Commit 4d035516 authored by Paul Burton's avatar Paul Burton Committed by Ralf Baechle
Browse files

MIPS: Enable L2 prefetching for CM >= 2.5 



On systems with CM 2.5 & beyond there may be L2 prefetch units present
which are not enabled by default. Detect them, configuring & enabling
prefetching when available.

Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11180/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 37f2a174

arch/mips/include/asm/mips-cm.h

+17 −0
Original line number Diff line number Diff line
@@ -195,6 +195,8 @@ BUILD_CM_R_(gic_status, MIPS_CM_GCB_OFS + 0xd0) 
BUILD_CM_R_(cpc_status,		MIPS_CM_GCB_OFS + 0xf0)

BUILD_CM_RW(l2_config,		MIPS_CM_GCB_OFS + 0x130)

BUILD_CM_RW(sys_config2,	MIPS_CM_GCB_OFS + 0x150)

BUILD_CM_RW(l2_pft_control,	MIPS_CM_GCB_OFS + 0x300)

BUILD_CM_RW(l2_pft_control_b,	MIPS_CM_GCB_OFS + 0x308)



/* Core Local & Core Other register accessor functions */

BUILD_CM_Cx_RW(reset_release,	0x00)
@@ -245,6 +247,7 @@ BUILD_CM_Cx_R_(tcid_8_priority, 0x80) 
		 ((minor) << CM_GCR_REV_MINOR_SHF))



#define CM_REV_CM2				CM_ENCODE_REV(6, 0)

#define CM_REV_CM2_5				CM_ENCODE_REV(7, 0)

#define CM_REV_CM3				CM_ENCODE_REV(8, 0)



/* GCR_ERROR_CAUSE register fields */
@@ -321,6 +324,20 @@ BUILD_CM_Cx_R_(tcid_8_priority, 0x80) 
#define CM_GCR_SYS_CONFIG2_MAXVPW_SHF		0

#define CM_GCR_SYS_CONFIG2_MAXVPW_MSK		(_ULCAST_(0xf) << 0)



/* GCR_L2_PFT_CONTROL register fields */

#define CM_GCR_L2_PFT_CONTROL_PAGEMASK_SHF	12

#define CM_GCR_L2_PFT_CONTROL_PAGEMASK_MSK	(_ULCAST_(0xfffff) << 12)

#define CM_GCR_L2_PFT_CONTROL_PFTEN_SHF		8

#define CM_GCR_L2_PFT_CONTROL_PFTEN_MSK		(_ULCAST_(0x1) << 8)

#define CM_GCR_L2_PFT_CONTROL_NPFT_SHF		0

#define CM_GCR_L2_PFT_CONTROL_NPFT_MSK		(_ULCAST_(0xff) << 0)



/* GCR_L2_PFT_CONTROL_B register fields */

#define CM_GCR_L2_PFT_CONTROL_B_CEN_SHF		8

#define CM_GCR_L2_PFT_CONTROL_B_CEN_MSK		(_ULCAST_(0x1) << 8)

#define CM_GCR_L2_PFT_CONTROL_B_PORTID_SHF	0

#define CM_GCR_L2_PFT_CONTROL_B_PORTID_MSK	(_ULCAST_(0xff) << 0)



/* GCR_Cx_COHERENCE register fields */

#define CM_GCR_Cx_COHERENCE_COHDOMAINEN_SHF	0

#define CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK	(_ULCAST_(0xff) << 0)

arch/mips/mm/sc-mips.c

+60 −1
Original line number Diff line number Diff line
@@ -51,11 +51,69 @@ static void mips_sc_disable(void) 
	/* L2 cache is permanently enabled */

}



static void mips_sc_prefetch_enable(void)

{

	unsigned long pftctl;



	if (mips_cm_revision() < CM_REV_CM2_5)

		return;



	/*

	 * If there is one or more L2 prefetch unit present then enable

	 * prefetching for both code & data, for all ports.

	 */

	pftctl = read_gcr_l2_pft_control();

	if (pftctl & CM_GCR_L2_PFT_CONTROL_NPFT_MSK) {

		pftctl &= ~CM_GCR_L2_PFT_CONTROL_PAGEMASK_MSK;

		pftctl |= PAGE_MASK & CM_GCR_L2_PFT_CONTROL_PAGEMASK_MSK;

		pftctl |= CM_GCR_L2_PFT_CONTROL_PFTEN_MSK;

		write_gcr_l2_pft_control(pftctl);



		pftctl = read_gcr_l2_pft_control_b();

		pftctl |= CM_GCR_L2_PFT_CONTROL_B_PORTID_MSK;

		pftctl |= CM_GCR_L2_PFT_CONTROL_B_CEN_MSK;

		write_gcr_l2_pft_control_b(pftctl);

	}

}



static void mips_sc_prefetch_disable(void)

{

	unsigned long pftctl;



	if (mips_cm_revision() < CM_REV_CM2_5)

		return;



	pftctl = read_gcr_l2_pft_control();

	pftctl &= ~CM_GCR_L2_PFT_CONTROL_PFTEN_MSK;

	write_gcr_l2_pft_control(pftctl);



	pftctl = read_gcr_l2_pft_control_b();

	pftctl &= ~CM_GCR_L2_PFT_CONTROL_B_PORTID_MSK;

	pftctl &= ~CM_GCR_L2_PFT_CONTROL_B_CEN_MSK;

	write_gcr_l2_pft_control_b(pftctl);

}



static bool mips_sc_prefetch_is_enabled(void)

{

	unsigned long pftctl;



	if (mips_cm_revision() < CM_REV_CM2_5)

		return false;



	pftctl = read_gcr_l2_pft_control();

	if (!(pftctl & CM_GCR_L2_PFT_CONTROL_NPFT_MSK))

		return false;

	return !!(pftctl & CM_GCR_L2_PFT_CONTROL_PFTEN_MSK);

}



static struct bcache_ops mips_sc_ops = {

	.bc_enable = mips_sc_enable,

	.bc_disable = mips_sc_disable,

	.bc_wback_inv = mips_sc_wback_inv,

	.bc_inv = mips_sc_inv

	.bc_inv = mips_sc_inv,

	.bc_prefetch_enable = mips_sc_prefetch_enable,

	.bc_prefetch_disable = mips_sc_prefetch_disable,

	.bc_prefetch_is_enabled = mips_sc_prefetch_is_enabled,

};



/*
@@ -186,6 +244,7 @@ int mips_sc_init(void) 
	int found = mips_sc_probe();

	if (found) {

		mips_sc_enable();

		mips_sc_prefetch_enable();

		bcops = &mips_sc_ops;

	}

	return found;

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