From 61868fb5c2e5e17ea5dd81b98c258453e172e23d Mon Sep 17 00:00:00 2001 From: Sebastian Sanchez Date: Sun, 25 Sep 2016 07:41:39 -0700 Subject: [PATCH] IB/hfi1: Combine shift copy and byte copy for SGE reads Prevent over-reading the SGE length by using byte reads for non quad-word reads. Reviewed-by: Dean Luick Signed-off-by: Sebastian Sanchez Signed-off-by: Dennis Dalessandro Signed-off-by: Doug Ledford --- drivers/infiniband/hw/hfi1/pio_copy.c | 160 ++++---------------------- 1 file changed, 23 insertions(+), 137 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/pio_copy.c b/drivers/infiniband/hw/hfi1/pio_copy.c index 7b0aa19ba062..aa7773643107 100644 --- a/drivers/infiniband/hw/hfi1/pio_copy.c +++ b/drivers/infiniband/hw/hfi1/pio_copy.c @@ -165,9 +165,6 @@ void pio_copy(struct hfi1_devdata *dd, struct pio_buf *pbuf, u64 pbc, preempt_enable(); } -/* USE_SHIFTS is faster in user-space tests on a Xeon X5570 @ 2.93GHz */ -#define USE_SHIFTS 1 -#ifdef USE_SHIFTS /* * Handle carry bytes using shifts and masks. * @@ -186,126 +183,6 @@ void pio_copy(struct hfi1_devdata *dd, struct pio_buf *pbuf, u64 pbc, */ #define mshift(x) (8 * (x)) -/* - * Read nbytes bytes from "from" and return them in the LSB bytes - * of pbuf->carry. Other bytes are zeroed. Any previous value - * pbuf->carry is lost. - * - * NOTES: - * o do not read from from if nbytes is zero - * o from may _not_ be u64 aligned - * o nbytes must not span a QW boundary - */ -static inline void read_low_bytes(struct pio_buf *pbuf, const void *from, - unsigned int nbytes) -{ - unsigned long off; - - if (nbytes == 0) { - pbuf->carry.val64 = 0; - } else { - /* align our pointer */ - off = (unsigned long)from & 0x7; - from = (void *)((unsigned long)from & ~0x7l); - pbuf->carry.val64 = ((*(u64 *)from) - << zshift(nbytes + off))/* zero upper bytes */ - >> zshift(nbytes); /* place at bottom */ - } - pbuf->carry_bytes = nbytes; -} - -/* - * Read nbytes bytes from "from" and put them at the next significant bytes - * of pbuf->carry. Unused bytes are zeroed. It is expected that the extra - * read does not overfill carry. - * - * NOTES: - * o from may _not_ be u64 aligned - * o nbytes may span a QW boundary - */ -static inline void read_extra_bytes(struct pio_buf *pbuf, - const void *from, unsigned int nbytes) -{ - unsigned long off = (unsigned long)from & 0x7; - unsigned int room, xbytes; - - /* align our pointer */ - from = (void *)((unsigned long)from & ~0x7l); - - /* check count first - don't read anything if count is zero */ - while (nbytes) { - /* find the number of bytes in this u64 */ - room = 8 - off; /* this u64 has room for this many bytes */ - xbytes = min(room, nbytes); - - /* - * shift down to zero lower bytes, shift up to zero upper - * bytes, shift back down to move into place - */ - pbuf->carry.val64 |= (((*(u64 *)from) - >> mshift(off)) - << zshift(xbytes)) - >> zshift(xbytes + pbuf->carry_bytes); - off = 0; - pbuf->carry_bytes += xbytes; - nbytes -= xbytes; - from += sizeof(u64); - } -} - -/* - * Write a quad word using parts of pbuf->carry and the next 8 bytes of src. - * Put the unused part of the next 8 bytes of src into the LSB bytes of - * pbuf->carry with the upper bytes zeroed.. - * - * NOTES: - * o result must keep unused bytes zeroed - * o src must be u64 aligned - */ -static inline void merge_write8( - struct pio_buf *pbuf, - void __iomem *dest, - const void *src) -{ - u64 new, temp; - - new = *(u64 *)src; - temp = pbuf->carry.val64 | (new << mshift(pbuf->carry_bytes)); - writeq(temp, dest); - pbuf->carry.val64 = new >> zshift(pbuf->carry_bytes); -} - -/* - * Write a quad word using all bytes of carry. - */ -static inline void carry8_write8(union mix carry, void __iomem *dest) -{ - writeq(carry.val64, dest); -} - -/* - * Write a quad word using all the valid bytes of carry. If carry - * has zero valid bytes, nothing is written. - * Returns 0 on nothing written, non-zero on quad word written. - */ -static inline int carry_write8(struct pio_buf *pbuf, void __iomem *dest) -{ - if (pbuf->carry_bytes) { - /* unused bytes are always kept zeroed, so just write */ - writeq(pbuf->carry.val64, dest); - return 1; - } - - return 0; -} - -#else /* USE_SHIFTS */ -/* - * Handle carry bytes using byte copies. - * - * NOTE: the value the unused portion of carry is left uninitialized. - */ - /* * Jump copy - no-loop copy for < 8 bytes. */ @@ -314,18 +191,25 @@ static inline void jcopy(u8 *dest, const u8 *src, u32 n) switch (n) { case 7: *dest++ = *src++; + /* fall through */ case 6: *dest++ = *src++; + /* fall through */ case 5: *dest++ = *src++; + /* fall through */ case 4: *dest++ = *src++; + /* fall through */ case 3: *dest++ = *src++; + /* fall through */ case 2: *dest++ = *src++; + /* fall through */ case 1: *dest++ = *src++; + /* fall through */ } } @@ -341,6 +225,7 @@ static inline void jcopy(u8 *dest, const u8 *src, u32 n) static inline void read_low_bytes(struct pio_buf *pbuf, const void *from, unsigned int nbytes) { + pbuf->carry.val64 = 0; jcopy(&pbuf->carry.val8[0], from, nbytes); pbuf->carry_bytes = nbytes; } @@ -362,25 +247,30 @@ static inline void read_extra_bytes(struct pio_buf *pbuf, /* * Write a quad word using parts of pbuf->carry and the next 8 bytes of src. - * Put the unused part of the next 8 bytes of src into the low bytes of - * pbuf->carry. + * Put the unused part of the next 8 bytes of src into the LSB bytes of + * pbuf->carry with the upper bytes zeroed.. + * + * NOTES: + * o result must keep unused bytes zeroed + * o src must be u64 aligned */ static inline void merge_write8( struct pio_buf *pbuf, - void *dest, + void __iomem *dest, const void *src) { - u32 remainder = 8 - pbuf->carry_bytes; + u64 new, temp; - jcopy(&pbuf->carry.val8[pbuf->carry_bytes], src, remainder); - writeq(pbuf->carry.val64, dest); - jcopy(&pbuf->carry.val8[0], src + remainder, pbuf->carry_bytes); + new = *(u64 *)src; + temp = pbuf->carry.val64 | (new << mshift(pbuf->carry_bytes)); + writeq(temp, dest); + pbuf->carry.val64 = new >> zshift(pbuf->carry_bytes); } /* * Write a quad word using all bytes of carry. */ -static inline void carry8_write8(union mix carry, void *dest) +static inline void carry8_write8(union mix carry, void __iomem *dest) { writeq(carry.val64, dest); } @@ -390,20 +280,16 @@ static inline void carry8_write8(union mix carry, void *dest) * has zero valid bytes, nothing is written. * Returns 0 on nothing written, non-zero on quad word written. */ -static inline int carry_write8(struct pio_buf *pbuf, void *dest) +static inline int carry_write8(struct pio_buf *pbuf, void __iomem *dest) { if (pbuf->carry_bytes) { - u64 zero = 0; - - jcopy(&pbuf->carry.val8[pbuf->carry_bytes], (u8 *)&zero, - 8 - pbuf->carry_bytes); + /* unused bytes are always kept zeroed, so just write */ writeq(pbuf->carry.val64, dest); return 1; } return 0; } -#endif /* USE_SHIFTS */ /* * Segmented PIO Copy - start -- 2.20.1