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| author | Guo Ren <ren_guo@c-sky.com> | 2019-08-20 20:15:44 +0800 |
|---|---|---|
| committer | Guo Ren <ren_guo@c-sky.com> | 2019-08-20 20:15:44 +0800 |
| commit | c7e6f0e99227b3dcdc5e62f789119e000887ff79 (patch) | |
| tree | bb4a79195274df2fd3903ebb41fa475af808b1a3 | |
| parent | dc140045c0cace809af872e3799e8fbe1b7d7f86 (diff) | |
| download | linux-c7e6f0e99227b3dcdc5e62f789119e000887ff79.tar.gz linux-c7e6f0e99227b3dcdc5e62f789119e000887ff79.tar.bz2 linux-c7e6f0e99227b3dcdc5e62f789119e000887ff79.zip | |
csky: Support kernel non-aligned access
We prohibit non-aligned access in kernel mode, but some special NIC
driver needs to support kernel-state unaligned access. For example,
when the bus does not support unaligned access, IP header parsing
will cause non-aligned access and driver does not recopy the skb
buffer to dma for performance reasons.
Added kernel_enable & user_enable to control unaligned access and
added kernel_count & user_count for statistical unaligned access.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
| -rw-r--r-- | arch/csky/abiv1/alignment.c | 62 |
1 files changed, 45 insertions, 17 deletions
diff --git a/arch/csky/abiv1/alignment.c b/arch/csky/abiv1/alignment.c index 27ef5b2c43ab..cb2a0d94a144 100644 --- a/arch/csky/abiv1/alignment.c +++ b/arch/csky/abiv1/alignment.c @@ -5,8 +5,10 @@ #include <linux/uaccess.h> #include <linux/ptrace.h> -static int align_enable = 1; -static int align_count; +static int align_kern_enable = 1; +static int align_usr_enable = 1; +static int align_kern_count = 0; +static int align_usr_count = 0; static inline uint32_t get_ptreg(struct pt_regs *regs, uint32_t rx) { @@ -32,9 +34,6 @@ static int ldb_asm(uint32_t addr, uint32_t *valp) uint32_t val; int err; - if (!access_ok((void *)addr, 1)) - return 1; - asm volatile ( "movi %0, 0\n" "1:\n" @@ -67,9 +66,6 @@ static int stb_asm(uint32_t addr, uint32_t val) { int err; - if (!access_ok((void *)addr, 1)) - return 1; - asm volatile ( "movi %0, 0\n" "1:\n" @@ -203,8 +199,6 @@ static int stw_c(struct pt_regs *regs, uint32_t rz, uint32_t addr) if (stb_asm(addr, byte3)) return 1; - align_count++; - return 0; } @@ -226,7 +220,14 @@ void csky_alignment(struct pt_regs *regs) uint32_t addr = 0; if (!user_mode(regs)) + goto kernel_area; + + if (!align_usr_enable) { + pr_err("%s user disabled.\n", __func__); goto bad_area; + } + + align_usr_count++; ret = get_user(tmp, (uint16_t *)instruction_pointer(regs)); if (ret) { @@ -234,6 +235,19 @@ void csky_alignment(struct pt_regs *regs) goto bad_area; } + goto good_area; + +kernel_area: + if (!align_kern_enable) { + pr_err("%s kernel disabled.\n", __func__); + goto bad_area; + } + + align_kern_count++; + + tmp = *(uint16_t *)instruction_pointer(regs); + +good_area: opcode = (uint32_t)tmp; rx = opcode & 0xf; @@ -286,18 +300,32 @@ bad_area: force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)addr); } -static struct ctl_table alignment_tbl[4] = { +static struct ctl_table alignment_tbl[5] = { + { + .procname = "kernel_enable", + .data = &align_kern_enable, + .maxlen = sizeof(align_kern_enable), + .mode = 0666, + .proc_handler = &proc_dointvec + }, + { + .procname = "user_enable", + .data = &align_usr_enable, + .maxlen = sizeof(align_usr_enable), + .mode = 0666, + .proc_handler = &proc_dointvec + }, { - .procname = "enable", - .data = &align_enable, - .maxlen = sizeof(align_enable), + .procname = "kernel_count", + .data = &align_kern_count, + .maxlen = sizeof(align_kern_count), .mode = 0666, .proc_handler = &proc_dointvec }, { - .procname = "count", - .data = &align_count, - .maxlen = sizeof(align_count), + .procname = "user_count", + .data = &align_usr_count, + .maxlen = sizeof(align_usr_count), .mode = 0666, .proc_handler = &proc_dointvec }, |