[PATCH 2/5] ARM: shmobile: rcar-gen2: Obtain jump stub region from DT

[Simon Horman]

From: Geert Uytterhoeven <geert+rene...@glider.be>

Add support for obtaining from DT the SRAM region to store the jump stub
for CPU core bringup, according to the renesas,smp-sram DT bindings.

If no region is specified in DT, the code falls back to hardcoded ICRAM1
as before, to maintain backwards compatibility.

Signed-off-by: Geert Uytterhoeven <geert+rene...@glider.be>
Signed-off-by: Simon Horman <horms+rene...@verge.net.au>
---
 arch/arm/mach-shmobile/pm-rcar-gen2.c | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-shmobile/pm-rcar-gen2.c 
b/arch/arm/mach-shmobile/pm-rcar-gen2.c
index 0178da7ace82..e5f215c8b218 100644
--- a/arch/arm/mach-shmobile/pm-rcar-gen2.c
+++ b/arch/arm/mach-shmobile/pm-rcar-gen2.c
@@ -11,7 +11,9 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/ioport.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/smp.h>
 #include <linux/soc/renesas/rcar-sysc.h>
 #include <asm/io.h>
@@ -69,8 +71,9 @@ void __init rcar_gen2_pm_init(void)
        struct device_node *np, *cpus;
        bool has_a7 = false;
        bool has_a15 = false;
-       phys_addr_t boot_vector_addr = ICRAM1;
+       struct resource res;
        u32 syscier = 0;
+       int error;
 
        if (once++)
                return;
@@ -91,14 +94,38 @@ void __init rcar_gen2_pm_init(void)
        else if (of_machine_is_compatible("renesas,r8a7791"))
                syscier = 0x00111003;
 
+       np = of_find_compatible_node(NULL, NULL, "renesas,smp-sram");
+       if (!np) {
+               /* No smp-sram in DT, fall back to hardcoded address */
+               res = (struct resource)DEFINE_RES_MEM(ICRAM1,
+                                                     shmobile_boot_size);
+               goto map;
+       }
+
+       error = of_address_to_resource(np, 0, &res);
+       if (error) {
+               pr_err("Failed to get smp-sram address: %d\n", error);
+               return;
+       }
+
+map:
        /* RAM for jump stub, because BAR requires 256KB aligned address */
-       p = ioremap_nocache(boot_vector_addr, shmobile_boot_size);
+       if (res.start & (256 * 1024 - 1) ||
+           resource_size(&res) < shmobile_boot_size) {
+               pr_err("Invalid smp-sram region\n");
+               return;
+       }
+
+       p = ioremap(res.start, resource_size(&res));
+       if (!p)
+               return;
+
        memcpy_toio(p, shmobile_boot_vector, shmobile_boot_size);
        iounmap(p);
 
        /* setup reset vectors */
        p = ioremap_nocache(RST, 0x63);
-       bar = phys_to_sbar(boot_vector_addr);
+       bar = phys_to_sbar(res.start);
        if (has_a15) {
                writel_relaxed(bar, p + CA15BAR);
                writel_relaxed(bar | SBAR_BAREN, p + CA15BAR);
-- 
2.1.4