diff options
| -rw-r--r-- | arch/powerpc/mm/fault.c | 17 | ||||
| -rw-r--r-- | arch/powerpc/mm/icswx.c | 113 | ||||
| -rw-r--r-- | arch/powerpc/mm/icswx.h | 23 | ||||
| -rw-r--r-- | arch/powerpc/platforms/Kconfig.cputype | 13 |
4 files changed, 165 insertions, 1 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 5efe8c96d37f..2f0d1b032a89 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -44,6 +44,8 @@ #include <asm/siginfo.h> #include <mm/mmu_decl.h> +#include "icswx.h" + #ifdef CONFIG_KPROBES static inline int notify_page_fault(struct pt_regs *regs) { @@ -143,6 +145,21 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address, is_write = error_code & ESR_DST; #endif /* CONFIG_4xx || CONFIG_BOOKE */ +#ifdef CONFIG_PPC_ICSWX + /* + * we need to do this early because this "data storage + * interrupt" does not update the DAR/DEAR so we don't want to + * look at it + */ + if (error_code & ICSWX_DSI_UCT) { + int ret; + + ret = acop_handle_fault(regs, address, error_code); + if (ret) + return ret; + } +#endif + if (notify_page_fault(regs)) return 0; diff --git a/arch/powerpc/mm/icswx.c b/arch/powerpc/mm/icswx.c index a98850fd7777..5d9a59eaad93 100644 --- a/arch/powerpc/mm/icswx.c +++ b/arch/powerpc/mm/icswx.c @@ -17,6 +17,8 @@ #include <linux/mm.h> #include <linux/spinlock.h> #include <linux/module.h> +#include <linux/uaccess.h> + #include "icswx.h" /* @@ -158,3 +160,114 @@ void drop_cop(unsigned long acop, struct mm_struct *mm) spin_unlock(&mm->page_table_lock); } EXPORT_SYMBOL_GPL(drop_cop); + +static int acop_use_cop(int ct) +{ + /* todo */ + return -1; +} + +/* + * Get the instruction word at the NIP + */ +static u32 acop_get_inst(struct pt_regs *regs) +{ + u32 inst; + u32 __user *p; + + p = (u32 __user *)regs->nip; + if (!access_ok(VERIFY_READ, p, sizeof(*p))) + return 0; + + if (__get_user(inst, p)) + return 0; + + return inst; +} + +/** + * @regs: regsiters at time of interrupt + * @address: storage address + * @error_code: Fault code, usually the DSISR or ESR depending on + * processor type + * + * Return 0 if we are able to resolve the data storage fault that + * results from a CT miss in the ACOP register. + */ +int acop_handle_fault(struct pt_regs *regs, unsigned long address, + unsigned long error_code) +{ + int ct; + u32 inst = 0; + + if (!cpu_has_feature(CPU_FTR_ICSWX)) { + pr_info("No coprocessors available"); + _exception(SIGILL, regs, ILL_ILLOPN, address); + } + + if (!user_mode(regs)) { + /* this could happen if the HV denies the + * kernel access, for now we just die */ + die("ICSWX from kernel failed", regs, SIGSEGV); + } + + /* Some implementations leave us a hint for the CT */ + ct = ICSWX_GET_CT_HINT(error_code); + if (ct < 0) { + /* we have to peek at the instruction word to figure out CT */ + u32 ccw; + u32 rs; + + inst = acop_get_inst(regs); + if (inst == 0) + return -1; + + rs = (inst >> (31 - 10)) & 0x1f; + ccw = regs->gpr[rs]; + ct = (ccw >> 16) & 0x3f; + } + + if (!acop_use_cop(ct)) + return 0; + + /* at this point the CT is unknown to the system */ + pr_warn("%s[%d]: Coprocessor %d is unavailable", + current->comm, current->pid, ct); + + /* get inst if we don't already have it */ + if (inst == 0) { + inst = acop_get_inst(regs); + if (inst == 0) + return -1; + } + + /* Check if the instruction is the "record form" */ + if (inst & 1) { + /* + * the instruction is "record" form so we can reject + * using CR0 + */ + regs->ccr &= ~(0xful << 28); + regs->ccr |= ICSWX_RC_NOT_FOUND << 28; + + /* Move on to the next instruction */ + regs->nip += 4; + } else { + /* + * There is no architected mechanism to report a bad + * CT so we could either SIGILL or report nothing. + * Since the non-record version should only bu used + * for "hints" or "don't care" we should probably do + * nothing. However, I could see how some people + * might want an SIGILL so it here if you want it. + */ +#ifdef CONFIG_PPC_ICSWX_USE_SIGILL + _exception(SIGILL, regs, ILL_ILLOPN, address); +#else + regs->nip += 4; +#endif + } + + return 0; +} +EXPORT_SYMBOL_GPL(acop_handle_fault); diff --git a/arch/powerpc/mm/icswx.h b/arch/powerpc/mm/icswx.h index 07514e49498e..42176bd0884c 100644 --- a/arch/powerpc/mm/icswx.h +++ b/arch/powerpc/mm/icswx.h @@ -36,4 +36,27 @@ extern void free_cop_pid(int free_pid); #define free_cop_pid(p) #endif +/* + * These are implementation bits for architected registers. If this + * ever becomes architecture the should be moved to reg.h et. al. + */ +/* UCT is the same bit for Server and Embedded */ +#define ICSWX_DSI_UCT 0x00004000 /* Unavailable Coprocessor Type */ + +#ifdef CONFIG_PPC_BOOK3E +/* Embedded implementation gives us no hints as to what the CT is */ +#define ICSWX_GET_CT_HINT(x) (-1) +#else +/* Server implementation contains the CT value in the DSISR */ +#define ICSWX_DSISR_CTMASK 0x00003f00 +#define ICSWX_GET_CT_HINT(x) (((x) & ICSWX_DSISR_CTMASK) >> 8) +#endif + +#define ICSWX_RC_STARTED 0x8 /* The request has been started */ +#define ICSWX_RC_NOT_IDLE 0x4 /* No coprocessor found idle */ +#define ICSWX_RC_NOT_FOUND 0x2 /* No coprocessor found */ +#define ICSWX_RC_UNDEFINED 0x1 /* Reserved */ + +extern int acop_handle_fault(struct pt_regs *regs, unsigned long address, + unsigned long error_code); #endif /* !_ARCH_POWERPC_MM_ICSWX_H_ */ diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 46d2a7c77dc0..836b44286b3e 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -257,9 +257,20 @@ config PPC_ICSWX_PID depends on PPC_ICSWX && POWER4 default y ---help--- - PID register in server is used explicitly for ICSWX. In + The PID register in server is used explicitly for ICSWX. In embedded systems PID managment is done by the system. +config PPC_ICSWX_USE_SIGILL + bool "Should a bad CT cause a SIGILL?" + depends on PPC_ICSWX + default n + ---help--- + Should a bad CT used for "non-record form ICSWX" cause an + illegal intruction signal or should it be silent as + architected. + + If in doubt, say N here. + config SPE bool "SPE Support" depends on E200 || (E500 && !PPC_E500MC) |