virt-dt: Allow reservation of secure region when in a RAM carveout

In this case the secure code lives in RAM, and hence the memory node in
the device tree needs to be adjusted. This avoids that the OS will map
and possibly access the reservation.

Add support for setting CONFIG_ARMV7_SECURE_RESERVE_SIZE to carve out
such a region. We only support cutting off memory from the beginning or
the end of a RAM bank as we do not want to increase their number (which
would happen if punching a hole) for simplicity reasons

This will be used in a subsequent patch for Jetson-TK1.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>

diff --git a/arch/arm/cpu/armv7/virt-dt.c b/arch/arm/cpu/armv7/virt-dt.c
index caaaaabccd6956c762a51296006769b22e78877a..32c368f1455343ac26c2ec8ac24709ff8b2d4899 100644 (file)
--- a/arch/arm/cpu/armv7/virt-dt.c
+++ b/arch/arm/cpu/armv7/virt-dt.c
@@ -16,6 +16,7 @@
  */
 
 #include <common.h>
+#include <errno.h>
 #include <stdio_dev.h>
 #include <linux/ctype.h>
 #include <linux/types.h>
@@ -88,6 +89,34 @@ static int fdt_psci(void *fdt)
        return 0;
 }
 
+int armv7_apply_memory_carveout(u64 *start, u64 *size)
+{
+#ifdef CONFIG_ARMV7_SECURE_RESERVE_SIZE
+       if (*start + *size < CONFIG_ARMV7_SECURE_BASE ||
+           *start >= (u64)CONFIG_ARMV7_SECURE_BASE +
+                     CONFIG_ARMV7_SECURE_RESERVE_SIZE)
+               return 0;
+
+       /* carveout must be at the beginning or the end of the bank */
+       if (*start == CONFIG_ARMV7_SECURE_BASE ||
+           *start + *size == (u64)CONFIG_ARMV7_SECURE_BASE +
+                             CONFIG_ARMV7_SECURE_RESERVE_SIZE) {
+               if (*size < CONFIG_ARMV7_SECURE_RESERVE_SIZE) {
+                       debug("Secure monitor larger than RAM bank!?\n");
+                       return -EINVAL;
+               }
+               *size -= CONFIG_ARMV7_SECURE_RESERVE_SIZE;
+               if (*start == CONFIG_ARMV7_SECURE_BASE)
+                       *start += CONFIG_ARMV7_SECURE_RESERVE_SIZE;
+               return 0;
+       }
+       debug("Secure monitor not located at beginning or end of RAM bank\n");
+       return -EINVAL;
+#else /* !CONFIG_ARMV7_SECURE_RESERVE_SIZE */
+       return 0;
+#endif
+}
+
 int psci_update_dt(void *fdt)
 {
 #ifdef CONFIG_ARMV7_NONSEC

diff --git a/arch/arm/include/asm/armv7.h b/arch/arm/include/asm/armv7.h
index 33af8851bb76043010c485470a88a54c054840fc..30e7939d8e48fa3fc897b90ee178d0001b2076fe 100644 (file)
--- a/arch/arm/include/asm/armv7.h
+++ b/arch/arm/include/asm/armv7.h
@@ -134,6 +134,7 @@ void v7_outer_cache_inval_range(u32 start, u32 end);
 #ifdef CONFIG_ARMV7_NONSEC
 
 int armv7_init_nonsec(void);
+int armv7_apply_memory_carveout(u64 *start, u64 *size);
 bool armv7_boot_nonsec(void);
 
 /* defined in assembly file */

diff --git a/arch/arm/lib/bootm-fdt.c b/arch/arm/lib/bootm-fdt.c
index 49ba6916398c5a80342160e663f06003bd6524b1..0eb10a86874371936bbfaf6ca2cb74523c32c616 100644 (file)
--- a/arch/arm/lib/bootm-fdt.c
+++ b/arch/arm/lib/bootm-fdt.c
@@ -17,6 +17,7 @@
 
 #include <common.h>
 #include <fdt_support.h>
+#include <asm/armv7.h>
 #include <asm/psci.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -31,6 +32,11 @@ int arch_fixup_fdt(void *blob)
        for (bank = 0; bank < CONFIG_NR_DRAM_BANKS; bank++) {
                start[bank] = bd->bi_dram[bank].start;
                size[bank] = bd->bi_dram[bank].size;
+#ifdef CONFIG_ARMV7_NONSEC
+               ret = armv7_apply_memory_carveout(&start[bank], &size[bank]);
+               if (ret)
+                       return ret;
+#endif
        }
 
        ret = fdt_fixup_memory_banks(blob, start, size, CONFIG_NR_DRAM_BANKS);