Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933433AbdC3G4E (ORCPT ); Thu, 30 Mar 2017 02:56:04 -0400 Received: from conuserg-07.nifty.com ([210.131.2.74]:39950 "EHLO conuserg-07.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932388AbdC3GtG (ORCPT ); Thu, 30 Mar 2017 02:49:06 -0400 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com v2U6kUck015463 X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: linux-mtd@lists.infradead.org Cc: Enrico Jorns , Artem Bityutskiy , Dinh Nguyen , Boris Brezillon , Marek Vasut , Graham Moore , David Woodhouse , Masami Hiramatsu , Chuanxiao Dong , Jassi Brar , Masahiro Yamada , linux-kernel@vger.kernel.org, Brian Norris , Richard Weinberger , Cyrille Pitchen Subject: [PATCH v3 22/37] mtd: nand: denali: rework interrupt handling Date: Thu, 30 Mar 2017 15:46:08 +0900 Message-Id: <1490856383-31560-23-git-send-email-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1490856383-31560-1-git-send-email-yamada.masahiro@socionext.com> References: <1490856383-31560-1-git-send-email-yamada.masahiro@socionext.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 20116 Lines: 647 Simplify the interrupt handling and fix issues: - The register field view of INTR_EN / INTR_STATUS is different among IP versions. The global macro DENALI_IRQ_ALL is hard-coded for Intel platforms. The interrupt mask should be determined at run-time depending on the running platform. - wait_for_irq() loops do {} while() until interested flags are asserted. The logic can be simplified. - The spin_lock() guard seems too complex (and suspicious in a race condition if wait_for_completion_timeout() bails out by timeout). - denali->complete is reused again and again, but reinit_completion() is missing. Add it. Re-work the code to make it more robust and easier to handle. While we are here, also rename the jump label "failed_req_irq" to more appropriate "disable_irq". Signed-off-by: Masahiro Yamada --- Changes in v3: None Changes in v2: - Newly added drivers/mtd/nand/denali.c | 320 +++++++++++++++++----------------------------- drivers/mtd/nand/denali.h | 1 + 2 files changed, 118 insertions(+), 203 deletions(-) diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c index ea566ea..75b045e0 100644 --- a/drivers/mtd/nand/denali.c +++ b/drivers/mtd/nand/denali.c @@ -31,21 +31,6 @@ MODULE_LICENSE("GPL"); #define DENALI_NAND_NAME "denali-nand" /* - * We define a macro here that combines all interrupts this driver uses into - * a single constant value, for convenience. - */ -#define DENALI_IRQ_ALL (INTR__DMA_CMD_COMP | \ - INTR__ECC_TRANSACTION_DONE | \ - INTR__ECC_ERR | \ - INTR__PROGRAM_FAIL | \ - INTR__LOAD_COMP | \ - INTR__PROGRAM_COMP | \ - INTR__TIME_OUT | \ - INTR__ERASE_FAIL | \ - INTR__RST_COMP | \ - INTR__ERASE_COMP) - -/* * indicates whether or not the internal value for the flash bank is * valid or not */ @@ -71,20 +56,14 @@ static inline struct denali_nand_info *mtd_to_denali(struct mtd_info *mtd) #define DENALI_READ 0 #define DENALI_WRITE 0x100 +#define DENALI_NR_BANKS 4 + /* * this is a helper macro that allows us to * format the bank into the proper bits for the controller */ #define BANK(x) ((x) << 24) -/* forward declarations */ -static void clear_interrupts(struct denali_nand_info *denali); -static uint32_t wait_for_irq(struct denali_nand_info *denali, - uint32_t irq_mask); -static void denali_irq_enable(struct denali_nand_info *denali, - uint32_t int_mask); -static uint32_t read_interrupt_status(struct denali_nand_info *denali); - /* * The bus interface clock, clk_x, is phase aligned with the core clock. The * clk_x is an integral multiple N of the core clk. The value N is configured @@ -143,22 +122,6 @@ static void read_status(struct denali_nand_info *denali) write_byte_to_buf(denali, 0); } -/* resets a specific device connected to the core */ -static void reset_bank(struct denali_nand_info *denali) -{ - uint32_t irq_status; - uint32_t irq_mask = INTR__RST_COMP | INTR__TIME_OUT; - - clear_interrupts(denali); - - iowrite32(1 << denali->flash_bank, denali->flash_reg + DEVICE_RESET); - - irq_status = wait_for_irq(denali, irq_mask); - - if (irq_status & INTR__TIME_OUT) - dev_err(denali->dev, "reset bank failed.\n"); -} - /* Reset the flash controller */ static uint16_t denali_nand_reset(struct denali_nand_info *denali) { @@ -201,169 +164,123 @@ static void detect_max_banks(struct denali_nand_info *denali) denali->max_banks <<= 1; } -static void denali_set_intr_modes(struct denali_nand_info *denali, - uint16_t INT_ENABLE) +static void denali_enable_irq(struct denali_nand_info *denali) { - if (INT_ENABLE) - iowrite32(1, denali->flash_reg + GLOBAL_INT_ENABLE); - else - iowrite32(0, denali->flash_reg + GLOBAL_INT_ENABLE); -} + int i; -/* - * validation function to verify that the controlling software is making - * a valid request - */ -static inline bool is_flash_bank_valid(int flash_bank) -{ - return flash_bank >= 0 && flash_bank < 4; + for (i = 0; i < DENALI_NR_BANKS; i++) + iowrite32(U32_MAX, denali->flash_reg + INTR_EN(i)); + iowrite32(GLOBAL_INT_EN_FLAG, denali->flash_reg + GLOBAL_INT_ENABLE); } -static void denali_irq_init(struct denali_nand_info *denali) +static void denali_disable_irq(struct denali_nand_info *denali) { - uint32_t int_mask; int i; - /* Disable global interrupts */ - denali_set_intr_modes(denali, false); - - int_mask = DENALI_IRQ_ALL; - - /* Clear all status bits */ - for (i = 0; i < denali->max_banks; ++i) - iowrite32(0xFFFF, denali->flash_reg + INTR_STATUS(i)); - - denali_irq_enable(denali, int_mask); + for (i = 0; i < DENALI_NR_BANKS; i++) + iowrite32(0, denali->flash_reg + INTR_EN(i)); + iowrite32(0, denali->flash_reg + GLOBAL_INT_ENABLE); } -static void denali_irq_cleanup(int irqnum, struct denali_nand_info *denali) +static void denali_clear_irq(struct denali_nand_info *denali, + int bank, uint32_t irq_status) { - denali_set_intr_modes(denali, false); + /* write one to clear bits */ + iowrite32(irq_status, denali->flash_reg + INTR_STATUS(bank)); } -static void denali_irq_enable(struct denali_nand_info *denali, - uint32_t int_mask) +static void denali_clear_irq_all(struct denali_nand_info *denali) { int i; - for (i = 0; i < denali->max_banks; ++i) - iowrite32(int_mask, denali->flash_reg + INTR_EN(i)); + for (i = 0; i < DENALI_NR_BANKS; i++) + denali_clear_irq(denali, i, U32_MAX); } -/* - * This function only returns when an interrupt that this driver cares about - * occurs. This is to reduce the overhead of servicing interrupts - */ -static inline uint32_t denali_irq_detected(struct denali_nand_info *denali) +static irqreturn_t denali_isr(int irq, void *dev_id) { - return read_interrupt_status(denali) & DENALI_IRQ_ALL; -} + struct denali_nand_info *denali = dev_id; + irqreturn_t ret = IRQ_NONE; + uint32_t irq_status; + int i; -/* Interrupts are cleared by writing a 1 to the appropriate status bit */ -static inline void clear_interrupt(struct denali_nand_info *denali, - uint32_t irq_mask) -{ - uint32_t intr_status_reg; + spin_lock(&denali->irq_lock); - intr_status_reg = INTR_STATUS(denali->flash_bank); + for (i = 0; i < DENALI_NR_BANKS; i++) { + irq_status = ioread32(denali->flash_reg + INTR_STATUS(i)); + if (irq_status) + ret = IRQ_HANDLED; - iowrite32(irq_mask, denali->flash_reg + intr_status_reg); -} + denali_clear_irq(denali, i, irq_status); -static void clear_interrupts(struct denali_nand_info *denali) -{ - uint32_t status; + if (i != denali->flash_bank) + continue; - spin_lock_irq(&denali->irq_lock); + denali->irq_status |= irq_status; - status = read_interrupt_status(denali); - clear_interrupt(denali, status); + if (denali->irq_status & denali->irq_mask) + complete(&denali->complete); + } + + spin_unlock(&denali->irq_lock); - denali->irq_status = 0x0; - spin_unlock_irq(&denali->irq_lock); + return ret; } -static uint32_t read_interrupt_status(struct denali_nand_info *denali) +static void denali_reset_irq(struct denali_nand_info *denali) { - uint32_t intr_status_reg; - - intr_status_reg = INTR_STATUS(denali->flash_bank); + unsigned long flags; - return ioread32(denali->flash_reg + intr_status_reg); + spin_lock_irqsave(&denali->irq_lock, flags); + denali->irq_status = 0; + denali->irq_mask = 0; + spin_unlock_irqrestore(&denali->irq_lock, flags); } -/* - * This is the interrupt service routine. It handles all interrupts - * sent to this device. Note that on CE4100, this is a shared interrupt. - */ -static irqreturn_t denali_isr(int irq, void *dev_id) +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali, + uint32_t irq_mask) { - struct denali_nand_info *denali = dev_id; + unsigned long time_left, flags; uint32_t irq_status; - irqreturn_t result = IRQ_NONE; - spin_lock(&denali->irq_lock); + spin_lock_irqsave(&denali->irq_lock, flags); - /* check to see if a valid NAND chip has been selected. */ - if (is_flash_bank_valid(denali->flash_bank)) { - /* - * check to see if controller generated the interrupt, - * since this is a shared interrupt - */ - irq_status = denali_irq_detected(denali); - if (irq_status != 0) { - /* handle interrupt */ - /* first acknowledge it */ - clear_interrupt(denali, irq_status); - /* - * store the status in the device context for someone - * to read - */ - denali->irq_status |= irq_status; - /* notify anyone who cares that it happened */ - complete(&denali->complete); - /* tell the OS that we've handled this */ - result = IRQ_HANDLED; - } + irq_status = denali->irq_status; + + if (irq_mask & irq_status) { + spin_unlock_irqrestore(&denali->irq_lock, flags); + return irq_status; } - spin_unlock(&denali->irq_lock); - return result; + + denali->irq_mask = irq_mask; + reinit_completion(&denali->complete); + spin_unlock_irqrestore(&denali->irq_lock, flags); + + time_left = wait_for_completion_timeout(&denali->complete, + msecs_to_jiffies(1000)); + if (!time_left) { + dev_err(denali->dev, "timeout while waiting for irq 0x%x\n", + denali->irq_mask); + return 0; + } + + return denali->irq_status; } -static uint32_t wait_for_irq(struct denali_nand_info *denali, uint32_t irq_mask) +/* resets a specific device connected to the core */ +static void reset_bank(struct denali_nand_info *denali) { - unsigned long comp_res; - uint32_t intr_status; - unsigned long timeout = msecs_to_jiffies(1000); + uint32_t irq_status; - do { - comp_res = - wait_for_completion_timeout(&denali->complete, timeout); - spin_lock_irq(&denali->irq_lock); - intr_status = denali->irq_status; - - if (intr_status & irq_mask) { - denali->irq_status &= ~irq_mask; - spin_unlock_irq(&denali->irq_lock); - /* our interrupt was detected */ - break; - } + denali_reset_irq(denali); - /* - * these are not the interrupts you are looking for - - * need to wait again - */ - spin_unlock_irq(&denali->irq_lock); - } while (comp_res != 0); + iowrite32(1 << denali->flash_bank, denali->flash_reg + DEVICE_RESET); - if (comp_res == 0) { - /* timeout */ - pr_err("timeout occurred, status = 0x%x, mask = 0x%x\n", - intr_status, irq_mask); + irq_status = denali_wait_for_irq(denali, + INTR__RST_COMP | INTR__TIME_OUT); - intr_status = 0; - } - return intr_status; + if (!(irq_status & INTR__RST_COMP)) + dev_err(denali->dev, "reset bank failed.\n"); } /* @@ -397,7 +314,7 @@ static int denali_send_pipeline_cmd(struct denali_nand_info *denali, setup_ecc_for_xfer(denali, ecc_en, transfer_spare); - clear_interrupts(denali); + denali_reset_irq(denali); addr = BANK(denali->flash_bank) | denali->page; @@ -479,9 +396,9 @@ static int write_oob_data(struct mtd_info *mtd, uint8_t *buf, int page) write_data_to_flash_mem(denali, buf, mtd->oobsize); /* wait for operation to complete */ - irq_status = wait_for_irq(denali, irq_mask); + irq_status = denali_wait_for_irq(denali, irq_mask); - if (irq_status == 0) { + if (!(irq_status & INTR__PROGRAM_COMP)) { dev_err(denali->dev, "OOB write failed\n"); status = -EIO; } @@ -510,9 +427,9 @@ static void read_oob_data(struct mtd_info *mtd, uint8_t *buf, int page) * can always use status0 bit as the * mask is identical for each bank. */ - irq_status = wait_for_irq(denali, irq_mask); + irq_status = denali_wait_for_irq(denali, irq_mask); - if (irq_status == 0) + if (!(irq_status & INTR__LOAD_COMP)) dev_err(denali->dev, "page on OOB timeout %d\n", denali->page); @@ -620,9 +537,9 @@ static int denali_sw_ecc_fixup(struct mtd_info *mtd, unsigned int err_byte, err_sector, err_device; uint8_t err_cor_value; unsigned int prev_sector = 0; + uint32_t irq_status; - /* read the ECC errors. we'll ignore them for now */ - denali_set_intr_modes(denali, false); + denali_reset_irq(denali); do { err_addr = ioread32(denali->flash_reg + ECC_ERROR_ADDRESS); @@ -674,10 +591,9 @@ static int denali_sw_ecc_fixup(struct mtd_info *mtd, * ECC_TRANSACTION_DONE interrupt, so here just wait for * a while for this interrupt */ - while (!(read_interrupt_status(denali) & INTR__ECC_TRANSACTION_DONE)) - cpu_relax(); - clear_interrupts(denali); - denali_set_intr_modes(denali, true); + irq_status = denali_wait_for_irq(denali, INTR__ECC_TRANSACTION_DONE); + if (!(irq_status & INTR__ECC_TRANSACTION_DONE)) + return -EIO; return max_bitflips; } @@ -778,15 +694,14 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip, dma_sync_single_for_device(denali->dev, addr, size, DMA_TO_DEVICE); - clear_interrupts(denali); + denali_reset_irq(denali); denali_enable_dma(denali, true); denali_setup_dma(denali, DENALI_WRITE); /* wait for operation to complete */ - irq_status = wait_for_irq(denali, irq_mask); - - if (irq_status == 0) { + irq_status = denali_wait_for_irq(denali, irq_mask); + if (!(irq_status & INTR__DMA_CMD_COMP)) { dev_err(denali->dev, "timeout on write_page (type = %d)\n", raw_xfer); ret = -EIO; @@ -865,11 +780,11 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip, denali_enable_dma(denali, true); dma_sync_single_for_device(denali->dev, addr, size, DMA_FROM_DEVICE); - clear_interrupts(denali); + denali_reset_irq(denali); denali_setup_dma(denali, DENALI_READ); /* wait for operation to complete */ - irq_status = wait_for_irq(denali, irq_mask); + irq_status = denali_wait_for_irq(denali, irq_mask); dma_sync_single_for_cpu(denali->dev, addr, size, DMA_FROM_DEVICE); @@ -901,6 +816,7 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip, dma_addr_t addr = denali->buf.dma_buf; size_t size = mtd->writesize + mtd->oobsize; uint32_t irq_mask = INTR__DMA_CMD_COMP; + uint32_t irq_status; denali->page = page; @@ -909,11 +825,13 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip, dma_sync_single_for_device(denali->dev, addr, size, DMA_FROM_DEVICE); - clear_interrupts(denali); + denali_reset_irq(denali); denali_setup_dma(denali, DENALI_READ); /* wait for operation to complete */ - wait_for_irq(denali, irq_mask); + irq_status = denali_wait_for_irq(denali, irq_mask); + if (irq_status & INTR__DMA_CMD_COMP) + return -ETIMEDOUT; dma_sync_single_for_cpu(denali->dev, addr, size, DMA_FROM_DEVICE); @@ -940,9 +858,7 @@ static void denali_select_chip(struct mtd_info *mtd, int chip) { struct denali_nand_info *denali = mtd_to_denali(mtd); - spin_lock_irq(&denali->irq_lock); denali->flash_bank = chip; - spin_unlock_irq(&denali->irq_lock); } static int denali_waitfunc(struct mtd_info *mtd, struct nand_chip *chip) @@ -953,19 +869,19 @@ static int denali_waitfunc(struct mtd_info *mtd, struct nand_chip *chip) static int denali_erase(struct mtd_info *mtd, int page) { struct denali_nand_info *denali = mtd_to_denali(mtd); - uint32_t cmd, irq_status; - clear_interrupts(denali); + denali_reset_irq(denali); /* setup page read request for access type */ cmd = MODE_10 | BANK(denali->flash_bank) | page; index_addr(denali, cmd, 0x1); /* wait for erase to complete or failure to occur */ - irq_status = wait_for_irq(denali, INTR__ERASE_COMP | INTR__ERASE_FAIL); + irq_status = denali_wait_for_irq(denali, + INTR__ERASE_COMP | INTR__ERASE_FAIL); - return irq_status & INTR__ERASE_FAIL ? NAND_STATUS_FAIL : PASS; + return irq_status & INTR__ERASE_COMP ? 0 : NAND_STATUS_FAIL; } static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col, @@ -1153,7 +1069,6 @@ static void denali_hw_init(struct denali_nand_info *denali) /* Should set value for these registers when init */ iowrite32(0, denali->flash_reg + TWO_ROW_ADDR_CYCLES); iowrite32(1, denali->flash_reg + ECC_ENABLE); - denali_irq_init(denali); } static int denali_calc_ecc_bytes(int ecc_size, int ecc_strength) @@ -1271,9 +1186,6 @@ static void denali_drv_init(struct denali_nand_info *denali) /* indicate that MTD has not selected a valid bank yet */ denali->flash_bank = CHIP_SELECT_INVALID; - - /* initialize our irq_status variable to indicate no interrupts */ - denali->irq_status = 0; } static int denali_multidev_fixup(struct denali_nand_info *denali) @@ -1343,6 +1255,8 @@ int denali_init(struct denali_nand_info *denali) denali_hw_init(denali); denali_drv_init(denali); + denali_clear_irq_all(denali); + /* Request IRQ after all the hardware initialization is finished */ ret = devm_request_irq(denali->dev, denali->irq, denali_isr, IRQF_SHARED, DENALI_NAND_NAME, denali); @@ -1351,8 +1265,8 @@ int denali_init(struct denali_nand_info *denali) return ret; } - /* now that our ISR is registered, we can enable interrupts */ - denali_set_intr_modes(denali, true); + denali_enable_irq(denali); + nand_set_flash_node(chip, denali->dev->of_node); /* Fallback to the default name if DT did not give "label" property */ if (!mtd->name) @@ -1374,7 +1288,7 @@ int denali_init(struct denali_nand_info *denali) */ ret = nand_scan_ident(mtd, denali->max_banks, NULL); if (ret) - goto failed_req_irq; + goto disable_irq; /* allocate the right size buffer now */ devm_kfree(denali->dev, denali->buf.buf); @@ -1383,7 +1297,7 @@ int denali_init(struct denali_nand_info *denali) GFP_KERNEL); if (!denali->buf.buf) { ret = -ENOMEM; - goto failed_req_irq; + goto disable_irq; } ret = dma_set_mask(denali->dev, @@ -1391,7 +1305,7 @@ int denali_init(struct denali_nand_info *denali) 64 : 32)); if (ret) { dev_err(denali->dev, "No usable DMA configuration\n"); - goto failed_req_irq; + goto disable_irq; } denali->buf.dma_buf = dma_map_single(denali->dev, denali->buf.buf, @@ -1400,7 +1314,7 @@ int denali_init(struct denali_nand_info *denali) if (dma_mapping_error(denali->dev, denali->buf.dma_buf)) { dev_err(denali->dev, "Failed to map DMA buffer\n"); ret = -EIO; - goto failed_req_irq; + goto disable_irq; } /* @@ -1442,7 +1356,7 @@ int denali_init(struct denali_nand_info *denali) !(chip->ecc.size == 1024 && denali->caps & DENALI_CAP_ECC_SIZE_1024)) { dev_err(denali->dev, "ECC size %d is not supported on this controller", chip->ecc.size); - goto failed_req_irq; + goto disable_irq; } if (!chip->ecc.strength && !(chip->ecc.options & NAND_ECC_MAXIMIZE)) { @@ -1454,13 +1368,13 @@ int denali_init(struct denali_nand_info *denali) if (chip->ecc.options & NAND_ECC_MAXIMIZE) { ret = denali_set_max_ecc_strength(denali); if (ret) - goto failed_req_irq; + goto disable_irq; } else if (!(denali->ecc_strength_avail & BIT(chip->ecc.strength))) { dev_err(denali->dev, "ECC strength %d is not supported on this controller.\n", chip->ecc.strength); ret = -EINVAL; - goto failed_req_irq; + goto disable_irq; } chip->ecc.bytes = denali_calc_ecc_bytes(chip->ecc.size, @@ -1493,21 +1407,21 @@ int denali_init(struct denali_nand_info *denali) ret = denali_multidev_fixup(denali); if (ret) - goto failed_req_irq; + goto disable_irq; ret = nand_scan_tail(mtd); if (ret) - goto failed_req_irq; + goto disable_irq; ret = mtd_device_register(mtd, NULL, 0); if (ret) { dev_err(denali->dev, "Failed to register MTD: %d\n", ret); - goto failed_req_irq; + goto disable_irq; } return 0; -failed_req_irq: - denali_irq_cleanup(denali->irq, denali); +disable_irq: + denali_disable_irq(denali); return ret; } @@ -1525,7 +1439,7 @@ void denali_remove(struct denali_nand_info *denali) int bufsize = mtd->writesize + mtd->oobsize; nand_release(mtd); - denali_irq_cleanup(denali->irq, denali); + denali_disable_irq(denali); dma_unmap_single(denali->dev, denali->buf.dma_buf, bufsize, DMA_BIDIRECTIONAL); } diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h index e55bb2e..7797340 100644 --- a/drivers/mtd/nand/denali.h +++ b/drivers/mtd/nand/denali.h @@ -326,6 +326,7 @@ struct denali_nand_info { /* elements used by ISR */ struct completion complete; spinlock_t irq_lock; + uint32_t irq_mask; uint32_t irq_status; int irq; -- 2.7.4