redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity
alistair23-linux/arch/s390/net/bpf_jit.h

67 lines
1.9 KiB
C
Raw Normal View History

s390/bpf: Add s390x eBPF JIT compiler backend 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>
2015-04-01 08:08:32 -06:00
/*
* BPF Jit compiler defines
*
* Copyright IBM Corp. 2012,2015
*
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
* Michael Holzheu <holzheu@linux.vnet.ibm.com>
*/
#ifndef __ARCH_S390_NET_BPF_JIT_H
#define __ARCH_S390_NET_BPF_JIT_H
#ifndef __ASSEMBLY__
#include <linux/filter.h>
#include <linux/types.h>
extern u8 sk_load_word_pos[], sk_load_half_pos[], sk_load_byte_pos[];
extern u8 sk_load_word[], sk_load_half[], sk_load_byte[];
#endif /* __ASSEMBLY__ */
/*
* Stackframe layout (packed stack):
*
* ^ high
* +---------------+ |
* | old backchain | |
* +---------------+ |
* | r15 - r6 | |
s390/bpf: implement bpf_tail_call() helper bpf_tail_call() arguments: - ctx......: Context pointer - jmp_table: One of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table - index....: Index in the jump table In this implementation s390x JIT does stack unwinding and jumps into the callee program prologue. Caller and callee use the same stack. With this patch a tail call generates the following code on s390x: if (index >= array->map.max_entries) goto out 000003ff8001c7e4: e31030100016 llgf %r1,16(%r3) 000003ff8001c7ea: ec41001fa065 clgrj %r4,%r1,10,3ff8001c828 if (tail_call_cnt++ > MAX_TAIL_CALL_CNT) goto out; 000003ff8001c7f0: a7080001 lhi %r0,1 000003ff8001c7f4: eb10f25000fa laal %r1,%r0,592(%r15) 000003ff8001c7fa: ec120017207f clij %r1,32,2,3ff8001c828 prog = array->prog[index]; if (prog == NULL) goto out; 000003ff8001c800: eb140003000d sllg %r1,%r4,3 000003ff8001c806: e31310800004 lg %r1,128(%r3,%r1) 000003ff8001c80c: ec18000e007d clgij %r1,0,8,3ff8001c828 Restore registers before calling function 000003ff8001c812: eb68f2980004 lmg %r6,%r8,664(%r15) 000003ff8001c818: ebbff2c00004 lmg %r11,%r15,704(%r15) goto *(prog->bpf_func + tail_call_start); 000003ff8001c81e: e31100200004 lg %r1,32(%r1,%r0) 000003ff8001c824: 47f01006 bc 15,6(%r1) Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-08 22:51:06 -06:00
* +---------------+ |
* | 4 byte align | |
* | tail_call_cnt | |
s390/bpf: Add s390x eBPF JIT compiler backend 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>
2015-04-01 08:08:32 -06:00
* BFP -> +===============+ |
* | | |
* | BPF stack | |
* | | |
* +---------------+ |
* | 8 byte hlen | |
* R15+168 -> +---------------+ |
* | 4 byte align | |
* +---------------+ |
* | 4 byte temp | |
* | for bpf_jit.S | |
* R15+160 -> +---------------+ |
* | new backchain | |
* R15+152 -> +---------------+ |
* | + 152 byte SA | |
* R15 -> +---------------+ + low
*
* We get 160 bytes stack space from calling function, but only use
s390/bpf: implement bpf_tail_call() helper bpf_tail_call() arguments: - ctx......: Context pointer - jmp_table: One of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table - index....: Index in the jump table In this implementation s390x JIT does stack unwinding and jumps into the callee program prologue. Caller and callee use the same stack. With this patch a tail call generates the following code on s390x: if (index >= array->map.max_entries) goto out 000003ff8001c7e4: e31030100016 llgf %r1,16(%r3) 000003ff8001c7ea: ec41001fa065 clgrj %r4,%r1,10,3ff8001c828 if (tail_call_cnt++ > MAX_TAIL_CALL_CNT) goto out; 000003ff8001c7f0: a7080001 lhi %r0,1 000003ff8001c7f4: eb10f25000fa laal %r1,%r0,592(%r15) 000003ff8001c7fa: ec120017207f clij %r1,32,2,3ff8001c828 prog = array->prog[index]; if (prog == NULL) goto out; 000003ff8001c800: eb140003000d sllg %r1,%r4,3 000003ff8001c806: e31310800004 lg %r1,128(%r3,%r1) 000003ff8001c80c: ec18000e007d clgij %r1,0,8,3ff8001c828 Restore registers before calling function 000003ff8001c812: eb68f2980004 lmg %r6,%r8,664(%r15) 000003ff8001c818: ebbff2c00004 lmg %r11,%r15,704(%r15) goto *(prog->bpf_func + tail_call_start); 000003ff8001c81e: e31100200004 lg %r1,32(%r1,%r0) 000003ff8001c824: 47f01006 bc 15,6(%r1) Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-08 22:51:06 -06:00
* 12 * 8 byte for old backchain, r15..r6, and tail_call_cnt.
s390/bpf: Add s390x eBPF JIT compiler backend 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>
2015-04-01 08:08:32 -06:00
*/
s390/bpf: fix stack allocation On s390x we have to provide 160 bytes stack space before we can call the next function. From the 160 bytes that we got from the previous function we only use 11 * 8 bytes and have 160 - 11 * 8 bytes left. Currently for BPF we allocate additional 160 - 11 * 8 bytes for the next function. This is wrong because then the next function only gets: (160 - 11 * 8) + (160 - 11 * 8) = 2 * 72 = 144 bytes Fix this and allocate enough memory for the next function. Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-01 23:48:34 -06:00
#define STK_SPACE (MAX_BPF_STACK + 8 + 4 + 4 + 160)
s390/bpf: implement bpf_tail_call() helper bpf_tail_call() arguments: - ctx......: Context pointer - jmp_table: One of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table - index....: Index in the jump table In this implementation s390x JIT does stack unwinding and jumps into the callee program prologue. Caller and callee use the same stack. With this patch a tail call generates the following code on s390x: if (index >= array->map.max_entries) goto out 000003ff8001c7e4: e31030100016 llgf %r1,16(%r3) 000003ff8001c7ea: ec41001fa065 clgrj %r4,%r1,10,3ff8001c828 if (tail_call_cnt++ > MAX_TAIL_CALL_CNT) goto out; 000003ff8001c7f0: a7080001 lhi %r0,1 000003ff8001c7f4: eb10f25000fa laal %r1,%r0,592(%r15) 000003ff8001c7fa: ec120017207f clij %r1,32,2,3ff8001c828 prog = array->prog[index]; if (prog == NULL) goto out; 000003ff8001c800: eb140003000d sllg %r1,%r4,3 000003ff8001c806: e31310800004 lg %r1,128(%r3,%r1) 000003ff8001c80c: ec18000e007d clgij %r1,0,8,3ff8001c828 Restore registers before calling function 000003ff8001c812: eb68f2980004 lmg %r6,%r8,664(%r15) 000003ff8001c818: ebbff2c00004 lmg %r11,%r15,704(%r15) goto *(prog->bpf_func + tail_call_start); 000003ff8001c81e: e31100200004 lg %r1,32(%r1,%r0) 000003ff8001c824: 47f01006 bc 15,6(%r1) Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-08 22:51:06 -06:00
#define STK_160_UNUSED (160 - 12 * 8)
s390/bpf: fix stack allocation On s390x we have to provide 160 bytes stack space before we can call the next function. From the 160 bytes that we got from the previous function we only use 11 * 8 bytes and have 160 - 11 * 8 bytes left. Currently for BPF we allocate additional 160 - 11 * 8 bytes for the next function. This is wrong because then the next function only gets: (160 - 11 * 8) + (160 - 11 * 8) = 2 * 72 = 144 bytes Fix this and allocate enough memory for the next function. Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-01 23:48:34 -06:00
#define STK_OFF (STK_SPACE - STK_160_UNUSED)
s390/bpf: Add s390x eBPF JIT compiler backend 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>
2015-04-01 08:08:32 -06:00
#define STK_OFF_TMP 160 /* Offset of tmp buffer on stack */
#define STK_OFF_HLEN 168 /* Offset of SKB header length on stack */
s390/bpf: implement bpf_tail_call() helper bpf_tail_call() arguments: - ctx......: Context pointer - jmp_table: One of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table - index....: Index in the jump table In this implementation s390x JIT does stack unwinding and jumps into the callee program prologue. Caller and callee use the same stack. With this patch a tail call generates the following code on s390x: if (index >= array->map.max_entries) goto out 000003ff8001c7e4: e31030100016 llgf %r1,16(%r3) 000003ff8001c7ea: ec41001fa065 clgrj %r4,%r1,10,3ff8001c828 if (tail_call_cnt++ > MAX_TAIL_CALL_CNT) goto out; 000003ff8001c7f0: a7080001 lhi %r0,1 000003ff8001c7f4: eb10f25000fa laal %r1,%r0,592(%r15) 000003ff8001c7fa: ec120017207f clij %r1,32,2,3ff8001c828 prog = array->prog[index]; if (prog == NULL) goto out; 000003ff8001c800: eb140003000d sllg %r1,%r4,3 000003ff8001c806: e31310800004 lg %r1,128(%r3,%r1) 000003ff8001c80c: ec18000e007d clgij %r1,0,8,3ff8001c828 Restore registers before calling function 000003ff8001c812: eb68f2980004 lmg %r6,%r8,664(%r15) 000003ff8001c818: ebbff2c00004 lmg %r11,%r15,704(%r15) goto *(prog->bpf_func + tail_call_start); 000003ff8001c81e: e31100200004 lg %r1,32(%r1,%r0) 000003ff8001c824: 47f01006 bc 15,6(%r1) Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-08 22:51:06 -06:00
#define STK_OFF_R6 (160 - 11 * 8) /* Offset of r6 on stack */
#define STK_OFF_TCCNT (160 - 12 * 8) /* Offset of tail_call_cnt on stack */
s390/bpf: Add s390x eBPF JIT compiler backend 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>
2015-04-01 08:08:32 -06:00
/* Offset to skip condition code check */
#define OFF_OK 4
#endif /* __ARCH_S390_NET_BPF_JIT_H */
Copy permalink