[PATCH 0/5] Fix some bugs on RV32 build fail and issue.

[PATCH 0/5] Fix some bugs on RV32 build fail and issue.

[Zong Li]

This patches fix up the building fail, less function and other issue on RV32.

Vincent Chen (1):
  RISC-V: Avoid corrupting the upper 32-bit of phys_addr_t in ioremap

Zong Li (4):
  RISC-V: Build tishift only on 64-bit
  RISC-V: Use swiotlb on RV64 only
  lib: Add umoddi3 and udivmoddi4 of GCC library routines
  RISC-V: Select GENERIC_LIB_UMODDI3 on RV32

 arch/riscv/Kconfig        |   1 +
 arch/riscv/kernel/setup.c |   3 +
 arch/riscv/lib/Makefile   |   3 +-
 arch/riscv/mm/ioremap.c   |   2 +-
 lib/Kconfig               |   3 +
 lib/Makefile              |   1 +
 lib/udivmoddi4.c          | 291 ++++++++++++++++++++++++++++++++++++++++++++++
 lib/umoddi3.c             |  16 +++
 8 files changed, 318 insertions(+), 2 deletions(-)
 create mode 100644 lib/udivmoddi4.c
 create mode 100644 lib/umoddi3.c

-- 
2.7.4

[PATCH 1/5] RISC-V: Build tishift only on 64-bit

[Zong Li]

Only RV64 supports 128 integer size.

Signed-off-by: Zong Li <zong@andestech.com>
---
 arch/riscv/lib/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 445ec84..5739bd0 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -2,6 +2,7 @@ lib-y	+= delay.o
 lib-y	+= memcpy.o
 lib-y	+= memset.o
 lib-y	+= uaccess.o
-lib-y	+= tishift.o
+
+lib-(CONFIG_64BIT) += tishift.o
 
 lib-$(CONFIG_32BIT) += udivdi3.o
-- 
2.7.4

[PATCH 2/5] RISC-V: Use swiotlb on RV64 only

[Zong Li]

Only RV64 supports swiotlb.

Signed-off-by: Zong Li <zong@andestech.com>
---
 arch/riscv/kernel/setup.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index aee6031..872a280 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -227,7 +227,10 @@ void __init setup_arch(char **cmdline_p)
 	setup_bootmem();
 	paging_init();
 	unflatten_device_tree();
+
+#ifdef CONFIG_64bit
 	swiotlb_init(1);
+#endif
 
 #ifdef CONFIG_SMP
 	setup_smp();
-- 
2.7.4

[PATCH 3/5] lib: Add umoddi3 and udivmoddi4 of GCC library routines

[Zong Li]

Add umoddi3 and udivmoddi4 support for 32-bit.

Signed-off-by: Zong Li <zong@andestech.com>
---
 lib/Kconfig      |   3 +
 lib/Makefile     |   1 +
 lib/udivmoddi4.c | 291 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/umoddi3.c    |  16 +++
 4 files changed, 311 insertions(+)
 create mode 100644 lib/udivmoddi4.c
 create mode 100644 lib/umoddi3.c

diff --git a/lib/Kconfig b/lib/Kconfig
index a3928d4..d82f206 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -621,3 +621,6 @@ config GENERIC_LIB_CMPDI2
 
 config GENERIC_LIB_UCMPDI2
 	bool
+
+config GENERIC_LIB_UMODDI3
+	bool
diff --git a/lib/Makefile b/lib/Makefile
index ca3f7eb..51bf24d 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -271,3 +271,4 @@ obj-$(CONFIG_GENERIC_LIB_LSHRDI3) += lshrdi3.o
 obj-$(CONFIG_GENERIC_LIB_MULDI3) += muldi3.o
 obj-$(CONFIG_GENERIC_LIB_CMPDI2) += cmpdi2.o
 obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o
+obj-$(CONFIG_GENERIC_LIB_UMODDI3) += umoddi3.o udivmoddi4.o
diff --git a/lib/udivmoddi4.c b/lib/udivmoddi4.c
new file mode 100644
index 0000000..69f2d36
--- /dev/null
+++ b/lib/udivmoddi4.c
@@ -0,0 +1,291 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/libgcc.h>
+
+#define count_leading_zeros(COUNT, X)   ((COUNT) = __builtin_clz(X))
+
+#define W_TYPE_SIZE 32
+
+#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))
+#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))
+#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))
+
+/* If we still don't have umul_ppmm, define it using plain C. */
+#if !defined(umul_ppmm)
+#define umul_ppmm(w1, w0, u, v)						\
+	do {								\
+		unsigned long __x0, __x1, __x2, __x3;			\
+		unsigned short __ul, __vl, __uh, __vh;			\
+									\
+		__ul = __ll_lowpart(u);					\
+		__uh = __ll_highpart(u);				\
+		__vl = __ll_lowpart(v);					\
+		__vh = __ll_highpart(v);				\
+									\
+		__x0 = (unsigned long) __ul * __vl;			\
+		__x1 = (unsigned long) __ul * __vh;			\
+		__x2 = (unsigned long) __uh * __vl;			\
+		__x3 = (unsigned long) __uh * __vh;			\
+									\
+		__x1 += __ll_highpart(__x0);				\
+		__x1 += __x2;						\
+		if (__x1 < __x2)					\
+			__x3 += __ll_B;					\
+									\
+		(w1) = __x3 + __ll_highpart(__x1);			\
+		(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
+	} while (0)
+#endif
+
+#if !defined(sub_ddmmss)
+#define sub_ddmmss(sh, sl, ah, al, bh, bl)				\
+	do {								\
+		unsigned long __x;					\
+		__x = (al) - (bl);					\
+		(sh) = (ah) - (bh) - (__x > (al));			\
+		(sl) = __x;						\
+	} while (0)
+#endif
+
+/* Define this unconditionally, so it can be used for debugging. */
+#define __udiv_qrnnd_c(q, r, n1, n0, d)					\
+	do {								\
+		unsigned long __d1, __d0, __q1, __q0;			\
+		unsigned long __r1, __r0, __m;				\
+		__d1 = __ll_highpart(d);				\
+		__d0 = __ll_lowpart(d);				\
+									\
+		__r1 = (n1) % __d1;					\
+		__q1 = (n1) / __d1;					\
+		__m = (unsigned long) __q1 * __d0;			\
+		__r1 = __r1 * __ll_B | __ll_highpart(n0);		\
+		if (__r1 < __m) {					\
+			__q1--, __r1 += (d);				\
+			if (__r1 >= (d))				\
+				if (__r1 < __m)				\
+					__q1--, __r1 += (d);		\
+		}							\
+		__r1 -= __m;						\
+									\
+		__r0 = __r1 % __d1;					\
+		__q0 = __r1 / __d1;					\
+		__m = (unsigned long) __q0 * __d0;			\
+		__r0 = __r0 * __ll_B | __ll_lowpart(n0);		\
+		if (__r0 < __m) {					\
+			__q0--, __r0 += (d);				\
+			if (__r0 >= (d))				\
+				if (__r0 < __m)				\
+					__q0--, __r0 += (d);		\
+		}							\
+		__r0 -= __m;						\
+									\
+		(q) = (unsigned long) __q1 * __ll_B | __q0;		\
+		(r) = __r0;						\
+	} while (0)
+
+/* If udiv_qrnnd was not defined for this processor, use __udiv_qrnnd_c. */
+#if !defined(udiv_qrnnd)
+#define UDIV_NEEDS_NORMALIZATION 1
+#define udiv_qrnnd __udiv_qrnnd_c
+#endif
+
+unsigned long long __udivmoddi4(unsigned long long u, unsigned long long v,
+				unsigned long long *rp)
+{
+	const DWunion nn = {.ll = u };
+	const DWunion dd = {.ll = v };
+	DWunion rr, ww;
+	unsigned long d0, d1, n0, n1, n2;
+	unsigned long q0 = 0, q1 = 0;
+	unsigned long b, bm;
+
+	d0 = dd.s.low;
+	d1 = dd.s.high;
+	n0 = nn.s.low;
+	n1 = nn.s.high;
+
+#if !UDIV_NEEDS_NORMALIZATION
+
+	if (d1 == 0) {
+		if (d0 > n1) {
+			/* 0q = nn / 0D */
+
+			udiv_qrnnd(q0, n0, n1, n0, d0);
+			q1 = 0;
+
+			/* Remainder in n0. */
+		} else {
+			/* qq = NN / 0d */
+
+			if (d0 == 0)
+				/* Divide intentionally by zero. */
+				d0 = 1 / d0;
+
+			udiv_qrnnd(q1, n1, 0, n1, d0);
+			udiv_qrnnd(q0, n0, n1, n0, d0);
+
+			/* Remainder in n0. */
+		}
+
+		if (rp != 0) {
+			rr.s.low = n0;
+			rr.s.high = 0;
+			*rp = rr.ll;
+		}
+#else /* UDIV_NEEDS_NORMALIZATION */
+
+	if (d1 == 0) {
+		if (d0 > n1) {
+			/* 0q = nn / 0D */
+
+			count_leading_zeros(bm, d0);
+
+			if (bm != 0) {
+				/*
+				 * Normalize, i.e. make the most significant bit
+				 * of the denominator set.
+				 */
+
+				d0 = d0 << bm;
+				n1 = (n1 << bm) | (n0 >> (W_TYPE_SIZE - bm));
+				n0 = n0 << bm;
+			}
+
+			udiv_qrnnd(q0, n0, n1, n0, d0);
+			q1 = 0;
+
+			/* Remainder in n0 >> bm. */
+		} else {
+			/* qq = NN / 0d */
+
+			if (d0 == 0)
+				/* Divide intentionally by zero. */
+				d0 = 1 / d0;
+
+			count_leading_zeros(bm, d0);
+
+			if (bm == 0) {
+				/*
+				 * From (n1 >= d0) /\ (the most significant bit
+				 * of d0 is set), conclude (the most significant
+				 * bit of n1 is set) /\ (theleading quotient
+				 * digit q1 = 1).
+				 *
+				 * This special case is necessary, not an
+				 * optimization. (Shifts counts of W_TYPE_SIZE
+				 * are undefined.)
+				 */
+
+				n1 -= d0;
+				q1 = 1;
+			} else {
+				/* Normalize. */
+
+				b = W_TYPE_SIZE - bm;
+
+				d0 = d0 << bm;
+				n2 = n1 >> b;
+				n1 = (n1 << bm) | (n0 >> b);
+				n0 = n0 << bm;
+
+				udiv_qrnnd(q1, n1, n2, n1, d0);
+			}
+
+			/* n1 != d0... */
+
+			udiv_qrnnd(q0, n0, n1, n0, d0);
+
+			/* Remainder in n0 >> bm. */
+		}
+
+		if (rp != 0) {
+			rr.s.low = n0 >> bm;
+			rr.s.high = 0;
+			*rp = rr.ll;
+		}
+#endif /* UDIV_NEEDS_NORMALIZATION */
+
+	} else {
+		if (d1 > n1) {
+			/* 00 = nn / DD */
+
+			q0 = 0;
+			q1 = 0;
+
+			/* Remainder in n1n0. */
+			if (rp != 0) {
+				rr.s.low = n0;
+				rr.s.high = n1;
+				*rp = rr.ll;
+			}
+		} else {
+			/* 0q = NN / dd */
+
+			count_leading_zeros(bm, d1);
+			if (bm == 0) {
+				/*
+				 * From (n1 >= d1) /\ (the most significant bit
+				 * of d1 is set), conclude (the most significant
+				 * bit of n1 is set) /\ (the quotient digit q0 =
+				 * 0 or 1).
+				 *
+				 * This special case is necessary, not an
+				 * optimization.
+				 */
+
+				/*
+				 * The condition on the next line takes
+				 * advantage of that n1 >= d1 (true due to
+				 * program flow).
+				 */
+				if (n1 > d1 || n0 >= d0) {
+					q0 = 1;
+					sub_ddmmss(n1, n0, n1, n0, d1, d0);
+				} else {
+					q0 = 0;
+				}
+
+				q1 = 0;
+
+				if (rp != 0) {
+					rr.s.low = n0;
+					rr.s.high = n1;
+					*rp = rr.ll;
+				}
+			} else {
+				unsigned long m1, m0;
+				/* Normalize. */
+
+				b = W_TYPE_SIZE - bm;
+
+				d1 = (d1 << bm) | (d0 >> b);
+				d0 = d0 << bm;
+				n2 = n1 >> b;
+				n1 = (n1 << bm) | (n0 >> b);
+				n0 = n0 << bm;
+
+				udiv_qrnnd(q0, n1, n2, n1, d1);
+				umul_ppmm(m1, m0, q0, d0);
+
+				if (m1 > n1 || (m1 == n1 && m0 > n0)) {
+					q0--;
+					sub_ddmmss(m1, m0, m1, m0, d1, d0);
+				}
+
+				q1 = 0;
+
+				/* Remainder in (n1n0 - m1m0) >> bm. */
+				if (rp != 0) {
+					sub_ddmmss(n1, n0, n1, n0, m1, m0);
+					rr.s.low = (n1 << b) | (n0 >> bm);
+					rr.s.high = n1 >> bm;
+					*rp = rr.ll;
+				}
+			}
+		}
+	}
+
+	ww.s.low = q0;
+	ww.s.high = q1;
+	return ww.ll;
+}
diff --git a/lib/umoddi3.c b/lib/umoddi3.c
new file mode 100644
index 0000000..85b2b86
--- /dev/null
+++ b/lib/umoddi3.c
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/module.h>
+#include <linux/libgcc.h>
+
+extern unsigned long long __udivmoddi4(unsigned long long u,
+				       unsigned long long v,
+				       unsigned long long *rp);
+
+unsigned long long __umoddi3(unsigned long long u, unsigned long long v)
+{
+	unsigned long long w;
+	(void)__udivmoddi4(u, v, &w);
+	return w;
+}
+EXPORT_SYMBOL(__umoddi3);
-- 
2.7.4

[PATCH 4/5] RISC-V: Select GENERIC_LIB_UMODDI3 on RV32

[Zong Li]

On 32-bit, it need to use __umoddi3 by some drivers.

Signed-off-by: Zong Li <zong@andestech.com>
---
 arch/riscv/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a344980..dc262fa 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -108,6 +108,7 @@ config ARCH_RV32I
 	select GENERIC_LIB_ASHRDI3
 	select GENERIC_LIB_LSHRDI3
 	select GENERIC_LIB_UCMPDI2
+	select GENERIC_LIB_UMODDI3
 
 config ARCH_RV64I
 	bool "RV64I"
-- 
2.7.4

[PATCH 5/5] RISC-V: Avoid corrupting the upper 32-bit of phys_addr_t in ioremap

[Zong Li]

From: Vincent Chen <vincentc@andestech.com>

For 32bit, the upper 32-bit of phys_addr_t will be flushed to zero
after AND with PAGE_MASK because the data type of PAGE_MASK is
unsigned long. To fix this problem, the page alignment is done by
subtracting the page offset instead of AND with PAGE_MASK.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
---
 arch/riscv/mm/ioremap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/mm/ioremap.c b/arch/riscv/mm/ioremap.c
index 70ef272..bd2f2db 100644
--- a/arch/riscv/mm/ioremap.c
+++ b/arch/riscv/mm/ioremap.c
@@ -42,7 +42,7 @@ static void __iomem *__ioremap_caller(phys_addr_t addr, size_t size,
 
 	/* Page-align mappings */
 	offset = addr & (~PAGE_MASK);
-	addr &= PAGE_MASK;
+	addr -= offset;
 	size = PAGE_ALIGN(size + offset);
 
 	area = get_vm_area_caller(size, VM_IOREMAP, caller);
-- 
2.7.4

Re: [PATCH 1/5] RISC-V: Build tishift only on 64-bit

[Christoph Hellwig]

On Tue, Sep 18, 2018 at 05:19:13PM +0800, Zong Li wrote:
> Only RV64 supports 128 integer size.
> 
> Signed-off-by: Zong Li <zong@andestech.com>

This looks fine.  Just curious, what do we even need 128-bit integers
for on riscv64?  Did you see any issues if you drop it entirely?

Re: [PATCH 2/5] RISC-V: Use swiotlb on RV64 only

[Christoph Hellwig]

On Tue, Sep 18, 2018 at 05:19:14PM +0800, Zong Li wrote:
> Only RV64 supports swiotlb.
> 
> Signed-off-by: Zong Li <zong@andestech.com>

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 3/5] lib: Add umoddi3 and udivmoddi4 of GCC library routines

[Christoph Hellwig]

On Tue, Sep 18, 2018 at 05:19:15PM +0800, Zong Li wrote:
> Add umoddi3 and udivmoddi4 support for 32-bit.

This probably wants a better explanation of why you need them.

> index 0000000..69f2d36
> --- /dev/null
> +++ b/lib/udivmoddi4.c
> @@ -0,0 +1,291 @@
> +// SPDX-License-Identifier: GPL-2.0

Who wrote this code, where does it come from?

Re: [PATCH 5/5] RISC-V: Avoid corrupting the upper 32-bit of phys_addr_t in ioremap

[Christoph Hellwig]

On Tue, Sep 18, 2018 at 05:19:17PM +0800, Zong Li wrote:
> From: Vincent Chen <vincentc@andestech.com>
> 
> For 32bit, the upper 32-bit of phys_addr_t will be flushed to zero
> after AND with PAGE_MASK because the data type of PAGE_MASK is
> unsigned long. To fix this problem, the page alignment is done by
> subtracting the page offset instead of AND with PAGE_MASK.
> 
> Signed-off-by: Vincent Chen <vincentc@andestech.com>

Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 3/5] lib: Add umoddi3 and udivmoddi4 of GCC library routines

[Zong Li]

Christoph Hellwig <hch@infradead.org> 於 2018年9月21日 週五 下午3:00寫道：
>
> On Tue, Sep 18, 2018 at 05:19:15PM +0800, Zong Li wrote:
> > Add umoddi3 and udivmoddi4 support for 32-bit.
>
> This probably wants a better explanation of why you need them.
>
> > index 0000000..69f2d36
> > --- /dev/null
> > +++ b/lib/udivmoddi4.c
> > @@ -0,0 +1,291 @@
> > +// SPDX-License-Identifier: GPL-2.0
>
> Who wrote this code, where does it come from?

The RV32 need the umoddi3 to do modulo when the operands are long long
type, like other libraries implementation such as ucmpdi2, lshrdi3 and
so on. I encounter the undefined reference 'umoddi3' when I use the in
house dma driver, although it is in house driver, but I think that
umoddi3 is a common function for RV32. The udivmoddi4 and umoddi3 are
copies from libgcc in gcc. There are other functions use the
udivmoddi4 in libgcc, so I separate the umoddi3 and udivmoddi4 for
flexible extension in the future.

Re: [PATCH 1/5] RISC-V: Build tishift only on 64-bit

[Zong Li]

Christoph Hellwig <hch@infradead.org> 於 2018年9月21日 週五 下午2:58寫道：
>
> On Tue, Sep 18, 2018 at 05:19:13PM +0800, Zong Li wrote:
> > Only RV64 supports 128 integer size.
> >
> > Signed-off-by: Zong Li <zong@andestech.com>
>
> This looks fine.  Just curious, what do we even need 128-bit integers
> for on riscv64?  Did you see any issues if you drop it entirely?

You can refer to this issue, but I didn't try it.
https://github.com/riscv/riscv-linux/issues/136

Re: [PATCH 3/5] lib: Add umoddi3 and udivmoddi4 of GCC library routines

[Andreas Schwab]

On Sep 25 2018, Zong Li <zongbox@gmail.com> wrote:

> The RV32 need the umoddi3 to do modulo when the operands are long long
> type, like other libraries implementation such as ucmpdi2, lshrdi3 and
> so on. I encounter the undefined reference 'umoddi3' when I use the in
> house dma driver, although it is in house driver, but I think that
> umoddi3 is a common function for RV32.

You probably should use the macros from <asm/div64.h> instead.

Andreas.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."

Re: [PATCH 3/5] lib: Add umoddi3 and udivmoddi4 of GCC library routines

[Christoph Hellwig]

On Tue, Sep 25, 2018 at 10:19:55AM +0800, Zong Li wrote:
> The RV32 need the umoddi3 to do modulo when the operands are long long
> type, like other libraries implementation such as ucmpdi2, lshrdi3 and
> so on. I encounter the undefined reference 'umoddi3' when I use the in
> house dma driver, although it is in house driver, but I think that
> umoddi3 is a common function for RV32. The udivmoddi4 and umoddi3 are
> copies from libgcc in gcc. There are other functions use the
> udivmoddi4 in libgcc, so I separate the umoddi3 and udivmoddi4 for
> flexible extension in the future.

I don't think libgcc is GPLv2 licensed, is it?  Also please retain
the copyright notices from libgcc.

Re: [PATCH 3/5] lib: Add umoddi3 and udivmoddi4 of GCC library routines

[Zong Li]

Christoph Hellwig <hch@infradead.org> 於 2018年9月25日 週二 下午11:25寫道：
>
> On Tue, Sep 25, 2018 at 10:19:55AM +0800, Zong Li wrote:
> > The RV32 need the umoddi3 to do modulo when the operands are long long
> > type, like other libraries implementation such as ucmpdi2, lshrdi3 and
> > so on. I encounter the undefined reference 'umoddi3' when I use the in
> > house dma driver, although it is in house driver, but I think that
> > umoddi3 is a common function for RV32. The udivmoddi4 and umoddi3 are
> > copies from libgcc in gcc. There are other functions use the
> > udivmoddi4 in libgcc, so I separate the umoddi3 and udivmoddi4 for
> > flexible extension in the future.
>
> I don't think libgcc is GPLv2 licensed, is it?  Also please retain
> the copyright notices from libgcc.

I will give next version patch. Thanks.

Re: [PATCH 3/5] lib: Add umoddi3 and udivmoddi4 of GCC library routines

[Zong Li]

Andreas Schwab <schwab@suse.de> 於 2018年9月25日 週二 下午3:20寫道：
>
> On Sep 25 2018, Zong Li <zongbox@gmail.com> wrote:
>
> > The RV32 need the umoddi3 to do modulo when the operands are long long
> > type, like other libraries implementation such as ucmpdi2, lshrdi3 and
> > so on. I encounter the undefined reference 'umoddi3' when I use the in
> > house dma driver, although it is in house driver, but I think that
> > umoddi3 is a common function for RV32.
>
> You probably should use the macros from <asm/div64.h> instead.

Hi Andreas,

This doesn't work for me, the divisor of my case is also long long type.