diff options
3 files changed, 167 insertions, 86 deletions
diff --git a/target/linux/bcm53xx/files/arch/arm/boot/compressed/cache-v7-min.S b/target/linux/bcm53xx/files/arch/arm/boot/compressed/cache-v7-min.S new file mode 100644 index 0000000000..945e5a1005 --- /dev/null +++ b/target/linux/bcm53xx/files/arch/arm/boot/compressed/cache-v7-min.S @@ -0,0 +1,67 @@ +/* + * This is a part of mm/cache-v7.S with extracted entry flushing D-cache. We + * need it for Broadcom devices with broken bootloader leaving cache enabled. + * + * Copyright (C) 2001 Deep Blue Solutions Ltd. + * Copyright (C) 2005 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/linkage.h> +#include <linux/init.h> + + __INIT + +/* + * v7_flush_dcache_all() + * + * Flush the whole D-cache. + * + * Corrupted registers: r0-r5, r7, r9-r11 + * + * - mm - mm_struct describing address space + */ +ENTRY(v7_flush_dcache_all) + mrc p15, 1, r0, c0, c0, 1 @ read clidr + ands r3, r0, #0x7000000 @ extract loc from clidr + mov r3, r3, lsr #23 @ left align loc bit field + beq finished @ if loc is 0, then no need to clean + mov r10, #0 @ start clean at cache level 0 +loop1: + add r2, r10, r10, lsr #1 @ work out 3x current cache level + mov r1, r0, lsr r2 @ extract cache type bits from clidr + and r1, r1, #7 @ mask of the bits for current cache only + cmp r1, #2 @ see what cache we have at this level + blt skip @ skip if no cache, or just i-cache + mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr + isb @ isb to sych the new cssr&csidr + mrc p15, 1, r1, c0, c0, 0 @ read the new csidr + and r2, r1, #7 @ extract the length of the cache lines + add r2, r2, #4 @ add 4 (line length offset) + ldr r4, =0x3ff + ands r4, r4, r1, lsr #3 @ find maximum number on the way size + clz r5, r4 @ find bit position of way size increment + ldr r7, =0x7fff + ands r7, r7, r1, lsr #13 @ extract max number of the index size +loop2: + mov r9, r4 @ create working copy of max way size +loop3: + orr r11, r10, r9, lsl r5 @ factor way and cache number into r11 + orr r11, r11, r7, lsl r2 @ factor index number into r11 + mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way + subs r9, r9, #1 @ decrement the way + bge loop3 + subs r7, r7, #1 @ decrement the index + bge loop2 +skip: + add r10, r10, #2 @ increment cache number + cmp r3, r10 + bgt loop1 +finished: + mov r10, #0 @ swith back to cache level 0 + mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr + isb + mov pc, lr diff --git a/target/linux/bcm53xx/patches-4.4/300-ARM-BCM5301X-Disable-MMU-and-Dcache-during-decompres.patch b/target/linux/bcm53xx/patches-4.4/300-ARM-BCM5301X-Disable-MMU-and-Dcache-during-decompres.patch new file mode 100644 index 0000000000..5dba027725 --- /dev/null +++ b/target/linux/bcm53xx/patches-4.4/300-ARM-BCM5301X-Disable-MMU-and-Dcache-during-decompres.patch @@ -0,0 +1,100 @@ +From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl> +Date: Wed, 24 Sep 2014 22:14:07 +0200 +Subject: [PATCH] ARM: BCM5301X: Disable MMU and Dcache during decompression +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Broadcom devices have broken CFE (bootloader) that leaves hardware in an +invalid state. It causes problems with booting Linux. On Northstar +devices kernel was randomly hanging in ~25% of tries during early init. +Hangs used to happen at random places in the start_kernel. On BCM53573 +kernel doesn't even seem to start booting. + +To workaround this problem we need to do following very early: +1) Clear 2 following bits in the SCTLR register: +#define CR_M (1 << 0) /* MMU enable */ +#define CR_C (1 << 2) /* Dcache enable */ +2) Flush the whole D-cache +3) Disable L2 cache + +Unfortunately this patch is not upstreamable as it does above things +unconditionally. We can't check if we are running on Broadcom platform +in any safe way and doing such hacks with ARCH_MULTI_V7 is unacceptable +as it could break other devices support. + +Signed-off-by: Rafał Miłecki <rafal@milecki.pl> +--- + +--- a/arch/arm/boot/compressed/Makefile ++++ b/arch/arm/boot/compressed/Makefile +@@ -31,6 +31,11 @@ ifeq ($(CONFIG_ARCH_ACORN),y) + OBJS += ll_char_wr.o font.o + endif + ++ifeq ($(CONFIG_ARCH_BCM_5301X),y) ++OBJS += head-bcm_5301x-mpcore.o ++OBJS += cache-v7-min.o ++endif ++ + ifeq ($(CONFIG_ARCH_SA1100),y) + OBJS += head-sa1100.o + endif +--- /dev/null ++++ b/arch/arm/boot/compressed/head-bcm_5301x-mpcore.S +@@ -0,0 +1,37 @@ ++/* ++ * ++ * Platform specific tweaks. This is merged into head.S by the linker. ++ * ++ */ ++ ++#include <linux/linkage.h> ++#include <asm/assembler.h> ++#include <asm/cp15.h> ++ ++ .section ".start", "ax" ++ ++/* ++ * This code section is spliced into the head code by the linker ++ */ ++ ++__plat_uncompress_start: ++ ++ @ Preserve r8/r7 i.e. kernel entry values ++ mov r12, r8 ++ ++ @ Clear MMU enable and Dcache enable bits ++ mrc p15, 0, r0, c1, c0, 0 @ Read SCTLR ++ bic r0, #CR_C|CR_M ++ mcr p15, 0, r0, c1, c0, 0 @ Write SCTLR ++ nop ++ ++ @ Call the cache invalidation routine ++ bl v7_flush_dcache_all ++ nop ++ mov r0,#0 ++ ldr r3, =0x19022000 @ L2 cache controller, control reg ++ str r0, [r3, #0x100] @ Disable L2 cache ++ nop ++ ++ @ Restore ++ mov r8, r12 +--- a/arch/arm/boot/compressed/cache-v7-min.S ++++ b/arch/arm/boot/compressed/cache-v7-min.S +@@ -51,7 +51,7 @@ loop2: + loop3: + orr r11, r10, r9, lsl r5 @ factor way and cache number into r11 + orr r11, r11, r7, lsl r2 @ factor index number into r11 +- mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way ++ mcr p15, 0, r11, c7, c6, 2 @ Invalidate line + subs r9, r9, #1 @ decrement the way + bge loop3 + subs r7, r7, #1 @ decrement the index +@@ -63,5 +63,6 @@ skip: + finished: + mov r10, #0 @ swith back to cache level 0 + mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr ++ dsb + isb + mov pc, lr diff --git a/target/linux/bcm53xx/patches-4.4/300-ARM-BCM5301X-Disable-MMU-and-Dcache-for-decompression.patch b/target/linux/bcm53xx/patches-4.4/300-ARM-BCM5301X-Disable-MMU-and-Dcache-for-decompression.patch deleted file mode 100644 index 62bda2e830..0000000000 --- a/target/linux/bcm53xx/patches-4.4/300-ARM-BCM5301X-Disable-MMU-and-Dcache-for-decompression.patch +++ /dev/null @@ -1,86 +0,0 @@ -From: Florian Fainelli <f.fainelli@gmail.com> -Subject: [PATCH] ARM: BCM5301x: Disable MMU and Dcache during decompression -Date: Tue, 14 Jul 2015 16:12:08 -0700 - -Use the existing __armv7_mmu_cache_flush() to perform the cache flush -since this does what we are after. - -Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> ---- - arch/arm/boot/compressed/Makefile | 4 +++ - arch/arm/boot/compressed/head-bcm_5301x-mpcore.S | 37 ++++++++++++++++++++++++ - arch/arm/boot/compressed/head.S | 2 ++ - 3 files changed, 43 insertions(+) - create mode 100644 arch/arm/boot/compressed/head-bcm_5301x-mpcore.S - ---- a/arch/arm/boot/compressed/Makefile -+++ b/arch/arm/boot/compressed/Makefile -@@ -31,6 +31,10 @@ ifeq ($(CONFIG_ARCH_ACORN),y) - OBJS += ll_char_wr.o font.o - endif - -+ifeq ($(CONFIG_ARCH_BCM_5301X),y) -+OBJS += head-bcm_5301x-mpcore.o -+endif -+ - ifeq ($(CONFIG_ARCH_SA1100),y) - OBJS += head-sa1100.o - endif ---- /dev/null -+++ b/arch/arm/boot/compressed/head-bcm_5301x-mpcore.S -@@ -0,0 +1,37 @@ -+/* -+ * -+ * Platform specific tweaks. This is merged into head.S by the linker. -+ * -+ */ -+ -+#include <linux/linkage.h> -+#include <asm/assembler.h> -+#include <asm/cp15.h> -+ -+ .section ".start", "ax" -+ -+/* -+ * This code section is spliced into the head code by the linker -+ */ -+ -+__plat_uncompress_start: -+ -+ @ Preserve r8/r7 i.e. kernel entry values -+ mov r12, r8 -+ -+ @ Clear MMU enable and Dcache enable bits -+ mrc p15, 0, r0, c1, c0, 0 @ Read SCTLR -+ bic r0, #CR_C|CR_M -+ mcr p15, 0, r0, c1, c0, 0 @ Write SCTLR -+ nop -+ -+ @ Call the cache invalidation routine -+ bl __armv7_mmu_cache_flush_fn -+ nop -+ mov r0,#0 -+ ldr r3, =0x19022000 @ L2 cache controller, control reg -+ str r0, [r3, #0x100] @ Disable L2 cache -+ nop -+ -+ @ Restore -+ mov r8, r12 ---- a/arch/arm/boot/compressed/head.S -+++ b/arch/arm/boot/compressed/head.S -@@ -1152,6 +1152,7 @@ __armv7_mmu_cache_flush: - hierarchical: - mcr p15, 0, r10, c7, c10, 5 @ DMB - stmfd sp!, {r0-r7, r9-r11} -+ENTRY(__armv7_mmu_cache_flush_fn) - mrc p15, 1, r0, c0, c0, 1 @ read clidr - ands r3, r0, #0x7000000 @ extract loc from clidr - mov r3, r3, lsr #23 @ left align loc bit field -@@ -1201,6 +1202,7 @@ iflush: - mcr p15, 0, r10, c7, c10, 4 @ DSB - mcr p15, 0, r10, c7, c5, 4 @ ISB - mov pc, lr -+ENDPROC(__armv7_mmu_cache_flush_fn) - - __armv5tej_mmu_cache_flush: - tst r4, #1 |