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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-03 06:20:12 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-03 06:20:12 +0300 |
commit | f5a8eb632b562bd9c16c389f5db3a5260fba4157 (patch) | |
tree | 82687234d772ff8f72a31e598fe16553885c56c9 /drivers/misc | |
parent | c9297d284126b80c9cfd72c690e0da531c99fc48 (diff) | |
parent | dd3b8c329aa270027fba61a02a12600972dc3983 (diff) | |
download | linux-f5a8eb632b562bd9c16c389f5db3a5260fba4157.tar.xz |
Merge tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pul removal of obsolete architecture ports from Arnd Bergmann:
"This removes the entire architecture code for blackfin, cris, frv,
m32r, metag, mn10300, score, and tile, including the associated device
drivers.
I have been working with the (former) maintainers for each one to
ensure that my interpretation was right and the code is definitely
unused in mainline kernels. Many had fond memories of working on the
respective ports to start with and getting them included in upstream,
but also saw no point in keeping the port alive without any users.
In the end, it seems that while the eight architectures are extremely
different, they all suffered the same fate: There was one company in
charge of an SoC line, a CPU microarchitecture and a software
ecosystem, which was more costly than licensing newer off-the-shelf
CPU cores from a third party (typically ARM, MIPS, or RISC-V). It
seems that all the SoC product lines are still around, but have not
used the custom CPU architectures for several years at this point. In
contrast, CPU instruction sets that remain popular and have actively
maintained kernel ports tend to all be used across multiple licensees.
[ See the new nds32 port merged in the previous commit for the next
generation of "one company in charge of an SoC line, a CPU
microarchitecture and a software ecosystem" - Linus ]
The removal came out of a discussion that is now documented at
https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
marking any ports as deprecated but remove them all at once after I
made sure that they are all unused. Some architectures (notably tile,
mn10300, and blackfin) are still being shipped in products with old
kernels, but those products will never be updated to newer kernel
releases.
After this series, we still have a few architectures without mainline
gcc support:
- unicore32 and hexagon both have very outdated gcc releases, but the
maintainers promised to work on providing something newer. At least
in case of hexagon, this will only be llvm, not gcc.
- openrisc, risc-v and nds32 are still in the process of finishing
their support or getting it added to mainline gcc in the first
place. They all have patched gcc-7.3 ports that work to some
degree, but complete upstream support won't happen before gcc-8.1.
Csky posted their first kernel patch set last week, their situation
will be similar
[ Palmer Dabbelt points out that RISC-V support is in mainline gcc
since gcc-7, although gcc-7.3.0 is the recommended minimum - Linus ]"
This really says it all:
2498 files changed, 95 insertions(+), 467668 deletions(-)
* tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (74 commits)
MAINTAINERS: UNICORE32: Change email account
staging: iio: remove iio-trig-bfin-timer driver
tty: hvc: remove tile driver
tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers
serial: remove tile uart driver
serial: remove m32r_sio driver
serial: remove blackfin drivers
serial: remove cris/etrax uart drivers
usb: Remove Blackfin references in USB support
usb: isp1362: remove blackfin arch glue
usb: musb: remove blackfin port
usb: host: remove tilegx platform glue
pwm: remove pwm-bfin driver
i2c: remove bfin-twi driver
spi: remove blackfin related host drivers
watchdog: remove bfin_wdt driver
can: remove bfin_can driver
mmc: remove bfin_sdh driver
input: misc: remove blackfin rotary driver
input: keyboard: remove bf54x driver
...
Diffstat (limited to 'drivers/misc')
-rw-r--r-- | drivers/misc/echo/echo.c | 73 | ||||
-rw-r--r-- | drivers/misc/echo/fir.h | 50 |
2 files changed, 0 insertions, 123 deletions
diff --git a/drivers/misc/echo/echo.c b/drivers/misc/echo/echo.c index 9597e9523cac..8a5adc0d2e88 100644 --- a/drivers/misc/echo/echo.c +++ b/drivers/misc/echo/echo.c @@ -115,78 +115,6 @@ /* adapting coeffs using the traditional stochastic descent (N)LMS algorithm */ -#ifdef __bfin__ -static inline void lms_adapt_bg(struct oslec_state *ec, int clean, int shift) -{ - int i; - int offset1; - int offset2; - int factor; - int exp; - int16_t *phist; - int n; - - if (shift > 0) - factor = clean << shift; - else - factor = clean >> -shift; - - /* Update the FIR taps */ - - offset2 = ec->curr_pos; - offset1 = ec->taps - offset2; - phist = &ec->fir_state_bg.history[offset2]; - - /* st: and en: help us locate the assembler in echo.s */ - - /* asm("st:"); */ - n = ec->taps; - for (i = 0; i < n; i++) { - exp = *phist++ * factor; - ec->fir_taps16[1][i] += (int16_t) ((exp + (1 << 14)) >> 15); - } - /* asm("en:"); */ - - /* Note the asm for the inner loop above generated by Blackfin gcc - 4.1.1 is pretty good (note even parallel instructions used): - - R0 = W [P0++] (X); - R0 *= R2; - R0 = R0 + R3 (NS) || - R1 = W [P1] (X) || - nop; - R0 >>>= 15; - R0 = R0 + R1; - W [P1++] = R0; - - A block based update algorithm would be much faster but the - above can't be improved on much. Every instruction saved in - the loop above is 2 MIPs/ch! The for loop above is where the - Blackfin spends most of it's time - about 17 MIPs/ch measured - with speedtest.c with 256 taps (32ms). Write-back and - Write-through cache gave about the same performance. - */ -} - -/* - IDEAS for further optimisation of lms_adapt_bg(): - - 1/ The rounding is quite costly. Could we keep as 32 bit coeffs - then make filter pluck the MS 16-bits of the coeffs when filtering? - However this would lower potential optimisation of filter, as I - think the dual-MAC architecture requires packed 16 bit coeffs. - - 2/ Block based update would be more efficient, as per comments above, - could use dual MAC architecture. - - 3/ Look for same sample Blackfin LMS code, see if we can get dual-MAC - packing. - - 4/ Execute the whole e/c in a block of say 20ms rather than sample - by sample. Processing a few samples every ms is inefficient. -*/ - -#else static inline void lms_adapt_bg(struct oslec_state *ec, int clean, int shift) { int i; @@ -215,7 +143,6 @@ static inline void lms_adapt_bg(struct oslec_state *ec, int clean, int shift) ec->fir_taps16[1][i] += (int16_t) ((exp + (1 << 14)) >> 15); } } -#endif static inline int top_bit(unsigned int bits) { diff --git a/drivers/misc/echo/fir.h b/drivers/misc/echo/fir.h index 7b9fabf1fea5..4e0f365f0577 100644 --- a/drivers/misc/echo/fir.h +++ b/drivers/misc/echo/fir.h @@ -27,14 +27,6 @@ #define _FIR_H_ /* - Blackfin NOTES & IDEAS: - - A simple dot product function is used to implement the filter. This performs - just one MAC/cycle which is inefficient but was easy to implement as a first - pass. The current Blackfin code also uses an unrolled form of the filter - history to avoid 0 length hardware loop issues. This is wasteful of - memory. - Ideas for improvement: 1/ Rewrite filter for dual MAC inner loop. The issue here is handling @@ -94,21 +86,13 @@ static inline const int16_t *fir16_create(struct fir16_state_t *fir, fir->taps = taps; fir->curr_pos = taps - 1; fir->coeffs = coeffs; -#if defined(__bfin__) - fir->history = kcalloc(2 * taps, sizeof(int16_t), GFP_KERNEL); -#else fir->history = kcalloc(taps, sizeof(int16_t), GFP_KERNEL); -#endif return fir->history; } static inline void fir16_flush(struct fir16_state_t *fir) { -#if defined(__bfin__) - memset(fir->history, 0, 2 * fir->taps * sizeof(int16_t)); -#else memset(fir->history, 0, fir->taps * sizeof(int16_t)); -#endif } static inline void fir16_free(struct fir16_state_t *fir) @@ -116,42 +100,9 @@ static inline void fir16_free(struct fir16_state_t *fir) kfree(fir->history); } -#ifdef __bfin__ -static inline int32_t dot_asm(short *x, short *y, int len) -{ - int dot; - - len--; - - __asm__("I0 = %1;\n\t" - "I1 = %2;\n\t" - "A0 = 0;\n\t" - "R0.L = W[I0++] || R1.L = W[I1++];\n\t" - "LOOP dot%= LC0 = %3;\n\t" - "LOOP_BEGIN dot%=;\n\t" - "A0 += R0.L * R1.L (IS) || R0.L = W[I0++] || R1.L = W[I1++];\n\t" - "LOOP_END dot%=;\n\t" - "A0 += R0.L*R1.L (IS);\n\t" - "R0 = A0;\n\t" - "%0 = R0;\n\t" - : "=&d"(dot) - : "a"(x), "a"(y), "a"(len) - : "I0", "I1", "A1", "A0", "R0", "R1" - ); - - return dot; -} -#endif - static inline int16_t fir16(struct fir16_state_t *fir, int16_t sample) { int32_t y; -#if defined(__bfin__) - fir->history[fir->curr_pos] = sample; - fir->history[fir->curr_pos + fir->taps] = sample; - y = dot_asm((int16_t *) fir->coeffs, &fir->history[fir->curr_pos], - fir->taps); -#else int i; int offset1; int offset2; @@ -165,7 +116,6 @@ static inline int16_t fir16(struct fir16_state_t *fir, int16_t sample) y += fir->coeffs[i] * fir->history[i - offset1]; for (; i >= 0; i--) y += fir->coeffs[i] * fir->history[i + offset2]; -#endif if (fir->curr_pos <= 0) fir->curr_pos = fir->taps; fir->curr_pos--; |