..a92aee7b977a 100644
--- a/arch/mips/include/asm/bmips.h
+++ b/arch/mips/include/asm/bmips.h
@@ -88,6 +88,7 @@ extern unsigned long bmips_tp1_irqs;
 
 extern void bmips_ebase_setup(void);
 extern asmlinkage void plat_wired_tlb_setup(void);
+extern void bmips_cpu_setup(void);
 
 static inline unsigned long bmips_read_zscm_reg(unsigned int offset)
 {
diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index 6d11788b4502..e02addc0307f 100644
--- a/arch/mips/kernel/smp-bmips.c
+++ b/arch/mips/kernel/smp-bmips.c
@@ -566,3 +566,90 @@ asmlinkage void __weak plat_wired_tlb_setup(void)
          * once the wired entries are present.
          */
 }
+
+void __init bmips_cpu_setup(void)
+{
+        void __iomem __maybe_unused *cbr = BMIPS_GET_CBR();
+        u32 __maybe_unused cfg;
+
+        switch (current_cpu_type()) {
+        case CPU_BMIPS3300:
+                /* Set BIU to async mode */
+                set_c0_brcm_bus_pll(BIT(22));
+                __sync();
+
+                /* put the BIU back in sync mode */
+                clear_c0_brcm_bus_pll(BIT(22));
+
+                /* clear BHTD to enable branch history table */
+                clear_c0_brcm_reset(BIT(16));
+
+                /* Flush and enable RAC */
+                cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG);
+                __raw_writel(cfg | 0x100, BMIPS_RAC_CONFIG);
+                __raw_readl(cbr + BMIPS_RAC_CONFIG);
+
+                cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG);
+                __raw_writel(cfg | 0xf, BMIPS_RAC_CONFIG);
+                __raw_readl(cbr + BMIPS_RAC_CONFIG);
+
+                cfg = __raw_readl(cbr + BMIPS_RAC_ADDRESS_RANGE);
+                __raw_writel(cfg | 0x0fff0000, cbr + BMIPS_RAC_ADDRESS_RANGE);
+                __raw_readl(cbr + BMIPS_RAC_ADDRESS_RANGE);
+                break;
+
+        case CPU_BMIPS4380:
+                /* CBG workaround for early BMIPS4380 CPUs */
+                switch (read_c0_prid()) {
+                case 0x2a040:
+                case 0x2a042:
+                case 0x2a044:
+                case 0x2a060:
+                        cfg = __raw_readl(cbr + BMIPS_L2_CONFIG);
+                        __raw_writel(cfg & ~0x07000000, cbr + BMIPS_L2_CONFIG);
+                        __raw_readl(cbr + BMIPS_L2_CONFIG);
+                }
+
+                /* clear BHTD to enable branch history table */
+                clear_c0_brcm_config_0(BIT(21));
+
+                /* XI/ROTR enable */
+                set_c0_brcm_config_0(BIT(23));
+                set_c0_brcm_cmt_ctrl(BIT(15));
+                break;
+
+        case CPU_BMIPS5000:
+                /* enable RDHWR, BRDHWR */
+                set_c0_brcm_config(BIT(17) | BIT(21));
+
+                /* Disable JTB */
+                __asm__ __volatile__(
+                "       .set    noreorder\n"
+                "       li      $8, 0x5a455048\n"
+                "       .word   0x4088b00f\n"   /* mtc0 t0, $22, 15 */
+                "       .word   0x4008b008\n"   /* mfc0 t0, $22, 8 */
+                "       li      $9, 0x00008000\n"
+                "       or      $8, $8, $9\n"
+                "       .word   0x4088b008\n"   /* mtc0 t0, $22, 8 */
+                "       sync\n"
+                "       li      $8, 0x0\n"
+                "       .word   0x4088b00f\n"   /* mtc0 t0, $22, 15 */
+                "       .set    reorder\n"
+                : : : "$8", "$9");
+
+                /* XI enable */
+                set_c0_brcm_config(BIT(27));
+
+                /* enable MIPS32R2 ROR instruction for XI TLB handlers */
+                __asm__ __volatile__(
+                "       li      $8, 0x5a455048\n"
+                "       .word   0x4088b00f\n"   /* mtc0 $8, $22, 15 */
+                "       nop; nop; nop\n"
+                "       .word   0x4008b008\n"   /* mfc0 $8, $22, 8 */
+                "       lui     $9, 0x0100\n"
+                "       or      $8, $9\n"
+                "       .word   0x4088b008\n"   /* mtc0 $8, $22, 8 */
+                : : : "$8", "$9");
+                break;
+        }
+}