mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-29 07:34:06 +08:00
0546231057
Replace 32 bit BPF JIT backend with new 64 bit eBPF backend. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
116 lines
3.3 KiB
ArmAsm
116 lines
3.3 KiB
ArmAsm
/*
|
|
* BPF Jit compiler for s390, help functions.
|
|
*
|
|
* Copyright IBM Corp. 2012,2015
|
|
*
|
|
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
* Michael Holzheu <holzheu@linux.vnet.ibm.com>
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include "bpf_jit.h"
|
|
|
|
/*
|
|
* Calling convention:
|
|
* registers %r7-%r10, %r11,%r13, and %r15 are call saved
|
|
*
|
|
* Input (64 bit):
|
|
* %r3 (%b2) = offset into skb data
|
|
* %r6 (%b5) = return address
|
|
* %r7 (%b6) = skb pointer
|
|
* %r12 = skb data pointer
|
|
*
|
|
* Output:
|
|
* %r14= %b0 = return value (read skb value)
|
|
*
|
|
* Work registers: %r2,%r4,%r5,%r14
|
|
*
|
|
* skb_copy_bits takes 4 parameters:
|
|
* %r2 = skb pointer
|
|
* %r3 = offset into skb data
|
|
* %r4 = pointer to temp buffer
|
|
* %r5 = length to copy
|
|
* Return value in %r2: 0 = ok
|
|
*
|
|
* bpf_internal_load_pointer_neg_helper takes 3 parameters:
|
|
* %r2 = skb pointer
|
|
* %r3 = offset into data
|
|
* %r4 = length to copy
|
|
* Return value in %r2: Pointer to data
|
|
*/
|
|
|
|
#define SKF_MAX_NEG_OFF -0x200000 /* SKF_LL_OFF from filter.h */
|
|
|
|
/*
|
|
* Load SIZE bytes from SKB
|
|
*/
|
|
#define sk_load_common(NAME, SIZE, LOAD) \
|
|
ENTRY(sk_load_##NAME); \
|
|
ltgr %r3,%r3; /* Is offset negative? */ \
|
|
jl sk_load_##NAME##_slow_neg; \
|
|
ENTRY(sk_load_##NAME##_pos); \
|
|
aghi %r3,SIZE; /* Offset + SIZE */ \
|
|
clg %r3,STK_OFF_HLEN(%r15); /* Offset + SIZE > hlen? */ \
|
|
jh sk_load_##NAME##_slow; \
|
|
LOAD %r14,-SIZE(%r3,%r12); /* Get data from skb */ \
|
|
b OFF_OK(%r6); /* Return */ \
|
|
\
|
|
sk_load_##NAME##_slow:; \
|
|
lgr %r2,%r7; /* Arg1 = skb pointer */ \
|
|
aghi %r3,-SIZE; /* Arg2 = offset */ \
|
|
la %r4,STK_OFF_TMP(%r15); /* Arg3 = temp bufffer */ \
|
|
lghi %r5,SIZE; /* Arg4 = size */ \
|
|
brasl %r14,skb_copy_bits; /* Get data from skb */ \
|
|
LOAD %r14,STK_OFF_TMP(%r15); /* Load from temp bufffer */ \
|
|
ltgr %r2,%r2; /* Set cc to (%r2 != 0) */ \
|
|
br %r6; /* Return */
|
|
|
|
sk_load_common(word, 4, llgf) /* r14 = *(u32 *) (skb->data+offset) */
|
|
sk_load_common(half, 2, llgh) /* r14 = *(u16 *) (skb->data+offset) */
|
|
|
|
/*
|
|
* Load 1 byte from SKB (optimized version)
|
|
*/
|
|
/* r14 = *(u8 *) (skb->data+offset) */
|
|
ENTRY(sk_load_byte)
|
|
ltgr %r3,%r3 # Is offset negative?
|
|
jl sk_load_byte_slow_neg
|
|
ENTRY(sk_load_byte_pos)
|
|
clg %r3,STK_OFF_HLEN(%r15) # Offset >= hlen?
|
|
jnl sk_load_byte_slow
|
|
llgc %r14,0(%r3,%r12) # Get byte from skb
|
|
b OFF_OK(%r6) # Return OK
|
|
|
|
sk_load_byte_slow:
|
|
lgr %r2,%r7 # Arg1 = skb pointer
|
|
# Arg2 = offset
|
|
la %r4,STK_OFF_TMP(%r15) # Arg3 = pointer to temp buffer
|
|
lghi %r5,1 # Arg4 = size (1 byte)
|
|
brasl %r14,skb_copy_bits # Get data from skb
|
|
llgc %r14,STK_OFF_TMP(%r15) # Load result from temp buffer
|
|
ltgr %r2,%r2 # Set cc to (%r2 != 0)
|
|
br %r6 # Return cc
|
|
|
|
#define sk_negative_common(NAME, SIZE, LOAD) \
|
|
sk_load_##NAME##_slow_neg:; \
|
|
cgfi %r3,SKF_MAX_NEG_OFF; \
|
|
jl bpf_error; \
|
|
lgr %r2,%r7; /* Arg1 = skb pointer */ \
|
|
/* Arg2 = offset */ \
|
|
lghi %r4,SIZE; /* Arg3 = size */ \
|
|
brasl %r14,bpf_internal_load_pointer_neg_helper; \
|
|
ltgr %r2,%r2; \
|
|
jz bpf_error; \
|
|
LOAD %r14,0(%r2); /* Get data from pointer */ \
|
|
xr %r3,%r3; /* Set cc to zero */ \
|
|
br %r6; /* Return cc */
|
|
|
|
sk_negative_common(word, 4, llgf)
|
|
sk_negative_common(half, 2, llgh)
|
|
sk_negative_common(byte, 1, llgc)
|
|
|
|
bpf_error:
|
|
# force a return 0 from jit handler
|
|
ltgr %r15,%r15 # Set condition code
|
|
br %r6
|