ARM: 6225/1: make TCM allocation static and common for all archs (1dbd30e9) · Commits · 戴 / test

Documentation/arm/memory.txt

+7 −1

Original line number	Diff line number	Diff line
		@@ -33,7 +33,13 @@ ffff0000 ffff0fff CPU vector page.

		fffe0000 fffeffff XScale cache flush area. This is used
		in proc-xscale.S to flush the whole data
		cache. Free for other usage on non-XScale.
		cache. (XScale does not have TCM.)

		fffe8000 fffeffff DTCM mapping area for platforms with
		DTCM mounted inside the CPU.

		fffe0000 fffe7fff ITCM mapping area for platforms with
		ITCM mounted inside the CPU.

		fff00000 fffdffff Fixmap mapping region. Addresses provided
		by fix_to_virt() will be located here.

Documentation/arm/tcm.txt

+19 −11

Original line number	Diff line number	Diff line
		@@ -19,8 +19,8 @@ defines a CPUID_TCM register that you can read out from the
		system control coprocessor. Documentation from ARM can be found
		at http://infocenter.arm.com, search for "TCM Status Register"
		to see documents for all CPUs. Reading this register you can
		determine if ITCM (bit 0) and/or DTCM (bit 16) is present in the
		machine.
		determine if ITCM (bits 1-0) and/or DTCM (bit 17-16) is present
		in the machine.

		There is further a TCM region register (search for "TCM Region
		Registers" at the ARM site) that can report and modify the location
		@@ -35,7 +35,15 @@ The TCM memory can then be remapped to another address again using
		the MMU, but notice that the TCM if often used in situations where
		the MMU is turned off. To avoid confusion the current Linux
		implementation will map the TCM 1 to 1 from physical to virtual
		memory in the location specified by the machine.
		memory in the location specified by the kernel. Currently Linux
		will map ITCM to 0xfffe0000 and on, and DTCM to 0xfffe8000 and
		on, supporting a maximum of 32KiB of ITCM and 32KiB of DTCM.

		Newer versions of the region registers also support dividing these
		TCMs in two separate banks, so for example an 8KiB ITCM is divided
		into two 4KiB banks with its own control registers. The idea is to
		be able to lock and hide one of the banks for use by the secure
		world (TrustZone).

		TCM is used for a few things:

		@@ -65,18 +73,18 @@ in <asm/tcm.h>. Using this interface it is possible to:
		memory. Such a heap is great for things like saving
		device state when shutting off device power domains.

		A machine that has TCM memory shall select HAVE_TCM in
		arch/arm/Kconfig for itself, and then the
		rest of the functionality will depend on the physical
		location and size of ITCM and DTCM to be defined in
		mach/memory.h for the machine. Code that needs to use
		TCM shall #include <asm/tcm.h> If the TCM is not located
		at the place given in memory.h it will be moved using
		the TCM Region registers.
		A machine that has TCM memory shall select HAVE_TCM from
		arch/arm/Kconfig for itself. Code that needs to use TCM shall
		#include <asm/tcm.h>

		Functions to go into itcm can be tagged like this:
		int __tcmfunc foo(int bar);

		Since these are marked to become long_calls and you may want
		to have functions called locally inside the TCM without
		wasting space, there is also the __tcmlocalfunc prefix that
		will make the call relative.

		Variables to go into dtcm can be tagged like this:
		int __tcmdata foo;

arch/arm/include/asm/memory.h

+9 −0

Original line number	Diff line number	Diff line
		@@ -123,6 +123,15 @@

		#endif /* !CONFIG_MMU */

		/*
		* We fix the TCM memories max 32 KiB ITCM resp DTCM at these
		* locations
		*/
		#ifdef CONFIG_HAVE_TCM
		#define ITCM_OFFSET UL(0xfffe0000)
		#define DTCM_OFFSET UL(0xfffe8000)
		#endif

		/*
		* Physical vs virtual RAM address space conversion. These are
		* private definitions which should NOT be used outside memory.h

arch/arm/kernel/tcm.c

+48 −43

Original line number	Diff line number	Diff line
		@@ -18,32 +18,30 @@
		#include <mach/memory.h>
		#include "tcm.h"

		/* Scream and warn about misuse */
		#if !defined(ITCM_OFFSET) \|\| !defined(ITCM_END) \|\| \
		!defined(DTCM_OFFSET) \|\| !defined(DTCM_END)
		#error "TCM support selected but offsets not defined!"
		#endif

		static struct gen_pool *tcm_pool;

		/* TCM section definitions from the linker */
		extern char __itcm_start, __sitcm_text, __eitcm_text;
		extern char __dtcm_start, __sdtcm_data, __edtcm_data;

		/* These will be increased as we run */
		u32 dtcm_end = DTCM_OFFSET;
		u32 itcm_end = ITCM_OFFSET;

		/*
		* TCM memory resources
		*/
		static struct resource dtcm_res = {
		.name = "DTCM RAM",
		.start = DTCM_OFFSET,
		.end = DTCM_END,
		.end = DTCM_OFFSET,
		.flags = IORESOURCE_MEM
		};

		static struct resource itcm_res = {
		.name = "ITCM RAM",
		.start = ITCM_OFFSET,
		.end = ITCM_END,
		.end = ITCM_OFFSET,
		.flags = IORESOURCE_MEM
		};

		@@ -51,7 +49,7 @@ static struct map_desc dtcm_iomap[] __initdata = {
		{
		.virtual = DTCM_OFFSET,
		.pfn = __phys_to_pfn(DTCM_OFFSET),
		.length = (DTCM_END - DTCM_OFFSET + 1),
		.length = 0,
		.type = MT_MEMORY_DTCM
		}
		};
		@@ -60,7 +58,7 @@ static struct map_desc itcm_iomap[] __initdata = {
		{
		.virtual = ITCM_OFFSET,
		.pfn = __phys_to_pfn(ITCM_OFFSET),
		.length = (ITCM_END - ITCM_OFFSET + 1),
		.length = 0,
		.type = MT_MEMORY_ITCM
		}
		};
		@@ -92,8 +90,8 @@ void tcm_free(void *addr, size_t len)
		}
		EXPORT_SYMBOL(tcm_free);

		static void __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
		u32 offset, u32 expected_size)
		static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
		u32 *offset)
		{
		const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
		256, 512, 1024, -1, -1, -1, -1 };
		@@ -120,8 +118,13 @@ static void __init setup_tcm_bank(u8 type, u8 bank, u8 banks,

		tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f];
		if (tcm_size < 0) {
		pr_err("CPU: %sTCM%d of unknown size!\n",
		pr_err("CPU: %sTCM%d of unknown size\n",
		type ? "I" : "D", bank);
		return -EINVAL;
		} else if (tcm_size > 32) {
		pr_err("CPU: %sTCM%d larger than 32k found\n",
		type ? "I" : "D", bank);
		return -EINVAL;
		} else {
		pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
		type ? "I" : "D",
		@@ -131,17 +134,8 @@ static void __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
		(tcm_region & 1) ? "" : "not ");
		}

		if (tcm_size != (expected_size >> 10)) {
		pr_crit("CPU: %sTCM%d was detected %dk but expected %dk!\n",
		type ? "I" : "D",
		bank,
		tcm_size,
		(expected_size >> 10));
		/* Adjust to the expected size? what can we do... */
		}

		/* Force move the TCM bank to where we want it, enable */
		tcm_region = offset \| (tcm_region & 0x00000ffeU) \| 1;
		tcm_region = *offset \| (tcm_region & 0x00000ffeU) \| 1;

		if (!type)
		asm("mcr p15, 0, %0, c9, c1, 0"
		@@ -152,17 +146,17 @@ static void __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
		: /* No output operands */
		: "r" (tcm_region));

		/* Increase offset */
		*offset += (tcm_size << 10);

		pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
		type ? "I" : "D",
		bank,
		tcm_size,
		(tcm_region & 0xfffff000U));
		return 0;
		}

		/* We expect to find what is configured for the platform */
		#define DTCM_EXPECTED (DTCM_END - DTCM_OFFSET + 1)
		#define ITCM_EXPECTED (ITCM_END - ITCM_OFFSET + 1)

		/*
		* This initializes the TCM memory
		*/
		@@ -170,40 +164,51 @@ void __init tcm_init(void)
		{
		u32 tcm_status = read_cpuid_tcmstatus();
		u8 dtcm_banks = (tcm_status >> 16) & 0x03;
		u32 dtcm_banksize = DTCM_EXPECTED / dtcm_banks;
		u8 itcm_banks = (tcm_status & 0x03);
		u32 itcm_banksize = ITCM_EXPECTED / itcm_banks;
		char *start;
		char *end;
		char *ram;
		int ret;
		int i;

		/* Setup DTCM if present */
		if (dtcm_banks > 0) {
		for (i = 0; i < dtcm_banks; i++) {
		setup_tcm_bank(0, i, dtcm_banks,
		DTCM_OFFSET + (i * dtcm_banksize),
		dtcm_banksize);
		ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end);
		if (ret)
		return;
		}
		dtcm_res.end = dtcm_end - 1;
		request_resource(&iomem_resource, &dtcm_res);
		dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET;
		iotable_init(dtcm_iomap, 1);
		/* Copy data from RAM to DTCM */
		start = &__sdtcm_data;
		end = &__edtcm_data;
		ram = &__dtcm_start;
		/* This means you compiled more code than fits into DTCM */
		BUG_ON((end - start) > (dtcm_end - DTCM_OFFSET));
		memcpy(start, ram, (end-start));
		pr_debug("CPU DTCM: copied data from %p - %p\n", start, end);
		}

		/* Setup ITCM if present */
		if (itcm_banks > 0) {
		for (i = 0; i < itcm_banks; i++) {
		setup_tcm_bank(1, i, itcm_banks,
		ITCM_OFFSET + (i * itcm_banksize),
		itcm_banksize);
		ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end);
		if (ret)
		return;
		}
		itcm_res.end = itcm_end - 1;
		request_resource(&iomem_resource, &itcm_res);
		itcm_iomap[0].length = itcm_end - ITCM_OFFSET;
		iotable_init(itcm_iomap, 1);
		/* Copy code from RAM to ITCM */
		start = &__sitcm_text;
		end = &__eitcm_text;
		ram = &__itcm_start;
		/* This means you compiled more code than fits into ITCM */
		BUG_ON((end - start) > (itcm_end - ITCM_OFFSET));
		memcpy(start, ram, (end-start));
		pr_debug("CPU ITCM: copied code from %p - %p\n", start, end);
		}
		@@ -232,9 +237,9 @@ static int __init setup_tcm_pool(void)

		/* Add the rest of DTCM to the TCM pool */
		if (tcm_status & (0x03 << 16)) {
		if (dtcm_pool_start < DTCM_END) {
		if (dtcm_pool_start < dtcm_end) {
		ret = gen_pool_add(tcm_pool, dtcm_pool_start,
		DTCM_END - dtcm_pool_start + 1, -1);
		dtcm_end - dtcm_pool_start, -1);
		if (ret) {
		pr_err("CPU DTCM: could not add DTCM " \
		"remainder to pool!\n");
		@@ -242,16 +247,16 @@ static int __init setup_tcm_pool(void)
		}
		pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
		"the TCM memory pool\n",
		DTCM_END - dtcm_pool_start + 1,
		dtcm_end - dtcm_pool_start,
		dtcm_pool_start);
		}
		}

		/* Add the rest of ITCM to the TCM pool */
		if (tcm_status & 0x03) {
		if (itcm_pool_start < ITCM_END) {
		if (itcm_pool_start < itcm_end) {
		ret = gen_pool_add(tcm_pool, itcm_pool_start,
		ITCM_END - itcm_pool_start + 1, -1);
		itcm_end - itcm_pool_start, -1);
		if (ret) {
		pr_err("CPU ITCM: could not add ITCM " \
		"remainder to pool!\n");
		@@ -259,7 +264,7 @@ static int __init setup_tcm_pool(void)
		}
		pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
		"the TCM memory pool\n",
		ITCM_END - itcm_pool_start + 1,
		itcm_end - itcm_pool_start,
		itcm_pool_start);
		}
		}

arch/arm/mach-u300/include/mach/memory.h

+0 −8

Original line number	Diff line number	Diff line
		@@ -34,14 +34,6 @@
		(CONFIG_MACH_U300_ACCESS_MEM_SIZE & 1))10241024 + 0x100)
		#endif

		/*
		* TCM memory whereabouts
		*/
		#define ITCM_OFFSET 0xffff2000
		#define ITCM_END 0xffff3fff
		#define DTCM_OFFSET 0xffff4000
		#define DTCM_END 0xffff5fff

		/*
		* We enable a real big DMA buffer if need be.
		*/

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