Michael Neuling [mi...@neuling.org] wrote:
> On Thu, 2017-03-16 at 20:33 -0700, Sukadev Bhattiprolu wrote:
> > #ifdef CONFIG_PPC_4K_PAGES
> > @@ -336,9 +337,6 @@ struct vas_window {
> > /* Feilds applicable only to receive windows */
> > enum vas_cop_type cop;
> > atomic_t num_txwins;
> > -
> > - int32_t hwirq;
> > - uint64_t irq_port;
>
> We are removing things already? :-)
:-) They are needed when we add support for user windows will
remove them in the earlier patch.
>
> > };
> >
> > /*
> > @@ -392,4 +390,59 @@ struct vas_winctx {
> > extern int vas_initialized;
> > extern int vas_window_reset(struct vas_instance *vinst, int winid);
> > extern struct vas_instance *find_vas_instance(int vasid);
> > +
> > +/*
> > + * VREG(x):
> > + * Expand a register's short name (eg: LPID) into two parameters:
> > + * - the register's short name in string form ("LPID"), and
> > + * - the name of the macro (eg: VAS_LPID_OFFSET), defining the
> > + * register's offset in the window context
> > + */
> > +#define VREG_SFX(n, s) __stringify(n), VAS_##n##s
> > +#define VREG(r) VREG_SFX(r, _OFFSET)
> > +
> > +#ifndef vas_debug
> > +static inline void vas_log_write(struct vas_window *win, char *name,
> > + void *regptr, uint64_t val)
> > +{
> > + if (val)
> > + pr_err("%swin #%d: %s reg %p, val 0x%llx\n",
> > + win->tx_win ? "Tx" : "Rx", win->winid, name,
> > + regptr, val);
> > +}
> > +
> > +#else /* vas_debug */
> > +
> > +#define vas_log_write(win, name, reg, val)
> > +
> > +#endif /* vas_debug */
> > +
> > +static inline void write_uwc_reg(struct vas_window *win, char *name,
> > + int32_t reg, uint64_t val)
> > +{
> > + void *regptr;
> > +
> > + regptr = win->uwc_map + reg;
> > + vas_log_write(win, name, regptr, val);
> > +
> > + out_be64(regptr, val);
> > +}
> > +
> > +static inline void write_hvwc_reg(struct vas_window *win, char *name,
> > + int32_t reg, uint64_t val)
> > +{
> > + void *regptr;
> > +
> > + regptr = win->hvwc_map + reg;
> > + vas_log_write(win, name, regptr, val);
> > +
> > + out_be64(regptr, val);
> > +}
> > +
> > +static inline uint64_t read_hvwc_reg(struct vas_window *win,
> > + char *name __maybe_unused, int32_t reg)
> > +{
> > + return in_be64(win->hvwc_map+reg);
> > +}
> > +
> > #endif
> > diff --git a/drivers/misc/vas/vas-window.c b/drivers/misc/vas/vas-window.c
> > index 32dd1d0..edf5c9f 100644
> > --- a/drivers/misc/vas/vas-window.c
> > +++ b/drivers/misc/vas/vas-window.c
> > @@ -14,6 +14,8 @@
> > #include <asm/vas.h>
> > #include "vas-internal.h"
> >
> > +static int fault_winid;
> > +
> > /*
> > * Compute the paste address region for the window @window using the
> > * ->win_base_addr and ->win_id_shift we got from device tree.
> > @@ -138,6 +140,338 @@ int map_wc_mmio_bars(struct vas_window *window)
> > return 0;
> > }
> >
> > +/*
> > + * Reset all valid registers in the HV and OS/User Window Contexts for
> > + * the window identified by @window.
> > + *
> > + * NOTE: We cannot really use a for loop to reset window context. Not all
> > + * offsets in a window context are valid registers and the valid
> > + * registers are not sequential. And, we can only write to offsets
> > + * with valid registers (or is that only in Simics?).
> > + */
> > +void reset_window_regs(struct vas_window *window)
> > +{
> > + write_hvwc_reg(window, VREG(LPID), 0ULL);
> > + write_hvwc_reg(window, VREG(PID), 0ULL);
> > + write_hvwc_reg(window, VREG(XLATE_MSR), 0ULL);
> > + write_hvwc_reg(window, VREG(XLATE_LPCR), 0ULL);
> > + write_hvwc_reg(window, VREG(XLATE_CTL), 0ULL);
> > + write_hvwc_reg(window, VREG(AMR), 0ULL);
> > + write_hvwc_reg(window, VREG(SEIDR), 0ULL);
> > + write_hvwc_reg(window, VREG(FAULT_TX_WIN), 0ULL);
> > + write_hvwc_reg(window, VREG(OSU_INTR_SRC_RA), 0ULL);
> > + write_hvwc_reg(window, VREG(HV_INTR_SRC_RA), 0ULL);
> > + write_hvwc_reg(window, VREG(PSWID), 0ULL);
> > + write_hvwc_reg(window, VREG(SPARE1), 0ULL);
> > + write_hvwc_reg(window, VREG(SPARE2), 0ULL);
> > + write_hvwc_reg(window, VREG(SPARE3), 0ULL);
> > + write_hvwc_reg(window, VREG(SPARE4), 0ULL);
> > + write_hvwc_reg(window, VREG(SPARE5), 0ULL);
> > + write_hvwc_reg(window, VREG(SPARE6), 0ULL);
> > + write_hvwc_reg(window, VREG(LFIFO_BAR), 0ULL);
> > + write_hvwc_reg(window, VREG(LDATA_STAMP_CTL), 0ULL);
> > + write_hvwc_reg(window, VREG(LDMA_CACHE_CTL), 0ULL);
> > + write_hvwc_reg(window, VREG(LRFIFO_PUSH), 0ULL);
> > + write_hvwc_reg(window, VREG(CURR_MSG_COUNT), 0ULL);
> > + write_hvwc_reg(window, VREG(LNOTIFY_AFTER_COUNT), 0ULL);
> > + write_hvwc_reg(window, VREG(LRX_WCRED), 0ULL);
> > + write_hvwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL);
> > + write_hvwc_reg(window, VREG(TX_WCRED), 0ULL);
> > + write_hvwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL);
> > + write_hvwc_reg(window, VREG(LFIFO_SIZE), 0ULL);
> > + write_hvwc_reg(window, VREG(WINCTL), 0ULL);
> > + write_hvwc_reg(window, VREG(WIN_STATUS), 0ULL);
> > + write_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL), 0ULL);
> > + write_hvwc_reg(window, VREG(TX_RSVD_BUF_COUNT), 0ULL);
> > + write_hvwc_reg(window, VREG(LRFIFO_WIN_PTR), 0ULL);
> > + write_hvwc_reg(window, VREG(LNOTIFY_CTL), 0ULL);
> > + write_hvwc_reg(window, VREG(LNOTIFY_PID), 0ULL);
> > + write_hvwc_reg(window, VREG(LNOTIFY_LPID), 0ULL);
> > + write_hvwc_reg(window, VREG(LNOTIFY_TID), 0ULL);
> > + write_hvwc_reg(window, VREG(LNOTIFY_SCOPE), 0ULL);
> > + write_hvwc_reg(window, VREG(NX_UTIL_ADDER), 0ULL);
> > +
> > + /* Skip read-only registers: NX_UTIL and NX_UTIL_SE */
> > +
> > + /*
> > + * The send and receive window credit adder registers are also
> > + * accessible from HVWC and have been initialized above. We don't
> > + * need to initialize from the OS/User Window Context, so skip
> > + * following calls:
> > + *
> > + * write_uwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL);
> > + * write_uwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL);
> > + */
> > +}
> > +
> > +/*
> > + * Initialize window context registers related to Address Translation.
> > + * These registers are common to send/receive windows although they
> > + * differ for user/kernel windows. As we resolve the TODOs we may
> > + * want to add fields to vas_winctx and move the initialization to
> > + * init_vas_winctx_regs().
> > + */
> > +static void init_xlate_regs(struct vas_window *window, bool user_win)
> > +{
> > + uint64_t lpcr, msr, val;
> > +
> > + msr = mfmsr();
> > + WARN_ON_ONCE(!(msr & MSR_SF));
>
> We don't support 32 bit userspace? I would return an error rather than this.
I will return an error and add a TODO for 32-bit.
>
> > +
> > + val = 0ULL;
> > + if (user_win) {
> > + val = SET_FIELD(VAS_XLATE_MSR_DR, val, true);
> > + val = SET_FIELD(VAS_XLATE_MSR_TA, val, false);
> > + val = SET_FIELD(VAS_XLATE_MSR_PR, val, true);
> > + val = SET_FIELD(VAS_XLATE_MSR_US, val, false);
> > + val = SET_FIELD(VAS_XLATE_MSR_HV, val, true);
> > + val = SET_FIELD(VAS_XLATE_MSR_SF, val, true);
> > + val = SET_FIELD(VAS_XLATE_MSR_UV, val, false);
> > + } else {
> > + val = SET_FIELD(VAS_XLATE_MSR_DR, val, false);
>
> kernel contexts don't go through the nestmmu?
I think so, but will check with Alistair/Ben.
>
> > + val = SET_FIELD(VAS_XLATE_MSR_TA, val, false);
> > + val = SET_FIELD(VAS_XLATE_MSR_PR, val, msr & MSR_PR);
>
> I don't understand this. It should just be 0 for the kernel.
Ok.
>
> > + val = SET_FIELD(VAS_XLATE_MSR_US, val, false);
> > + val = SET_FIELD(VAS_XLATE_MSR_HV, val, true);
> > + val = SET_FIELD(VAS_XLATE_MSR_SF, val, true);
> > + val = SET_FIELD(VAS_XLATE_MSR_UV, val, false);
> > + }
> > + write_hvwc_reg(window, VREG(XLATE_MSR), val);
> > +
> > + lpcr = mfspr(SPRN_LPCR);
> > + val = 0ULL;
> > + /*
> > + * NOTE: From Section 5.7.6.1 Segment Lookaside Buffer of the
> > + * Power ISA, v2.07, Page size encoding is 0 = 4KB, 5 = 64KB.
> > + *
> > + * NOTE: From Section 1.3.1, Address Translation Context of the
> > + * Nest MMU Workbook, LPCR_SC should be 0 for Power9.
> > + */
> > + val = SET_FIELD(VAS_XLATE_LPCR_PAGE_SIZE, val, 5);
> > + val = SET_FIELD(VAS_XLATE_LPCR_ISL, val, lpcr & LPCR_ISL);
> > + val = SET_FIELD(VAS_XLATE_LPCR_TC, val, lpcr & LPCR_TC);
> > + val = SET_FIELD(VAS_XLATE_LPCR_SC, val, 0);
> > + write_hvwc_reg(window, VREG(XLATE_LPCR), val);
> > +
> > + /*
> > + * Section 1.3.1 (Address translation Context) of NMMU workbook.
> > + * 0b00 Hashed Page Table mode
> > + * 0b01 Reserved
> > + * 0b10 Radix on HPT - not supported in P9
> > + * 0b11 Radix on Radix (only mode supported in Linux on
> > P9).
>
> Linux supports hash on P9.
Ok. I was quoting from the Nest MMU spec. Will remove the text in ()s.
>
> Does VAS only support radix? If so you should error out if we are booted
> hash.
I think VAS just offloads the translation to NestMMU and doesn't really
depend on radix/HPT. I was going by the comment in the spec.
>
> > + */
> > + val = 0ULL;
> > + val = SET_FIELD(VAS_XLATE_MODE, val, 0x3);
>
> You can use radix_enabled() to set this for hash vs radix.
Ok.
>
> > + write_hvwc_reg(window, VREG(XLATE_CTL), val);
> > +
> > + /*
> > + * TODO: Can we mfspr(AMR) even for user windows?
> > + */
> > + val = 0ULL;
> > + val = SET_FIELD(VAS_AMR, val, mfspr(SPRN_AMR));
> > + write_hvwc_reg(window, VREG(AMR), val);
> > +
> > + /*
> > + * TODO: Assuming Secure Executable ID Register (SEIDR) is only used
> > + * in the ultravisor mode. Since MSR(UV) is 0 for now, set
> > SEIDR
> > + * to 0 as well, although we should 'mfspr(SEIDR)' at some
> > point.
> > + */
> > + val = 0ULL;
> > + val = SET_FIELD(VAS_SEIDR, val, 0);
> > + write_hvwc_reg(window, VREG(SEIDR), val);
> > +}
> > +
> > +/*
> > + * Initialize Reserved Send Buffer Count for the send window. It involves
> > + * writing to the register, reading it back to confirm that the hardware
> > + * has enough buffers to reserve. See section 1.3.1.2.1 of VAS workbook.
> > + *
> > + * Since we can only make a best-effort attempt to fulfill the request,
> > + * we don't return any errors if we cannot.
> > + *
> > + * TODO: Reserved (aka dedicated) send buffers are not supported yet.
> > + */
> > +static void init_rsvd_tx_buf_count(struct vas_window *txwin,
> > + struct vas_winctx *winctx)
> > +{
> > + write_hvwc_reg(txwin, VREG(TX_RSVD_BUF_COUNT), 0ULL);
> > +}
> > +
> > +/*
> > + * Compute the log2() of the FIFO size expressed as kilobytes. It is
> > intended
> > + * to be used to initialize the Local FIFO Size Register defined in Section
> > + * 3.14.25 of the VAS Workbook.
>
> There is a ilog2() function..
Ok, will use that.
Thanks,
Suka
