[PATCH v2 1/5] kvx: Implement setjmp/longjmp/initjmp

[PATCH v2 1/5] kvx: Implement setjmp/longjmp/initjmp

[Jules Maselbas]

Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
---
changes v1 -> v2: nothing
---
 arch/kvx/Kconfig              |  1 +
 arch/kvx/include/asm/setjmp.h | 15 +++++++
 arch/kvx/lib/Makefile         |  2 +-
 arch/kvx/lib/setjmp.S         | 85 +++++++++++++++++++++++++++++++++++
 4 files changed, 102 insertions(+), 1 deletion(-)
 create mode 100644 arch/kvx/include/asm/setjmp.h
 create mode 100644 arch/kvx/lib/setjmp.S

diff --git a/arch/kvx/Kconfig b/arch/kvx/Kconfig
index 3327021e1..8483ae6e6 100644
--- a/arch/kvx/Kconfig
+++ b/arch/kvx/Kconfig
@@ -11,6 +11,7 @@ config KVX
 	select ELF
 	select FLEXIBLE_BOOTARGS
 	select GENERIC_FIND_NEXT_BIT
+	select HAS_ARCH_SJLJ
 	select LIBFDT
 	select MFD_SYSCON
 	select OF_BAREBOX_DRIVERS
diff --git a/arch/kvx/include/asm/setjmp.h b/arch/kvx/include/asm/setjmp.h
new file mode 100644
index 000000000..3cfc698d9
--- /dev/null
+++ b/arch/kvx/include/asm/setjmp.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* SPDX-FileCopyrightText: 2021 Jules Maselbas <jmaselbas@kalray.eu>, Kalray Inc. */
+
+#ifndef _ASM_KVX_SETJMP_H_
+#define _ASM_KVX_SETJMP_H_
+
+#include <linux/types.h>
+
+typedef u64 jmp_buf[22];
+
+int initjmp(jmp_buf jmp, void __noreturn (*func)(void), void *stack_top);
+int setjmp(jmp_buf jmp) __attribute__((returns_twice));
+void longjmp(jmp_buf jmp, int ret) __attribute__((noreturn));
+
+#endif /* _ASM_KVX_SETJMP_H_ */
diff --git a/arch/kvx/lib/Makefile b/arch/kvx/lib/Makefile
index 6e56462da..cee08b0fa 100644
--- a/arch/kvx/lib/Makefile
+++ b/arch/kvx/lib/Makefile
@@ -3,4 +3,4 @@
 # Copyright (C) 2019 Kalray Inc.
 #
 
-obj-y	+= cpuinfo.o board.o dtb.o poweroff.o bootm.o
+obj-y	+= cpuinfo.o board.o dtb.o poweroff.o bootm.o setjmp.o
diff --git a/arch/kvx/lib/setjmp.S b/arch/kvx/lib/setjmp.S
new file mode 100644
index 000000000..829299711
--- /dev/null
+++ b/arch/kvx/lib/setjmp.S
@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: LGPL-2.1 */
+/* SPDX-FileCopyrightText: 2021 Jules Maselbas <jmaselbas@kalray.eu>, Kalray Inc. */
+
+#define REG_SIZE 8
+
+#include <linux/linkage.h>
+
+/* jmp_buf layout:
+ * [0]  = $ra,  $sp,  $cs,  $r14,
+ * [4]  = $r20, $r21, $r22, $r23,
+ * [8]  = $r24, $r25, $r26, $r27,
+ * [12] = $r28, $r29, $r30, $r31,
+ * [16] = $r18, $r19,
+ * [18] = $lc,  $le,  $ls,  xxxx
+ */
+
+/**
+ * int initjmp(jmp_buf jmp, void __noreturn (*func)(void), void *stack_top);
+ */
+ENTRY(initjmp)
+	/* store $ra */
+	sd (0 * REG_SIZE)[$r0] = $r1
+	;;
+	/* store $sp */
+	sd (1 * REG_SIZE)[$r0] = $r2
+	make $r0 = 0
+	ret
+	;;
+ENDPROC(initjmp)
+
+/**
+ * int setjmp(jmp_buf jmp);
+ */
+ENTRY(setjmp)
+	sq (16 * REG_SIZE)[$r0] = $r18r19
+	get $r40 = $ra
+	copyd $r41 = $sp
+	;;
+	so (4 * REG_SIZE)[$r0] = $r20r21r22r23
+	get $r42 = $cs
+	copyd $r43 = $r14
+	;;
+	so (0 * REG_SIZE)[$r0] = $r40r41r42r43
+	get $r40 = $lc
+	;;
+	so (8 * REG_SIZE)[$r0] = $r24r25r26r27
+	get $r41 = $le
+	;;
+	so (12 * REG_SIZE)[$r0] = $r28r29r30r31
+	get $r42 = $ls
+	;;
+	so (18 * REG_SIZE)[$r0] = $r40r41r42r43
+	make $r0 = 0
+	ret
+	;;
+ENDPROC(setjmp)
+
+/**
+ * void longjmp(jmp_buf jmp, int ret);
+ */
+ENTRY(longjmp)
+	lo $r40r41r42r43 = (0 * REG_SIZE)[$r0]
+	;;
+	lo $r44r45r46r47 = (18 * REG_SIZE)[$r0]
+	set $ra = $r40
+	copyd $sp = $r41
+	;;
+	lo $r20r21r22r23 = (4 * REG_SIZE)[$r0]
+	set $cs = $r42
+	copyd $r14 = $r43
+	;;
+	lo $r24r25r26r27 = (8 * REG_SIZE)[$r0]
+	set $lc = $r44
+	;;
+	lo $r28r29r30r31 = (12 * REG_SIZE)[$r0]
+	set $le = $r45
+	;;
+	lq $r18r19 = (16 * REG_SIZE)[$r0]
+	set $ls = $r46
+	;;
+	/* According to man, if retval is equal to 0, then we should return 1 */
+	maxud $r0 = $r1, 1
+	ret
+	;;
+ENDPROC(longjmp)
-- 
2.17.1



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[PATCH v2 2/5] kvx: Implement dcache invalidation primitive

[Jules Maselbas]

From: Yann Sionneau <ysionneau@kalray.eu>

Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
---
changes v1 -> v2:
 - renamed kvx_dcache_invalidate_mem_area to invalidate_dcache_range
 - replace the implemetation with a simpler version
---
 arch/kvx/Kconfig             |  1 +
 arch/kvx/include/asm/cache.h | 13 +++++++++++++
 arch/kvx/lib/Makefile        |  2 +-
 arch/kvx/lib/cache.c         | 25 +++++++++++++++++++++++++
 4 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 arch/kvx/lib/cache.c

diff --git a/arch/kvx/Kconfig b/arch/kvx/Kconfig
index 8483ae6e6..4e02613ec 100644
--- a/arch/kvx/Kconfig
+++ b/arch/kvx/Kconfig
@@ -12,6 +12,7 @@ config KVX
 	select FLEXIBLE_BOOTARGS
 	select GENERIC_FIND_NEXT_BIT
 	select HAS_ARCH_SJLJ
+	select HAS_CACHE
 	select LIBFDT
 	select MFD_SYSCON
 	select OF_BAREBOX_DRIVERS
diff --git a/arch/kvx/include/asm/cache.h b/arch/kvx/include/asm/cache.h
index 3be176725..0bf3c8f06 100644
--- a/arch/kvx/include/asm/cache.h
+++ b/arch/kvx/include/asm/cache.h
@@ -8,6 +8,8 @@
 
 #include <linux/types.h>
 
+void invalidate_dcache_range(unsigned long addr, unsigned long stop);
+
 static inline void sync_caches_for_execution(void)
 {
 	__builtin_kvx_fence();
@@ -15,4 +17,15 @@ static inline void sync_caches_for_execution(void)
 	__builtin_kvx_barrier();
 }
 
+static inline void sync_dcache_icache(void)
+{
+	sync_caches_for_execution();
+}
+
+static inline void dcache_inval(void)
+{
+	__builtin_kvx_fence();
+	__builtin_kvx_dinval();
+}
+
 #endif /* __KVX_CACHE_H */
diff --git a/arch/kvx/lib/Makefile b/arch/kvx/lib/Makefile
index cee08b0fa..d271ebccf 100644
--- a/arch/kvx/lib/Makefile
+++ b/arch/kvx/lib/Makefile
@@ -3,4 +3,4 @@
 # Copyright (C) 2019 Kalray Inc.
 #
 
-obj-y	+= cpuinfo.o board.o dtb.o poweroff.o bootm.o setjmp.o
+obj-y	+= cpuinfo.o board.o dtb.o poweroff.o bootm.o setjmp.o cache.o
diff --git a/arch/kvx/lib/cache.c b/arch/kvx/lib/cache.c
new file mode 100644
index 000000000..bd074de79
--- /dev/null
+++ b/arch/kvx/lib/cache.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2021 Yann Sionneau <ysionneau@kalray.eu>, Kalray Inc.
+
+#include <asm/cache.h>
+#include <linux/kernel.h>
+
+#define KVX_DCACHE_LINE_SIZE    (64)
+#define KVX_DCACHE_SIZE (128*1024)
+
+void invalidate_dcache_range(unsigned long addr, unsigned long stop)
+{
+	long size;
+
+	addr = ALIGN_DOWN(addr, KVX_DCACHE_LINE_SIZE);
+	size = stop - addr;
+
+	if (size < KVX_DCACHE_SIZE) {
+		while (addr < stop) {
+			__builtin_kvx_dinvall((void *)addr);
+			addr += KVX_DCACHE_LINE_SIZE;
+		}
+	} else {
+		__builtin_kvx_dinval();
+	}
+}
-- 
2.17.1



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[PATCH v2 3/5] kvx: Implement dma handling primitives

[Jules Maselbas]

From: Yann Sionneau <ysionneau@kalray.eu>

Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
---
changes v1 -> v2:
 - add BUILD_BUG_ON_MSG in dma_alloc_coherent
 - renamed kvx_dcache_invalidate_mem_area to invalidate_dcache_range
 - add comment on dcache beeing write-through
---
 arch/kvx/Kconfig                |  1 +
 arch/kvx/include/asm/dma.h      | 32 +++++++++++
 arch/kvx/include/asm/sys_arch.h |  3 ++
 arch/kvx/lib/Makefile           |  2 +-
 arch/kvx/lib/dma-default.c      | 94 +++++++++++++++++++++++++++++++++
 5 files changed, 131 insertions(+), 1 deletion(-)
 create mode 100644 arch/kvx/include/asm/dma.h
 create mode 100644 arch/kvx/lib/dma-default.c

diff --git a/arch/kvx/Kconfig b/arch/kvx/Kconfig
index 4e02613ec..093444088 100644
--- a/arch/kvx/Kconfig
+++ b/arch/kvx/Kconfig
@@ -13,6 +13,7 @@ config KVX
 	select GENERIC_FIND_NEXT_BIT
 	select HAS_ARCH_SJLJ
 	select HAS_CACHE
+	select HAS_DMA
 	select LIBFDT
 	select MFD_SYSCON
 	select OF_BAREBOX_DRIVERS
diff --git a/arch/kvx/include/asm/dma.h b/arch/kvx/include/asm/dma.h
new file mode 100644
index 000000000..a7ecf279a
--- /dev/null
+++ b/arch/kvx/include/asm/dma.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* SPDX-FileCopyrightText: 2021 Yann Sionneau <ysionneau@kalray.eu>, Kalray Inc. */
+
+#ifndef __ASM_DMA_H
+#define __ASM_DMA_H
+
+#include <common.h>
+
+#define KVX_DDR_32BIT_RAM_WINDOW_BA	(0x80000000ULL)
+#define KVX_DDR_64BIT_RAM_WINDOW_BA	(0x100000000ULL)
+#define MAX_32BIT_ADDR			(0xffffffffULL)
+
+#define dma_alloc dma_alloc
+static inline void *dma_alloc(size_t size)
+{
+	return xmemalign(64, ALIGN(size, 64));
+}
+
+static inline void *dma_alloc_coherent(size_t size, dma_addr_t *dma_handle)
+{
+	BUILD_BUG_ON_MSG(1, "dma_alloc_coherent not supported: "
+			"MMU support is required to map uncached pages");
+	return NULL;
+}
+
+static inline void dma_free_coherent(void *mem, dma_addr_t dma_handle,
+				     size_t size)
+{
+	free(mem);
+}
+
+#endif /* __ASM_DMA_H */
diff --git a/arch/kvx/include/asm/sys_arch.h b/arch/kvx/include/asm/sys_arch.h
index 9df32c4e7..ce07a5598 100644
--- a/arch/kvx/include/asm/sys_arch.h
+++ b/arch/kvx/include/asm/sys_arch.h
@@ -11,6 +11,9 @@
 #define EXCEPTION_STRIDE	0x40
 #define EXCEPTION_ALIGNMENT	0x100
 
+#define kvx_cluster_id() ((int) \
+	((kvx_sfr_get(PCR) & KVX_SFR_PCR_CID_MASK) \
+					>> KVX_SFR_PCR_CID_SHIFT))
 #define KVX_SFR_START(__sfr_reg) \
 	(KVX_SFR_## __sfr_reg ## _SHIFT)
 
diff --git a/arch/kvx/lib/Makefile b/arch/kvx/lib/Makefile
index d271ebccf..c730e1c23 100644
--- a/arch/kvx/lib/Makefile
+++ b/arch/kvx/lib/Makefile
@@ -3,4 +3,4 @@
 # Copyright (C) 2019 Kalray Inc.
 #
 
-obj-y	+= cpuinfo.o board.o dtb.o poweroff.o bootm.o setjmp.o cache.o
+obj-y	+= cpuinfo.o board.o dtb.o poweroff.o bootm.o setjmp.o cache.o dma-default.o
diff --git a/arch/kvx/lib/dma-default.c b/arch/kvx/lib/dma-default.c
new file mode 100644
index 000000000..2a4144696
--- /dev/null
+++ b/arch/kvx/lib/dma-default.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2021 Yann Sionneau <ysionneau@kalray.eu>, Kalray Inc.
+
+#include <dma.h>
+#include <asm/barrier.h>
+#include <asm/io.h>
+#include <asm/cache.h>
+#include <asm/sfr.h>
+#include <asm/sys_arch.h>
+
+/*
+ * The implementation of arch should follow the following rules:
+ *		map		for_cpu		for_device	unmap
+ * TO_DEV	writeback	none		writeback	none
+ * FROM_DEV	invalidate	invalidate(*)	invalidate	invalidate(*)
+ * BIDIR	writeback	invalidate	writeback	invalidate
+ *
+ * (*) - only necessary if the CPU speculatively prefetches.
+ *
+ * (see https://lkml.org/lkml/2018/5/18/979)
+ */
+
+void dma_sync_single_for_device(dma_addr_t addr, size_t size,
+				enum dma_data_direction dir)
+{
+	/* dcache is Write-Through: no need to flush to force writeback */
+	switch (dir) {
+	case DMA_FROM_DEVICE:
+		invalidate_dcache_range(addr, addr + size);
+		break;
+	case DMA_TO_DEVICE:
+	case DMA_BIDIRECTIONAL:
+		/* allow device to read buffer written by CPU */
+		wmb();
+		break;
+	default:
+		BUG();
+	}
+}
+
+void dma_sync_single_for_cpu(dma_addr_t addr, size_t size,
+				enum dma_data_direction dir)
+{
+	/* CPU does not speculatively prefetches */
+	switch (dir) {
+	case DMA_FROM_DEVICE:
+		/* invalidate has been done during map/for_device */
+	case DMA_TO_DEVICE:
+		break;
+	case DMA_BIDIRECTIONAL:
+		invalidate_dcache_range(addr, addr + size);
+		break;
+	default:
+		BUG();
+	}
+}
+
+#define KVX_DDR_ALIAS_OFFSET \
+	(KVX_DDR_64BIT_RAM_WINDOW_BA - KVX_DDR_32BIT_RAM_WINDOW_BA)
+#define KVX_DDR_ALIAS_WINDOW \
+	(KVX_DDR_64BIT_RAM_WINDOW_BA + KVX_DDR_ALIAS_OFFSET)
+
+/* Local smem is aliased between 0 and 16MB */
+#define KVX_SMEM_LOCAL_ALIAS 0x1000000ULL
+
+dma_addr_t dma_map_single(struct device_d *dev, void *ptr, size_t size,
+			  enum dma_data_direction dir)
+{
+	uintptr_t addr = (uintptr_t) ptr;
+
+	dma_sync_single_for_device(addr, size, dir);
+
+	/* Local smem alias should never be used for dma */
+	if (addr < KVX_SMEM_LOCAL_ALIAS)
+		return addr + (1 + kvx_cluster_id()) * KVX_SMEM_LOCAL_ALIAS;
+
+	if (dev->dma_mask && addr <= dev->dma_mask)
+		return addr;
+
+	if (addr >= KVX_DDR_ALIAS_WINDOW)
+		return DMA_ERROR_CODE;
+
+	addr -= KVX_DDR_ALIAS_OFFSET;
+	if (dev->dma_mask && addr > dev->dma_mask)
+		return DMA_ERROR_CODE;
+
+	return addr;
+}
+
+void dma_unmap_single(struct device_d *dev, dma_addr_t addr, size_t size,
+		      enum dma_data_direction dir)
+{
+	dma_sync_single_for_cpu(addr, size, dir);
+}
-- 
2.17.1



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[PATCH v2 4/5] kvx: Request enough privilege to boot Linux

[Jules Maselbas]

At startup barebox must take all the privileges that will be
requested by Linux.

Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
---
changes v1 -> v2: nothing
---
 arch/kvx/cpu/start.S             |  4 ++++
 arch/kvx/include/asm/privilege.h | 16 ++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/arch/kvx/cpu/start.S b/arch/kvx/cpu/start.S
index d90272c71..a647e8a51 100644
--- a/arch/kvx/cpu/start.S
+++ b/arch/kvx/cpu/start.S
@@ -115,6 +115,10 @@ ENDPROC(kvx_start)
 	wfxl $psow = $r21 ;\
 	;; ;\
 	wfxm $psow = $r22 ;\
+	;; ;\
+	make $r21 = DO_WFXL_VALUE_##__pl ;\
+	;; ;\
+	wfxl $dow = $r21 ;\
 	;;
 
 /**
diff --git a/arch/kvx/include/asm/privilege.h b/arch/kvx/include/asm/privilege.h
index 36b9ade49..f183b24d4 100644
--- a/arch/kvx/include/asm/privilege.h
+++ b/arch/kvx/include/asm/privilege.h
@@ -113,6 +113,21 @@
 #define ITO_WFXM_VALUE_PL_CUR_PLUS_1	ITO_WFXM_VALUE(PL_CUR_PLUS_1)
 #define ITO_WFXM_VALUE_PL_CUR		ITO_WFXM_VALUE(PL_CUR)
 
+/**
+ * Debug Owner configuration
+ */
+
+#define DO_WFXL_OWN(__field, __pl) \
+	SFR_SET_VAL_WFXL(DO, __field, __pl)
+
+#define DO_WFXL_VALUE(__pl) (DO_WFXL_OWN(B0, __pl) | \
+			     DO_WFXL_OWN(B1, __pl) | \
+			     DO_WFXL_OWN(W0, __pl) | \
+			     DO_WFXL_OWN(W1, __pl))
+
+#define DO_WFXL_VALUE_PL_CUR_PLUS_1     DO_WFXL_VALUE(PL_CUR_PLUS_1)
+#define DO_WFXL_VALUE_PL_CUR            DO_WFXL_VALUE(PL_CUR)
+
 /**
  * Misc owner configuration
  */
@@ -160,6 +175,7 @@
 					 PSO_WFXL_OWN(IE, __pl) | \
 					 PSO_WFXL_OWN(HLE, __pl) | \
 					 PSO_WFXL_OWN(SRE, __pl) | \
+					 PSO_WFXL_OWN(DAUS, __pl) | \
 					 PSO_WFXL_OWN(ICE, __pl) | \
 					 PSO_WFXL_OWN(USE, __pl) | \
 					 PSO_WFXL_OWN(DCE, __pl) | \
-- 
2.17.1



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[PATCH v2 5/5] kvx: lib: dtb: Remove unused variable

[Jules Maselbas]

Local variables `root` and `ret` are not used anymore, remove them.

Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
---
changes v1 -> v2: nothing
---
 arch/kvx/lib/dtb.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/kvx/lib/dtb.c b/arch/kvx/lib/dtb.c
index 54ffddaf0..09898017c 100644
--- a/arch/kvx/lib/dtb.c
+++ b/arch/kvx/lib/dtb.c
@@ -9,9 +9,6 @@
 
 static int of_kvx_init(void)
 {
-	int ret;
-	struct device_node *root;
-
 	barebox_register_fdt(boot_dtb);
 
 	return 0;
-- 
2.17.1



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Re: [PATCH v2 1/5] kvx: Implement setjmp/longjmp/initjmp

[Sascha Hauer]

On Fri, Mar 05, 2021 at 07:33:23PM +0100, Jules Maselbas wrote:
> Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
> ---
> changes v1 -> v2: nothing
> ---
>  arch/kvx/Kconfig              |  1 +
>  arch/kvx/include/asm/setjmp.h | 15 +++++++
>  arch/kvx/lib/Makefile         |  2 +-
>  arch/kvx/lib/setjmp.S         | 85 +++++++++++++++++++++++++++++++++++
>  4 files changed, 102 insertions(+), 1 deletion(-)
>  create mode 100644 arch/kvx/include/asm/setjmp.h
>  create mode 100644 arch/kvx/lib/setjmp.S

Applied, thanks

Sascha

> 
> diff --git a/arch/kvx/Kconfig b/arch/kvx/Kconfig
> index 3327021e1..8483ae6e6 100644
> --- a/arch/kvx/Kconfig
> +++ b/arch/kvx/Kconfig
> @@ -11,6 +11,7 @@ config KVX
>  	select ELF
>  	select FLEXIBLE_BOOTARGS
>  	select GENERIC_FIND_NEXT_BIT
> +	select HAS_ARCH_SJLJ
>  	select LIBFDT
>  	select MFD_SYSCON
>  	select OF_BAREBOX_DRIVERS
> diff --git a/arch/kvx/include/asm/setjmp.h b/arch/kvx/include/asm/setjmp.h
> new file mode 100644
> index 000000000..3cfc698d9
> --- /dev/null
> +++ b/arch/kvx/include/asm/setjmp.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/* SPDX-FileCopyrightText: 2021 Jules Maselbas <jmaselbas@kalray.eu>, Kalray Inc. */
> +
> +#ifndef _ASM_KVX_SETJMP_H_
> +#define _ASM_KVX_SETJMP_H_
> +
> +#include <linux/types.h>
> +
> +typedef u64 jmp_buf[22];
> +
> +int initjmp(jmp_buf jmp, void __noreturn (*func)(void), void *stack_top);
> +int setjmp(jmp_buf jmp) __attribute__((returns_twice));
> +void longjmp(jmp_buf jmp, int ret) __attribute__((noreturn));
> +
> +#endif /* _ASM_KVX_SETJMP_H_ */
> diff --git a/arch/kvx/lib/Makefile b/arch/kvx/lib/Makefile
> index 6e56462da..cee08b0fa 100644
> --- a/arch/kvx/lib/Makefile
> +++ b/arch/kvx/lib/Makefile
> @@ -3,4 +3,4 @@
>  # Copyright (C) 2019 Kalray Inc.
>  #
>  
> -obj-y	+= cpuinfo.o board.o dtb.o poweroff.o bootm.o
> +obj-y	+= cpuinfo.o board.o dtb.o poweroff.o bootm.o setjmp.o
> diff --git a/arch/kvx/lib/setjmp.S b/arch/kvx/lib/setjmp.S
> new file mode 100644
> index 000000000..829299711
> --- /dev/null
> +++ b/arch/kvx/lib/setjmp.S
> @@ -0,0 +1,85 @@
> +/* SPDX-License-Identifier: LGPL-2.1 */
> +/* SPDX-FileCopyrightText: 2021 Jules Maselbas <jmaselbas@kalray.eu>, Kalray Inc. */
> +
> +#define REG_SIZE 8
> +
> +#include <linux/linkage.h>
> +
> +/* jmp_buf layout:
> + * [0]  = $ra,  $sp,  $cs,  $r14,
> + * [4]  = $r20, $r21, $r22, $r23,
> + * [8]  = $r24, $r25, $r26, $r27,
> + * [12] = $r28, $r29, $r30, $r31,
> + * [16] = $r18, $r19,
> + * [18] = $lc,  $le,  $ls,  xxxx
> + */
> +
> +/**
> + * int initjmp(jmp_buf jmp, void __noreturn (*func)(void), void *stack_top);
> + */
> +ENTRY(initjmp)
> +	/* store $ra */
> +	sd (0 * REG_SIZE)[$r0] = $r1
> +	;;
> +	/* store $sp */
> +	sd (1 * REG_SIZE)[$r0] = $r2
> +	make $r0 = 0
> +	ret
> +	;;
> +ENDPROC(initjmp)
> +
> +/**
> + * int setjmp(jmp_buf jmp);
> + */
> +ENTRY(setjmp)
> +	sq (16 * REG_SIZE)[$r0] = $r18r19
> +	get $r40 = $ra
> +	copyd $r41 = $sp
> +	;;
> +	so (4 * REG_SIZE)[$r0] = $r20r21r22r23
> +	get $r42 = $cs
> +	copyd $r43 = $r14
> +	;;
> +	so (0 * REG_SIZE)[$r0] = $r40r41r42r43
> +	get $r40 = $lc
> +	;;
> +	so (8 * REG_SIZE)[$r0] = $r24r25r26r27
> +	get $r41 = $le
> +	;;
> +	so (12 * REG_SIZE)[$r0] = $r28r29r30r31
> +	get $r42 = $ls
> +	;;
> +	so (18 * REG_SIZE)[$r0] = $r40r41r42r43
> +	make $r0 = 0
> +	ret
> +	;;
> +ENDPROC(setjmp)
> +
> +/**
> + * void longjmp(jmp_buf jmp, int ret);
> + */
> +ENTRY(longjmp)
> +	lo $r40r41r42r43 = (0 * REG_SIZE)[$r0]
> +	;;
> +	lo $r44r45r46r47 = (18 * REG_SIZE)[$r0]
> +	set $ra = $r40
> +	copyd $sp = $r41
> +	;;
> +	lo $r20r21r22r23 = (4 * REG_SIZE)[$r0]
> +	set $cs = $r42
> +	copyd $r14 = $r43
> +	;;
> +	lo $r24r25r26r27 = (8 * REG_SIZE)[$r0]
> +	set $lc = $r44
> +	;;
> +	lo $r28r29r30r31 = (12 * REG_SIZE)[$r0]
> +	set $le = $r45
> +	;;
> +	lq $r18r19 = (16 * REG_SIZE)[$r0]
> +	set $ls = $r46
> +	;;
> +	/* According to man, if retval is equal to 0, then we should return 1 */
> +	maxud $r0 = $r1, 1
> +	ret
> +	;;
> +ENDPROC(longjmp)
> -- 
> 2.17.1
> 
> 
> 
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox
> 
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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Re: [PATCH v2 3/5] kvx: Implement dma handling primitives

[Ahmad Fatoum]

Hello Jules, Yann,

On 05.03.21 19:33, Jules Maselbas wrote:
> From: Yann Sionneau <ysionneau@kalray.eu>
> 
> Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>

[snip]

> diff --git a/arch/kvx/lib/dma-default.c b/arch/kvx/lib/dma-default.c
> new file mode 100644
> index 000000000..2a4144696
> --- /dev/null
> +++ b/arch/kvx/lib/dma-default.c
> @@ -0,0 +1,94 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +// SPDX-FileCopyrightText: 2021 Yann Sionneau <ysionneau@kalray.eu>, Kalray Inc.
> +
> +#include <dma.h>
> +#include <asm/barrier.h>
> +#include <asm/io.h>
> +#include <asm/cache.h>
> +#include <asm/sfr.h>
> +#include <asm/sys_arch.h>
> +
> +/*
> + * The implementation of arch should follow the following rules:
> + *		map		for_cpu		for_device	unmap
> + * TO_DEV	writeback	none		writeback	none
> + * FROM_DEV	invalidate	invalidate(*)	invalidate	invalidate(*)
> + * BIDIR	writeback	invalidate	writeback	invalidate
> + *
> + * (*) - only necessary if the CPU speculatively prefetches.
> + *
> + * (see https://lkml.org/lkml/2018/5/18/979)
> + */
> +
> +void dma_sync_single_for_device(dma_addr_t addr, size_t size,
> +				enum dma_data_direction dir)
> +{
> +	/* dcache is Write-Through: no need to flush to force writeback */
> +	switch (dir) {
> +	case DMA_FROM_DEVICE:
> +		invalidate_dcache_range(addr, addr + size);
> +		break;
> +	case DMA_TO_DEVICE:
> +	case DMA_BIDIRECTIONAL:
> +		/* allow device to read buffer written by CPU */
> +		wmb();
> +		break;
> +	default:
> +		BUG();
> +	}
> +}
> +
> +void dma_sync_single_for_cpu(dma_addr_t addr, size_t size,
> +				enum dma_data_direction dir)
> +{
> +	/* CPU does not speculatively prefetches */
> +	switch (dir) {
> +	case DMA_FROM_DEVICE:
> +		/* invalidate has been done during map/for_device */
> +	case DMA_TO_DEVICE:
> +		break;
> +	case DMA_BIDIRECTIONAL:
> +		invalidate_dcache_range(addr, addr + size);
> +		break;
> +	default:
> +		BUG();
> +	}
> +}

Both of these work on CPU pointers.

> +
> +#define KVX_DDR_ALIAS_OFFSET \
> +	(KVX_DDR_64BIT_RAM_WINDOW_BA - KVX_DDR_32BIT_RAM_WINDOW_BA)
> +#define KVX_DDR_ALIAS_WINDOW \
> +	(KVX_DDR_64BIT_RAM_WINDOW_BA + KVX_DDR_ALIAS_OFFSET)
> +
> +/* Local smem is aliased between 0 and 16MB */
> +#define KVX_SMEM_LOCAL_ALIAS 0x1000000ULL
> +
> +dma_addr_t dma_map_single(struct device_d *dev, void *ptr, size_t size,
> +			  enum dma_data_direction dir)
> +{
> +	uintptr_t addr = (uintptr_t) ptr;
> +
> +	dma_sync_single_for_device(addr, size, dir);

So this is correct.

> +
> +	/* Local smem alias should never be used for dma */
> +	if (addr < KVX_SMEM_LOCAL_ALIAS)
> +		return addr + (1 + kvx_cluster_id()) * KVX_SMEM_LOCAL_ALIAS;
> +
> +	if (dev->dma_mask && addr <= dev->dma_mask)
> +		return addr;
> +
> +	if (addr >= KVX_DDR_ALIAS_WINDOW)
> +		return DMA_ERROR_CODE;
> +
> +	addr -= KVX_DDR_ALIAS_OFFSET;
> +	if (dev->dma_mask && addr > dev->dma_mask)
> +		return DMA_ERROR_CODE;
> +
> +	return addr;
> +}

Now you compute a dma_addr_t as CPU pointer - KVX_DDR_ALIAS_OFFSET.

> +
> +void dma_unmap_single(struct device_d *dev, dma_addr_t addr, size_t size,
> +		      enum dma_data_direction dir)
> +{
> +	dma_sync_single_for_cpu(addr, size, dir);

And then that dma_addr_t is passed here without + KVX_DDR_ALIAS_OFFSET
to get a CPU pointer out.
So for DMA_BIDIRECTIONAL you'd invalidate the wrong cache region.


I stumbled upon this, because I noticed that that kvx whould've failed to
build starting with v2021.04.0, because following commits conflict with each other:

3f975f810bd3 ("dma: move dma_map/unmap_single from ARM to common code") commited on 2021-03-03
4808d6f80073 ("kvx: Implement dma handling primitives") commited on 2021-03-05

Now, dma_map_single() is defined twice for kvx.

As dma_(un?)map_single is always called with a dev argument, couldn't you define the
DMA offsets in the device tree and use the common drivers/dma/map.c implementation
for these two functions?

Cheers,
Ahmad

> +}
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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Re: [PATCH v2 3/5] kvx: Implement dma handling primitives

[Jules Maselbas]

Hi Ahmad,

On Mon, May 17, 2021 at 12:42:21PM +0200, Ahmad Fatoum wrote:
> Hello Jules, Yann,
> 
> On 05.03.21 19:33, Jules Maselbas wrote:
> > From: Yann Sionneau <ysionneau@kalray.eu>
> > 
> > Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
> 
> [snip]
> 
> > diff --git a/arch/kvx/lib/dma-default.c b/arch/kvx/lib/dma-default.c
> > new file mode 100644
> > index 000000000..2a4144696
> > --- /dev/null
> > +++ b/arch/kvx/lib/dma-default.c
> > @@ -0,0 +1,94 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +// SPDX-FileCopyrightText: 2021 Yann Sionneau <ysionneau@kalray.eu>, Kalray Inc.
> > +
> > +#include <dma.h>
> > +#include <asm/barrier.h>
> > +#include <asm/io.h>
> > +#include <asm/cache.h>
> > +#include <asm/sfr.h>
> > +#include <asm/sys_arch.h>
> > +
> > +/*
> > + * The implementation of arch should follow the following rules:
> > + *		map		for_cpu		for_device	unmap
> > + * TO_DEV	writeback	none		writeback	none
> > + * FROM_DEV	invalidate	invalidate(*)	invalidate	invalidate(*)
> > + * BIDIR	writeback	invalidate	writeback	invalidate
> > + *
> > + * (*) - only necessary if the CPU speculatively prefetches.
> > + *
> > + * (see https://lkml.org/lkml/2018/5/18/979)
> > + */
> > +
> > +void dma_sync_single_for_device(dma_addr_t addr, size_t size,
> > +				enum dma_data_direction dir)
> > +{
> > +	/* dcache is Write-Through: no need to flush to force writeback */
> > +	switch (dir) {
> > +	case DMA_FROM_DEVICE:
> > +		invalidate_dcache_range(addr, addr + size);
> > +		break;
> > +	case DMA_TO_DEVICE:
> > +	case DMA_BIDIRECTIONAL:
> > +		/* allow device to read buffer written by CPU */
> > +		wmb();
> > +		break;
> > +	default:
> > +		BUG();
> > +	}
> > +}
> > +
> > +void dma_sync_single_for_cpu(dma_addr_t addr, size_t size,
> > +				enum dma_data_direction dir)
> > +{
> > +	/* CPU does not speculatively prefetches */
> > +	switch (dir) {
> > +	case DMA_FROM_DEVICE:
> > +		/* invalidate has been done during map/for_device */
> > +	case DMA_TO_DEVICE:
> > +		break;
> > +	case DMA_BIDIRECTIONAL:
> > +		invalidate_dcache_range(addr, addr + size);
> > +		break;
> > +	default:
> > +		BUG();
> > +	}
> > +}
> 
> Both of these work on CPU pointers.
> 
> > +
> > +#define KVX_DDR_ALIAS_OFFSET \
> > +	(KVX_DDR_64BIT_RAM_WINDOW_BA - KVX_DDR_32BIT_RAM_WINDOW_BA)
> > +#define KVX_DDR_ALIAS_WINDOW \
> > +	(KVX_DDR_64BIT_RAM_WINDOW_BA + KVX_DDR_ALIAS_OFFSET)
> > +
> > +/* Local smem is aliased between 0 and 16MB */
> > +#define KVX_SMEM_LOCAL_ALIAS 0x1000000ULL
> > +
> > +dma_addr_t dma_map_single(struct device_d *dev, void *ptr, size_t size,
> > +			  enum dma_data_direction dir)
> > +{
> > +	uintptr_t addr = (uintptr_t) ptr;
> > +
> > +	dma_sync_single_for_device(addr, size, dir);
> 
> So this is correct.
> 
> > +
> > +	/* Local smem alias should never be used for dma */
> > +	if (addr < KVX_SMEM_LOCAL_ALIAS)
> > +		return addr + (1 + kvx_cluster_id()) * KVX_SMEM_LOCAL_ALIAS;
> > +
> > +	if (dev->dma_mask && addr <= dev->dma_mask)
> > +		return addr;
> > +
> > +	if (addr >= KVX_DDR_ALIAS_WINDOW)
> > +		return DMA_ERROR_CODE;
> > +
> > +	addr -= KVX_DDR_ALIAS_OFFSET;
> > +	if (dev->dma_mask && addr > dev->dma_mask)
> > +		return DMA_ERROR_CODE;
> > +
> > +	return addr;
> > +}
> 
> Now you compute a dma_addr_t as CPU pointer - KVX_DDR_ALIAS_OFFSET.
> 
> > +
> > +void dma_unmap_single(struct device_d *dev, dma_addr_t addr, size_t size,
> > +		      enum dma_data_direction dir)
> > +{
> > +	dma_sync_single_for_cpu(addr, size, dir);
> 
> And then that dma_addr_t is passed here without + KVX_DDR_ALIAS_OFFSET
> to get a CPU pointer out.
> So for DMA_BIDIRECTIONAL you'd invalidate the wrong cache region.
Yes, this is bogus but I believe in our case dma_unmap_single is never
called with DMA_BIDIRECTIONAL.

> 
> I stumbled upon this, because I noticed that that kvx whould've failed to
> build starting with v2021.04.0, because following commits conflict with each other:
> 3f975f810bd3 ("dma: move dma_map/unmap_single from ARM to common code") commited on 2021-03-03
> 4808d6f80073 ("kvx: Implement dma handling primitives") commited on 2021-03-05
> 
> Now, dma_map_single() is defined twice for kvx.
Yes,  I noticed this as well when rebasing on barebox v2021.04.

> As dma_(un?)map_single is always called with a dev argument, couldn't you define the
> DMA offsets in the device tree and use the common drivers/dma/map.c implementation
> for these two functions?
Our custom implementation will be removed in favor of the common
implementation and the uses of dma-range.

I had to add a dma-range to the dwc2 device nodes in our device tree, so
when the driver does dma_map/unmap the common implementation will do the
correct remap to the aliased region (so addresses fits in 32bit).

However I do not know how Linux handle a mix of dma-range and iommu.
Since I didn't had much time to test this we are still using v2021.03. 


Thanks,
Jules


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