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

MIPS: mm: Pass scratch register through to iPTE_SW 



Rather than hardcode a scratch register for the XPA case in iPTE_SW,
pass one through from the work registers allocated by the caller. This
allows for the XPA path to function correctly regardless of the work
registers in use.

Without doing this there are cases (where KScratch registers are
unavailable) in which iPTE_SW will incorrectly clobber $1 despite it
already being in use for the PTE or PTE pointer.

Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
Reviewed-by: default avatarJames Hogan <james.hogan@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13121/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent f3832196

arch/mips/mm/tlbex.c

+11 −13
Original line number Diff line number Diff line
@@ -1639,14 +1639,12 @@ iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr) 


static void

iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr,

	unsigned int mode)

	unsigned int mode, unsigned int scratch)

{

#ifdef CONFIG_PHYS_ADDR_T_64BIT

	unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);



	if (config_enabled(CONFIG_XPA) && !cpu_has_64bits) {

		const int scratch = 1; /* Our extra working register */



		uasm_i_lui(p, scratch, (mode >> 16));

		uasm_i_or(p, pte, pte, scratch);

	} else
@@ -1743,11 +1741,11 @@ build_pte_present(u32 **p, struct uasm_reloc **r, 
/* Make PTE valid, store result in PTR. */

static void

build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte,

		 unsigned int ptr)

		 unsigned int ptr, unsigned int scratch)

{

	unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;



	iPTE_SW(p, r, pte, ptr, mode);

	iPTE_SW(p, r, pte, ptr, mode, scratch);

}



/*
@@ -1783,12 +1781,12 @@ build_pte_writable(u32 **p, struct uasm_reloc **r, 
 */

static void

build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte,

		 unsigned int ptr)

		 unsigned int ptr, unsigned int scratch)

{

	unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID

			     | _PAGE_DIRTY);



	iPTE_SW(p, r, pte, ptr, mode);

	iPTE_SW(p, r, pte, ptr, mode, scratch);

}



/*
@@ -1893,7 +1891,7 @@ static void build_r3000_tlb_load_handler(void) 
	build_r3000_tlbchange_handler_head(&p, K0, K1);

	build_pte_present(&p, &r, K0, K1, -1, label_nopage_tlbl);

	uasm_i_nop(&p); /* load delay */

	build_make_valid(&p, &r, K0, K1);

	build_make_valid(&p, &r, K0, K1, -1);

	build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);



	uasm_l_nopage_tlbl(&l, p);
@@ -1924,7 +1922,7 @@ static void build_r3000_tlb_store_handler(void) 
	build_r3000_tlbchange_handler_head(&p, K0, K1);

	build_pte_writable(&p, &r, K0, K1, -1, label_nopage_tlbs);

	uasm_i_nop(&p); /* load delay */

	build_make_write(&p, &r, K0, K1);

	build_make_write(&p, &r, K0, K1, -1);

	build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);



	uasm_l_nopage_tlbs(&l, p);
@@ -1955,7 +1953,7 @@ static void build_r3000_tlb_modify_handler(void) 
	build_r3000_tlbchange_handler_head(&p, K0, K1);

	build_pte_modifiable(&p, &r, K0, K1,  -1, label_nopage_tlbm);

	uasm_i_nop(&p); /* load delay */

	build_make_write(&p, &r, K0, K1);

	build_make_write(&p, &r, K0, K1, -1);

	build_r3000_pte_reload_tlbwi(&p, K0, K1);



	uasm_l_nopage_tlbm(&l, p);
@@ -2123,7 +2121,7 @@ static void build_r4000_tlb_load_handler(void) 
		}

		uasm_l_tlbl_goaround1(&l, p);

	}

	build_make_valid(&p, &r, wr.r1, wr.r2);

	build_make_valid(&p, &r, wr.r1, wr.r2, wr.r3);

	build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);



#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
@@ -2237,7 +2235,7 @@ static void build_r4000_tlb_store_handler(void) 
	build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);

	if (m4kc_tlbp_war())

		build_tlb_probe_entry(&p);

	build_make_write(&p, &r, wr.r1, wr.r2);

	build_make_write(&p, &r, wr.r1, wr.r2, wr.r3);

	build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);



#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
@@ -2293,7 +2291,7 @@ static void build_r4000_tlb_modify_handler(void) 
	if (m4kc_tlbp_war())

		build_tlb_probe_entry(&p);

	/* Present and writable bits set, set accessed and dirty bits. */

	build_make_write(&p, &r, wr.r1, wr.r2);

	build_make_write(&p, &r, wr.r1, wr.r2, wr.r3);

	build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);



#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT

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