[PATCH] ARM: Delete ARM11MPCore (ARM11 ARMv6K SMP) support
Linus Walleij
linus.walleij at linaro.org
Mon Dec 4 14:36:44 PST 2023
This ARM11 SMP configuration was one of the first SMP configurations
the ARM kernel supported, but it has the downside of odd DMA handling,
odd cache tagging, and often (as of recent) completely broken cache
handling on the ARM RealView PB11MPCore test chips. To boot the
platform it was necessary to completely disable the cache.
When it comes to the EB 11MPCore it is unclear if this ever worked.
These reference designs are now the only ARMv6K SMP platforms.
As only reference designs of purely academic interest remain, and
since the special-cased DMA and PMU code is hard to maintain and
doesn't really work, it is not really worth our time.
Delete the ARM11MPCore support along with:
- The special DMA quirk CONFIG_DMA_CACHE_RWFO that is only used
on ARMv6K SMP, and we are the last ARMV6K system leaving the
building and the cache handling is awkward, so good-bye.
- The special PMU handling that was only used by ARM11MPCore.
The following is left behind:
- TIMER_OF_DECLARE(arm_twd_11mp, "arm,arm11mp-twd-timer", ...)
in arch/arm/kernel/smp_twd.c, this is still in use by Marvell MMP3
arch/arm/boot/dts/marvell/mmp3.dtsi
- IRQCHIP_DECLARE(arm11mp_gic, "arm,arm11mp-gic", ...)
in drivers/irqchip/irq-gic.c, this is still in use by Marvell MMP3
arch/arm/boot/dts/marvell/mmp3.dtsi
These are unfortunate but will need to be kept around for
compatibility. New Marvell-specific compatibles should however probably
be added.
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
arch/arm/kernel/perf_event_v6.c | 34 ------------------------------
arch/arm/mach-versatile/Kconfig | 17 ---------------
arch/arm/mach-versatile/platsmp-realview.c | 2 --
arch/arm/mach-versatile/realview.c | 1 -
arch/arm/mm/Kconfig | 18 ----------------
arch/arm/mm/cache-v6.S | 31 ---------------------------
6 files changed, 103 deletions(-)
diff --git a/arch/arm/kernel/perf_event_v6.c b/arch/arm/kernel/perf_event_v6.c
index 1ae99deeec54..3115077f6abc 100644
--- a/arch/arm/kernel/perf_event_v6.c
+++ b/arch/arm/kernel/perf_event_v6.c
@@ -525,40 +525,7 @@ static int armv6_1176_pmu_init(struct arm_pmu *cpu_pmu)
return 0;
}
-/*
- * ARMv6mpcore is almost identical to single core ARMv6 with the exception
- * that some of the events have different enumerations and that there is no
- * *hack* to stop the programmable counters. To stop the counters we simply
- * disable the interrupt reporting and update the event. When unthrottling we
- * reset the period and enable the interrupt reporting.
- */
-
-static int armv6mpcore_map_event(struct perf_event *event)
-{
- return armpmu_map_event(event, &armv6mpcore_perf_map,
- &armv6mpcore_perf_cache_map, 0xFF);
-}
-
-static int armv6mpcore_pmu_init(struct arm_pmu *cpu_pmu)
-{
- cpu_pmu->name = "armv6_11mpcore";
- cpu_pmu->handle_irq = armv6pmu_handle_irq;
- cpu_pmu->enable = armv6pmu_enable_event;
- cpu_pmu->disable = armv6mpcore_pmu_disable_event;
- cpu_pmu->read_counter = armv6pmu_read_counter;
- cpu_pmu->write_counter = armv6pmu_write_counter;
- cpu_pmu->get_event_idx = armv6pmu_get_event_idx;
- cpu_pmu->clear_event_idx = armv6pmu_clear_event_idx;
- cpu_pmu->start = armv6pmu_start;
- cpu_pmu->stop = armv6pmu_stop;
- cpu_pmu->map_event = armv6mpcore_map_event;
- cpu_pmu->num_events = 3;
-
- return 0;
-}
-
static const struct of_device_id armv6_pmu_of_device_ids[] = {
- {.compatible = "arm,arm11mpcore-pmu", .data = armv6mpcore_pmu_init},
{.compatible = "arm,arm1176-pmu", .data = armv6_1176_pmu_init},
{.compatible = "arm,arm1136-pmu", .data = armv6_1136_pmu_init},
{ /* sentinel value */ }
@@ -568,7 +535,6 @@ static const struct pmu_probe_info armv6_pmu_probe_table[] = {
ARM_PMU_PROBE(ARM_CPU_PART_ARM1136, armv6_1136_pmu_init),
ARM_PMU_PROBE(ARM_CPU_PART_ARM1156, armv6_1156_pmu_init),
ARM_PMU_PROBE(ARM_CPU_PART_ARM1176, armv6_1176_pmu_init),
- ARM_PMU_PROBE(ARM_CPU_PART_ARM11MPCORE, armv6mpcore_pmu_init),
{ /* sentinel value */ }
};
diff --git a/arch/arm/mach-versatile/Kconfig b/arch/arm/mach-versatile/Kconfig
index b1519b4dc03a..e029270c2687 100644
--- a/arch/arm/mach-versatile/Kconfig
+++ b/arch/arm/mach-versatile/Kconfig
@@ -201,23 +201,6 @@ config REALVIEW_EB_A9MP
Enable support for the Cortex-A9MPCore tile fitted to the
Realview(R) Emulation Baseboard platform.
-config REALVIEW_EB_ARM11MP
- bool "Support ARM11MPCore Tile"
- depends on MACH_REALVIEW_EB && ARCH_MULTI_V6
- select HAVE_SMP
- help
- Enable support for the ARM11MPCore tile fitted to the Realview(R)
- Emulation Baseboard platform.
-
-config MACH_REALVIEW_PB11MP
- bool "Support RealView(R) Platform Baseboard for ARM11MPCore"
- depends on ARCH_MULTI_V6
- select HAVE_SMP
- help
- Include support for the ARM(R) RealView(R) Platform Baseboard for
- the ARM11MPCore. This platform has an on-board ARM11MPCore and has
- support for PCI-E and Compact Flash.
-
# ARMv6 CPU without K extensions, but does have the new exclusive ops
config MACH_REALVIEW_PB1176
bool "Support RealView(R) Platform Baseboard for ARM1176JZF-S"
diff --git a/arch/arm/mach-versatile/platsmp-realview.c b/arch/arm/mach-versatile/platsmp-realview.c
index 5d363385c801..4c3e089ac686 100644
--- a/arch/arm/mach-versatile/platsmp-realview.c
+++ b/arch/arm/mach-versatile/platsmp-realview.c
@@ -18,7 +18,6 @@
#define REALVIEW_SYS_FLAGSSET_OFFSET 0x30
static const struct of_device_id realview_scu_match[] = {
- { .compatible = "arm,arm11mp-scu", },
{ .compatible = "arm,cortex-a9-scu", },
{ .compatible = "arm,cortex-a5-scu", },
{ }
@@ -27,7 +26,6 @@ static const struct of_device_id realview_scu_match[] = {
static const struct of_device_id realview_syscon_match[] = {
{ .compatible = "arm,core-module-integrator", },
{ .compatible = "arm,realview-eb-syscon", },
- { .compatible = "arm,realview-pb11mp-syscon", },
{ .compatible = "arm,realview-pbx-syscon", },
{ },
};
diff --git a/arch/arm/mach-versatile/realview.c b/arch/arm/mach-versatile/realview.c
index a3933e2373d5..36a6f6bc4fdd 100644
--- a/arch/arm/mach-versatile/realview.c
+++ b/arch/arm/mach-versatile/realview.c
@@ -9,7 +9,6 @@
static const char *const realview_dt_platform_compat[] __initconst = {
"arm,realview-eb",
"arm,realview-pb1176",
- "arm,realview-pb11mp",
"arm,realview-pba8",
"arm,realview-pbx",
NULL,
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index c164cde50243..2b6f50dd5478 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -937,24 +937,6 @@ config VDSO
You must have glibc 2.22 or later for programs to seamlessly
take advantage of this.
-config DMA_CACHE_RWFO
- bool "Enable read/write for ownership DMA cache maintenance"
- depends on CPU_V6K && SMP
- default y
- help
- The Snoop Control Unit on ARM11MPCore does not detect the
- cache maintenance operations and the dma_{map,unmap}_area()
- functions may leave stale cache entries on other CPUs. By
- enabling this option, Read or Write For Ownership in the ARMv6
- DMA cache maintenance functions is performed. These LDR/STR
- instructions change the cache line state to shared or modified
- so that the cache operation has the desired effect.
-
- Note that the workaround is only valid on processors that do
- not perform speculative loads into the D-cache. For such
- processors, if cache maintenance operations are not broadcast
- in hardware, other workarounds are needed (e.g. cache
- maintenance broadcasting in software via FIQ).
config OUTER_CACHE
bool
diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
index 250c83bf7158..44211d8a296f 100644
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -201,10 +201,6 @@ ENTRY(v6_flush_kern_dcache_area)
* - end - virtual end address of region
*/
v6_dma_inv_range:
-#ifdef CONFIG_DMA_CACHE_RWFO
- ldrb r2, [r0] @ read for ownership
- strb r2, [r0] @ write for ownership
-#endif
tst r0, #D_CACHE_LINE_SIZE - 1
bic r0, r0, #D_CACHE_LINE_SIZE - 1
#ifdef HARVARD_CACHE
@@ -213,10 +209,6 @@ v6_dma_inv_range:
mcrne p15, 0, r0, c7, c11, 1 @ clean unified line
#endif
tst r1, #D_CACHE_LINE_SIZE - 1
-#ifdef CONFIG_DMA_CACHE_RWFO
- ldrbne r2, [r1, #-1] @ read for ownership
- strbne r2, [r1, #-1] @ write for ownership
-#endif
bic r1, r1, #D_CACHE_LINE_SIZE - 1
#ifdef HARVARD_CACHE
mcrne p15, 0, r1, c7, c14, 1 @ clean & invalidate D line
@@ -231,10 +223,6 @@ v6_dma_inv_range:
#endif
add r0, r0, #D_CACHE_LINE_SIZE
cmp r0, r1
-#ifdef CONFIG_DMA_CACHE_RWFO
- ldrlo r2, [r0] @ read for ownership
- strlo r2, [r0] @ write for ownership
-#endif
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
@@ -248,9 +236,6 @@ v6_dma_inv_range:
v6_dma_clean_range:
bic r0, r0, #D_CACHE_LINE_SIZE - 1
1:
-#ifdef CONFIG_DMA_CACHE_RWFO
- ldr r2, [r0] @ read for ownership
-#endif
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c10, 1 @ clean D line
#else
@@ -269,10 +254,6 @@ v6_dma_clean_range:
* - end - virtual end address of region
*/
ENTRY(v6_dma_flush_range)
-#ifdef CONFIG_DMA_CACHE_RWFO
- ldrb r2, [r0] @ read for ownership
- strb r2, [r0] @ write for ownership
-#endif
bic r0, r0, #D_CACHE_LINE_SIZE - 1
1:
#ifdef HARVARD_CACHE
@@ -282,10 +263,6 @@ ENTRY(v6_dma_flush_range)
#endif
add r0, r0, #D_CACHE_LINE_SIZE
cmp r0, r1
-#ifdef CONFIG_DMA_CACHE_RWFO
- ldrblo r2, [r0] @ read for ownership
- strblo r2, [r0] @ write for ownership
-#endif
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
@@ -301,13 +278,7 @@ ENTRY(v6_dma_map_area)
add r1, r1, r0
teq r2, #DMA_FROM_DEVICE
beq v6_dma_inv_range
-#ifndef CONFIG_DMA_CACHE_RWFO
b v6_dma_clean_range
-#else
- teq r2, #DMA_TO_DEVICE
- beq v6_dma_clean_range
- b v6_dma_flush_range
-#endif
ENDPROC(v6_dma_map_area)
/*
@@ -317,11 +288,9 @@ ENDPROC(v6_dma_map_area)
* - dir - DMA direction
*/
ENTRY(v6_dma_unmap_area)
-#ifndef CONFIG_DMA_CACHE_RWFO
add r1, r1, r0
teq r2, #DMA_TO_DEVICE
bne v6_dma_inv_range
-#endif
ret lr
ENDPROC(v6_dma_unmap_area)
---
base-commit: d570fe67df85c84be7cc33ca9e9568d9601b494f
change-id: 20231202-drop-11mpcore-d556cc5f7d99
Best regards,
--
Linus Walleij <linus.walleij at linaro.org>
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