Merge tag 'lkmm.2023.04.07a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck...

[linux-block.git] / arch / loongarch / kernel / setup.c

diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
index bae84ccf6d3671c29e1849ec1542693d1ef5a06f..4444b13418f0e0621d56d339ba4302c4d0ec2f29 100644 (file)
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -160,6 +160,27 @@ static void __init smbios_parse(void)
        dmi_walk(find_tokens, NULL);
 }
 
+#ifdef CONFIG_ARCH_WRITECOMBINE
+pgprot_t pgprot_wc = PAGE_KERNEL_WUC;
+#else
+pgprot_t pgprot_wc = PAGE_KERNEL_SUC;
+#endif
+
+EXPORT_SYMBOL(pgprot_wc);
+
+static int __init setup_writecombine(char *p)
+{
+       if (!strcmp(p, "on"))
+               pgprot_wc = PAGE_KERNEL_WUC;
+       else if (!strcmp(p, "off"))
+               pgprot_wc = PAGE_KERNEL_SUC;
+       else
+               pr_warn("Unknown writecombine setting \"%s\".\n", p);
+
+       return 0;
+}
+early_param("writecombine", setup_writecombine);
+
 static int usermem __initdata;
 
 static int __init early_parse_mem(char *p)
@@ -368,8 +389,8 @@ static void __init arch_mem_init(char **cmdline_p)
        /*
         * In order to reduce the possibility of kernel panic when failed to
         * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate
-        * low memory as small as possible before plat_swiotlb_setup(), so
-        * make sparse_init() using top-down allocation.
+        * low memory as small as possible before swiotlb_init(), so make
+        * sparse_init() using top-down allocation.
         */
        memblock_set_bottom_up(false);
        sparse_init();