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authorLinus Torvalds <torvalds@linux-foundation.org>2017-02-23 18:58:18 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-23 18:58:18 -0800
commitef96152e6a36e0510387cb174178b7982c1ae879 (patch)
treef2b881feb97893dd6e73380fe206bbfd5110559e /lib
parentd5500a074741b78b7f778b4ab3415d5ecdcda0a7 (diff)
parent64a577196d66b44e37384bc5c4d78c61f59d5b2a (diff)
downloadlinux-ef96152e6a36e0510387cb174178b7982c1ae879.tar.gz
linux-ef96152e6a36e0510387cb174178b7982c1ae879.tar.xz
Merge tag 'drm-for-v4.11-less-shouty' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie: "This is the main drm pull request for v4.11. Nothing too major, the tinydrm and mmu-less support should make writing smaller drivers easier for some of the simpler platforms, and there are a bunch of documentation updates. Intel grew displayport MST audio support which is hopefully useful to people, and FBC is on by default for GEN9+ (so people know where to look for regressions). AMDGPU has a lot of fixes that would like new firmware files installed for some GPUs. Other than that it's pretty scattered all over. I may have a follow up pull request as I know BenH has a bunch of AST rework and fixes and I'd like to get those in once they've been tested by AST, and I've got at least one pull request I'm just trying to get the author to fix up. Core: - drm_mm reworked - Connector list locking and iterators - Documentation updates - Format handling rework - MMU-less support for fbdev helpers - drm_crtc_from_index helper - Core CRC API - Remove drm_framebuffer_unregister_private - Debugfs cleanup - EDID/Infoframe fixes - Release callback - Tinydrm support (smaller drivers for simple hw) panel: - Add support for some new simple panels i915: - FBC by default for gen9+ - Shared dpll cleanups and docs - GEN8 powerdomain cleanup - DMC support on GLK - DP MST audio support - HuC loading support - GVT init ordering fixes - GVT IOMMU workaround fix amdgpu/radeon: - Power/clockgating improvements - Preliminary SR-IOV support - TTM buffer priority and eviction fixes - SI DPM quirks removed due to firmware fixes - Powerplay improvements - VCE/UVD powergating fixes - Cleanup SI GFX code to match CI/VI - Support for > 2 displays on 3/5 crtc asics - SI headless fixes nouveau: - Rework securre boot code in prep for GP10x secure boot - Channel recovery improvements - Initial power budget code - MMU rework preperation vmwgfx: - Bunch of fixes and cleanups exynos: - Runtime PM support for MIC driver - Cleanups to use atomic helpers - UHD Support for TM2/TM2E boards - Trigger mode fix for Rinato board etnaviv: - Shader performance fix - Command stream validator fixes - Command buffer suballocator rockchip: - CDN DisplayPort support - IOMMU support for arm64 platform imx-drm: - Fix i.MX5 TV encoder probing - Remove lower fb size limits msm: - Support for HW cursor on MDP5 devices - DSI encoder cleanup - GPU DT bindings cleanup sti: - stih410 cleanups - Create fbdev at binding - HQVDP fixes - Remove stih416 chip functionality - DVI/HDMI mode selection fixes - FPS statistic reporting omapdrm: - IRQ code cleanup dwi-hdmi bridge: - Cleanups and fixes adv-bridge: - Updates for nexus sii8520 bridge: - Add interlace mode support - Rework HDMI and lots of fixes qxl: - probing/teardown cleanups ZTE drm: - HDMI audio via SPDIF interface - Video Layer overlay plane support - Add TV encoder output device atmel-hlcdc: - Rework fbdev creation logic tegra: - OF node fix fsl-dcu: - Minor fixes mali-dp: - Assorted fixes sunxi: - Minor fix" [ This was the "fixed" pull, that still had build warnings due to people not even having build tested the result. I'm not a happy camper I've fixed the things I noticed up in this merge. - Linus ] * tag 'drm-for-v4.11-less-shouty' of git://people.freedesktop.org/~airlied/linux: (1177 commits) lib/Kconfig: make PRIME_NUMBERS not user selectable drm/tinydrm: helpers: Properly fix backlight dependency drm/tinydrm: mipi-dbi: Fix field width specifier warning drm/tinydrm: mipi-dbi: Silence: ‘cmd’ may be used uninitialized drm/sti: fix build warnings in sti_drv.c and sti_vtg.c files drm/amd/powerplay: fix PSI feature on Polars12 drm/amdgpu: refuse to reserve io mem for split VRAM buffers drm/ttm: fix use-after-free races in vm fault handling drm/tinydrm: Add support for Multi-Inno MI0283QT display dt-bindings: Add Multi-Inno MI0283QT binding dt-bindings: display/panel: Add common rotation property of: Add vendor prefix for Multi-Inno drm/tinydrm: Add MIPI DBI support drm/tinydrm: Add helper functions drm: Add DRM support for tiny LCD displays drm/amd/amdgpu: post card if there is real hw resetting performed drm/nouveau/tmr: provide backtrace when a timeout is hit drm/nouveau/pci/g92: Fix rearm drm/nouveau/drm/therm/fan: add a fallback if no fan control is specified in the vbios drm/nouveau/hwmon: expose power_max and power_crit ..
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig3
-rw-r--r--lib/Makefile2
-rw-r--r--lib/prime_numbers.c315
3 files changed, 320 insertions, 0 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index f3552604e47a..87ecd41031bd 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -553,4 +553,7 @@ config SBITMAP
config PARMAN
tristate
+config PRIME_NUMBERS
+ tristate
+
endmenu
diff --git a/lib/Makefile b/lib/Makefile
index 6b768b58a38d..f1a0364af377 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -198,6 +198,8 @@ obj-$(CONFIG_ASN1) += asn1_decoder.o
obj-$(CONFIG_FONT_SUPPORT) += fonts/
+obj-$(CONFIG_PRIME_NUMBERS) += prime_numbers.o
+
hostprogs-y := gen_crc32table
clean-files := crc32table.h
diff --git a/lib/prime_numbers.c b/lib/prime_numbers.c
new file mode 100644
index 000000000000..550eec457c2e
--- /dev/null
+++ b/lib/prime_numbers.c
@@ -0,0 +1,315 @@
+#define pr_fmt(fmt) "prime numbers: " fmt "\n"
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/prime_numbers.h>
+#include <linux/slab.h>
+
+#define bitmap_size(nbits) (BITS_TO_LONGS(nbits) * sizeof(unsigned long))
+
+struct primes {
+ struct rcu_head rcu;
+ unsigned long last, sz;
+ unsigned long primes[];
+};
+
+#if BITS_PER_LONG == 64
+static const struct primes small_primes = {
+ .last = 61,
+ .sz = 64,
+ .primes = {
+ BIT(2) |
+ BIT(3) |
+ BIT(5) |
+ BIT(7) |
+ BIT(11) |
+ BIT(13) |
+ BIT(17) |
+ BIT(19) |
+ BIT(23) |
+ BIT(29) |
+ BIT(31) |
+ BIT(37) |
+ BIT(41) |
+ BIT(43) |
+ BIT(47) |
+ BIT(53) |
+ BIT(59) |
+ BIT(61)
+ }
+};
+#elif BITS_PER_LONG == 32
+static const struct primes small_primes = {
+ .last = 31,
+ .sz = 32,
+ .primes = {
+ BIT(2) |
+ BIT(3) |
+ BIT(5) |
+ BIT(7) |
+ BIT(11) |
+ BIT(13) |
+ BIT(17) |
+ BIT(19) |
+ BIT(23) |
+ BIT(29) |
+ BIT(31)
+ }
+};
+#else
+#error "unhandled BITS_PER_LONG"
+#endif
+
+static DEFINE_MUTEX(lock);
+static const struct primes __rcu *primes = RCU_INITIALIZER(&small_primes);
+
+static unsigned long selftest_max;
+
+static bool slow_is_prime_number(unsigned long x)
+{
+ unsigned long y = int_sqrt(x);
+
+ while (y > 1) {
+ if ((x % y) == 0)
+ break;
+ y--;
+ }
+
+ return y == 1;
+}
+
+static unsigned long slow_next_prime_number(unsigned long x)
+{
+ while (x < ULONG_MAX && !slow_is_prime_number(++x))
+ ;
+
+ return x;
+}
+
+static unsigned long clear_multiples(unsigned long x,
+ unsigned long *p,
+ unsigned long start,
+ unsigned long end)
+{
+ unsigned long m;
+
+ m = 2 * x;
+ if (m < start)
+ m = roundup(start, x);
+
+ while (m < end) {
+ __clear_bit(m, p);
+ m += x;
+ }
+
+ return x;
+}
+
+static bool expand_to_next_prime(unsigned long x)
+{
+ const struct primes *p;
+ struct primes *new;
+ unsigned long sz, y;
+
+ /* Betrand's Postulate (or Chebyshev's theorem) states that if n > 3,
+ * there is always at least one prime p between n and 2n - 2.
+ * Equivalently, if n > 1, then there is always at least one prime p
+ * such that n < p < 2n.
+ *
+ * http://mathworld.wolfram.com/BertrandsPostulate.html
+ * https://en.wikipedia.org/wiki/Bertrand's_postulate
+ */
+ sz = 2 * x;
+ if (sz < x)
+ return false;
+
+ sz = round_up(sz, BITS_PER_LONG);
+ new = kmalloc(sizeof(*new) + bitmap_size(sz),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!new)
+ return false;
+
+ mutex_lock(&lock);
+ p = rcu_dereference_protected(primes, lockdep_is_held(&lock));
+ if (x < p->last) {
+ kfree(new);
+ goto unlock;
+ }
+
+ /* Where memory permits, track the primes using the
+ * Sieve of Eratosthenes. The sieve is to remove all multiples of known
+ * primes from the set, what remains in the set is therefore prime.
+ */
+ bitmap_fill(new->primes, sz);
+ bitmap_copy(new->primes, p->primes, p->sz);
+ for (y = 2UL; y < sz; y = find_next_bit(new->primes, sz, y + 1))
+ new->last = clear_multiples(y, new->primes, p->sz, sz);
+ new->sz = sz;
+
+ BUG_ON(new->last <= x);
+
+ rcu_assign_pointer(primes, new);
+ if (p != &small_primes)
+ kfree_rcu((struct primes *)p, rcu);
+
+unlock:
+ mutex_unlock(&lock);
+ return true;
+}
+
+static void free_primes(void)
+{
+ const struct primes *p;
+
+ mutex_lock(&lock);
+ p = rcu_dereference_protected(primes, lockdep_is_held(&lock));
+ if (p != &small_primes) {
+ rcu_assign_pointer(primes, &small_primes);
+ kfree_rcu((struct primes *)p, rcu);
+ }
+ mutex_unlock(&lock);
+}
+
+/**
+ * next_prime_number - return the next prime number
+ * @x: the starting point for searching to test
+ *
+ * A prime number is an integer greater than 1 that is only divisible by
+ * itself and 1. The set of prime numbers is computed using the Sieve of
+ * Eratoshenes (on finding a prime, all multiples of that prime are removed
+ * from the set) enabling a fast lookup of the next prime number larger than
+ * @x. If the sieve fails (memory limitation), the search falls back to using
+ * slow trial-divison, up to the value of ULONG_MAX (which is reported as the
+ * final prime as a sentinel).
+ *
+ * Returns: the next prime number larger than @x
+ */
+unsigned long next_prime_number(unsigned long x)
+{
+ const struct primes *p;
+
+ rcu_read_lock();
+ p = rcu_dereference(primes);
+ while (x >= p->last) {
+ rcu_read_unlock();
+
+ if (!expand_to_next_prime(x))
+ return slow_next_prime_number(x);
+
+ rcu_read_lock();
+ p = rcu_dereference(primes);
+ }
+ x = find_next_bit(p->primes, p->last, x + 1);
+ rcu_read_unlock();
+
+ return x;
+}
+EXPORT_SYMBOL(next_prime_number);
+
+/**
+ * is_prime_number - test whether the given number is prime
+ * @x: the number to test
+ *
+ * A prime number is an integer greater than 1 that is only divisible by
+ * itself and 1. Internally a cache of prime numbers is kept (to speed up
+ * searching for sequential primes, see next_prime_number()), but if the number
+ * falls outside of that cache, its primality is tested using trial-divison.
+ *
+ * Returns: true if @x is prime, false for composite numbers.
+ */
+bool is_prime_number(unsigned long x)
+{
+ const struct primes *p;
+ bool result;
+
+ rcu_read_lock();
+ p = rcu_dereference(primes);
+ while (x >= p->sz) {
+ rcu_read_unlock();
+
+ if (!expand_to_next_prime(x))
+ return slow_is_prime_number(x);
+
+ rcu_read_lock();
+ p = rcu_dereference(primes);
+ }
+ result = test_bit(x, p->primes);
+ rcu_read_unlock();
+
+ return result;
+}
+EXPORT_SYMBOL(is_prime_number);
+
+static void dump_primes(void)
+{
+ const struct primes *p;
+ char *buf;
+
+ buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+
+ rcu_read_lock();
+ p = rcu_dereference(primes);
+
+ if (buf)
+ bitmap_print_to_pagebuf(true, buf, p->primes, p->sz);
+ pr_info("primes.{last=%lu, .sz=%lu, .primes[]=...x%lx} = %s",
+ p->last, p->sz, p->primes[BITS_TO_LONGS(p->sz) - 1], buf);
+
+ rcu_read_unlock();
+
+ kfree(buf);
+}
+
+static int selftest(unsigned long max)
+{
+ unsigned long x, last;
+
+ if (!max)
+ return 0;
+
+ for (last = 0, x = 2; x < max; x++) {
+ bool slow = slow_is_prime_number(x);
+ bool fast = is_prime_number(x);
+
+ if (slow != fast) {
+ pr_err("inconsistent result for is-prime(%lu): slow=%s, fast=%s!",
+ x, slow ? "yes" : "no", fast ? "yes" : "no");
+ goto err;
+ }
+
+ if (!slow)
+ continue;
+
+ if (next_prime_number(last) != x) {
+ pr_err("incorrect result for next-prime(%lu): expected %lu, got %lu",
+ last, x, next_prime_number(last));
+ goto err;
+ }
+ last = x;
+ }
+
+ pr_info("selftest(%lu) passed, last prime was %lu", x, last);
+ return 0;
+
+err:
+ dump_primes();
+ return -EINVAL;
+}
+
+static int __init primes_init(void)
+{
+ return selftest(selftest_max);
+}
+
+static void __exit primes_exit(void)
+{
+ free_primes();
+}
+
+module_init(primes_init);
+module_exit(primes_exit);
+
+module_param_named(selftest, selftest_max, ulong, 0400);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL");