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-rw-r--r--arch/arm/mach-bcm/bcm_kona_smc.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/arch/arm/mach-bcm/bcm_kona_smc.c b/arch/arm/mach-bcm/bcm_kona_smc.c
new file mode 100644
index 000000000..185335843
--- /dev/null
+++ b/arch/arm/mach-bcm/bcm_kona_smc.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2013 Broadcom Corporation
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+
+#include <asm/cacheflush.h>
+#include <linux/of_address.h>
+
+#include "bcm_kona_smc.h"
+
+static u32 bcm_smc_buffer_phys; /* physical address */
+static void __iomem *bcm_smc_buffer; /* virtual address */
+
+struct bcm_kona_smc_data {
+ unsigned service_id;
+ unsigned arg0;
+ unsigned arg1;
+ unsigned arg2;
+ unsigned arg3;
+ unsigned result;
+};
+
+static const struct of_device_id bcm_kona_smc_ids[] __initconst = {
+ {.compatible = "brcm,kona-smc"},
+ {.compatible = "bcm,kona-smc"}, /* deprecated name */
+ {},
+};
+
+/* Map in the args buffer area */
+int __init bcm_kona_smc_init(void)
+{
+ struct device_node *node;
+ const __be32 *prop_val;
+ u64 prop_size = 0;
+ unsigned long buffer_size;
+ u32 buffer_phys;
+
+ /* Read buffer addr and size from the device tree node */
+ node = of_find_matching_node(NULL, bcm_kona_smc_ids);
+ if (!node)
+ return -ENODEV;
+
+ prop_val = of_get_address(node, 0, &prop_size, NULL);
+ of_node_put(node);
+ if (!prop_val)
+ return -EINVAL;
+
+ /* We assume space for four 32-bit arguments */
+ if (prop_size < 4 * sizeof(u32) || prop_size > (u64)ULONG_MAX)
+ return -EINVAL;
+ buffer_size = (unsigned long)prop_size;
+
+ buffer_phys = be32_to_cpup(prop_val);
+ if (!buffer_phys)
+ return -EINVAL;
+
+ bcm_smc_buffer = ioremap(buffer_phys, buffer_size);
+ if (!bcm_smc_buffer)
+ return -ENOMEM;
+ bcm_smc_buffer_phys = buffer_phys;
+
+ pr_info("Kona Secure API initialized\n");
+
+ return 0;
+}
+
+/*
+ * int bcm_kona_do_smc(u32 service_id, u32 buffer_addr)
+ *
+ * Only core 0 can run the secure monitor code. If an "smc" request
+ * is initiated on a different core it must be redirected to core 0
+ * for execution. We rely on the caller to handle this.
+ *
+ * Each "smc" request supplies a service id and the address of a
+ * buffer containing parameters related to the service to be
+ * performed. A flags value defines the behavior of the level 2
+ * cache and interrupt handling while the secure monitor executes.
+ *
+ * Parameters to the "smc" request are passed in r4-r6 as follows:
+ * r4 service id
+ * r5 flags (SEC_ROM_*)
+ * r6 physical address of buffer with other parameters
+ *
+ * Execution of an "smc" request produces two distinct results.
+ *
+ * First, the secure monitor call itself (regardless of the specific
+ * service request) can succeed, or can produce an error. When an
+ * "smc" request completes this value is found in r12; it should
+ * always be SEC_EXIT_NORMAL.
+ *
+ * In addition, the particular service performed produces a result.
+ * The values that should be expected depend on the service. We
+ * therefore return this value to the caller, so it can handle the
+ * request result appropriately. This result value is found in r0
+ * when the "smc" request completes.
+ */
+static int bcm_kona_do_smc(u32 service_id, u32 buffer_phys)
+{
+ register u32 ip asm("ip"); /* Also called r12 */
+ register u32 r0 asm("r0");
+ register u32 r4 asm("r4");
+ register u32 r5 asm("r5");
+ register u32 r6 asm("r6");
+
+ r4 = service_id;
+ r5 = 0x3; /* Keep IRQ and FIQ off in SM */
+ r6 = buffer_phys;
+
+ asm volatile (
+ /* Make sure we got the registers we want */
+ __asmeq("%0", "ip")
+ __asmeq("%1", "r0")
+ __asmeq("%2", "r4")
+ __asmeq("%3", "r5")
+ __asmeq("%4", "r6")
+ ".arch_extension sec\n"
+ " smc #0\n"
+ : "=r" (ip), "=r" (r0)
+ : "r" (r4), "r" (r5), "r" (r6)
+ : "r1", "r2", "r3", "r7", "lr");
+
+ BUG_ON(ip != SEC_EXIT_NORMAL);
+
+ return r0;
+}
+
+/* __bcm_kona_smc() should only run on CPU 0, with pre-emption disabled */
+static void __bcm_kona_smc(void *info)
+{
+ struct bcm_kona_smc_data *data = info;
+ u32 __iomem *args = bcm_smc_buffer;
+
+ BUG_ON(smp_processor_id() != 0);
+ BUG_ON(!args);
+
+ /* Copy the four 32 bit argument values into the bounce area */
+ writel_relaxed(data->arg0, args++);
+ writel_relaxed(data->arg1, args++);
+ writel_relaxed(data->arg2, args++);
+ writel(data->arg3, args);
+
+ /* Flush caches for input data passed to Secure Monitor */
+ flush_cache_all();
+
+ /* Trap into Secure Monitor and record the request result */
+ data->result = bcm_kona_do_smc(data->service_id, bcm_smc_buffer_phys);
+}
+
+unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1,
+ unsigned arg2, unsigned arg3)
+{
+ struct bcm_kona_smc_data data;
+
+ data.service_id = service_id;
+ data.arg0 = arg0;
+ data.arg1 = arg1;
+ data.arg2 = arg2;
+ data.arg3 = arg3;
+ data.result = 0;
+
+ /*
+ * Due to a limitation of the secure monitor, we must use the SMP
+ * infrastructure to forward all secure monitor calls to Core 0.
+ */
+ smp_call_function_single(0, __bcm_kona_smc, &data, 1);
+
+ return data.result;
+}