commit 1b19b269007dd742d891ffdfab8c85b86bd4a681
author Bryan Brattlof <bb@ti.com> Mon Apr 14 15:20:02 2025 -0500
committer Tom Rini <trini@konsulko.com> Thu Apr 24 10:45:37 2025 -0600
tree 5e46d8c01f119cfd9aebaf7675cce8158c761215
parent 5c323182a9e0c32b40ebfcc8519a28482f1b4bbb

arm: mach-k3: support disabling a single firewall region

During boot some firewall regions could contain the R5's code which if
we change the firewalls settings will crash the core. To get around this
issue, define a new function which allows us to specify specific regions
we want unlocked.

Signed-off-by: Bryan Brattlof <bb@ti.com>

arch/arm/mach-k3/common.h

diff --git a/arch/arm/mach-k3/common.h b/arch/arm/mach-k3/common.h
index 7bd72da..2ec60c7 100644
--- a/arch/arm/mach-k3/common.h
+++ b/arch/arm/mach-k3/common.h
@@ -35,6 +35,7 @@
 void setup_k3_mpu_regions(void);
 int early_console_init(void);
 void disable_linefill_optimization(void);
+int remove_fwl_region(struct fwl_data *fwl);
 void remove_fwl_configs(struct fwl_data *fwl_data, size_t fwl_data_size);
 int load_firmware(char *name_fw, char *name_loadaddr, u32 *loadaddr);
 void k3_sysfw_print_ver(void);

arch/arm/mach-k3/r5/common.c

diff --git a/arch/arm/mach-k3/r5/common.c b/arch/arm/mach-k3/r5/common.c
index 0f6c294..0d97e7f 100644
--- a/arch/arm/mach-k3/r5/common.c
+++ b/arch/arm/mach-k3/r5/common.c
@@ -253,6 +253,31 @@
 	asm("mcr p15, 0, %0, c1, c0, 1" : : "r" (actlr));
 }
 
+int remove_fwl_region(struct fwl_data *fwl)
+{
+	struct ti_sci_handle *sci = get_ti_sci_handle();
+	struct ti_sci_fwl_ops *ops = &sci->ops.fwl_ops;
+	struct ti_sci_msg_fwl_region region;
+	int ret;
+
+	region.fwl_id = fwl->fwl_id;
+	region.region = fwl->regions;
+	region.n_permission_regs = 3;
+
+	ops->get_fwl_region(sci, &region);
+
+	/* zero out the enable field of the firewall */
+	region.control = region.control & ~0xF;
+
+	pr_debug("Disabling firewall id: %d region: %d\n",
+		 region.fwl_id, region.region);
+
+	ret = ops->set_fwl_region(sci, &region);
+	if (ret)
+		pr_err("Could not disable firewall\n");
+	return ret;
+}
+
 static void remove_fwl_regions(struct fwl_data fwl_data, size_t num_regions,
 			       enum k3_firewall_region_type fwl_type)
 {