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powerpc/8xx: Remove CPU6 ERRATA Workaround 

CPU6 ERRATA affects only MPC860 revisions prior to C.0. Manufacturing
of those revisiosn was stopped in 1999-2000.
Therefore, it has been almost 20 years since this ERRATA has been
fixed in the silicon.

This patch removes the workaround for that ERRATA.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Christophe Leroy 2018-01-12 13:45:19 +01:00 committed by Michael Ellerman
parent 9a3b849bfe
commit 2a45addd21
4 changed files with 12 additions and 137 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/powerpc/configs/mpc866_ads_defconfig
View File

@ -13,7 +13,6 @@ CONFIG_EXPERT=y
CONFIG_PARTITION_ADVANCED=y
CONFIG_MPC86XADS=y
CONFIG_8xx_COPYBACK=y
CONFIG_8xx_CPU6=y
CONFIG_GEN_RTC=y
CONFIG_HZ_1000=y
CONFIG_MATH_EMULATION=y

82
arch/powerpc/include/asm/reg_8xx.h
View File

@ -66,86 +66,4 @@
#define DC_DFWT 0x40000000 /* Data cache is forced write through */
#define DC_LES 0x20000000 /* Caches are little endian mode */
#ifdef CONFIG_8xx_CPU6
#define do_mtspr_cpu6(rn, rn_addr, v) \
do { \
int _reg_cpu6 = rn_addr, _tmp_cpu6; \
asm volatile("stw %0, %1;" \
"lwz %0, %1;" \
"mtspr " __stringify(rn) ",%2" : \
: "r" (_reg_cpu6), "m"(_tmp_cpu6), \
"r" ((unsigned long)(v)) \
: "memory"); \
} while (0)
#define do_mtspr(rn, v) asm volatile("mtspr " __stringify(rn) ",%0" : \
: "r" ((unsigned long)(v)) \
: "memory")
#define mtspr(rn, v) \
do { \
if (rn == SPRN_IMMR) \
do_mtspr_cpu6(rn, 0x3d30, v); \
else if (rn == SPRN_IC_CST) \
do_mtspr_cpu6(rn, 0x2110, v); \
else if (rn == SPRN_IC_ADR) \
do_mtspr_cpu6(rn, 0x2310, v); \
else if (rn == SPRN_IC_DAT) \
do_mtspr_cpu6(rn, 0x2510, v); \
else if (rn == SPRN_DC_CST) \
do_mtspr_cpu6(rn, 0x3110, v); \
else if (rn == SPRN_DC_ADR) \
do_mtspr_cpu6(rn, 0x3310, v); \
else if (rn == SPRN_DC_DAT) \
do_mtspr_cpu6(rn, 0x3510, v); \
else if (rn == SPRN_MI_CTR) \
do_mtspr_cpu6(rn, 0x2180, v); \
else if (rn == SPRN_MI_AP) \
do_mtspr_cpu6(rn, 0x2580, v); \
else if (rn == SPRN_MI_EPN) \
do_mtspr_cpu6(rn, 0x2780, v); \
else if (rn == SPRN_MI_TWC) \
do_mtspr_cpu6(rn, 0x2b80, v); \
else if (rn == SPRN_MI_RPN) \
do_mtspr_cpu6(rn, 0x2d80, v); \
else if (rn == SPRN_MI_CAM) \
do_mtspr_cpu6(rn, 0x2190, v); \
else if (rn == SPRN_MI_RAM0) \
do_mtspr_cpu6(rn, 0x2390, v); \
else if (rn == SPRN_MI_RAM1) \
do_mtspr_cpu6(rn, 0x2590, v); \
else if (rn == SPRN_MD_CTR) \
do_mtspr_cpu6(rn, 0x3180, v); \
else if (rn == SPRN_M_CASID) \
do_mtspr_cpu6(rn, 0x3380, v); \
else if (rn == SPRN_MD_AP) \
do_mtspr_cpu6(rn, 0x3580, v); \
else if (rn == SPRN_MD_EPN) \
do_mtspr_cpu6(rn, 0x3780, v); \
else if (rn == SPRN_M_TWB) \
do_mtspr_cpu6(rn, 0x3980, v); \
else if (rn == SPRN_MD_TWC) \
do_mtspr_cpu6(rn, 0x3b80, v); \
else if (rn == SPRN_MD_RPN) \
do_mtspr_cpu6(rn, 0x3d80, v); \
else if (rn == SPRN_M_TW) \
do_mtspr_cpu6(rn, 0x3f80, v); \
else if (rn == SPRN_MD_CAM) \
do_mtspr_cpu6(rn, 0x3190, v); \
else if (rn == SPRN_MD_RAM0) \
do_mtspr_cpu6(rn, 0x3390, v); \
else if (rn == SPRN_MD_RAM1) \
do_mtspr_cpu6(rn, 0x3590, v); \
else if (rn == SPRN_DEC) \
do_mtspr_cpu6(rn, 0x2c00, v); \
else if (rn == SPRN_TBWL) \
do_mtspr_cpu6(rn, 0x3880, v); \
else if (rn == SPRN_TBWU) \
do_mtspr_cpu6(rn, 0x3a80, v); \
else if (rn == SPRN_DPDR) \
do_mtspr_cpu6(rn, 0x2d30, v); \
else \
do_mtspr(rn, v); \
} while (0)
#endif
#endif /* _ASM_POWERPC_REG_8xx_H */

54
arch/powerpc/kernel/head_8xx.S
View File

@ -33,23 +33,6 @@
#include <asm/fixmap.h>
#include <asm/export.h>
/* Macro to make the code more readable. */
#ifdef CONFIG_8xx_CPU6
#define SPRN_MI_TWC_ADDR 0x2b80
#define SPRN_MI_RPN_ADDR 0x2d80
#define SPRN_MD_TWC_ADDR 0x3b80
#define SPRN_MD_RPN_ADDR 0x3d80
#define MTSPR_CPU6(spr, reg, treg) \
li treg, spr##_ADDR; \
stw treg, 12(r0); \
lwz treg, 12(r0); \
mtspr spr, reg
#else
#define MTSPR_CPU6(spr, reg, treg) \
mtspr spr, reg
#endif
#if CONFIG_TASK_SIZE <= 0x80000000 && CONFIG_PAGE_OFFSET >= 0x80000000
/* By simply checking Address >= 0x80000000, we know if its a kernel address */
#define SIMPLE_KERNEL_ADDRESS 1
@ -326,7 +309,7 @@ SystemCall:
#endif
InstructionTLBMiss:
#if defined(CONFIG_8xx_CPU6) || defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)
#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)
mtspr SPRN_SPRG_SCRATCH2, r3
#endif
EXCEPTION_PROLOG_0
@ -393,7 +376,7 @@ _ENTRY(ITLBMiss_cmp)
/* Insert the APG into the TWC from the Linux PTE. */
rlwimi r11, r10, 0, 25, 26
/* Load the MI_TWC with the attributes for this "segment." */
MTSPR_CPU6(SPRN_MI_TWC, r11, r3) /* Set segment attributes */
mtspr SPRN_MI_TWC, r11 /* Set segment attributes */
#if defined (CONFIG_HUGETLB_PAGE) && defined (CONFIG_PPC_4K_PAGES)
rlwimi r10, r11, 1, MI_SPS16K
@ -415,10 +398,10 @@ _ENTRY(ITLBMiss_cmp)
#else
rlwimi r10, r11, 0, 0x0ff8 /* Set 24-27, clear 20-23,28 */
#endif
MTSPR_CPU6(SPRN_MI_RPN, r10, r3) /* Update TLB entry */
mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
/* Restore registers */
#if defined(CONFIG_8xx_CPU6) || defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)
#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)
mfspr r3, SPRN_SPRG_SCRATCH2
#endif
EXCEPTION_EPILOG_0
@ -512,7 +495,7 @@ _ENTRY(DTLBMiss_jmp)
* It is bit 25 in the Linux PTE and bit 30 in the TWC
*/
rlwimi r11, r10, 32-5, 30, 30
MTSPR_CPU6(SPRN_MD_TWC, r11, r3)
mtspr SPRN_MD_TWC, r11
/* In 4k pages mode, SPS (bit 28) in RPN must match PS[1] (bit 29)
* In 16k pages mode, SPS is always 1 */
@ -546,7 +529,7 @@ _ENTRY(DTLBMiss_jmp)
rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */
#endif
rlwimi r10, r11, 0, 20, 20 /* clear 20 */
MTSPR_CPU6(SPRN_MD_RPN, r10, r3) /* Update TLB entry */
mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
/* Restore registers */
mfspr r3, SPRN_SPRG_SCRATCH2
@ -684,12 +667,12 @@ DTLBMissIMMR:
mtcr r3
/* Set 512k byte guarded page and mark it valid */
li r10, MD_PS512K | MD_GUARDED | MD_SVALID
MTSPR_CPU6(SPRN_MD_TWC, r10, r11)
mtspr SPRN_MD_TWC, r10
mfspr r10, SPRN_IMMR /* Get current IMMR */
rlwinm r10, r10, 0, 0xfff80000 /* Get 512 kbytes boundary */
ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_SHARED | _PAGE_DIRTY | \
_PAGE_PRESENT | _PAGE_NO_CACHE
MTSPR_CPU6(SPRN_MD_RPN, r10, r11) /* Update TLB entry */
mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
li r11, RPN_PATTERN
mtspr SPRN_DAR, r11 /* Tag DAR */
@ -701,11 +684,11 @@ DTLBMissLinear:
mtcr r3
/* Set 8M byte page and mark it valid */
li r11, MD_PS8MEG | MD_SVALID
MTSPR_CPU6(SPRN_MD_TWC, r11, r3)
mtspr SPRN_MD_TWC, r11
rlwinm r10, r10, 0, 0x0f800000 /* 8xx supports max 256Mb RAM */
ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_SHARED | _PAGE_DIRTY | \
_PAGE_PRESENT
MTSPR_CPU6(SPRN_MD_RPN, r10, r11) /* Update TLB entry */
mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
li r11, RPN_PATTERN
mtspr SPRN_DAR, r11 /* Tag DAR */
@ -718,11 +701,11 @@ ITLBMissLinear:
mtcr r3
/* Set 8M byte page and mark it valid */
li r11, MI_PS8MEG | MI_SVALID | _PAGE_EXEC
MTSPR_CPU6(SPRN_MI_TWC, r11, r3)
mtspr SPRN_MI_TWC, r11
rlwinm r10, r10, 0, 0x0f800000 /* 8xx supports max 256Mb RAM */
ori r10, r10, 0xf0 | MI_SPS16K | _PAGE_SHARED | _PAGE_DIRTY | \
_PAGE_PRESENT
MTSPR_CPU6(SPRN_MI_RPN, r10, r11) /* Update TLB entry */
mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
mfspr r3, SPRN_SPRG_SCRATCH2
EXCEPTION_EPILOG_0
@ -933,13 +916,6 @@ start_here:
*/
lis r6, swapper_pg_dir@ha
tophys(r6,r6)
#ifdef CONFIG_8xx_CPU6
lis r4, cpu6_errata_word@h
ori r4, r4, cpu6_errata_word@l
li r3, 0x3f80
stw r3, 12(r4)
lwz r3, 12(r4)
#endif
mtspr SPRN_M_TW, r6
lis r4,2f@h
ori r4,r4,2f@l
@ -1094,12 +1070,6 @@ swapper_pg_dir:
abatron_pteptrs:
.space 8
#ifdef CONFIG_8xx_CPU6
.globl cpu6_errata_word
cpu6_errata_word:
.space 16
#endif
#ifdef CONFIG_PPC_8xx_PERF_EVENT
.globl itlb_miss_counter
itlb_miss_counter:

12
arch/powerpc/platforms/8xx/Kconfig
View File

@ -116,18 +116,6 @@ config 8xx_GPIO
If in doubt, say Y here.
config 8xx_CPU6
bool "CPU6 Silicon Errata (860 Pre Rev. C)"
help
MPC860 CPUs, prior to Rev C have some bugs in the silicon, which
require workarounds for Linux (and most other OSes to work). If you
get a BUG() very early in boot, this might fix the problem. For
more details read the document entitled "MPC860 Family Device Errata
Reference" on Freescale's website. This option also incurs a
performance hit.
If in doubt, say N here.
config 8xx_CPU15
bool "CPU15 Silicon Errata"
depends on !HUGETLB_PAGE