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net/octeontx: fix build with SVE
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[ upstream commit e88bd47 ]

Building with gcc 10.2 with SVE extension enabled got error:

{standard input}: Assembler messages:
{standard input}:91: Error: selected processor does not support `addvl x4,x8,#-1'
{standard input}:95: Error: selected processor does not support `ptrue p1.d,all'
{standard input}:135: Error: selected processor does not support `whilelo p2.d,xzr,x5'
{standard input}:137: Error: selected processor does not support `decb x1'

This is because inline assembly code explicitly resets cpu model to
not have SVE support. Thus SVE instructions generated by compiler
auto vectorization got rejected by assembler.

Added SVE to the cpu model specified by inline assembly for SVE support.
Not replacing the inline assembly with C atomics because the driver relies
on specific LSE instruction to interface to co-processor [1].

Fixes: f0c7bb1 ("net/octeontx/base: add octeontx IO operations")

[1] https://mails.dpdk.org/archives/dev/2021-January/196092.html

Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Jerin Jacob <jerinj@marvell.com>
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Reyfone authored and cpaelzer committed Feb 2, 2021
1 parent ea20847 commit f474bb5
Showing 1 changed file with 8 additions and 2 deletions.
10 changes: 8 additions & 2 deletions drivers/net/octeontx/base/octeontx_io.h
Original file line number Diff line number Diff line change
Expand Up @@ -52,6 +52,11 @@ do { \
#endif

#if defined(RTE_ARCH_ARM64)
#if defined(__ARM_FEATURE_SVE)
#define __LSE_PREAMBLE " .cpu generic+lse+sve\n"
#else
#define __LSE_PREAMBLE " .cpu generic+lse\n"
#endif
/**
* Perform an atomic fetch-and-add operation.
*/
Expand All @@ -61,7 +66,7 @@ octeontx_reg_ldadd_u64(void *addr, int64_t off)
uint64_t old_val;

__asm__ volatile(
" .cpu generic+lse\n"
__LSE_PREAMBLE
" ldadd %1, %0, [%2]\n"
: "=r" (old_val) : "r" (off), "r" (addr) : "memory");

Expand Down Expand Up @@ -98,12 +103,13 @@ octeontx_reg_lmtst(void *lmtline_va, void *ioreg_va, const uint64_t cmdbuf[],

/* LDEOR initiates atomic transfer to I/O device */
__asm__ volatile(
" .cpu generic+lse\n"
__LSE_PREAMBLE
" ldeor xzr, %0, [%1]\n"
: "=r" (result) : "r" (ioreg_va) : "memory");
} while (!result);
}

#undef __LSE_PREAMBLE
#else

static inline uint64_t
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