Commit Graph

1091 Commits (faab169307285af3e74b6b817b2fa0de480346d3)
 

Author SHA1 Message Date
Michael Neuling 7fa7b45faa
Merge pull request #337 from paulusmack/fixes
ECP5: Adjust PLL constants so the PLL lock indication works
3 years ago
Paul Mackerras d458b5845c ECP5: Adjust PLL constants so the PLL lock indication works
At present, code (such as simple_random) which produces serial port
output during the first few milliseconds of operation produces garbled
output.  The reason is that the clock has not yet stabilized and is
running slow, resulting in the bit time of the serial characters being
too long.

The ECP5 data sheet says that the phase detector should be operated
between 10 and 400 MHz.  The current code operates it at 2MHz.
Consequently, the PLL lock indication doesn't work, i.e. it is always
zero.  The current code works around that by inverting it, i.e. taking
the "not locked" indication to mean "locked".

Instead, we now run it at 12MHz, chosen because the common external
clock inputs on ECP5 boards are 12MHz and 48MHz.  Normally this would
mean that the available system clock frequencies would be multiples of
12MHz, but this is a little inconvenient as we use 40MHz on the Orange
Crab v0.21 boards.  Instead, by using the secondary clock output for
feedback, we can have any divisor of the PLL frequency as the system
clock frequency.

The ECP5 data sheet says the PLL oscillator can run at 400 to 800
MHz.  Here we choose 480MHz since that allows us to generate 40MHz and
48MHz easily and is a multiple of 12MHz.

With this, the lock signal works correctly, and the inversion can be
removed.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Michael Neuling 8a030502a2
Merge pull request #336 from paulusmack/fixes
Makefile: Correct parameters for the Orange Crab 85F
3 years ago
Paul Mackerras a5c9b3c412 Makefile: Add a target for the Orange Crab v0.21 with LFE5U-85F
The existing orange crab target is for an older board with a
LFE5UM5G-85F device.  Newer orange crab boards (v0.21) have a
LFE5U-85F device in the -8 speed grade, so make a new target for them
called ORANGE-CRAB-0.21.

Also add flags to ecppack to indicate that the bitstream should be
compressed and can be loaded at 38.8MHz.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Michael Neuling 9cbe1f4a17
Merge pull request #334 from antonblanchard/icbi-issue
Add a test for icbi and dcbz issues
3 years ago
Anton Blanchard 099862bee9
Merge pull request #335 from ozbenh/misc
Misc cleanups and icache fix
3 years ago
Benjamin Herrenschmidt e675eba0df icache: req_laddr becomes req_raddr
Uses real_addr_t and only stores the real address bits

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Benjamin Herrenschmidt 5cfa65e836 Introduce addr_to_wb() and wb_to_addr() helpers
These convert addresses to/from wishbone addresses, and use them
in parts of the caches, in order to make the code a bit more readable.

Along the way, rename some functions in the caches to make it a bit
clearer what they operate on and fix a bug in the icache STOP_RELOAD state where
the wb address wasn't properly converted.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Benjamin Herrenschmidt d745995207 Introduce real_addr_t and addr_to_real()
This moves REAL_ADDR_BITS out of the caches and defines a real_addr_t
type for a real address, along with a addr_to_real() conversion helper.

It makes the vhdl a bit more readable

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Anton Blanchard 2d142a6c01 tests/misc: Add a store/dcbz test
We have a bug where an store near a dcbz can cause the dcbz to only zero
8 bytes. Add a test case for this.

Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
3 years ago
Anton Blanchard 00259458c7 tests/misc: Add an icbi test
We have a bug where an icbi can cause an instruction to execute twice.
Add a test case for this.

Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
3 years ago
Anton Blanchard 13439c76ba
Merge pull request #333 from ozbenh/wukong
Add support for  QMTech Wukong v2 board
3 years ago
Benjamin Herrenschmidt d564672a82 Regenerate litedram and liteeth
Note: There are a few patches to upstream to fix an upstream breakage
of litedram standalone generator, and fix some issues with liteeth
in the way it's used on Wukong. All these have pending pull requests.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Benjamin Herrenschmidt da0189af1e Add support for QMTech Wukong v2 board
For now only the V2 of the board (slightly different pinout)
and only the A100T variant. I also haven't added GPIOs or anything
else on the PMODs really.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Benjamin Herrenschmidt 621a0f6b28 fpga/clk_gen_plle2: Add support for 50Mhz->100Mhz
50Mhz clkin, 100Mhz sys_clk, as needed for Wukon v2

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Benjamin Herrenschmidt 4b1a413a2f Add support for more spansion flash
That's the one on the Wukong v2

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Anton Blanchard c7579d74b0
Merge pull request #332 from paulusmack/fixes
Bug fixes
3 years ago
Paul Mackerras 70270c066a dcache: Fix bug with dcbz closely following stores with the same tag
This fixes a bug where a dcbz can get incorrectly handled as an
ordinary 8-byte store if it arrives while the dcache state machine is
handling other stores with the same tag value (i.e. within the same
set-sized area of memory).  The logic that says whether to include a
new store in the current wishbone cycle didn't take into account
whether the new store was a dcbz.  This adds a "req.dcbz = '0'" factor
so that it does.  This is necessary because dcbz is handled more like
a cache line refill (but writing to memory rather than reading) than
an ordinary store.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras 9b3b57710a icache: Fix icache invalidation
This fixes two bugs in the flash invalidation of the icache.

The first is that an instruction could get executed twice.  The
i-cache RAM is 2 instructions (64 bits) wide, so one read can supply
results for 2 cycles.  The fetch1 stage tells icache when the address
is equal to the address of the previous cycle plus 4, and in cases
where that is true, bit 2 of the address is 1, and the previous cycle
was a cache hit, we just use the second word of the doubleword read
from the cache RAM.  However, the cache hit/miss logic also continues
to operate, so in the case where the first word hits but the second
word misses (because of an icache invalidation or a snoop occurring in
the first cycle), we supply the instruction from the data previously
read from the icache RAM but also stall fetch1 and start a cache
reload sequence, and subsequently supply the second instruction
again.  This fixes the issue by inhibiting req_is_miss and stall_out
when use_previous is true.

The second bug is that if an icache invalidation occurs while
reloading a line, we continue to reload the line, and make it valid
when the reload finishes, even though some of the data may have been
read before the invalidation occurred.  This adds a new state
STOP_RELOAD which we go to if an invalidation happens while we are in
CLR_TAG or WAIT_ACK state.  In STOP_RELOAD state we don't request any
more reads from memory and wait for the reads we have previously
requested to be acked, and then go to IDLE state.  Data returned is
still written to the icache RAM, but that doesn't matter because the
line is invalid and is never made valid.

Note that we don't have to worry about invalidations due to snooped
writes while reloading a line, because the wishbone arbiter won't
switch to another master once it has started sending our reload
requests to memory.  Thus a store to memory will either happen before
any of our reads have got to memory, or after we have finished the
reload (in which case we will no longer be in WAIT_ACK state).

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras 83dea94793 decode1: Conditional trap instructions don't need to be single-issue
They can generate interrupts, but that doesn't mean they have to
single-issue.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras 9aaa6d3ca3
Merge pull request #330 from antonblanchard/orange-crab-freq
Orange Crab is 48MHz not 50MHz, bump PLL frequency
3 years ago
Anton Blanchard 537e446562
Merge pull request #331 from ozbenh/misc
jtag tooling improvements & gitignore fix
3 years ago
Benjamin Herrenschmidt e6cb72fcd9 Add liteeth/build to gitignore
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Benjamin Herrenschmidt b557ec3a05 mw_debug: Default to jtag backend if unspecified
It avoids typing it all the time

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Benjamin Herrenschmidt 4bdfef9a20 mw_debug: Probe cable if unspecified
Instead of defaulting to DigilentHS1

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Benjamin Herrenschmidt 814d6914d0 flash-arty: Add cable argument
To select the cable config. Defaults to arty

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 years ago
Anton Blanchard af6bc48d36
Merge pull request #329 from paulusmack/wb-fix
Wishbone addressing fix
3 years ago
Anton Blanchard 06266fe84a Orange Crab is 48MHz not 50MHz, bump PLL frequency
I'm not sure why I set the input frequency for the Orange Crab to 50MHz.
Since we easily make timing now, bump our output frequency to 48MHz as
well.

Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
3 years ago
Michael Neuling 0a415410c9
Merge pull request #328 from paulusmack/shortmult
core: Add a short multiplier
3 years ago
Michael Neuling c2f5db6fca
Merge pull request #327 from paulusmack/master
loadstore1 timing improvement
3 years ago
Paul Mackerras ca4eb46aea Make wishbone addresses be in units of doublewords or words
This makes the 64-bit wishbone buses have the address expressed in
units of doublewords (64 bits), and similarly for the 32-bit buses the
address is in units of words (32 bits).  This is to comply with the
wishbone spec.  Previously the addresses on the wishbone buses were in
units of bytes regardless of the bus data width, which is not correct
and caused problems with interfacing with externally-generated logic.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras 734e4c4a52 core: Add a short multiplier
This adds an optional 16 bit x 16 bit signed multiplier and uses it
for multiply instructions that return the low 64 bits of the product
(mull[dw][o] and mulli, but not maddld) when the operands are both in
the range -2^15 .. 2^15 - 1.   The "short" 16-bit multiplier produces
its result combinatorially, so a multiply that uses it executes in one
cycle.  This improves the coremark result by about 4%, since coremark
does quite a lot of multiplies and they almost all have operands that
fit into 16 bits.

The presence of the short multiplier is controlled by a generic at the
execute1, SOC, core and top levels.  For now, it defaults to off for
all platforms, and can be enabled using the --has_short_mult flag to
fusesoc.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras bb5f356386 loadstore1: Make r1.req.addr not depend on l_in.valid
Some critical path reports showed r1.req.addr depending on l_in.valid,
which then depended ultimately on the dcache's r1.ls_valid.  In fact
we can update r1.req.addr (and other fields of r1.req, except for
r1.req.valid) independently of l_in.valid as long as busy = 0.
We do also need to preserve r1.req.addr0 when l_in.valid = 0, so we
pull it out of r1.req and store it separately in r1.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Michael Neuling 2224b28c2c
Merge pull request #324 from paulusmack/master
Performance and timing improvements
3 years ago
Paul Mackerras 54b0e8b8c8 core: Predict not-taken conditional branches using BTC
This adds a bit to the BTC to store whether the corresponding branch
instruction was taken last time it was encountered.  That lets us pass
a not-taken prediction down to decode1, which for backwards direct
branches inhibits it from redirecting fetch to the target of the
branch.  This increases coremark by about 2%.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras 0cdaa2778f xilinx-mult: Move some registers later in the data flow
This changes s0 to use the P register rather than the A/B/C input
registers, thus improving the timing of the multiplier output.  The
m00, m02 and m03 multipliers now use their P registers rather than the
M registers, moving the addition they do from the second cycle to the
first.

Also, the XOR that inverts the 32 LSBs is moved before the output
register.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras 77d9891d2f
Merge pull request #326 from antonblanchard/dcache-nc-fix
dcache: Loads from non-cacheable PTEs load entire 64 bits
3 years ago
Anton Blanchard 39e1d10069
Merge pull request #325 from paulusmack/fixes
decode1: Fix form of isel marked as single-issue
3 years ago
Anton Blanchard b29c58f3d1 dcache: Loads from non-cacheable PTEs load entire 64 bits
A non-cacheable load should only load the data requested and no more. We
do the right thing for real mode cache inhibited storage instructions,
but when loading through a non-cacheable PTE we load the entire 64 bits
regardless of the size.

Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
3 years ago
Paul Mackerras d4cfdb1bfe decode1: Fix form of isel marked as single-issue
The row in the decode table for isel with BC=0 was inadvertently left
marked as single-issue by commit 813f834012 ("Add CR hazard
detection", 2019-10-15).  Fix it.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Michael Neuling 09bd01a49e
Merge pull request #323 from paulusmack/fixes
More instruction fixes
3 years ago
Paul Mackerras 06e07c69a8 decode1: Fix maddld and maddhdu to not set CR0
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras a68921edca core: Fix mcrxrx, addpcis and bpermd
- mcrxrx put the bits in the wrong order

- addpcis was setting CR0 if the instruction bit 0 = 1, which it
  shouldn't

- bpermd was producing 0 always and additionally had the wrong bit
  numbering

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Michael Neuling 18eb029f0a
Merge pull request #322 from paulusmack/fixes
Fix bug with load hitting two previous stores
3 years ago
Paul Mackerras ba34914465 tests/misc: Add a test for a load that hits two preceding stores
This checks that the store forwarding machinery in the dcache
correctly combines forwarded stores when they are partial stores
(i.e. only writing part of the doubleword, as for a byte store).

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras 0b23a5e760 dcache: Simplify data input to improve timing
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras 1a9834c506 dcache: Fix bug with forwarding of stores
We have two stages of forwarding to cover the two cycles of latency
between when something is written to BRAM and when that new data can
be read from BRAM.  When the writes to BRAM result from store
instructions, the write may write only some bytes of a row (8 bytes)
and not others, so we have a mask to enable only the written bytes to
be forwarded.  However, we only forward written data from either the
first stage of forwarding or the second, not both.  So if we have
two stores in succession that write different bytes of the same row,
and then a load from the row, we will only forward the data from the
second store, and miss the data from the first store; thus the load
will get the wrong value.

To fix this, we make the decision on which forward stage to use for
each byte individually.  This results in a 4-input multiplexer feeding
r1.data_out, with its inputs being the BRAM, the wishbone, the current
write data, and the 2nd-stage forwarding register.  Each byte of the
multiplexer is separately controlled.  The code for this multiplexer
is moved to the dcache_fast_hit process since it is used for cache
hits as well as cache misses.

This also simplifies the BRAM code by ensuring that we can use the
same source for the BRAM address and way selection for writes, whether
we are writing store data or cache line refill data from memory.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Paul Mackerras f812832ad7 dcache: Move way selection and forwarding earlier
This moves the way multiplexer for the data from the BRAM, and the
multiplexers for forwarding data from earlier stores or refills,
before a clock edge rather than after, so that now the data output
from the dcache comes from a clean latch.  To do this we remove the
extra latch on the output of the data BRAM (i.e. ADD_BUF=false) and
rearrange the logic.  The choice whether to forward or not now depends
not on way comparisons but rather on a tag comparisons, for the sake
of timing.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
3 years ago
Michael Neuling a9e6263aab
Merge pull request #319 from antonblanchard/verilator-ci
Add some Verilator CI tests
3 years ago
Michael Neuling 8bbb0018b4
Merge pull request #318 from paulusmack/pmu
PMU enhancements
3 years ago