Commit 8b5850f8 authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARC: Support for single cycle Close Coupled Mem (CCM) 



* Includes mapping of CCMs in address space
* Annotations to move arbitrary code/data into CCM
* Moving some of the critical code/data into CCM
* Runtime detection/reporting

Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 9c57564e

arch/arc/Kconfig

+27 −0
Original line number Diff line number Diff line
@@ -198,6 +198,33 @@ config ARC_CACHE_PAGES 


endif	#ARC_CACHE



config ARC_HAS_ICCM

	bool "Use ICCM"

	help

	  Single Cycle RAMS to store Fast Path Code

	default n



config ARC_ICCM_SZ

	int "ICCM Size in KB"

	default "64"

	depends on ARC_HAS_ICCM



config ARC_HAS_DCCM

	bool "Use DCCM"

	help

	  Single Cycle RAMS to store Fast Path Data

	default n



config ARC_DCCM_SZ

	int "DCCM Size in KB"

	default "64"

	depends on ARC_HAS_DCCM



config ARC_DCCM_BASE

	hex "DCCM map address"

	default "0xA0000000"

	depends on ARC_HAS_DCCM



config ARC_HAS_HW_MPY

	bool "Use Hardware Multiplier (Normal or Faster XMAC)"

	default y

arch/arc/include/asm/linkage.h

+33 −0
Original line number Diff line number Diff line
@@ -25,6 +25,39 @@ 
	.size \ name, ASM_PREV_SYM_ADDR(\name)

.endm



/* annotation for data we want in DCCM - if enabled in .config */

.macro ARCFP_DATA nm

#ifdef CONFIG_ARC_HAS_DCCM

	.section .data.arcfp

#else

	.section .data

#endif

	.global \nm

.endm



/* annotation for data we want in DCCM - if enabled in .config */

.macro ARCFP_CODE

#ifdef CONFIG_ARC_HAS_ICCM

	.section .text.arcfp, "ax",@progbits

#else

	.section .text, "ax",@progbits

#endif

.endm



#else	/* !__ASSEMBLY__ */



#ifdef CONFIG_ARC_HAS_ICCM

#define __arcfp_code __attribute__((__section__(".text.arcfp")))

#else

#define __arcfp_code __attribute__((__section__(".text")))

#endif



#ifdef CONFIG_ARC_HAS_DCCM

#define __arcfp_data __attribute__((__section__(".data.arcfp")))

#else

#define __arcfp_data __attribute__((__section__(".data")))

#endif



#endif /* __ASSEMBLY__ */



#endif

arch/arc/kernel/entry.S

+2 −2
Original line number Diff line number Diff line
@@ -149,7 +149,7 @@ VECTOR reserved ; Reserved Exceptions 


;##################### Scratch Mem for IRQ stack switching #############



	.section .data		; NOT .global

ARCFP_DATA int1_saved_reg

	.align 32

	.type   int1_saved_reg, @object

	.size   int1_saved_reg, 4
@@ -159,7 +159,7 @@ int1_saved_reg: 
/* Each Interrupt level needs it's own scratch */

#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS



	.section .data		; NOT .global

ARCFP_DATA int2_saved_reg

	.type   int2_saved_reg, @object

	.size   int2_saved_reg, 4

int2_saved_reg:

arch/arc/kernel/setup.c

+52 −1
Original line number Diff line number Diff line
@@ -64,6 +64,33 @@ void __init read_arc_build_cfg_regs(void) 
	cpu->extn.ext_arith = read_aux_reg(ARC_REG_EXTARITH_BCR);

	cpu->extn.crc = read_aux_reg(ARC_REG_CRC_BCR);



	/* Note that we read the CCM BCRs independent of kernel config

	 * This is to catch the cases where user doesn't know that

	 * CCMs are present in hardware build

	 */

	{

		struct bcr_iccm iccm;

		struct bcr_dccm dccm;

		struct bcr_dccm_base dccm_base;

		unsigned int bcr_32bit_val;



		bcr_32bit_val = read_aux_reg(ARC_REG_ICCM_BCR);

		if (bcr_32bit_val) {

			iccm = *((struct bcr_iccm *)&bcr_32bit_val);

			cpu->iccm.base_addr = iccm.base << 16;

			cpu->iccm.sz = 0x2000 << (iccm.sz - 1);

		}



		bcr_32bit_val = read_aux_reg(ARC_REG_DCCM_BCR);

		if (bcr_32bit_val) {

			dccm = *((struct bcr_dccm *)&bcr_32bit_val);

			cpu->dccm.sz = 0x800 << (dccm.sz);



			READ_BCR(ARC_REG_DCCMBASE_BCR, dccm_base);

			cpu->dccm.base_addr = dccm_base.addr << 8;

		}

	}



	READ_BCR(ARC_REG_XY_MEM_BCR, cpu->extn_xymem);



	read_decode_mmu_bcr();
@@ -211,6 +238,30 @@ char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len) 
	return buf;

}



void __init arc_chk_ccms(void)

{

#if defined(CONFIG_ARC_HAS_DCCM) || defined(CONFIG_ARC_HAS_ICCM)

	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];



#ifdef CONFIG_ARC_HAS_DCCM

	/*

	 * DCCM can be arbit placed in hardware.

	 * Make sure it's placement/sz matches what Linux is built with

	 */

	if ((unsigned int)__arc_dccm_base != cpu->dccm.base_addr)

		panic("Linux built with incorrect DCCM Base address\n");



	if (CONFIG_ARC_DCCM_SZ != cpu->dccm.sz)

		panic("Linux built with incorrect DCCM Size\n");

#endif



#ifdef CONFIG_ARC_HAS_ICCM

	if (CONFIG_ARC_ICCM_SZ != cpu->iccm.sz)

		panic("Linux built with incorrect ICCM Size\n");

#endif

#endif

}



/*

 * Ensure that FP hardware and kernel config match

 * -If hardware contains DPFP, kernel needs to save/restore FPU state
@@ -255,7 +306,7 @@ void __init setup_processor(void) 


	arc_mmu_init();

	arc_cache_init();



	arc_chk_ccms();



	printk(arc_extn_mumbojumbo(cpu_id, str, sizeof(str)));

arch/arc/kernel/vmlinux.lds.S

+21 −0
Original line number Diff line number Diff line
@@ -23,6 +23,12 @@ jiffies = jiffies_64; 


SECTIONS

{

	/*

	 * ICCM starts at 0x8000_0000. So if kernel is relocated to some other

	 * address, make sure peripheral at 0x8z doesn't clash with ICCM

	 * Essentially vector is also in ICCM.

	 */



	. = CONFIG_LINUX_LINK_BASE;



	_int_vec_base_lds = .;
@@ -31,6 +37,13 @@ SECTIONS 
		. = ALIGN(PAGE_SIZE);

	}



#ifdef CONFIG_ARC_HAS_ICCM

	.text.arcfp : {

		*(.text.arcfp)

		. = ALIGN(CONFIG_ARC_ICCM_SZ * 1024);

	}

#endif



	/*

	 * The reason for having a seperate subsection .init.ramfs is to

	 * prevent objump from including it in kernel dumps
@@ -134,4 +147,12 @@ SECTIONS 
	.debug_loc 0 : { *(.debug_loc) }

	.debug_macinfo 0 : { *(.debug_macinfo) }



#ifdef CONFIG_ARC_HAS_DCCM

	. = CONFIG_ARC_DCCM_BASE;

	__arc_dccm_base = .;

	.data.arcfp : {

		*(.data.arcfp)

	}

	. = ALIGN(CONFIG_ARC_DCCM_SZ * 1024);

#endif

}