From: Tomer Maimon <tmaimon77@gmail.com> To: broonie@kernel.org, dwmw2@infradead.org, computersforpeace@gmail.com, marek.vasut@gmail.com, miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com, bbrezillon@kernel.org, yogeshnarayan.gaur@nxp.com, tudor.ambarus@microchip.com, gregkh@linuxfoundation.org, frieder.schrempf@exceet.de, tglx@linutronix.de Cc: linux-spi@vger.kernel.org, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, Tomer Maimon <tmaimon77@gmail.com> Subject: [RFC v1 0/3] *spi-mem: adding setup and callback function Date: Mon, 29 Jul 2019 17:25:01 +0300 [thread overview] Message-ID: <20190729142504.188336-1-tmaimon77@gmail.com> (raw) Lately we have working on Flash interface unit (FIU) SPI driver that using spi-mem interface, Our FIU HW module support direct Flash Rd//Wr. In our SOC (32 bit dual core ARM) we have 3 FIU's that using memory mapping as follow: FIU0 - have 2 chip select and each one have 128MB memory mapping (total 256MB memory mapping) FIU1 - have 4 chip select and each one have 128MB memory mapping (total 512MB memory mapping) FIU2 - have 4 chip select and each one have 16MB memory mapping (total 32MB memory mapping) Totally 800MB memory mapping. When the FIU driver probe it don't know the size of each Flash that connected to the FIU, so the entire memory mapping is allocated for each FIU according the FIU device tree memory map parameters. It means, if we enable all three FIU's the drivers will try to allocate totally 800MB. In 32bit system it is problematic because the kernel have only 1GB of memory allocation so the vmalloc cannot take 800MB. When implementing the FIU driver in the mtd/spi-nor we allocating memory address only for detected Flash with exact size (usually we are not using 128MB Flash), and in that case usually we allocating much less memory. To solve this issue we needed to overcome two things: 1. Get argument from the upper layer (spi-mem layer) 2. Calling the get argument function after SPI_NOR_SCAN function. (the MTD Flash size filled in SPI_NOR_SCAN function) The attach patch set solving the describe issue by: 1. Add spi-mem callback function and value to the SPI device for passing an argument from the spi-mem layer to the spi layer 2. Add spi-mem setup function to the spi-memory operation that running after the spi-mem probe finished. 3. Implement function callback in the m25p80 driver that execute get Flash size. The patch set tested on NPCM750 EVB with FIU driver (implemented with SPI-MEM interface). Thanks for your attention. Tomer Tomer Maimon (3): spi: spi-mem: add spi-mem setup function spi: spi-mem: add callback function to spi-mem device mtd: m25p80: add get Flash size callback support drivers/mtd/devices/m25p80.c | 12 ++++++++++++ drivers/spi/spi-mem.c | 27 ++++++++++++++++++++++++++- include/linux/spi/spi-mem.h | 11 +++++++++++ 3 files changed, 49 insertions(+), 1 deletion(-) -- 2.18.0
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From: Tomer Maimon <tmaimon77@gmail.com> To: broonie@kernel.org, dwmw2@infradead.org, computersforpeace@gmail.com, marek.vasut@gmail.com, miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com, bbrezillon@kernel.org, yogeshnarayan.gaur@nxp.com, tudor.ambarus@microchip.com, gregkh@linuxfoundation.org, frieder.schrempf@exceet.de, tglx@linutronix.de Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, Tomer Maimon <tmaimon77@gmail.com>, linux-spi@vger.kernel.org Subject: [RFC v1 0/3] *spi-mem: adding setup and callback function Date: Mon, 29 Jul 2019 17:25:01 +0300 [thread overview] Message-ID: <20190729142504.188336-1-tmaimon77@gmail.com> (raw) Lately we have working on Flash interface unit (FIU) SPI driver that using spi-mem interface, Our FIU HW module support direct Flash Rd//Wr. In our SOC (32 bit dual core ARM) we have 3 FIU's that using memory mapping as follow: FIU0 - have 2 chip select and each one have 128MB memory mapping (total 256MB memory mapping) FIU1 - have 4 chip select and each one have 128MB memory mapping (total 512MB memory mapping) FIU2 - have 4 chip select and each one have 16MB memory mapping (total 32MB memory mapping) Totally 800MB memory mapping. When the FIU driver probe it don't know the size of each Flash that connected to the FIU, so the entire memory mapping is allocated for each FIU according the FIU device tree memory map parameters. It means, if we enable all three FIU's the drivers will try to allocate totally 800MB. In 32bit system it is problematic because the kernel have only 1GB of memory allocation so the vmalloc cannot take 800MB. When implementing the FIU driver in the mtd/spi-nor we allocating memory address only for detected Flash with exact size (usually we are not using 128MB Flash), and in that case usually we allocating much less memory. To solve this issue we needed to overcome two things: 1. Get argument from the upper layer (spi-mem layer) 2. Calling the get argument function after SPI_NOR_SCAN function. (the MTD Flash size filled in SPI_NOR_SCAN function) The attach patch set solving the describe issue by: 1. Add spi-mem callback function and value to the SPI device for passing an argument from the spi-mem layer to the spi layer 2. Add spi-mem setup function to the spi-memory operation that running after the spi-mem probe finished. 3. Implement function callback in the m25p80 driver that execute get Flash size. The patch set tested on NPCM750 EVB with FIU driver (implemented with SPI-MEM interface). Thanks for your attention. Tomer Tomer Maimon (3): spi: spi-mem: add spi-mem setup function spi: spi-mem: add callback function to spi-mem device mtd: m25p80: add get Flash size callback support drivers/mtd/devices/m25p80.c | 12 ++++++++++++ drivers/spi/spi-mem.c | 27 ++++++++++++++++++++++++++- include/linux/spi/spi-mem.h | 11 +++++++++++ 3 files changed, 49 insertions(+), 1 deletion(-) -- 2.18.0 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/
next reply other threads:[~2019-07-29 14:26 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-07-29 14:25 Tomer Maimon [this message] 2019-07-29 14:25 ` [RFC v1 0/3] *spi-mem: adding setup and callback function Tomer Maimon 2019-07-29 14:25 ` [RFC v1 1/3] spi: spi-mem: add spi-mem setup function Tomer Maimon 2019-07-29 14:25 ` Tomer Maimon 2019-07-29 14:25 ` [RFC v1 2/3] spi: spi-mem: add callback function to spi-mem device Tomer Maimon 2019-07-29 14:25 ` Tomer Maimon 2019-07-29 14:25 ` [RFC v1 3/3] mtd: m25p80: add get Flash size callback support Tomer Maimon 2019-07-29 14:25 ` Tomer Maimon 2019-07-29 15:28 ` [RFC v1 0/3] *spi-mem: adding setup and callback function Boris Brezillon 2019-07-29 15:28 ` Boris Brezillon [not found] ` <CAP6Zq1iPXDX_Gtz6ZWYm3JoHgHjdapotVLGw-Lq4tc2X-6eAug@mail.gmail.com> 2019-07-30 6:54 ` Boris Brezillon 2019-07-30 16:53 ` Sergei Shtylyov 2019-07-30 17:48 ` Vignesh Raghavendra 2019-07-30 18:04 ` Boris Brezillon [not found] ` <CAP6Zq1hfVoS8+VU0rAtKAX7D22qTVHDMosiCRMKV8sQB_m0qOQ@mail.gmail.com> 2019-08-01 6:42 ` Vignesh Raghavendra
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