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authorLinus Torvalds <torvalds@linux-foundation.org>2018-04-03 06:20:12 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-03 06:20:12 +0300
commitf5a8eb632b562bd9c16c389f5db3a5260fba4157 (patch)
tree82687234d772ff8f72a31e598fe16553885c56c9 /drivers/misc/echo/echo.c
parentc9297d284126b80c9cfd72c690e0da531c99fc48 (diff)
parentdd3b8c329aa270027fba61a02a12600972dc3983 (diff)
downloadlinux-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this series, we still have a few architectures without mainline gcc support: - unicore32 and hexagon both have very outdated gcc releases, but the maintainers promised to work on providing something newer.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/echo/echo.c')
-rw-r--r--drivers/misc/echo/echo.c73
1 files changed, 0 insertions, 73 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)
{