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authorGuo Ren <guoren@linux.alibaba.com>2019-11-27 08:44:33 +0800
committerGuo Ren <guoren@linux.alibaba.com>2020-02-21 15:43:24 +0800
commitf525bb2c9e7cf1e3c43ab57704c9e1c836d30b34 (patch)
tree6caa93dc823ca08b3f43bae3e22d70f1c92ebff9 /arch/csky/include/asm/memory.h
parent2f78c73f78c39dabc5c44ad8dd61fd6ec65636d6 (diff)
downloadlinux-sh-f525bb2c9e7cf1e3c43ab57704c9e1c836d30b34.tar.gz
csky: Tightly-Coupled Memory or Sram support
The implementation are not only used by TCM but also used by sram on SOC bus. It follow existed linux tcm software interface, so that old tcm application codes could be re-used directly. Software interface list in asm/tcm.h: - Variables/Const: __tcmdata, __tcmconst - Functions: __tcmfunc, __tcmlocalfunc - Malloc/Free: tcm_alloc, tcm_free In linux menuconfig: - Choose a TCM contain instrctions + data or separated in ITCM/DTCM. - Determine TCM_BASE (DTCM_BASE) in phyiscal address. - Determine size of TCM or ITCM(DTCM) in page counts. Here is hello tcm example from Documentation/arm/tcm.rst which could be directly used: /* Uninitialized data */ static u32 __tcmdata tcmvar; /* Initialized data */ static u32 __tcmdata tcmassigned = 0x2BADBABEU; /* Constant */ static const u32 __tcmconst tcmconst = 0xCAFEBABEU; static void __tcmlocalfunc tcm_to_tcm(void) { int i; for (i = 0; i < 100; i++) tcmvar ++; } static void __tcmfunc hello_tcm(void) { /* Some abstract code that runs in ITCM */ int i; for (i = 0; i < 100; i++) { tcmvar ++; } tcm_to_tcm(); } static void __init test_tcm(void) { u32 *tcmem; int i; hello_tcm(); printk("Hello TCM executed from ITCM RAM\n"); printk("TCM variable from testrun: %u @ %p\n", tcmvar, &tcmvar); tcmvar = 0xDEADBEEFU; printk("TCM variable: 0x%x @ %p\n", tcmvar, &tcmvar); printk("TCM assigned variable: 0x%x @ %p\n", tcmassigned, &tcmassigned); printk("TCM constant: 0x%x @ %p\n", tcmconst, &tcmconst); /* Allocate some TCM memory from the pool */ tcmem = tcm_alloc(20); if (tcmem) { printk("TCM Allocated 20 bytes of TCM @ %p\n", tcmem); tcmem[0] = 0xDEADBEEFU; tcmem[1] = 0x2BADBABEU; tcmem[2] = 0xCAFEBABEU; tcmem[3] = 0xDEADBEEFU; tcmem[4] = 0x2BADBABEU; for (i = 0; i < 5; i++) printk("TCM tcmem[%d] = %08x\n", i, tcmem[i]); tcm_free(tcmem, 20); } } TODO: - Separate fixup mapping from highmem - Support abiv1 Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Diffstat (limited to 'arch/csky/include/asm/memory.h')
-rw-r--r--arch/csky/include/asm/memory.h22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/csky/include/asm/memory.h b/arch/csky/include/asm/memory.h
new file mode 100644
index 000000000000..cdffbd0a500b
--- /dev/null
+++ b/arch/csky/include/asm/memory.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_MEMORY_H
+#define __ASM_CSKY_MEMORY_H
+
+#include <linux/compiler.h>
+#include <linux/const.h>
+#include <linux/types.h>
+#include <linux/sizes.h>
+
+#define FIXADDR_TOP _AC(0xffffc000, UL)
+
+#ifdef CONFIG_HAVE_TCM
+#ifdef CONFIG_HAVE_DTCM
+#define TCM_NR_PAGES (CONFIG_ITCM_NR_PAGES + CONFIG_DTCM_NR_PAGES)
+#else
+#define TCM_NR_PAGES (CONFIG_ITCM_NR_PAGES)
+#endif
+#define FIXADDR_TCM _AC(FIXADDR_TOP - (TCM_NR_PAGES * PAGE_SIZE), UL)
+#endif
+
+#endif