mainlining shenanigans
f525bb2c9e
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>
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
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| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.